Impacts of Climate Related Geo-engineering on Biological Diversity

Study carried out in line with CBD Decision X/33

Draft Reviewed – 23 January 2012

Not for Citation or Circulation

This is a draft report for a second round of review. The draft report compiles and synthesizes available scientific information on the possible impacts of geo-engineering techniques on biodiversity, including preliminary information on associated social, economic and cultural considerations. The report also considers definitions and understandings of climate-related geo-engineering relevant to the Convention on Biological Diversity (CBD). The report is being prepared in response to CBD Decision X/33, paragraph 9(l). The final report will take into account the additional review comments.

EXECUTIVE SUMMARY / KEY MESSAGES

Biodiversity, ecosystems and their services are critical to human well being. Protection of biodiversity and ecosystems requires that drivers of biodiversity loss are reduced. The main direct drivers of biodiversity loss are habitat conversion, over-exploitation, the introduction of invasive species, pollution and climate change. These in turn are being driven by demographic, economic, technological, socio-political and cultural changes. Climate change is becoming increasingly important as a driver of the biodiversity loss and the degradation of ecosystem services. It is best addressed by a rapid and significant reduction in greenhouse gas emissions through a transition to a low-carbon economy. However, given the insufficient action to date to reduce greenhouse gas emissions, the use of geo-engineering techniques has been suggested to limit the magnitude of human-induced climate change and or its impacts.

Proposed climate-related geo-engineering techniques

In this report, climate-related geo-engineering is defined as a deliberate intervention in the planetary environment of a nature and scale intended to counteract anthropogenic climate change and/or its impacts through, inter alia, solar radiation management or removing greenhouse gases from the atmosphere.1 There is a range of alternative definitions and understandings of the term (Section 2.1).

Solar radiation management (SRM) techniques aim to counteract warming by reducing the incidence and subsequent absorption of incoming solar radiation but would not treat the root cause of anthropogenic climate change arising from greenhouse gas concentrations in the atmosphere. They would rapidly have an effect once deployed at the appropriate scale, and thus are the only proposed approach that might allow a rapid reduction in temperatures should it be deemed necessary. SRM techniques would not address ocean acidification. They would introduce a new dynamic between the warming effects of greenhouse gases and the cooling effects of SRM with uncertain climatic implications especially at the regional scale. Proposed SRM techniques include:

1. Space-based approaches: reducing the amount of solar energy reaching the Earth by positioning sun-shields in space with the aim of reflecting or deflecting solar radiation;2. Changes in stratospheric aerosols: injecting sulphates or other types of particles into the upper atmosphere, with the aim of increasing the scattering of sunlight back to space;

1 This does not include carbon capture and storage from fossil fuels when carbon dioxide is captured before it is released into the atmosphere. References in parentheses indicate where full information can be found in the main report.

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3. Increases in cloud reflectivity: increasing the concentration of cloud-condensation nuclei in the lower atmosphere, thereby whitening clouds with the aim of increasing the reflection of solar radiation; 4. Increases in surface albedo: modifying land or ocean surfaces with the aim of reflecting more solar radiation.

Theoretically, these techniques could be implemented separately or in combination, at a range of scales. Different techniques are at different stages of development and some are of doubtful effectiveness. (Section 2.2.1)Carbon dioxide removal (CDR) involves techniques aimed at removing CO2, a major greenhouse gas, from the atmosphere, allowing outgoing long-wave (thermal infra-red) radiation to escape more easily. In principle, other greenhouse gases (such as N2O, and CH4), could also be removed from the atmosphere, but such approaches have yet to be developed. Proposed types of CDR approaches include:

1. Ocean Fertilization: the enrichment of nutrients in marine environments with the principal intention of stimulating primary productivity in the ocean, and hence CO 2 uptake from the atmosphere, and the deposition of carbon in the deep ocean; 2. Enhanced weathering: artificially increasing the rate by which carbon dioxide is naturally removed from the atmosphere by the weathering (dissolution) of carbonate and silicate rocks;3. Increasing carbon sequestration through ecosystem management: through, for example: afforestation, reforestation or enhancing soil carbon;4. Sequestration of carbon as biomass and its subsequent storage: through, for example, biochar or long term storage of crop residue; and5. Direct capture of carbon from the atmosphere and its subsequent storage, for example, using “artificial trees” and storage in geological formations or in the deep ocean.

CDR approaches involve two steps: (1) carbon sequestration or removal of CO2 from the atmosphere; and (2) storage of the sequestered carbon. In the first three techniques, these two steps occur together; in the fourth and fifth, sequestration and storage may be separated in time and space. Ecosystem-based approaches such as afforestation, reforestation or the enhancement of soil carbon are already employed as climate change mitigation activities and are not regarded by some as geo-engineering technologies. To have a significant impact on the climate, CDR interventions, individually or collectively, would need to involve the removal from the atmosphere of several Gt C/yr (gigatonnes of carbon per year), maintained over decades and more probably centuries. It is unlikely that such approaches could be deployed on a large enough scale to alter the climate quickly. Different techniques are at different stages of development and some are of doubtful effectiveness. (Section 2.2.2)

Climate change and ocean acidification, and their impacts on biodiversity

The continued increase in atmospheric greenhouse gases has profound implications for global and regional average temperatures, and also precipitation, ice-sheet dynamics, sea-level rise, ocean acidification and the frequency and magnitude of extreme events. Future climatic perturbations could be abrupt or irreversible, and potentially extend over millennial time scales; they will inevitably have major consequences for natural and human systems, severely affecting biodiversity and incurring very high socio-economic costs (Section 3.1).

Since 2000, the average rate of increase in global greenhouse gas emissions has been ~3.1% per year. As a result, it has become much more challenging to achieve the 450 ppm CO2eq target. Avoidance of high risk of dangerous climate change therefore requires an urgent and massive effort to reduce greenhouse gas emissions. If such efforts are not made, geo-engineering approaches will increasingly be postulated to offset at least some of the impacts of climate change, despite the risks and uncertainties involved (Section 3.1.2).

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Even with strong climate mitigation policies, further climate change is inevitable due to lagged responses in the Earth climate system. Thus increases in global mean surface temperature of 0.3 - 2.2oC are projected to occur over several centuries after atmospheric concentrations of greenhouse gases have been stabilized, with associated increases in sea level due to thermally-driven expansion and ice-melt. (Section 3.1.2)

Climate change poses an increasingly severe range of threats to biodiversity and ecosystem services, with ~10% of species estimated to be at risk of extinction for every 1⁰C rise in global mean temperature. Temperature, precipitation and other climate attributes strongly influence the distribution and abundance of species, their interactions and the associated functioning of ecosystems. Projected climate change is not only more rapid than naturally-occurring climate change (e.g. during ice age cycles, that did allow relatively gradual vegetation shifts, population movements and genetic adaptation), but the scope for adaptive responses is now reduced by other anthropogenic pressures, including over-exploitation, habitat loss, fragmentation and degradation, the introduction of non-native species, and pollution. Extinction risk is therefore increased, since the abundance and genetic diversity of many species are already much reduced. (Section 3.2.1)

The terrestrial impacts of projected climate change are likely to be greatest for montane and Arctic habitats, for coastal areas affected by sea-level change, and wherever there are major changes in water availability. Species with limited adaptive capability will be particularly at risk; for example, tropical fauna that are already close to their optimal temperatures. However, insect pests and disease vectors in temperate regions are expected to benefit. Forest ecosystems, and the goods and services they provide, are likely to be affected as much, or more, by changes in hydrological regimes (affecting fire risk) and pest abundance, than by direct effects of temperature change. (Section 3.2.2)

Marine species and ecosystems are increasingly subject to ocean acidification as well as changes in temperature. Climate driven changes in the distribution of marine organisms are already occurring, more rapidly than on land. The loss of summer sea-ice in the Arctic will have major biodiversity implications. Biological impacts of ocean acidification (an inevitable chemical consequence of the increase in atmospheric CO2) are less certain; nevertheless, an atmospheric CO2 concentration of 450 ppm would decrease surface pH change by ~0.2 units, with the likelihood of large-scale and ecologically significant effects. Tropical corals seem to be especially at risk, being vulnerable to the combination of ocean acidification, temperature stress (coral bleaching), coastal pollution (eutrophication and increased sediment load) and sea-level rise. (Section 3.2.3)

The biosphere plays a key role in climate processes, especially as part of the carbon and water cycles. Carbon is naturally sequestered and stored by terrestrial and marine ecosystems, through biologically-driven processes. Proportionately small changes in ocean and terrestrial carbon stores, caused by changes in the balance of exchange processes, can have large implications for atmospheric CO2 levels. (Section 3.3)

Potential impacts on biodiversity of SRM geo-engineering techniques

SRM geo-engineering techniques, if effective in abating the magnitude of warming, could reduce some of the climate-change related impacts on biodiversity. At the same time, the proposed SRM techniques may have their own negative impacts on biodiversity. Thus, if a proposed geo-engineering measures can be shown to be likely feasible and effective in reducing the negative impacts of climate change, these projected positive impacts need to be considered alongside any projected negative impacts of the geo-engineering measure. (Chapter 4 – Introduction)

Uniform dimming of sunlight through an unspecified generic SRM technique, to compensate for the temperature increase from increased CO2 concentrations, would be expected to reduce the greenhouse-gas induced temperature change experienced by most areas of the planet. Overall, this would be expected to reduce some of the impacts of climate

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change on biodiversity, but this will vary region by region. However, only very limited modelling work has been done and many uncertainties remain concerning the ability to realize uniform dimming and on the side effects of SRM techniques on biodiversity. It is therefore not possible to predict the net effect with any degree of confidence. (Section 4.1.1)

SRM would introduce a new dynamic between the heating effects of greenhouse gases and the cooling effects of SRM. The combination of changes – high CO2 concentrations, unpredictably altered precipitation patterns, and in some cases more diffuse light, – would be unlike any known combination that extant species and ecosystems have experienced in their evolutionary history. However, it is not clear whether the environment of the SRM world would be more or less challenging for individual species and ecosystems than that caused by the climate change that it would be seeking to counter. (Section 4.1.3)

SRM does not reduce atmospheric CO2 concentrations, and therefore would not reduce ocean acidification nor its adverse affects on marine biodiversity. SRM also would not address the effects (positive or negative) of high CO2 concentrations on terrestrial ecosystems. Therefore, SRM is not an alternative to CO2 emission reductions. (Section 4.1.4)

Rapid termination of SRM, that had been deployed for some time and is masking a high degree of warming, would almost certainly have very large negative impacts on biodiversity and ecosystem services that would be far more severe than those resulting from gradual climate change. (Section 4.1.5)

Stratospheric aerosol injection, using sulphate particles, would affect the overall quantity and quality of light reaching the biosphere, have minor effects on atmospheric acidity, and could also affect stratospheric ozone depletion, with knock-on effects on biodiversity and ecosystem services. Stratospheric aerosols would decrease the amount of photosynthetically active radiation (PAR) reaching the Earth, but would increase the proportion of diffuse (as opposed to direct) radiation. This would be expected to affect community composition and structure. It may lead to an increase of gross primary productivity (GPP) in certain ecosystems such as forests. However, the magnitude and nature of effects on biodiversity are likely to be mixed, and are currently not well understood. Ocean productivity would likely decrease. Increased ozone depletion, primarily in the polar regions, would cause an increase in the amount of ultra violet (UV) radiation reaching the Earth, which would affect some species more than others. (Section 4.2.1)

Cloud brightening could cause atmospheric and oceanic perturbations with possibly significant effects on terrestrial and marine biodiversity and ecosystems. However, there is a high degree of inconsistency among findings. Cloud brightening is expected to cause localized cooling, the effects of which are poorly understood. (Section 4.2.2)

If surface albedo changes were large enough to have an effect on the global climate, they would have to be deployed across a very large area – with consequent impacts on ecosystems – or would involve a very high degree of localized cooling. For instance, covering deserts with reflective material on a scale large enough to be effective in addressing the impacts of climate change would have significant negative effects on biodiversity, for instance on species richness and population densities, as well as on the customary use of biodiversity. (Section 4.2.3)

Potential impacts on biodiversity of CDR geo-engineering techniques

CDR techniques, if effective and feasible, would be expected to reduce the negative impacts on biodiversity of climate change and, in some cases, of ocean acidification. By removing carbon dioxide (CO2) from the atmosphere, CDR techniques reduce the concentration of the main causal agent of anthropogenic climate change. Depending on the technique employed, ocean acidification may be reduced as well. They are generally slow in affecting the atmospheric CO2 concentration and there are further substantial time–lags in the climatic benefits. Several of the techniques are of doubtful effectiveness. In addition, the positive effects from reduced impacts of climate change and/or ocean acidification due to

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reduced atmospheric CO2 concentrations may be offset by the direct impacts on biodiversity of the particular CDR technique employed. (Section 5.1)

Individual CDR techniques have impacts on terrestrial and/or ocean ecosystems. In some biologically-driven processes (ocean fertilization; afforestation, reforestation and soil carbon enhancement), carbon sequestration or removal of CO2 from the atmosphere and storage of the sequestered carbon occur together or are inseparable. In these cases, impacts on biodiversity are confined to marine and terrestrial systems respectively. In other cases, the steps are discrete, and various combinations of sequestration and storage options are possible. Carbon sequestered as biomass, for example, could be either: dumped in the ocean as crop residues; incorporated into the soil as charcoal; or used as fuel with the resultant CO2

sequestered at source and stored either in sub-surface reservoirs or the deep ocean. In these cases, each step will have different and additive potential impacts on biodiversity, and potentially separate impacts on marine and terrestrial environments. (Section 5.1)

Ocean fertilization involves increased biological primary production with inevitable changes in phytoplankton community structure and species diversity and implications for the wider food-web. Ocean fertilization may be achieved through the external addition of nutrients (Fe or N or P) or, possibly, by modifying ocean upwelling and downwelling. If carried out on a climatically significant scale, changes may include an increased risk of harmful algal blooms, and greater densities and biomass of benthos. Increases in net primary productivity in one region will likely be offset by decreases in adjacent areas. Ocean fertilization is expected to increase biogeochemical cycling which may be associated with increased production of methane and nitrous oxide, significantly reducing the effectiveness of the technique. Ocean fertilization may slow near-surface ocean acidification but would increase acidification of the deep ocean. The limited experiments conducted to date indicate that this is a technique of doubtful effectiveness. (Section 5.2.1)

Enhanced weathering would involve large-scale mining and transportation of carbonate and silicate rocks, and the spreading of solid or liquid materials on land or sea with major impacts on terrestrial and coastal ecosystems and, in some techniques, locally excessive alkalinity in marine systems. Carbon dioxide is naturally removed from the atmosphere by the weathering (dissolution) of carbonate and silicate rocks. This process could be artificially accelerated through a range of proposed techniques that include releasing calcium carbonate or other dissolution products of alkaline minerals into the ocean or spreading abundant silicate minerals such as olivine over agricultural soils, with potential for negative impacts. In the ocean, this technique could contribute to countering ocean acidification. (Section 5.2.2)

The impacts on biodiversity of ecosystem carbon storage through afforestation, reforestation, or the enhancement of soil carbon depend on the method and scale of implementation. If managed well, this approach has the potential to increase or maintain biodiversity. Since afforestation, reforestation and land-use change are already being promoted as climate change mitigation options, much guidance has already been developed. For example, the CBD has developed guidance to maximize the benefits of these approaches to biodiversity, such as the use of assemblages of native species, and to minimize the disadvantages and risks such as the use of potentially invasive species and monocultures. (Section 5.2.3)

Production of biomass for carbon sequestration on a scale large enough to be climatically significant would likely entail competition for land with food and other crops and/or large-scale land-use change with significant impacts on biodiversity as well as greenhouse gas emissions that may partially offset, eliminate or even exceed the carbon sequestered as biomass. However, the coupling of biomass production with its use as bioenergy in power stations equipped with effective carbon capture at source and storage has the potential to be carbon negative. The net effects on biodiversity and greenhouse gas emissions would depend on the approaches used. The storage or disposal of biomass may

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have impacts on biodiversity separate from those involved in its production. Removal of organic matter from agricultural ecosystems is likely to have negative impacts on agricultural productivity and biodiversity. (Section 5.2.4.1)

The impacts of the long-term storage of charcoal in soils (“biochar”) on the structure and function of soil itself, as well as on crop yields, mycorrhizal fungi, soil microbial communities and detritivores, are not yet fully understood. (Section 5.2.4.2.1)

Ocean storage of biomass (e.g. crop residues) would likely have negative impacts on biodiversity. Deposition of ballasted bales would likely have significant local physical impacts on the seabed due to the sheer mass of the material. Wider chemical and biological impacts are likely. Longer-term indirect effects of oxygen depletion and deep-water acidification could be regionally significant if there is cumulative deposition, and subsequent decomposition, of many gigatonnes of organic carbon. (Section 5.2.4.2.2)

Capture of carbon dioxide from ambient air through physico-chemical methods (“artificial trees “) would require a large amount of energy and in some cases fresh water, but otherwise would have relatively small direct impacts on biodiversity. However, capturing CO2 from the ambient air (where its concentration is 0.04%) is much more difficult and energy intensive than capturing CO2 from exhaust streams of power stations (where it is about 300 times higher) and is unlikely to be viable without additional carbon-free energy sources. CO2 that has already been extracted from the atmosphere must be stored either in the ocean or in sub-surface geological reservoirs with additional potential impacts. (Section 5.2.5.1)

Ocean CO2 storage will necessarily alter the local chemical environment, with a high likelihood of biological effects. Effects on mid-water and deep benthic fauna/ecosystems is likely through the exposure, primarily of marine invertebrates and possibly unicellular organisms, to pH changes of 0.1 to 0.3 units. Total destruction of deep seabed biota that cannot flee can be expected if lakes of liquid CO2 are created. The scale of such impacts would depend on the seabed topography, with deeper lakes of CO2 affecting less seafloor area for a given amount of CO2. However, pH reductions would still occur in large volumes of water near such lakes. The chronic effects on ecosystems of direct CO2 injection into the ocean over large ocean areas and long time scales have not yet been studied, and the capacity of ecosystems to compensate or adjust to such CO2 induced shifts is unknown. (Section 5.2.5.2.1)

Leakage from CO2 stored in sub-surface geological reservoirs, though considered unlikely if sites are well selected, would have biodiversity implications on a very local scale. CO2 storage in sub-surface geological reservoirs is already being implemented at pilot-scale levels. (Section 5.2.5.2.2)

Social, economic, cultural and ethical considerations of climate-related geo-engineering

There are a number of social, economic and cultural considerations from geo-engineering technologies that may emerge, regardless of the specific geo-engineering approach. These considerations have clear parallels to on-going discussions on social dimensions of climate change, emerging technologies, and complex global risks. Social perceptions of risks, in general, are highly differentiated across social groups, and highly dynamic, and pose particular challenges in settings defined by complex bio-geophysical interactions. (Section 6.3)

The very fact that the international community is presented with geo-engineering as a potential option to be further explored is a major social and cultural issue. Humanity is now the major changing force on the planet. This has important repercussions, not only because it forces us to consider multiple and interacting global environmental changes, but also because it opens up difficult discussions on whether it is desirable to move from unintentional modifications of the Earth system, to an approach where we intentionally try to modify the climate and associated bio-geophysical systems to avoid the worst outcomes of

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climate change. Hence, the very fact that the international community is presented with geo-engineering as a potential option to be further explored is a major social and cultural issue. (Section 6.3.1)

Unintended side effects may result from the large-scale application of geo-engineering techniques. This is an often-raised concern especially for Solar Radiation Management. While technological innovation has helped to transform societies and improve the quality of life, it has not always done so in a sustainable way. Failures to respond to early warnings of unintended consequences of particular technologies have been documented. Accordingly, there are calls for increased consideration of whether technological approaches are the best option for addressing problems created by the application of earlier technologies. (Section 6.3.2)

An additional issue is the possibility of technological, political and social “lock in” - that is, the possibility that the development of geo-engineering technologies also result in the emergence of vested interests and increasing social momentum. It has been argued that this path of dependency could make deployment more likely, and/or limit the reversibility of geo-engineering techniques. (Section 6.3.2)

Ethical considerations related to geo-engineering include issues of “moral hazard” and distributional and inter-generational issues, as well as the question of whether it is ethically permissible to remediate one pollutant by introducing another. (Section 6.3.1)

Geo-engineering could raise a number of questions regarding the distribution of resources and impacts within and amongst societies and across time. First, access to natural resources is needed for some geo-engineering. Competition for limited resources can be expected to increase if geo-engineering techniques emerge as a competing activity for land or water use. Second, the distribution of impacts of geo-engineering are not likely to be even or uniform as are the impacts of climate change itself. (Section 6.3.4)

In cases in which geo-engineering experimentation or interventions have (or are suspected to have) transboundary effects or impacts on areas beyond national jurisdiction, geopolitical tensions could arise regardless of causation of actual negative impacts, especially in the absence of international agreement. Third, as with climate change, geo-engineering could also entail intergenerational issues: future generations might be faced with the need to maintain geo-engineering measures in general in order to avoid impacts of climate change. (Section 6.3.5)

Synthesis: Changes in the drivers of biodiversity loss

In the absence of action to reduce greenhouse gas emissions, an increasingly severe range of threats to biodiversity and ecosystem services is projected to result from climate change and the associated phenomenon of ocean acidification. The impacts are exacerbated by the other anthropogenic pressures on biodiversity (such as over-exploitation; habitat loss, fragmentation and degradation; the introduction of non-native species; and pollution). In addition, climate change is projected to actually increase the risk of some of the other drivers. (Section 7.1)

Climate change could be addressed by a rapid and significant reduction in greenhouse gas emissions through a transition to a low-carbon economy with overall positive impacts on biodiversity. Measures to achieve such a transition would avoid the adverse impacts of climate change on biodiversity. Generally, other impacts on biodiversity of these measures, mediated through other drivers of biodiversity loss, would be small or positive. Although some of the measures have potential negative side-effects on biodiversity, these can be minimized by careful design. (Section 7.1)

The deployment of geo-engineering techniques, if feasible and effective, could reduce some aspects of climate change and its impacts on biodiversity. At the same time, geo-engineering techniques are associated with their own negative impacts on biodiversity .

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The net effect will vary among techniques and is difficult to predict. Most geo-engineering techniques have significant risks and uncertainties. For some techniques, there would likely be increases in land use change, and there could also be an increase in other drivers of biodiversity loss. (Section 7.1)

There are many areas where knowledge is still very limited. These include (i) how will the proposed geo-engineering techniques affect weather and climate regionally and globally; (ii) how do biodiversity and ecosystems and their services respond to changes in climate; (iii) the direct effects of geo-engineering on biodiversity; and (iv) what are the social and economic implications. (Section 7.3)

There is very limited understanding among stakeholders of geo-engineering concepts, techniques and their potential impacts on biodiversity. There is also as yet little information on the perspectives of indigenous peoples and local communities on geo-engineering, especially in developing countries. Considering the role these communities play in actively managing ecosystem, this is a major gap. (Section 7.3)

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CHAPTER 1: MANDATE, CONTEXT AND SCOPE OF WORK

1.1. Mandate

At the tenth meeting of the Conference of the Parties (COP-10) to the Convention on Biological Diversity (CBD), Parties adopted a decision on climate-related geo-engineering and its impacts on the achievement of the objectives of the CBD as part of its decision on biodiversity and climate change.

Specifically, in paragraph 8 of that decision, the Conference of the Parties:

Invite[d] Parties and other Governments, according to national circumstances and priorities, as well as relevant organizations and processes, to consider the guidance below on ways to conserve, sustainably use and restore biodiversity and ecosystem services while contributing to climate change mitigation and adaptation to (….)

(w) Ensure, in line and consistent with decision IX/16 C, on ocean fertilization and biodiversity and climate change, in the absence of science based, global, transparent and effective control and regulatory mechanisms for geo-engineering, and in accordance with the precautionary approach and Article 14 of the Convention, that no climate-related geo-engineering activities2 that may affect biodiversity take place, until there is an adequate scientific basis on which to justify such activities and appropriate consideration of the associated risks for the environment and biodiversity and associated social, economic and cultural impacts, with the exception of small scale scientific research studies that would be conducted in a controlled setting in accordance with Article 3 of the Convention, and only if they are justified by the need to gather specific scientific data and are subject to a thorough prior assessment of the potential impacts on the environment;

(x) Make sure that ocean fertilization activities are addressed in accordance with decision IX/16 C, acknowledging the work of the London Convention/London Protocol;”

Further, in paragraph 9 of that decision the Conference of the Parties:

“Request[ed] the Executive Secretary to:

(l) compile and synthesize available scientific information, and views and experiences of indigenous and local communities and other stakeholders, on the possible impacts of geo engineering techniques on biodiversity and associated social, economic and cultural considerations, and options on definitions and understandings of climate-related geo-engineering relevant to the Convention on Biological Diversity and make it available for consideration at a meeting of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) prior to the eleventh meeting of the Conference of the Parties; and

(m) Taking into account the possible need for science based global, transparent and effective control and regulatory mechanisms, subject to the availability of financial resources, undertake a study on gaps in such existing mechanisms for climate-related geo-engineering relevant to the Convention on Biological Diversity, bearing in mind that such mechanisms may not be best placed under the Convention on Biological

2 Without prejudice to future deliberations on the definition of geo-engineering activities, understanding that any technologies that deliberately reduce solar insolation or increase carbon sequestration from the atmosphere on a large scale that may affect biodiversity (excluding carbon capture and storage from fossil fuels when it captures carbon dioxide before it is released into the atmosphere) should be considered as forms of geo-engineering which are relevant to the Convention on Biological Diversity until a more precise definition can be developed. It is noted that solar insolation is defined as a measure of solar radiation energy received on a given surface area in a given hour and that carbon sequestration is defined as the process of increasing the carbon content of a reservoir/pool other than the atmosphere

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Diversity, for consideration by SBSTTA prior to a future meeting of the Conference of the Parties and to communicate the results to relevant organizations.”

Accordingly, this draft paper has been prepared by a group of experts and the CBD Secretariat following discussions of a liaison group3 convened thanks to financial support from the Government of the United Kingdom of Great Britain and Northern Ireland, and the Government of Norway. The report compiles and synthesizes available scientific information on the possible impacts of geo-engineering techniques on biodiversity, including preliminary information on associated social, economic and cultural considerations. Related legal and regulatory matters are treated in a separate study.

1.2. The context for the consideration of potential impacts of geo-engineering on biodiversity

Biodiversity, ecosystems and their services (provisioning, regulating, cultural and supporting) are critical to human well being. They are being directly and adversely affected by habitat conversion, over-exploitation, the introduction of invasive species, pollution and climate change. These in turn are being driven by demographic, economic, technological, socio-political and cultural changes. Protection of biodiversity and ecosystems means that we urgently need to address these direct drivers of change.

Climate change, which is becoming increasingly important as a driver of the loss of biodiversity and degradation of ecosystems and their services, is best addressed by a rapid and significant reduction in greenhouse gas emissions through a transition to a low-carbon economy in both the way we produce and use energy and the way we manage our land. However, given the lack of international action to reduce greenhouse gas emissions, the use of geo-engineering techniques has been suggested as an alternative or to complement efforts to reduce greenhouse gas emissions in order to limit the magnitude of human-induced climate change (Figure 1.1).

To assess the impact of geo-engineering techniques on biodiversity – the mandate for this report – requires, inter alia, an evaluation of the positive and negative effects of these techniques on the various drivers of biodiversity loss, compared to the alternatives of (i) climate change mitigation and (ii) taking no action (or insufficient action) to address climate change. The elements of a framework for assessing the impacts are informed by the guidance on impact assessment developed in the framework of the Convention as discussed in the next section of this chapter.

The assessment includes an evaluation of the benefits of reducing changes in climate through the application of geo-engineering techniques compared to potential adverse consequences of these techniques. Chapter 3 provides a summary of the impact of climate change on biodiversity and ecosystems and their services as a baseline for assessing the impact of geo-engineering techniques as these are only being suggested as an alternative to, or complementary to, a transition to a low carbon economy which would directly reduce greenhouse gas emissions. Realization of the potential positive impacts of geo-engineering impacts on biodiversity clearly depends on the efficacy and feasibility of the techniques in reducing climate change or its impacts. Therefore, drawing upon earlier work, the study, reviews any evidence in this regard in chapter 2 and chapters 4 and 5.

3 Lead authors are: Robert Watson (Chair), Paulo Artaxo, Ralph Bodle, Victor Galaz, Georgina Mace, Andrew Parker, David Santillo, Chris Vivian, and Phillip Williamson. Others who provided inputs during the Liaison Group meeting and/or commented on drafts are: Oyvind Christophersen, Ana Delgado, Tewolde Berhan Gebre Egziabher, Almuth Ernsting, James Rodger Fleming, Tim Kruger, Ronal W. Larson, Miguel Lovera, Ricardo Melamed, Helena Paul, Stephen Salter, Dmitry Zamolodchikov, Karin Zaunberger, and Chizoba Chinweze. The complete list of peer reviewers will be available in the final report. The report has been edited by David Cooper, Jaime Webbe and Annie Cung of the CBD Secretariat with the assistance of Emma Woods.

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Figure 1.1. Linkage between biodiversity, ecosystem goods and services and human well-being4

Biodiversity can affect ecosystem services directly (pathway 1) or indirectly, through ecosystem processes (pathway 2). Both routes subsequently affect human well-being (pathway 3).

1.3. Relevant guidance under the Convention on Biological Diversity

The decision on geo-engineering adopted by the Conference of the Parties at its tenth meeting, in paragraph 8(w), refers to the precautionary approach and to Article 14 of the Convention.

The precautionary approach contained in Principle 15 of the Rio Declaration on Environment and Development is an approach to uncertainty, and provides for action to avoid serious or irreversible environmental harm in advance of scientific certainty of such harm. In the context of the Convention, it is referred to in numerous decisions and pieces of guidance, including inter alia in the Strategic Plan for Biodiversity 2011-2020; the ecosystem approach; the voluntary guidelines on biodiversity-inclusive impact assessment; the Addis Ababa principles and guidelines for the sustainable use of biodiversity; the guiding principles for the prevention, introduction and mitigation of impacts of alien species that threaten ecosystems, habitats or species; the programme of work on marine and coastal biological diversity; the proposals for the design and implementation of incentive measures; the Cartagena Protocol on Biosafety; agricultural biodiversity in the context of Genetic Use Restriction Technologies; and forest biodiversity with regard to genetically modified trees.

In decision X/33, the Conference of the Parties calls for precaution in the absence of an adequate scientific basis on which to justify geo-engineering activities and appropriate consideration of the associated risks for the environment and biodiversity and associated

4 Díaz S., Fargione J., Chapin F.S. III & Tilman D. (2006) Biodiversity loss threatens human well-being. PLoS Biol 4, e277. doi:10.1371/journal.pbio.0040277

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social, economic and cultural impacts. Further consideration of the precautionary approach is provided in the companion study on the regulatory framework of climate-related geo-engineering relevant to the Convention on Biological Diversity.

Article 14 of the Convention is on impact assessment, minimizing adverse impacts as well as liability and redress. It includes provisions on environmental impact assessment of proposed projects as well as strategic environmental assessment of programmes and policies that are likely to have significant adverse impacts on biodiversity. To assist Parties in this area, a set of voluntary guidelines were developed:

Voluntary guidelines for biodiversity-inclusive impact assessment, adopted through decision VIII/28;

Additional guidance on biodiversity-inclusive Strategic Environmental Assessment, endorsed through decision VIII/28;

Akwé:Kon voluntary guidelines for the conduct of cultural, environmental and social impact assessment regarding developments proposed to take place on, or which are likely to impact on, sacred sites and on lands and waters traditionally occupied or used by indigenous and local communities, adopted through decision VII/16;

Tkarihwaié:ri code of ethical conduct to ensure respect for the cultural and intellectual heritage of indigenous and local communities; and

Draft voluntary guidelines for the consideration of biodiversity in environmental impact assessments (EIAs) and strategic environmental assessments (SEAs) in marine and coastal areas. These seek to address governance issues including in marine areas beyond national jurisdiction.

Article 14 further includes provisions for activities which are likely to have significant adverse effects on the biodiversity of other States or areas beyond the limits of national jurisdiction. Given the large scale of geo-engineering interventions, the need for notification, exchange of information and consultation as well as readiness for emergency responses called for in this provision would likely apply to the originator of such geo-engineering activities. To date, the Convention has not developed further guidance in this area. Equally, the issue of liability and redress, including restoration and compensation for damage to biodiversity caused by activities under the jurisdiction of other States is still under debate.

These aforementioned guidelines developed under Article 14 provide useful elements that can inform analysis of the impacts of geo-engineering on biodiversity, both at the level of specific activities and at the level of broader assessments such as the present report.5 Given the broad scope of the present study, the guidelines for biodiversity-inclusive strategic environmental assessment are most relevant.

The guidelines suggest that the following should be considered:

(1) How the proposed techniques are expected to impact on the various components and levels of biodiversity and across ecosystem types, the implications of this for ecosystem services, and for the people who depend on such services;

(2) How the proposed techniques are expected to affect the key direct and indirect drivers of biodiversity change.

Where such information is available, Chapters 3, 4 and 5 provide information on the various components of biodiversity and on the range of ecosystems, the implications of this for ecosystem services. However, in many cases such detailed information is not available. In particular, information on the potential impacts on biodiversity at the genetic level is lacking.

At a global scale, the largest driver of terrestrial biodiversity loss has been, and continues to be, land use change. In the oceans, overexploitation has also been a major cause of loss. Climate change is rapidly increasing in importance as a driver of biodiversity loss. However,

5 The Assessment framework developed under the London Convention/London Protocol may also be relevant

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the drivers of loss vary among ecosystems and from region to region6, 7. The potential impacts of geo-engineering and of alternative actions on the drivers of biodiversity loss are briefly considered in chapter 7.

The CBD guidelines on impacts assessment also highlight, as key principles, stakeholder involvement, transparency and good quality information.

As already noted above, good quality information is often limiting. This study should therefore be regarded as a first step in assessing the potential impacts of geo-engineering techniques on biodiversity. The report recognizes many areas where knowledge is still very limited. These include: (i) how will the proposed geo-engineering techniques affect weather and climate regionally and globally; and (ii) how do biodiversity and ecosystems and their services respond to changes in climate; (iii) the direct effects of geo-engineering on biodiversity; and (iv) what are the social and economic implications.

With a view to encouraging involvement of stakeholders, a number of consultations have been held8. Moreover, this report is being made available for two rounds of peer review. These efforts notwithstanding, it is recognized that the opportunities for full and effective participation of stakeholders has been limited. To some extent, this is an inevitable consequence of the relative novelty of the issue under discussion. Some indigenous and local communities and stakeholder groups do not consider themselves sufficiently prepared to contribute to such an effort in a full and effective manner. At the same time, it is hoped that this report, and related efforts, will help to expand information and understanding on the issue9.

1.4. Scope of techniques examined in this study

There is a range of views as to what should be considered as climate-related geo-engineering relevant to the CBD. Approaches may include both hardware- or technology-based engineering as well as natural processes that might have a measurable impact on the global climate, depending on the spatial and temporal scale of interventions. Some approaches that may be considered as geo-engineering could also be considered as climate change mitigation and/or adaptation, for example, some ecosystem restoration activities.

This study takes an inclusive approach without prejudice to the definition of geo-engineering that may be agreed under the Convention or elsewhere. Examination of an intervention in this study does not indicate that the Secretariat or the experts involved necessarily consider that the intervention should be regarded as within the scope of the term geo-engineering.

In particular it should be noted that COP excluded from the scope of its guidance on geo-engineering (decision X/33, paragraph 8(w)) carbon capture and storage from fossil fuels when it captures carbon dioxide before it is released into the atmosphere. However, some of the component technologies are included in this study, where relevant.

Accordingly, the scope of the study is limited and should not be taken as a comprehensive analysis of all matters related to geo-engineering.

6 Millennium Ecosystem Assessment. 2005. Ecosystems and Human Wellbeing: Synthesis. Washington (DC): Island Press.7 Secretariat of the Convention on Biological Diversity (2010) Global Biodiversity Outlook 3.Montréal, 94 pages.8 - Mini-workshop on biodiversity and climate-related geo-engineering, 10 June 2011, Bonn, Germany- Liaison Group Meeting on Climate-Related Geo Engineering as it relates to the Convention on Biological Diversity, 29 June – 1 July, 2011, London, UK- Informal Dialogue with Indigenous Peoples and Local Communities on Biodiversity Aspects of Geo-engineering the Climate, Side event during the Seventh Meeting of the Ad Hoc Open-ended Working Group on Article 8(j) and Related Provisions, 2 November 2011, Montreal, Canada- Consultation on Climate-related Geo-engineering relevant to the Convention on Biological Diversity, Side event during the fifteenth meeting of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA 15), 9 November 2011, Montreal, Canada 9 Online discussion on indigenous peoples and local communities and geo-engineering, Climate Frontlines - Global forum for indigenous peoples, small islands and vulnerable communities.

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1.5. Structure of the document

The range of techniques considered as “geo-engineering” is briefly reviewed in Chapter 2. Chapter 2 also considers definitions for geo-engineering as it relates to the CBD based on a compilation and summary of existing definitions.

Geo-engineering techniques are being proposed to offset at least some of the negative impacts of climate change, which would then be expected to have benefits for biodiversity. Therefore, Chapter 3 provides a summary of projected climate change and the related phenomenon of ocean acidification and the consequent impacts on biodiversity.

The range of potential impacts on biodiversity of geo-engineering techniques are reviewed in Chapters 4 and 5. Chapters 4 and 5 consider the potential impacts of Solar Radiation Management (SRM) approaches and Carbon Dioxide Removal (CDR) techniques respectively. They consider the potential impacts of geo-engineering deployed at scales intended to reduce solar radiation to have a significant effect on global warming or sequester a climatically significant amount of CO2 from the atmosphere, on biodiversity, where information is available and on ecosystem services.

A preliminary review of some of the possible social, economic and cultural impacts associated with the impacts of geo-engineering on biodiversity is provided in Chapter 6

Finally, some general conclusions are presented in Chapter 7.

1.6. Key sources of information

The study builds on past work on geo-engineering, climate change and biodiversity including information available from the Intergovernmental Panel on Climate Change10, the Royal Society11 the report of the IGBP workshop on Ecosystem Impacts of Geo-engineering12, the Technology Assessment of Climate Engineering by the US Government Accountability Office13, and CBD Technical Series reports14,15. However, it should be noted that the peer-reviewed literature is rather limited and many uncertainties remain.

While the study focuses on recent literature, it is important to note that the concept of engineering the climate is not new16,17,18. The main focus of ideas developed in the 1950s and 1960s was however to increase, not decrease, temperatures (particularly in the Arctic), or increase rainfall on a regional basis. However, from the 1970s, some of the examples have been designed to limit human-induced changes in the climate. Examples of additional historic

10 IPPC (1995) Working Group II, Chapter 25 on Mitigation: Cross-Sectoral and Other Issues; and IPCC (2007) Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp11 The Royal Society. (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp12 Russell, L.M. et al. (2012). Ecosystem Impacts of Geoengineering: A Review for Developing a Science Plan. In press Ambio13 U.S. Government Accountability Office (2011) Technology Assessment: Climate engineering. Technical

status, future directions, and potential tresponses. GAO-11-71. www.gao.gov/new.items/d1171.pdf14 Secretariat of the Convention on Biological Diversity (2009). Scientific Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity. Technical Series No. 45. CBD, Montreal, 53 pp15 Secretariat of the Convention on Biological Diversity (2009) Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Technical Series No.41. CBD, Montreal, 126 pp16 Lamb, H.H. (1977) Climatic History and the Future, Parts III and IV. Princeton University Press, 835 pp17 Fleming,J.R. (2010) Fixing the Sky: The Checkered History of Weather and Climate Control. Columbia University Press, New York, 344 pp18 U.S. Government Accountability Office (2011) Technology Assessment: Climate engineering. Technical status, future directions, and potential tresponses. GAO-11-71. www.gao.gov/new.items/d1171.pdf

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examples of climate control are presented in Table 1 below (a more extensive table is available as Table 1.1 in the report of the U.S. Government Accountability Office19).

Table 1: Some historical examples of proposals for climate related geo-engineering

Date Who Proposal

1877 N. Shaler Re-routing the Pacific’s warm Kuroshio Current through the Bering Strait to raise Arctic temperatures by around 15°C

1958 M. Gorodsky and V. Cherenkov

Placing metallic potassium particles into Earth’s polar orbit to diffuse light reaching Earth and thereby thaw permafrost in Russia, Canada, and Alaska and melt polar ice

1960s M. Budyko and others Melting of Arctic sea-ice by adding soot to its surface

1977 C. Marchetti Disposal of liquid CO2 to the deep ocean, via the Mediterranean outflow

1990 J. Martin Adding iron to the ocean to enhance CO2 drawdown

1992 NAS Committee on Science, Engineering, and Public Policy

Adding dust to the stratosphere to increase the reflection of sunlight

Finally, a number of professional societies20 have considered this issue and called for further research efforts on geo-engineering. At the same, there has already been considerable public discussion and enunciation of social, economic and cultural issues as well as ethical considerations and concerns raised outside of scholarly journals, for example, by civil society organizations, indigenous communities as well as in popular books. Some reference to this debate is also included in the document.

19 U.S. Government Accountability Office (2011) Technology Assessment: Climate engineering. Technical status, future directions, and potential tresponses. GAO-11-71. www.gao.gov/new.items/d1171.pdf20 For example, the American Meteorological Society and the American Geophysical Union.

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CHAPTER 2: DEFINITIONS AND FEATURES OF GEO-ENGINEERING APPROACHES AND TECHNIQUES

2.1 Definitions of climate-Related geo-engineering relevant for the Convention on Biological Diversity

There is a broad range of definitions available for geo-engineering (Annex 1). Many of these definitions contain common elements but within different formulations. A starting point is the interim definition adopted by the Conference of the Parties to the CBD:21

“Without prejudice to future deliberations on the definition of geo-engineering activities, understanding that any technologies that deliberately reduce solar insolation or increase carbon sequestration from the atmosphere on a large scale that may affect biodiversity (excluding carbon capture and storage from fossil fuels when it captures carbon dioxide before it is released into the atmosphere) should be considered as forms of geo-engineering which are relevant to the Convention on Biological Diversity until a more precise definition can be developed. It is noted that solar insolation is defined as a measure of solar radiation energy received on a given surface area in a given hour and that carbon sequestration is defined as the process of increasing the carbon content of a reservoir/pool other than the atmosphere.”

Based on the above, and consistent with the definitions listed in Annex 1, in this report: Climate-related Geo-engineering is defined as:

A deliberate intervention in the planetary environment of a nature and scale intended to counteract anthropogenic climate change and/or its impacts, through, inter alia, solar radiation management or removing greenhouse gases from the atmosphere.

This definition includes, but is not limited to, solar radiation management (SRM) and carbon dioxide removal (CDR) techniques with the implication that the interventions, individually, or in combination, could, in principle, be carried out on a scale large enough to have a significant effect on the Earth’s climate, even comparable in magnitude to anthropogenic climate change. Unlike some others, this definition includes the removal of greenhouse gases other than carbon dioxide. However such approaches are not further examined in this report due to limited peer reviewed literature on the methods and their potential impacts. Further proposed methods are potentially also covered by the above but are not given detailed attention for the same reasons. The definition continues to exclude carbon capture and storage from fossil fuels when it captures carbon dioxide before it is released into the atmosphere22.

As noted in Chapter 1, there is currently a range of views concerning the inclusion or exclusion within the definition of geo-engineering of a number of activities involving bio-energy, afforestation and reforestation, and changing land management practices.

There is also a range of views concerning the inclusion or exclusion of weather modification technologies, such as cloud seeding, within the definition of geo-engineering. Proponents argue that the history, intention, institutions, technologies themselves, and impacts are closely related to geo-engineering.23

The above definition is broad in scope, suitable for broad-based analysis such as this study.

21 Footnote to decision X/33, paragraph 8(w)22 Carbon Capture and Storage includes the storage of CO2 in depleted hydrocarbon reservoirs and saline aquifers as well as through the injection of liquid CO2 into basalt or peridotite rocks at depth where it reacts with the rock minerals to form calcium and magnesium carbonates.23 As explored by the UK House of Commons Science and Technology Committee 2010 “the regulation of geo-

engineering: fifth report of session 2009-10; ETC Group “Geopiracy – the case against geo-engineering” 2010

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More specific definitions that are perhaps narrower in scope and allow for more precise legal interpretations may be required for some purposes, such as providing policy advice and regulation. Such definitions might be confined to specific techniques or classes of techniques. For example, definitions relating to SRM techniques or CDR techniques that have the potential for significant negative transboundary implications or the potential to directly affect the global commons in a negative way may warrant separate treatment.

2.2 Features of Solar Radiation Management and Carbon Dioxide Removal mechanisms

Based on the definitions of geo-engineering proposed in section 2.1, this study considers a range of both solar radiation management (SRM) techniques and carbon dioxide removal (CDR) methods.

When considering the potential effectiveness and impacts of such approaches, the report examines the spatial and temporal scales at which the approaches would have to operate in order to offset the projected changes arising from future anthropogenic emissions of greenhouse gases. These projected changes are based on a set of scenarios for anthropogenic emissions of greenhouse gases developed by the Intergovernmental Panel on Climate Change (IPCC) as Special Report Emissions Scenarios (SRES) (see Chapter 3, section 3.1).

2.2.1 Solar Radiation Management (SRM)

Description

Solar radiation management (SRM) techniques would counteract warming by reducing the incidence and subsequent absorption of incoming solar (short-wave) radiation (often referred to as insolation), not treat the root cause of anthropogenic climate change arising from increasing greenhouse gas concentrations in the atmosphere8. SRM methods are designed to make the Earth more reflective by increasing the planetary albedo, or by otherwise diverting incoming solar radiation24. This provides a cooling effect, to counteract the warming influence of increasing greenhouse gases. It may be possible that some of these techniques could be applied to be effective within particular regions or latitude bands. This might allow the largest counter-acting effects to be concentrated there, with lesser effects elsewhere.

Solar radiation management would rapidly have an effect on climate once deployed at the appropriate scale. However, SRM techniques would not address ocean acidification or the CO2

fertilization effect25. Moreover, they would introduce a new dynamic between the warming effects of greenhouse gases and the cooling effects of SRM with uncertain climatic implications especially at the regional scale.

Proposed SRM techniques considered in this document comprise four main categories:

5. Space-based approaches: reducing the amount of solar energy reaching Earth by positioning sun-shields in space with the aim of reflecting or deflecting solar radiation;

6. Changes in stratospheric aerosols: injecting a wide range of types of particles into the upper atmosphere, with the aim of increasing the scattering of sunlight back to space26;

7. Increases in cloud reflectivity: increasing the concentration of cloud-condensation nuclei in the lower atmosphere, thereby whitening clouds with the aim of increasing the reflection of solar radiation;

24 The Royal Society. (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp25 CO2 fertilization effect: Higher CO2 concentrations in the atmosphere increase productivity in some plant

groups under certain conditions

26 Sulphur dioxide emissions into the troposphere (as currently happening from coal-fired power stations for example) result in an increase in sulfate aerosol concentration that also reflects solar radiation and therefore have a similar counteracting effect to stratospheric aerosols.

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8. Increases in surface albedo: modifying land or ocean surfaces, with the aim of increasing the reflection of more solar radiation. This could include growing crops with highly reflective foliage, painting surfaces in the built environment white, or covering areas (e.g. of desert) with reflective material.

Scope in terms of the scale of the responses

The aim of SRM is to counteract the positive radiative forcing of greenhouse gases with a negative forcing. To be effective in reducing a rise in global temperature, the reduction in absorbed solar radiation would need to be a significant proportion of the increases in radiative forcing at the top of the atmosphere caused by anthropogenic greenhouse gases. For example, to fully counteract the warming effect of a doubling of the CO2 concentration would require a reduction in total incoming solar radiation by about 1.8% and the absorbed heat energy by about 4 Wm-2 (watts per square meter) as a global average.

The impact on radiative forcing of a given SRM method is dependent on altitude (whether the method is applied at the surface, in the atmosphere, or in space), as well as the geographical location of its main deployment site(s). Other factors that need to be taken into account include the negative radiative forcing of other anthropogenic emissions such as sulphate and nitrate aerosols that together may provide a forcing of up to –2.1 Wm -2 by 210027. Such uncertainties and interactions make it difficult to assess the scale of geo-engineering that would be required, although quantitative estimates of the effectiveness of different techniques have been made28.

2.2.2 Carbon Dioxide Removal (CDR)

Description

Carbon dioxide removal (CDR) involves techniques aimed at removing CO2, a major greenhouse gas, from the atmosphere, allowing outgoing long-wave (thermal infra-red) radiation to escape more easily29. In principle, other greenhouse gases (such as N2O, and CH4), could also be removed from the atmosphere, but such approaches have yet to be developed.

Carbon Dioxide Removal (CDR) geo-engineering approaches actually involve two steps:

(1) carbon sequestration or removal of CO2 from the atmosphere; and

(2) storage of the sequestered carbon.

In some biologically- and chemically-driven processes, these steps occur together or are inseparable. This is the case in ocean fertilization techniques and in the case of afforestation, reforestation and soil carbon enhancement. In these cases the whole process, and their impacts on biodiversity, are confined to marine and terrestrial systems respectively.

In other cases, the steps are discrete and various combinations of sequestration and storage options are possible. Carbon sequestered in terrestrial ecosystems as biomass, for example, could be disposed either in the ocean as plant residues or incorporated into the soil as charcoal. It could also be used as fuel with the resultant CO2 sequestered at source and stored either in sub-surface reservoirs or the deep ocean. In these cases, each step will have its advantages and disadvantages, and both need to be examined.

Proposed CDR removal techniques considered in this document include:

27 IPCC (2007) Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp28 Lenton T.M. and Vaughan N.E. (2009) The radiative forcing potential of different climate geoengineering options. Atmospheric Chemistry and Physics, 9, 5539-5561.29 The Royal Society. (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp

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1. Ocean Fertilization: the enrichment of nutrients in marine environments with the principal intention of stimulating primary productivity in the ocean, and hence CO2

uptake from the atmosphere, and the deposition of carbon in the deep ocean. Two techniques may be employed with the intention of achieving these effects:

(a) Direct ocean fertilization: the artificial addition of limiting nutrients from external (non-marine) sources. The approach includes addition of the micronutrient iron, or the macronutrients nitrogen or phosphorus (Activities carried out as part of conventional aquaculture are not included, nor is the creation of artificial reefs.);

(b) Up-welling or down-welling modification: for the specific purpose of enhancing nutrient supply, and hence biologically-driven carbon transfer to the deep sea. (This excludes other human activities which might cause fertilization as a side effect, for example, by pumping cold, deep water to the surface for cooling or energy-generating purposes);

2. Enhanced weathering: artificially increasing the rate by which carbon dioxide is naturally removed from the atmosphere by the weathering (dissolution) of carbonate and silicate rocks, including;

(a) Enhanced ocean alkalinity: adding the dissolution products of alkaline minerals (e.g. calcium carbonate and calcium hydroxide) in order to chemically enhance ocean storage of CO2; it also would buffer the ocean to decreasing pH, and thereby help to counter ocean acidification;

(b) Enhanced weathering of rocks: silicate rocks reacting with CO2 to form solid carbonate and silicate minerals and spreading abundant silicate minerals such as olivine over agricultural soils;

3. Increasing carbon sequestration through ecosystem management30:

(a) Afforestation: direct human-induced conversion of land that has not been forested (for a period of at least 50 years) to forested land through planting, seeding and/or the human-induced promotion of natural seed sources;

(b) Reforestation: Direct human-induced conversion of non-forested land to forested land through planting, seeding and/or the human-induced promotion of natural seed sources, on land that was previously forested but converted to non-forested land. (For the first commitment period of the Kyoto Protocol, reforestation activities will be limited to reforestation occurring on those lands that did not contain forest on 31 December 1989);

(c) Enhancing soil carbon: through improved land management activities including retaining captured CO2 so that it does not reach the atmosphere and enhancing soil carbon via livestock management;

4. Sequestration of carbon as biomass and its subsequent storage – this consists of two discrete steps, with various options for the storage step:

(a) Production of biomass: This can be done through the use of conventional crops, trees and algae, and possibly also through plants bioengineered to grow faster and sequester more carbon.

(b) Bio-energy carbon capture and storage (BECCS): Bioenergy with CO2 sequestration combining existing technology for bioenergy / biofuels and for carbon capture and storage (geological storage);

30 For the purpose of this report, the definitions of afforestation and reforestation were taken from the IPCC in order to be consistent with the work of the CBD Second Ad hoc Technical Expert Group on Biodiversity and Climate Change, although other definitions do exist.

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(c) Biochar: the production of black carbon, most commonly through pyrolysis (heating, in a low- or zero oxygen environment) and its deliberate application to soils31;

(d) Ocean biomass storage: depositing crop waste or other terrestrial biomass onto the deep ocean seabed, possibly in high sedimentation areas;

5. Capture of carbon from the atmosphere and its subsequent storage – this consists of two discrete steps with various options for the storage step:

(a) Direct carbon capture from ambient air (artificial trees): the capture of CO2 from the air by its adsorption onto solids, its absorption into highly alkaline solutions and/or its absorption into moderately alkaline solutions using a catalyst;

(b) Sub-surface storage in geological formations: storage in oil or gas fields, un-minable coal beds, and deep saline formations such as sedimentary rocks containing high concentrations of dissolved salts.

(c) Ocean CO2 storage: ocean storage of carbon by adding liquid CO2 (e.g. as obtained from air capture) into the water column (i) via a fixed pipeline or a moving ship, (ii) through injecting liquid CO2 into deep sea sediments at > 3,000 m depth or (iii) by depositing liquid CO2 via a pipeline onto the sea floor. At depths below 3,000 m, liquid CO2 is denser than water and is expected to form a “lake” that would delay its dissolution into the surrounding environment;

As mentioned above, there is a range of views as to whether activities such as large-scale afforestation or reforestation should be classified as geo-engineering. These approaches are already widely deployed, albeit on a relatively small scale, for climate change mitigation as well as other purposes, and involve minimal use of novel technologies. For the same reasons, there is debate over whether biomass-based carbon should be included. However, for the sake of completeness, all of these approaches are discussed in this report without prejudice to any subsequent discussions within the CBD on definitions or policy on geo-engineering.

Scope in terms of the scale of the response

The terrestrial biosphere currently takes up about 2.6 GtC (gigatonnes of carbon) per year from the atmosphere, although this is partially offset by carbon dioxide emissions of about 0.9 GtC per year from tropical deforestation and other land use changes. In comparison, the current CO2 release rate from fossil fuel burning alone is about 9.1 GtC/yr 32; so to have a significant positive impact, one or more CDR interventions would need to involve the removal from the atmosphere of several GtC/yr, maintained over decades and more probably centuries. It is very unlikely that such approaches could be deployed on a large enough scale to alter the climate quickly, and so they would be of little help if there was a need for ‘emergency action’ to cool the planet on a short time scale.

2.2.3 Comparison between SRM and CDR techniques

Although described above separately, it is possible that, if geo-engineering were to be undertaken, a combination of SRM and CDR techniques could be used, alongside mitigation through emission reductions, with the objective of off-setting at least some of the impacts of changes to the climate system from past or ongoing emissions. While SRM and CDR interventions would both have global effects, since climate operates on a global scale, some of the proposed SRM interventions (e.g. changing cloud albedo) could result in strong hemispheric or regional disparities, e.g. with regard to changes in the frequency of extreme

31 Spokas, K. (2010). Review of the stability of biochar in soils: predictability of O:C molar ratios, Carbon Management (2010) 1(2), 289–30)32 Global Carbon Project (2011) Carbon budget and trends 2010. www.globalcarbonproject.org/carbonbudget, released 4 December 2011.

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events. Under conditions of rapid climate change, the unequivocal separation of impact causality between those arising from the SRM intervention and those that would have happened anyway would not be easy. Likewise, CDR techniques will ultimately reduce global CO2 concentrations but may affect local to regional conditions more in the short term.

In general, SRM techniques can have a relatively rapid impact on the radiation budget once deployed, whereas the effects of many of the CDR processes are relatively slow. Furthermore, while SRM techniques offset the radiative effects of all greenhouse gases, they do not alleviate the potential impacts of changes in atmospheric chemistry, such as ocean acidification. In contrast, most (but not all) CDR techniques do address changes in atmospheric CO2 concentrations, but they do not address the radiative effects of increased atmospheric concentrations of non-carbon dioxide greenhouse gases (e.g. methane, nitrous oxide, tropospheric ozone, halocarbons) and black carbon. Furthermore, whilst some CDR techniques would reduce ocean acidification, that benefit is compromised to varying degrees if the CO2 removed from the atmosphere is subsequently added to the ocean.

To facilitate further comparison between techniques, Tables 2.1 and 2.2 summarize SRM and CDR approaches respectively and provide a simplified assessment of their effectiveness, cost readiness, risks and reversibility. The assessments are based primarily upon those provided in the peer-reviewed Royal Society Report33 with further details provided in the legend to the tables. They address primarily risks to the climate system and its biogeophysical implications and do not necessarily reflect broader implications for ecosystem services or social impacts. Further discussion of the risks is included in Chapters 4 and 5.

It should be noted that the estimates provided for each of the criteria in these assessments are relative. With regard to readiness, for example, the GAO report ranks all geo-engineering technologies as immature (low technology readiness level (TRL) 2 or 3 on a scale of 1 to 9).34

Clearly, interventions that are deemed to be safe are highly preferable, but, given the high levels of uncertainty associated with geo-engineering, in case the safety evaluation is incorrect, then interventions with a relatively short time to reverse any adverse effects are, by many, deemed preferable because the unintended consequences can be reversed relatively quickly.

However, it should be noted that for any listed geo-engineering technique to be effective over the long-term, it would need to be continued for decadal to century timescales (and potentially for millennia), or until such time as the atmospheric levels of greenhouse gases have been stabilised at levels that no longer present unacceptable danger to ecosystems, food production and economic development (possibly to below current levels). This ‘treadmill’ problem is particularly acute for SRM interventions, whose intensity would need to be progressively increased unless other actions are taken to stabilise greenhouse gas concentrations. The cessation of SRM interventions would also be a highly risky process, and if, after being deployed for some time, were to be carried out rapidly, would likely result in a rapid increase in the solar radiation reaching the Earth’s surface, and associated very rapid increase in surface temperature35. Thus, high reversibility could have both advantages and disadvantages.

2.2.3 Additional speculative techniques:

In addition to the SRM and CDR techniques described above, a number of other highly speculative approaches have been mooted. These have not been evaluated and are not discussed further in this report. They include some approaches based on increasing the rate of loss of long-wave heat radiation. One is to reduce the amount of cirrus clouds by injection of

33 The Royal Society. (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp34 U.S. Government Accountability Office (2011) Technology Assessment: Climate engineering. Technical

status, future directions, and potential responses. GAO-11-71. www.gao.gov/new.items/d1171.pdf

35 In one model simulation, the rate was up to 20 times greater than present-day rates. Matthews H.D. and Caldeira K. (2007) Transient climate-carbon simulations of planetary geoengineering. PNAS, 104, 9949-9954

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an appropriate substance to form ice particles as a sink for upper tropospheric water vapour. Another is to use icebreakers to open up passages in the fall and winter in order to reduce the insulating effect of the Arctic ice (so more heat is transferred from the ocean to the atmosphere), thus promoting the thickening of adjacent ice (and so increasing the amount of reflected solar radiation the next spring). Using micron-size bubbles in water to increase albedo and cool the water has been proposed36.

There are also other types of approaches that might involve land surface modification, such as draining seawater into the Qattara Depression to limit sea level rise, or blocking the Bering Strait to promote formation of sea ice.

36 Proposed by Seitz, R. (2011) Bright water: hydrosols, water conservation and climate change. Climatic Change. Doi:10.1007/s10584-010-9965-8; however see Robock, A. (2011). "Bubble, bubble, toil and trouble." Climatic Change 105: 383-385 DOI: 10.1007/s10584-010-0017-1

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Table 2.1: Classification of SRM techniques and summary of featuresTechnique(s) Relative Effectiveness Relative

Direct Cost

Relative Readiness Relative Risks and Uncertainty

Relative Reversibili-tyMechanism Scale OA? To deploy To Act Risk Uncertainty

Notes to the columns (see below) (1) (2) (3) (4) (5) (6) (7) (8) (9)

Space-based reflectors High Large No V.High V.Low Moderate Moderate

Moderate Medium

Stratospheric aerosols High Large No Low Moderate Fast High High Fast

Cloud reflectivity Medium Medium No Moderate Moderate Fast High High Fast

Surface albedo Built environment High Small No V.High Moderate Fast Low Low Medium

Crops High Medium No Moderate Moderate Fast Low Medium Fast

Deserts High Large No V.High Moderate Fast V.High V.High Medium

Notes to the columns of tables 2.1 and 2.2:The assessments are based primarily upon those provided in the peer-reviewed Royal Society Report. They address primarily risks to the climate system and its biogeophysical implications and do not necessarily reflect broader implications for ecosystem series or social impacts. The risks are further discussed in Chapters 4 and 5. The estimates provided for each of the criteria in these assessments are relative.Effectiveness: a measure of the potential of geo-engineering techniques to offset impacts of climate change and, specifically, for SRM techniques to modify solar radiation and for CDR techniques to sequester CO2 from the atmosphere. Three sub-criteria are provided: (1) The degree of evidence that the mechanism would actually work, based on theoretical understanding and, where appropriate, experimental results; (2) The potential scale of operation: For CDR, ‘Large’ is several GtC per year; ‘Medium’ is about 1 GtC per year; and ‘small’ is less than 0.1 GtC per year. For SRM, ‘Large’ is several Wm -2; ‘Medium’ is about 1 Wm-2; and ‘Small’ is less than 0.1 Wm-2; (3) Whether or not the technique also addresses the problem of ocean acidification;Cost (4) estimate of the cost of deploying the technology on a significant scale;Readiness: including (5) a measure of whether a technique to either affect solar radiation or reduce the atmospheric concentration of CO 2, and hence impact on the earth’s climate, can be deployed on a large-scale within 10 years. This measure refers purely to technical readiness, and excludes what is economically, socially and politically possible. A technology might be ready to deploy tomorrow, but impossible to deploy due to economic, social or political obstacles.(6) How quickly the technology, once deployed, would act to offset climate change effects on a significant scale:Risk: a measure of the potential for adverse effects of a technique, including:(7) risk of anticipated negative effects and the magnitude of those effects(8) Probability of unanticipated negative effects (uncertainty)Reversibility: (9) the degree to which the impact of a geo-engineering intervention is safely reversible if it is found to have unintended adverse environmental consequences. As with the ‘Readiness’ measure, ‘Reversibility’ reflects a purely technological point of view, regardless of the termination effect. A geo-engineering technology might be technically reversible, but impossible to reverse due to economic, social and political concerns (e.g. employment, vested interests, etc.).

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Table2.2: Classification of CDR techniques and summary of featuresTechnique(s) Relative

Location of Impacts

Relative Effectiveness Relative Cost

Relative Readiness

Relative Risks and Uncertainty

Relative Revers-ibilty

Capture Storage Mechan-ism

Scale OA? To deploy

To Act Risk Uncertainty

Notes (see legend to Table 2.1 and below) (1) (2) (3) (4) (5) (6) (7) (8) (9)

1. Ocean Fertilization

direct external fertilization

Fe – Ocean – Poor Small No Low Medium Slow High V.High Medium

N / P – Ocean – Poor V.Small No Moderate Medium Slow High V.High Medium

up/downwelling modification – Ocean – V. Poor Unknown No Unknown V. low Unknown V.High V.High Unknown

2. Enhanced weathering

Ocean alkalinity (ocean) – Ocean+ – Good Large Yes High Low Slow Moderate Moderate None

Spreading of base minerals – Land+ – Good Large Yes High Low Slow Moderate Moderate None

3. Terrestrial Ecosystem management

Afforestation – Land – Good Small Yes Moderate High Medium Low-Mod Low Medium

Reforestation – Land – Good Small Yes Moderate High Medium Low Low Medium

Soil carbon enhancement – Land – Good Small Yes Moderate High Slow Low Low Medium

4. Biomass Biomass Production Land na Medium Medium Yes Moderate High Slow Moderate Moderate Medium

Biofuels with CCS na Sub-S Medium Medium na High Medium Low Moderate Moderate Slow

Charcoal storage Land Medium Small Moderate Medium Low Moderate Moderate Slow

Ocean biomass storage Ocean Poor Small High Low Low High High None

5. Air Capture & CO2 Storage

Air capture Either na High Medium Yes V.High Low Medium Low Low na

Ocean CO2 storage na Ocean Low Medium na High Low Low V. High High None

Sub-surface CO2 reservoirs Sub-S Good Medium High Low Low Moderate Moderate na

+ Ocean alkalinity: will also have indirect impacts on land through mining and transport of materials.

+ Spreading of alkaline minerals: will eventually have impacts (largely positive) on oceans through run-off to oceans.

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CHAPTER 3: OVERVIEW OF CLIMATE CHANGE AND OCEAN ACIDIFICATION AND OF THE THEIR IMPACTS ON BIODIVERSITY

Geo-engineering techniques are being proposed to counteract some of the negative impacts of climate change, which include impacts on biodiversity. This chapter therefore provides an overview of projected climate change (Section 3.1) and its impacts on biodiversity and ecosystems (Section 3.2), in order to provide context, and a possible baseline which can be taken into account when the impacts of geo-engineering techniques are reviewed in subsequent chapters.

3.1 Overview of projected climate change and ocean acidification.

Human activities have already increased the concentration of greenhouse gases, such as CO2, in the atmosphere. These changes affect the Earth’s energy budget, and are considered to be the main cause of the ~0.8°C average increase in global surface temperature that has been recorded over the last century37. The continued increase in atmospheric greenhouse gases has profound implications not only for global and regional average temperatures, but also precipitation, ice-sheet dynamics, sea-level rise, ocean acidification and the frequency and magnitude of extreme events. Future climatic perturbations could be abrupt or irreversible, and are likely to extend over millennial time scales; they will inevitably have major consequences for natural and human systems, severely affecting biodiversity and incurring very high socio-economic costs.

3.1.1 Scenarios and models

The Intergovernmental Panel on Climate Change (IPCC) developed future scenarios for anthropogenic emissions of greenhouse gases in its Special Report on Emissions Scenarios (SRES). These were grouped into four families (A1, A2, B1 and B2) according to assumptions regarding the rates of global economic growth, population growth, and technological development38. The SRES A1 family includes three illustrative scenarios relating to dependence on fossil fuels (A1FI, fossil fuel intensive; A1B, balanced; and A1T, non-fossil energy sources); the other families each have only one illustrative member. The B1 scenario assumes the rapid introduction of resource-efficient technologies, together with global population peaking at 8.7 billion in 2050.

The six SRES illustrative scenarios were used in the IPCC’s fourth assessment report (AR4) in a suite of climate change models to estimate a range of future global warming of 1.1 to 6.4°C by 2100, with a ‘best estimate’ range of 1.8 to 4.0°C (Figures 3.1 and 3.2)39. A 7th

scenario assumed that atmospheric concentrations of greenhouse gases remain constant at year 2000 values. Note in Fig 3.2 the very large regional differences in temperature increase, and between land and ocean areas, with increases of up to 7°C for the Arctic. The projected precipitation changes also have high spatial variability, with both increases and decreases of ~20% in most continents.

37 Intergovernmental Panel on Climate Change (IPCC). 2008. Climate Change 2007 – Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Pachauri R.K. & Resinger A. (Eds). IPCC, Geneva, Switzerland, pp 104.

38 Intergovernmental Panel on Climate Change (IPCC). 2000. Emissions Scenarios. Nakicenovic N. & Swart R. (Eds). Cambridge University Press, UK, pp 570.39 Intergovernmental Panel on Climate Change (IPCC). 2008. Climate Change 2007 – Synthesis Report.

Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Pachauri R.K. & Resinger A. (Eds). IPCC, Geneva, Switzerland, pp 104.

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Figure 3.1: Illustrative scenarios for greenhouse gas annual emissions from 2000 to 2100

Left: Six illustrative scenarios for greenhouse gas annual emissions from 2000 to 2100, as gigatonnes of CO2 equivalent. Greenhouse gases include CO2, CH4, N2O and F-gases. The gray shaded area shows the 80th percentile range of other scenarios published since the IPCC Special Report on Emission Scenarios; the dashed lines [labelled post-SRES (max) and post-SRES (min)] show the full range of post-SRES scenarios. Right: Vertical bars show range of temperature increases and best estimates for IPCC’s six illustrative emission scenarios, based on multi-model comparisons between 1980-1999 and 2090-2099. Temporal changes in global surface warming also shown graphically for scenarios A2, A1B and B1 (red, green and dark blue lines respectively), with pink line showing temperature change if atmospheric concentrations of greenhouse gases could be held constant at year 2000 values.

Figure 3.2: Projected patterns of temperature increase and precipitation change

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Projected increase in annual mean temperature (upper map) and percentage precipitation change (lower maps; left, December to February; right, June to August) for the SRES A1B scenario, based on multi-model comparisons between 1980-1999 and 2090-2099. Couloured areas on precipitation maps are where >66% of the models agree in the sign of the change; for stippled areas, >90% of the models agree in the sign of the change.

IPCC AR4 estimated global sea level rise (relative to 1990) to be 0.2 to 0.6 m by 2100; however, those projections excluded ice sheet changes. Taking such effects into account, more recent empirical estimates40 give projected sea level increases of 0.4 – 2.1 m, with similar values obtained from measurements of ice-sheet mass balance41, although with large uncertainties relating to current loss rates (particularly for Antarctica)42. Future sea level change will not be globally uniform43: regional variability may be up to 10-20 cm for a projected global end-of-century rise of around 1 m.

The broad pattern of climate change observed since ~1850 has been consistent with model simulations, with high latitudes warming more than the tropics, land areas warming more than oceans, and the warming trend accelerating over the past 50 years. Over the next 100 years, interactions between changes in temperature and precipitation (Figure 3.2) will become more critical; for example, affecting soil moisture and water availability in both natural and managed ecosystems. These effects are likely to vary across regions and seasons, although with marked differences between model projections. By 2050, water availability may increase by up to 40% in high latitudes and some wet tropical areas, while decreasing by as much as 30% in already dry regions in the mid-latitudes and tropics44. Additional analyses45

of 40 global climate model projections using the SRES A2 scenario indicate that Northern Africa, Southern Europe and parts of Central Asia could warm by 6-8°C by 2100, whilst precipitation decreases by ≥10%.

The IPCC SRES scenarios can be considered inherently optimistic, in that they assume continued improvements in the amounts of energy and carbon needed for future economic growth. Such assumptions have not recently been met46; if future improvements in energy efficiency are not achieved, emissions reductions may need to be up to three times greater 47

than estimated in AR4.

A new generation of emission scenarios giving greater awareness to such issues is currently under development48 for use in the IPCC fifth assessment report (AR5). These will include both baseline and mitigation scenarios, with emphasis on Representative Concentration Pathways (RCPs) and cumulative emissions to achieve stabilization of greenhouse gas

40 Rahmstorf S. 2010. A new view on sea level rise. Nature Reports Climate Change. Published online 6 April 2010; doi: 10.1038/climate.2010.29

41 Rignot E., Velicogna I., van den Broeke M.R., Monaghan A. & Lenaerts J. 2011. Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophysical Research Letters, 38, L05503, doi: 10.1029/2011GL04658342 Zwally H.J. & Giovinetto M.B. 2011. Overview and assessment of Antarctic ice-sheet mass balance estimates: 1992-2009. Surveys in Geeophysics, 32, 351-376; doi: 10.1007/s10712-011-9123-543 Milne G.A., Gehrels W.R., Hughes C.W. & Tamisiea M.E. 2009. Identifying the causes of sea level change. Nature Geosciences 2, 471-478.44 Intergovernmental Panel on Climate Change (IPCC). 2008. Climate Change 2007 – Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Pachauri R.K. & Resinger A. (Eds). IPCC, Geneva, Switzerland, pp 104.45 Sanderson M.G, Hemming D.L & Betts R.A. 2011. Regional temperature and precipitation changes under high-end (≥4°C) global warming. Phil. Trans. R. Soc. A, 369, 85-98; doi: 10.1098/rsta.2010.028346 Pielke R., Wigley T. & Green C. 2008. Dangerous assumptions. Nature, 452, 531-2

47 Pielke R., Wigley T. & Green C. 2008. Dangerous assumptions. Nature, 452, 531-2

48 UNFCCC Subsidiary Body for Scientific and Technological Advice. 2011. Report on the Workshop on the Research Dialogue, 34th SBSTA session, Bonn 6-16 June 2011, FCCC/SBSTA/2011/INF.6 (paras 19-23 and 37-38). http://unfccc.int/resource/docs/2011/sbsta/eng/inf06.pdf

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concentrations at various target levels, linked to their climatic impacts. For example, stabilization at 450, 550 and 650 ppm CO2eq (carbon dioxide equivalent; taking account of anthropogenic greenhouse gases and aerosols in addition to carbon dioxide), is expected to provide around a 50% chance of limiting future global temperature increase to 2°C, 3°C and 4°C respectively. Note that anthropogenic sulphate aerosols have a negative CO2eq value; thus if their emissions are reduced, the rate of warming would increase.

3.1.2 Current trajectories for climate change

One of the goals of the United Nations Framework Convention on Climate Change is to prevent dangerous anthropogenic interference in the climate system. This aim is stated in the UNFCCC Objective (Article 2 of the Convention):

“The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.”

However, there are both political and technical difficulties in deciding what ‘dangerous’ means in terms of equivalent temperature increase and other climate changes (and hence CO2eq stabilization value). The Copenhagen Accord49 recognized “the scientific view that the increase in global temperature should be below 2°C”, which equates to a target of around 400-450 ppm CO2eq. Currently the ensemble of greenhouse gases and aerosols are equivalent to around 495 ppm CO2eq, but the cooling effect of anthropogenic sulphate aerosols offset around 100 ppm CO2eq. Progress towards achieving emission reduction targets for greenhouse gases has been recently reviewed50,51.

Lower stabilization targets have also been proposed52,53,54 on the basis that a 2°C temperature increase represents an unacceptable level of climate change55. To achieve these lower targets, reductions from current CO2eq levels (i.e. negative emissions, through CDR geo-engineering) would almost certainly be needed.

Since 2000, the average rate of increase in global greenhouse gas emissions has been 3.1% per year (Figure 3.3) )56,57 matching or exceeding the rates of the highest IPCC SRES

49 UNFCCC. 2010. Copenhagen Accord. http://unfccc.int/resource/docs/2009/cop15/eng/107.pdf 50 UNEP. 2011. Bridging the Emissions Gap. United Nations Environment Programme (UNEP), 52 pp;

www.unep.org/pdf/UNEP_bridging_gap.pdf

51 IAEA. 2011. Climate Change and Nuclear Power 2011. International Atomic Energy Authority (IAEA). 40 pp. www.iaea.org/OurWork/ST/NE/Pess?assets/11-43751_ccnp_brochure.pdf

52 Rockström J. et al. 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society, 14, Article 32; www.ecologyandsociety.org/vol14/iss2/art32

53 Hansen J. et al. 2008. Target atmospheric CO2: where should humanity aim? Open Atmos. Sci. J., 2, 217-231; doi 10.2174/1874282300802010217

54 Veron J.E.N. et al. 2009. The coral reef crisis: the critical importance of <350 ppm CO2. Marine Pollution Bulletin, 58, 1428-1436; doi: 10.1016/j.marpolbul.2009.09.009

55 Anderson K. & Bows A. 2011. Beyond ‘dangerous’ climate change: emission scenarios for a new world. Phil. Trans. Roy. Soc. A. 369, 20-44; doi: 10.1098/rsta.2010.029056 Peters GP, Marland G, Le Quéré C, Boden T, Canadell JG, Raupach MR. 2011. Rapid growth in CO2 emissions after the 2008-2009 global financial crisis. Nature Climate Change, doi. 10.1038/nclimate1332; published online 4 Dec 2011.

57 Global Carbon Project. 2011. Carbon budget and trends 2010. www.globalcarbonproject.org/carbonbudget,

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scenarios for that period (A1B, A1FI and A2) despite the Kyoto Protocol and the recent global economic downturn. As a result, it has become much more challenging to achieve the 450 ppm CO2eq target. For example, for ~50% success in reaching that target, it has been estimated that global greenhouse gas emissions would need to peak in the period 2015-2020, with an annual reduction of emissions of >5% thereafter58. Whilst such changes in emissions are not unrealistic for some developed countries, at the global level, the necessary planning (and political will) for radical changes in energy infrastructure and associated economic development59,60,61 are not yet in place. If such efforts are not made, geo-engineering approaches will increasingly be postulated to offset at least some of the impacts of climate change, despite the risks and uncertainties involved.

Figure 3.3. Global emissions of CO2 for 1980-2010 in comparison to IPCC SRES emission scenarios for 2000-202562.

The average rate of increase of CO2 emissions since 2000 has been around 3% per year (increasing atmospheric concentrations by ~2 ppm per year), tracking the highest IPCC emission scenarios used for AR4 climate projections. The increase in emissions in 2010 was 5.9%, the highest total annual growth recorded.

released 4 Dec 2011.

58 Anderson K. & Bows A. 2008. Reframing the climate change challenge in light of post-2000 emission trends. Phil. Trans. Roy. Soc. A, 366, 3863-3882; doi: 10.1098/rsta.2008.013859 Brown L.R. (2011) World on the Edge. How to Prevent Environmental and Economic Collapse. Earth Policy

Institute; www.earth-policy.org/books/wote

60 UNEP 2011. Bridging the Emissions Gap. United Nations Environment Programme (UNEP), 52 pp; www.unep.org/pdf/UNEP_bridging_gap.pdf

61 IAEA. 2011. Climate Change and Nuclear Power 2011. International Atomic Energy Authority (IAEA). 40 pp. www.iaea.org/OurWork/ST/NE/Pess?assets/11-43751_ccnp_brochure.pdf

62 Le Quéré, C. 2011. The response of the carbon sinks to recent climate change, and current and expected emissions in the short term from fossil fuel burning and land use. Presentation at UNFCCC SBSTA Workshop, Bonn 2-3 June 2011; http://unfccc.int/files/methods_and_science/research_and_systematic_observations/application/pdf/15_le_quere_response_of_carbon_sinks.pdf

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Climate-carbon-cycle feedbacks were not included in all of the climate models used for AR4 (but will be included in AR5). Ensemble-based analyses63 of the A1FI scenario with such feedbacks matched the upper end of the AR4 projections, indicating that an increase of 4°C relative to pre-industrial levels could be reached as soon as the early 2060s. The omission of non-linearities, irreversible changes64 and tipping points65 from global climate models makes them more stable than the real world. As a result of that greater stability, models can be poor at simulating previous abrupt climate change due to natural causes66. However, the recent improvements in Earth system models (and computing capacity) give increasing confidence in their representations of future climate-ecosystem interactions.

Even with strong climate mitigation policies, further climate change is inevitable due to lagged responses in the Earth climate system (so-called unrealized warming). Thus, increases in global mean surface temperature of 0.3 - 2.2oC are projected to occur over several centuries after atmospheric concentrations of greenhouse gases have been stabilized67, with associated increases in sea level due to thermally-driven expansion and ice-melt. Due to the long residence time of CO2 in the atmosphere, it is an extremely slow and difficult process to return to a CO2 stabilisation target once this has been exceeded. For other short-lived greenhouse gases, climate system behaviour also prolongs their warming effects68. Figure 3.4 shows the modelled decline in atmospheric CO2 concentrations based on the assumption that emissions could be instantly reduced to zero after peaks of 450-850 ppm had been reached.

Figure 3.4: Changes in atmospheric CO2 concentrations based on emission cessation after certain levels of CO2 have been reached69

63 Betts R.A. et al. 2011. When could global warming reach 4°C? Phil. Trans. R. Soc. A, 369, 67-84; doi: 10.1098/rsta.2010.029264 Solomon S., Plattner G.-K., Knutti R. & Friedlingstein P. 2009. Irreversible climate change due to carbon dioxide emissions. Proc. Natl. Acad. Sci U.S.A, 106, 1704-1709; doi: 10.1073/pnas.081272110665 Lenton T.M. et al. 2008. Tipping elements in the Earth’s climate system. Proc. Natl. Acad. Sci. U.S.A., 105, 1786-1793; doi:10.1073/pnas.070541410566 Valdes P. 2011. Built for stability. Nature Geosciences 4, 414-416; doi: 10.1038/ngeo1200 67 Plattner G.-K. et al 2008. Long-term climate commitments projected with climate-carbon cycle models. 2008.

Journal of Climate, 21, 2721-2751

68 Solomon S et al. 2010. Persistence of climate changes due to a range of greenhouse gases. Proc. Natl. Acad. Sci. U.S.A., 107, 18354-18359

69 Solomon S., Plattner G.-K., Knutti R. & Friedlingstein P. 2009. Irreversible climate change due to carbon dioxide emissions. Proc. Natl. Acad. Sci U.S.A, 106, 1704-1709; doi: 10.1073/pnas.0812721106

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Even if anthropogenic CO2 emissions could be abruptly halted, atmospheric CO2 levels are projected to remain much higher than pre-industrial values for at least the next thousand years.

Such lag effects have particular importance for ocean acidification. Thus, changes in surface ocean pH (due to the solubility of CO2, and the formation of carbonic acid) closely follow the changes in atmospheric CO2. The penetration of such pH changes to the ocean interior is, however, very much slower, depending on the century-to-millennium timescale of ocean mixing70,71.

Differences between the behaviour and impacts of different greenhouse gases and aerosols are not discussed in detail here, but are also very important. For example: tropospheric ozone, methane and black carbon all have relative short atmospheric lifetimes, and therefore may be amenable to emission control with relatively rapid benefits, not only to climate but also human health (black carbon) and agricultural productivity (tropospheric ozone)72. Black carbon particles have significant heating effect on the lower troposphere and potential effect on the hydrological cycle through changes in cloud microphysics, and snow and ice surface albedo73.

3.2 Observed and projected impacts of climate change, including ocean acidification, on biodiversity

3.2.1 Overview of climate change impacts on biodiversity

70 The Royal Society. 2005. Ocean acidification due to increasing atmospheric carbon dioxide. Policy document 12/05, Royal Society, London; 60 pp. http://royalsociety.org/Ocean-acidification-due-to-increasing-atmospheric-carbon-dioxide 71 Joos, F., Frölicher T.L., Steinacher M. & Plattner G-K. (2011) Impact of climate change mitigation on ocean acidification projections. In: Ocean Acidification (Eds: J.-P. Gattuso & L. Hansson), Oxford University Press, p 272- 290.72 UNEP-WMO. Integrated Assessment of Black Carbon and Troposheric Ozone. Summary for Decision

Makers. www.wmo.int/pages/prog/arep/gaw/other_pub.html

73 Ramanathan V & Carmichael G. 2008. Global and regional climate changes due to black carbon. Nature Geoscience 1, 221-227; doi: 10.1038/ngeo156

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Temperature, rainfall and other components of climate strongly influence the distribution and abundance of species; they also affect the functioning of ecosystems, through species interactions. Whilst vegetation shifts, population movements and genetic adaptation have lessened the impacts of previous, naturally-occurring climate change (e.g. during geologically-recent ice age cycles)74, the scope for such responses is now reduced by other anthropogenic pressures on biodiversity, including over-exploitation; habitat loss, fragmentation and degradation75; the introduction of non-native species; and pollution, and the rapid pace of projected climate change. Thus, anthropogenic climate change carries a higher extinction risk76, since the abundance (and genetic diversity) of many species is already much depleted. Human security may also be compromised by climate change77,78, with indirect (but potentially serious) biodiversity consequences in many regions.

Whilst some species may benefit from climate change, many more will not. Observed impacts and adaptation responses arising from anthropogenic climate changes that have occurred to date include the following79:

Shift in geographical distributions towards higher latitudes and (for terrestrial species) to higher elevations80. This response is compromised by habitat loss and anthropogenic barriers to range change;

Phenological changes relating to seasonal timing of life-cycle events;

Disruption of biotic interactions, due to differential changes in seasonal timing; e.g. mismatch between peak of resource demand by reproducing animals and the peak of resource availability;

Changes in photosynthetic rates and primary production in response to CO2 fertilization and increased nutrient availability (nitrogen deposition and coastal eutrophication). Overall, gross primary production is expected to increase, although fast growing species are likely to be favoured over slower growing ones, and different climate forcing agents (e.g. CO2, tropospheric ozone, aerosols and methane) may have very different effects81.

As noted above, the AR4 estimates future global warming to be within the range 1.1°C to 6.4°C by 2100. Five reasons for concern for a similar temperature range had been previously identified in the IPCC’s third assessment report82, relating to risks to unique and threatened (eco)systems; risks of extreme weather events; disparities of (human) impacts and vulnerabilities; aggregate damages to net global markets; and risks of large-scale discontinuities. These reasons for concern were re-assessed using the same methodology 83,

74 Jackson S.T. & Overpeck J.T. 2000. Responses of plant populations and communities to environmental changes of the late Quaternary. Paleobiology 26 (sp4): 194-22075 Ellis E. 2011. Anthropogenic transformation of the terrestrial biosphere. Phil Trans. Roy. Soc. A, 369, 1010-1035; doi: 10.1098/rsta.2010.033176 Maclean I.M.D. & Wilson R.J. 2011. Recent ecological responses to climate change support predictions of high extinction risk. PNAS (online); doi 10.1073/pnas.1017352108.77 Barnett J. & Adger W.N. 2007. Climate change, human security and violent conflict. Political Geography 26, 639-655.78 Hsiang S.M., Meng K.C., & Cane M.A. 2011. Civil conflicts are associated with the global climate. Nature, 476, 438-441.79 Secretariat of the Convention on Biological Diversity. 2009. Connecting Biodiversity and Climate Change Mitigation and Adaptation. Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Montreal, Technical Series No. 41, 126 pages. 80 Cheng I.-C., Hill J.K., Ohlemüller R., Roy D.B. & Thomas C.D. 2011. Rapid range shift of species associated with high levels of climate warming. Science 333, 1024-102681 Huntingford C. et al. 2011. Highly contrasting effects of different climate forcing agents on terrestrial ecosystem services. Phil. Trans. Roy. Soc. A, 369, 2026-2037; doi: 10.1098/rsta.2010.0314 82 Smith J.B., Schellnhuber H.-J. & Mirza M.M.Q. 2001. Vulnerability to climate change and reasons for concern: a synthesis. Chapter 19 in IPCC Third Assessment Report, Working Group II, p 913-967. Cambridge University Press, Cambridge, UK.83 Smith J. B. et al. 2009. Assessing dangerous climate change through an update of the Intergovernmental Panel

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with the conclusion that smaller future increases in global mean temperature – of around 1°C – lead to high risks to many unique and threatened systems, such as “coral reefs, tropical glaciers, endangered species, unique ecosystems, biodiversity hotspots, small island states and indigenous communities” (Figure 3.5).

Figure 3.5: Projected impacts of global warming, as “Reasons for Concern”

Updated “reasons for concern” plotted against increase in global mean temperature84. Note that: i) this figure relates risk and vulnerability to temperature increase without reference to a future date; ii) the figure authors state that the colour scheme is not intended to equate to ‘dangerous climatic interference’ (since that is a value judgement); and iii) there was a marked worsening of the authors’ prognosis in comparison to an assessment published 8 years earlier, using the same methodologies.

The relatively specific and quantifiable risk of rate of extinction was assessed by the CBD’s Second Ad hoc Technical Expert Group on Biodiversity and Climate Change, with the estimate that ~10% of species will be at risk of extinction for every 1°C rise in global mean temperature85. A recent meta-analysis86 provides a similar, although lower, estimate, indicating that extinction is likely for 10-14% of all species by 2100. Irreversible losses at such scales must inevitably lead to adverse impacts on many ecosystems and their services87, with negative social, cultural and economic consequences. Due to the complex nature of the climate-biodiversity link, there will inevitably be uncertainty about the extent and speed at which climate change will impact biodiversity, species interactions88, ecosystem services, the

on Climate Change (IPCC) ‘‘reasons for concern’’. Proc. Natl. Acad. Sci. U.S.A., 106: 4133–4137. doi: 10.1073/pnas.081235510684 Smith J.B., Schellnhuber H.-J. & Mirza M.M.Q. 2001. Vulnerability to climate change and reasons for concern: a synthesis. Chapter 19 in IPCC Third Assessment Report, Working Group II, p 913-967. Cambridge University Press, Cambridge, UK.85 Secretariat of the Convention on Biological Diversity (2009) Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Technical Series No. 41. CBD, Montreal, 126 pp86 Maclean I.M.D. & Wilson R.J. 2011. Recent ecological responses to climate change support predictions of high extinction risk. PNAS (online); doi 10.1073/pnas.1017352108.

87 Isbell F., Calcagno V., Hector A., Connolly J., Harpole W.S., Reich P.B., Scherer-Lorenzen M., Schmid B, Tilman D, van Ruiven J., Weigelt A., Wilsey B.J., Zavaleta E.S. & Loreau M. 2011. High plant diversity is needed to maintain ecosystem services. Nature (online) doi: 10.1038/nature1028288 Brooker R.W., Travis J.M.J, Clark E.J. & Dytham C. 2007. Modelling species range shifts in a changing climate: The impacts of biotic interactions, dispersal distance and rate of climate change. J Theoretical Biology, 245, 59-65

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thresholds of climate change above which ecosystems no longer function in their current form89, and the effectiveness of potential conservation measures90,91.

3.2.2 Projected impacts on terrestrial ecosystems

The geographical locations where greatest terrestrial biodiversity change might be expected has been assessed using multi-model ensembles and SRES A2 and B1 emission scenarios to predict the appearance or disappearance of new and existing climatic conditions92 (Figure 3.6). The A2 scenario indicates that, by 2100, 12-39% of the Earth’s land surface will experience novel climatic conditions (where the 21st century climate does not overlap with 20th century climate); in addition, 10-48% will experience disappearing climatic conditions (where the 20th century climate does not overlap with the 21st century climate).

Figure 3.6: Novel and disappearing terrestrial climatic conditions by 2100

Model projections of novel (upper) and disappearing (lower) terrestrial climatic conditions by 2100. Left-hand maps: based on A2 emission scenario; right-hand maps: based on B1 emission scenario. Novel climatic conditions are projected to develop primarily in the tropics and subtropics. Disappearing climatic conditions are concentrated in tropical montane regions and the poleward portions of continents. Scale shows relative change, with greatest impact at the yellow/red end of the spectrum.

Montane habitats (e.g. cloud forests, alpine ecosystems) and endemic species have also been identified93 as being particularly vulnerable because of their narrow geographic and climatic ranges, and hence limited – or non-existent – dispersal opportunities. Other terrestrial and coastal habitats considered to be at high risk include tundra ecosystems, tropical forests and mangroves. For coastal habitats, rising sea level will be an additional environmental stress.

A more physiological approach to assessing climatic vulnerability and resilience found that temperate terrestrial ectotherms (cold-blooded animals, mostly invertebrates) might benefit

89 Pereira H.M., et al. 2010. Scenarios for global biodiversity in the 21st century. Science, 330, 1496-1501.90 Hoegh-Guldberg O., Hughes L., McIntyre S., Lindenmayer D.B., Parmesan C., Possingham H.P. & Thomas C.D. 2008. Assisted colonization and rapid climate change. Science, 321, 345-346.91 Dawson T.P., Jackson S.T., House J.I., Prentice I.C. & Mace G.M. 2011. Beyond predictions: biodiversity conservation in a changing climate. Science, 332, 53-58.92 Williams J.W., Jackson S.T. & Kutzbach J.E. 2007. Projected distributions of novel and disappearing climates

by 2100 AD. Proc. Natl. Acad. Sci. U.S.A., 104, 5738-5742; doi: 10.1073/pnas.0606292104

93 Secretariat of the Convention on Biological Diversity (2009) Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Technical Series No. 41. CBD, Montreal, 126 pp

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from higher temperatures, whilst tropical species, already close to their optimal temperature, would be disadvantaged even though the amount of change to which they will be exposed is smaller (Figure 3.7)94. More limited data for vertebrate ectotherms (frogs, lizards and turtles) demonstrated a similar pattern indicating a higher risk to tropical species from climate change. In temperate regions, insect crop pests and disease vectors would be amongst those likely to benefit from higher temperatures (with negative implications for ecosystem services, food security and human health), particularly if their natural predators are disadvantaged by climate change.

In general, vulnerability to climate change across species will be a function of the extent of climate change to which they are exposed relative to the species’ natural adaptive capacity. This capability varies substantially according to species biology and ecology, as well as interactions with other affected species. Species and ecosystems most susceptible to decline will be those that not only experience high rates of climate change (including increased frequency of extreme events), but also have low tolerance of change and poor adaptive capacities95.

Figure 3.7: Projected impact of projected future warming (for 2100) on the fitness of terrestrial ectotherms96

Latitudinal impacts of climate change, based on thermal tolerance. A) and B), insect data; map shows negative impacts in blue, positive impacts in yellow/red. C), comparison of latitudinal change in thermal tolerance for insects with more limited data for turtles, lizards and frog.

Given their importance in the carbon cycle, the response of forest ecosystems to projected climate change is a critical issue for natural ecosystems, biogeochemical feedbacks and human society97. Key unresolved issues include the relative importance of water availability, seasonal temperature ranges and variability, the frequency of fire and pest abundance, and constraints on migration rates. Whilst tropical forests may be at risk, recent high resolution

94 Deutsch C.A. et al 2008. Impacts of climate warming on terrestrial ectotherms across latitude. Proc. Natl. Acad. Sci. U.S.A., 105, 6668-6672; doi: 10.1073/pnas.070947210595 Dawson T.P., Jackson S.T., House J.I., Prentice I.C. & Mace G.M. 2011. Beyond predictions: biodiversity conservation in a changing climate. Science, 332, 53-58.96 Deutsch C.A. et al 2008. Impacts of climate warming on terrestrial ectotherms across latitude. Proc. Natl. Acad. Sci. U.S.A., 105, 6668-6672; doi: 10.1073/pnas.070947210597 Bonan G. 2008. Forests and climate change: forcings, feedbacks, and the climate benefit of forests. Science, 320, 1444-1449; doi: 10.1126/science.1155121

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modelling has given some cause for optimism98, in that losses in one region may be offset by expansion elsewhere.

3.2.3 Projected impacts on marine ecosystems

The marine environment is also vulnerable to climate change, with the additional stress of ocean acidification. Although, future surface temperature changes (with the exception of the Arctic) may not be as high as on land (Figure 3.2), major poleward distributional changes have already been observed; for example, involving population movements of hundreds and thousands of kilometres by fish99 and plankton100,101 respectively in the North East Atlantic. Increases in marine pathogenic bacteria have also been ascribed to climate change102.

For temperate waters, increases in planktonic biodiversity (in terms of species numbers) have recently occurred in response to ocean warming103. Such changes do not, however, necessarily result in increased productivity nor benefits to ecosystem services, e.g. fisheries. In the Arctic, the projected loss of year-round sea ice this century104 is likely to enhance pelagic biodiversity and productivity, but will negatively impact charismatic mammalian predators (polar bears and seals). The loss of ice will also re-connect the Pacific and Atlantic Oceans, with potential for major introductions (and novel interactions) for a wide variety of taxa via trans-Arctic exchange105.

Marine species and ecosystems are also increasingly subject to an additional and yet closely linked threat: ocean acidification. Such a process is an inevitable consequence of the increase in atmospheric CO2: this gas dissolves in sea water, to form carbonic acid; subsequently, concentrations of hydrogen ions and bicarbonate ions increase, whilst levels of carbonate ions decrease.

By 2100, a pH decrease of 0.5 units in global surface seawater is projected under SRES scenario A1FI106. corresponding to a 300% increase in the concentration of hydrogen ions. This may benefit small-celled phytoplankton (microscopic algae and cyanobacteria), but could have potentially serious implications for many other marine organisms, including commercially-important species that are likely to be subject to thermal stress 107. Experiments on ocean acidification impacts have given variable results, with some species showing positive or neutral responses to lowered pH; nevertheless, a meta-analysis108 of 73 studies

98 Zelazowski P, Malhi Y, Huntingford C, Sitch S. & Fisher J.B. 2011. Changes in the potential distribution of humid tropical forests on a warmer planet. Phil. Trans. Roy. Soc. A, 369,, 137-160; doi: 10.1098/rsta.2010.023899 Perry A.L., Low P.J., Ellis J.R. & Reynolds J.D. 2005. Climate change and distribution shifts in marine fishes.

Science 308,1912-1915; doi: 10.1126/science.1111322

100 Beaugrand, G., Reid, P.C., Ibanez, F., Lindley, J.A. & Edwards, M. 2002. Reorganization of North Atlantic marine copepod biodiversity and climate. Science, 296:1692-1694.101 Perry A.L., Low P.J., Ellis J.R. & Reynolds J.D. 2005. Climate change and distribution shifts in marine fishes. Science 308,1912-1915; doi: 10.1126/science.1111322 102 Vezzuli, L., Brettar, I., Pezzati, E., Reid, P.C., Colwell, R.R., Höfle, M.G. & Pruzzo, C. (2011) Long-term effects of ocean warming on the prokaryotic community: evidence from the vibrios. The ISME Journal. advance online publication; doi: 10.1038/ismej.2011.89103 Beaugrand, G., Edwards, M. & Legendre, L (2010) Marine biodiversity, ecosystem functioning, and carbon cycles. Proc. Nat. Acad. Sci. USA, 107, 10120-10124; doi: 10.1073/pnas.0913855107104 Boé, J., Hall, A. & Qu, X. (2009) September sea-ice cover in the Arctic Ocean projected to vanish by 2100. Nature geosciences, 2, 341-343; doi: 10.1038/ngeo467105 Greene C.H., Pershing A.J., Cronin T.M. & Ceci N. 2008. Arctic climate change and its impacts on the ecology of the North Atlantic. Ecology, 89 (Supplement),S24–S38106 Caldeira K. & Wickett M.E. 2005. Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean. J. Geophysical Research- Oceans, 110, C09S04107 Secretariat of the Convention on Biological Diversity. 2009. Scientific Synthesis of the Impacts ofOcean Acidification on Marine Biodiversity. Montreal, Technical Series No. 46, 61 pp108 Kroeker K.J., Kordas R.L., Crim R.N. & Singh G.G. 2010. Meta-analysis reveals negative yet variable effects of ocean acidification on marine organisms. Ecology Letters 13, 1419-1434; doi: 10.1111/j.1461-0248.2010.01518.x

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showed that laboratory survival, calcification and growth were all significantly reduced when a wide range of organisms was exposed to conditions likely to occur in 2100 (Figure 3.8). For a recent overview, including pH effects on physiology and energy metabolism, see Gattuso & Hansson109 .

Figure 3.8: Meta-analysis of experimental studies on effect of pH change projected for 2100

Effect of pH decrease of 0.4 units on reproduction, photosynthesis, growth, calcification and survival under laboratory conditions for a wide taxonomic range of marine organisms. Mean effects and 95% confidence limits calculated from log-transformed response ratios, here re-converted to a linear scale. Redrawn with lead author’s permission110.

The threshold for ‘dangerous’ ocean acidification has yet to be defined at the intergovernmental level, in part because its ecological impacts and economic consequences are currently not well quantified111,112. An atmospheric CO2 stabilisation target of 450 ppm could still risk large-scale and ecologically-significant impacts. Thus, at that level: 11% of the surface ocean would experience a pH fall of >0.2 relative to pre-industrial levels; only 8% of present-day coral reefs would experience conditions considered optimal for calcification, compared with 98% at pre-industrial atmospheric CO2 levels113; and around 10% of the surface Arctic Ocean would be aragonite-undersaturated for part of the year 114 (increasing

109 Gattuso J_P & Hansson L. (eds) 2011. Ocean Acidification. Oxford University Press, 326 pp..

110 Kroeker K.J., Kordas R.L., Crim R.N. & Singh G.G. 2010. Meta-analysis reveals negative yet variable effects of ocean acidification on marine organisms. Ecology Letters 13, 1419-1434; doi: 10.1111/j.1461-0248.2010.01518.x

111 Turley, C., Eby, M., Ridgwell, A.J., Schmidt, D.N., Findlay, H.S., Brownlee, C., Riebesell, U., Gattuso, J.-P., Fabry, V.J. & Feely R.A. (2010) The societal challenge of ocean acidification. Mar. Poll. Bull. 60, 787–792.112 Cooley, S. R. & Doney, S.C. (2009) Anticipating ocean acidification’s economic consequences for commercial fisheries. Environ. Res. Letters 4, 024007, doi: 10.1088/1748-9326/4/2/024007113 Cao, L. & Caldeira, K. (2008) Atmospheric CO2 stabilization and ocean acidification. Geophy. Res. Letters 35, L19609; doi: 10.1029/2008GL035072114 Steinacher, M., Joos, F., Frölicher, T.L., Plattner, G.-K. & Doney, S.C. (2009) Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model. Biogeosciences 6, 515-533; doi: 10.5194/bg-6-515-2009

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metabolic costs for a wide range of calcifying organisms). Potentially severe local impacts could occur elsewhere in upwelling regions and coastal regions115, with wider feedbacks116.

Both cold water and tropical corals seem likely to be seriously impacted by ocean acidification; however, the latter are especially vulnerable since they are also subject to temperature stress (coral bleaching), coastal pollution (eutrophication and increased sediment load) and sea-level rise. Population recovery time from bleaching would be prolonged if growth is slowed due to acidification (together with other stresses), although responses are variable and dependent on local factors117. The biodiversity value of corals is extremely high, since they provide a habitat structure for very many other organisms; they protect tropical coastlines from erosion; they have significant biotechnological potential; and they are highly-regarded aesthetically. More than half a billion people are estimated to depend directly or indirectly on coral reefs for their livelihoods118.

3.3.4 The role of biodiversity in the Earth System and in delivering ecosystem services

The biosphere plays a key role in the Earth system, especially as part of the global cycles of carbon, nutrients and water, thereby providing ecosystem services of immense human value. Interactions between species/ecosystems and a very wide range of other natural and human-driven processes must therefore also be considered when assessing the impacts of climate change (and geo-engineering) on biodiversity. The conservation and restoration of natural terrestrial, freshwater and marine biodiversity are essential for the overall goals of both the CBD and UNFCCC, not only on account of ecosystems’ active role in global cycles but also in supporting adaptation to climate change.

Carbon is naturally sequestered and stored by terrestrial and marine ecosystems, through biologically-driven processes. The amount of carbon in the atmosphere, ~750Gt, is much less than the ~2,500 Gt C stored in terrestrial ecosystems119; a further 1,000 Gt C occurs in the upper layer of the ocean, and an additional ~37,000 Gt C is stored in the deep ocean, exchanging with the atmospheric over relatively long time scales. On average ~160 Gt C exchange annually between the biosphere (both ocean and terrestrial ecosystems) and atmosphere. Proportionately small changes in ocean and terrestrial carbon stores, caused by changes in the balance of exchange processes, might therefore have large implications for atmospheric CO2 levels. Such a change has already been observed: in the past 50 years, the fraction of CO2 emissions that remains in the atmosphere each year has slowly increased, from about 40% to 45%, and models suggest that this trend was caused by a decrease in the uptake of CO2 by natural carbon sinks, in response to climate change and variability120.

It is therefore important to improve our representation of biogeochemical feedbacks (mostly driven by plants and microbes, on land and in the ocean) in Earth system models – not just climate models – in order to understand how biodiversity may influence, and be influenced by, human activities. The range of non-climatic factors important in this context, as direct and indirect drivers of biodiversity change, and the range of ecosystem goods and services that are involved are summarised in Figure 1.1. 115 Feely, R.A., Alin, S.R., Newton, J., Sabine, C.L., Warner, M., Devol, A., Krembs, C. & Maloy, C. (2010) The combined effects of ocean acidification, mixing, and respiration on pH and carbonate saturation in an urbanized estuary. Est. Coastal & Shelf Sci. 88, 442-449; doi: 10.1016/j.ecss.2010.05.004116 Gehlen, M., Gruber, N., Gangstø R., Bopp, L. & Oschlies, A. (2011) Biogechemical consequences of ocean acidification and feedbacks toi the Earth system. In: Ocean Acidification (Ed: J.-P. Gattusso & L. Hansson), Oxford University Press, p 230- 248.117 Pandolfi J.M., Connolly S.R., Marshall D.J. & Cohen A.L. 2011. Projecting Coral Reef Futures Under Global Warming and Ocean Acidification. Science, 333, 418-422.118 TEEB. 2009. The Economics of Ecosystems and Biodiversity: Climate Issues Update, September 2009. www.unep.ch/etb/ebulletin/pdf/TEEB-ClimateIssuesUpdate-Sep2009.pdf 119 Ravindranath, N.H. & Ostwald, M. 2008., Carbon Inventory Methods Handbook for Greenhouse Gas Inventory, Carbon Mitigation and Roundwood Production Projects. Springer Verlag, Advances in Global Change Research, pp 304, ISBN 978-1-4020-6546-0.120 Le Quere C., Raupach M.R., Canadell J.G., Marland G. & et al. 2009. Trends in the sources and sinks of carbon dioxide. Nature Geosciences, 2, 831-836.

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3.4 Projected socio-economic and cultural impacts of climate change

The scientific literature on the societal implications of projected climate change is vast, and a detailed assessment is inappropriate here. Nevertheless, a very brief overview of the socio-economic consequences of current trajectories is necessary, to complete the conceptual picture of linkages between climate, biodiversity, ecosystems, ecosystem goods and services, and human well-being, as indicated in Fig 3.9 above. Such considerations provide important context for the discussion of how geo-engineering (with its own impacts) might be used counteract climate change. Chapter 6 gives additional attention to the socio-economic and cultural aspects of geo-engineering.

The Stern Review121 estimated that, without action, the overall costs of climate change would be equivalent to a future annual loss of 5-20% of gross domestic product. Although that analysis was much discussed122 and criticised by some economists, a similar range and scale of projected economic impacts of climate change were identified in the IPCC Fourth Assessment Report (Working Group II). Table 3.1 summarises those findings on a regional basis. The IPCC Fifth Assessment Report, now nearing completion, will provide additional information, using improved projections (e.g. for sea level rise) and a wider range of impacts (e.g. including ocean acidification).

Table 3.1. Examples of some projected socio-economic impacts of climate change for different regions (all with very high or high confidence). Information from IPCC AR4 Synthesis Report123

Africa By 2020, agricultural yields reduced by up to 50% in some countries, affecting food security and exacerbating malnutrition. 75-250 million people exposed to increased water stress.

By 2080, arid and semi-arid land likely to increase by 5-8%. By 2100, sea level rise will affect low-lying coastal areas with large populations; adaptation

costs could be at least 5-10% of Gross Domestic Product

Asia By 2050, decreased freshwater availability in Central, South,East and South-East Asia, Coastal areas, especially heavily populated regions in South, East and South-East Asia, at

increased flooding risk from the sea (and, in some megadeltas, river flooding) Associated increased risk of endemic morbidity and mortality due to diarrhoeal disease

Australia and New Zealand  

By 2020, significant biodiversity loss in the Great Barrier Reef, Queensland Wet Tropics and other ecologically rich sites

By 2030, reduced agricultural and forest production over much of southern and eastern Australia, and parts of New Zealand, due to increased drought and fire.

By 2050, ongoing coastal development and population growth exacerbate risks from sea level rise and increases in the severity and frequency of storms and coastal flooding. 

Europe Negative impacts include increased risk of inland flash floods and more frequent coastal flooding and increased erosion (due to storminess and sea level rise).

Mountainous areas will experience glacier retreat, reduced snow cover and species losses of up to 60% by 2080 (under high emissions scenarios).

In southern Europe, reduced water availability, hydropower potential, summer tourism and crop productivity, together with increased health risks due to heat waves and wildfires.

Latin America

By 2050, gradual replacement of tropical forest by savanna in eastern Amazonia; elsewhere semi-arid vegetation will tend to be replaced by arid-land vegetation. Associated risk of significant biodiversity loss through species extinction

Decreased productivity of many crops and livestock, with adversely affecting food security.

121 Stern N. 2006. The Economics of Climate Change. The Stern Review. 712 pp, Cambridge University Press, Cambridge, UK

122 Barker et al. 2008. Special Topic: The Stern Review Debate (6 editorials and 8 related papers). Climatic Change, 89, 173-446.

123 IPCC. 2008. Climate Change 2007 – Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Pachauri R.K. & Resinger A. (Eds). IPCC, Geneva, Switzerland, 104 pp.

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Hydrological changes are expected to significantly affect water availability for human consumption, agriculture and energy generation.  

North America  

Moderate climate change is projected to increase yields of rain-fed agriculture by 5-20%, but with important variability among regions. Major challenges expected for crops near the warm end of their suitable range or which depend on highly utilised water resources.

Increased number, intensity and duration of heat waves during the course of the century, with potential for adverse health impacts.

Coastal communities and habitats will be increasingly stressed by climate change impacts interacting with development and pollution. 

Polar Regions  

Reductions in thickness and extent of glaciers, ice sheets and sea ice; changes in natural ecosystems include adverse effects on migratory birds, mammals and higher predators.

For human communities in the Arctic, impacts are projected to be mixed; detrimental impacts include those on infrastructure and traditional indigenous ways of life.

In both polar regions, specific ecosystems and habitats are projected to be vulnerable, as climatic barriers to species invasions are lowered.  

Small Islands  

Sea level rise is expected to exacerbate inundation, storm surge, erosion and other coastal hazards, threatening vital infrastructure that supports the livelihood of island communities.

Reduced water resources in many small islands, e.g. in the Caribbean and Pacific, may become insufficient to meet demand during low-rainfall periods.

Higher temperatures will increase frequency of coral bleaching and, for mid- and high-latitude islands, the risk of invasion by non-native species.

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CHAPTER 4: POTENTIAL IMPACTS ON BIODIVERSITY OF SOLAR RADIATION MANAGEMENT GEO-ENGINEERING TECHNIQUES

As summarised in Chapter 3, if climate change continues unchecked, it will pose an increasingly severe range of threats to biodiversity and ecosystem services. However, climate change is just one of many factors influencing biodiversity loss. Effective actions to reduce the magnitude of climate change would be expected to reduce climate change-related threats to biodiversity. However, they may be augmented or offset by the proximate impacts of the measure itself. Thus if a proposed SRM measure can be shown to likely be feasible and effective in reducing the negative impacts of climate change, these projected positive impacts need to be considered alongside any projected negative impacts of the geo-engineering measure.

This chapter explores whether and how SRM techniques – in general and individually – might be able to reduce climate-imposed threats to biodiversity and ecosystem services. It also examines the potentially damaging side effects of SRM techniques, as well as the uncertainties surrounding their impacts.

Carbon Dioxide Removal (CDR) techniques are examined in Chapter 5.

This chapter first examines the projected positive and negative impacts that are common to all SRM techniques (section 4.1). Then the impacts specific to particular techniques are reviewed (section 4.2).

4.1. Potential impacts on biodiversity of a generic SRM approach that results in uniform dimming.

4.1.1. Potential reduction in temperature and other climate change effects from SRM that results in uniform dimming

To date, most studies of the potential impacts of SRM have consisted of observations of the natural world (e.g. volcanic eruptions) or computer modelling. Models have typically examined a world in which SRM is assumed to bring about uniform dimming to counter increased climate change (e.g. a world with doubled CO2). Their results suggest that almost all areas of the planet would experience significantly less temperature change in the world of high greenhouse gases together with a uniform dimming of solar radiation, than with climate change alone124.

In general, modelling suggests that overall changes to precipitation would not be any worse than the world with climate change, and at best there would be significantly less change in most regions. However, the positive impacts of the technique on reducing changes in temperature and precipitation are least in equatorial regions, among the most biodiverse regions. These simulations suggest that SRM, if feasible and effective in creating uniform dimming, could reduce the overall global changes in temperature and rainfall resulting from climate change, but could also lead to some geographical redistribution of the effects of climate change125,126.

The speed with which SRM would be expected to reduce temperatures (see section 2.2.1) is a unique attribute of these techniques. While SRM would start reducing temperature immediately after deployment at scale, it would take decades (or longer) for emissions cuts or

124 Caldeira, K, and Wood, L, 2008, Global and Arctic climate engineering: numerical model studies. Philosophical Transactions of the Royal Society A, 366, 366, 4039-4056. doi:10.1098/rsta.2008.0132 125 Caldeira, K, and Wood, L, 2008, Global and Arctic climate engineering: numerical model studies. Philosophical Transactions of the Royal Society A, 366, 366, 4039-4056. doi:10.1098/rsta.2008.0132.126 K. Ricke, G. Morgan, M. Allen (2010) Regional climate response to solar radiation management. Nature Geosciences, 3: 537-541.

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CDR deployment to lower global temperatures. This means that SRM would be the only approach known to date that might allow a rapid reduction in temperatures should it be deemed necessary.

Overall, if the cooling from SRM was realised as models project, it would be expected to reduce many of the impacts of climate change on biodiversity. However, only limited modelling work has been done and many uncertainties remain concerning the side effects of SRM techniques on biodiversity (as noted in the following sections). It is therefore not possible to predict the net effect with any degree of confidence. Scientists are also unable to predict with a high degree of confidence which areas might experience changes in temperature and precipitation under SRM deployment, and even further from being able to predict which ecosystems, and elements thereof, might be affected, and how.

The uncertainty surrounding regional climatic changes in a 2xCO2 world and a 2xCO2 + SRM world stems from the uncertain nature of climate modelling. The specific regional results from individual climate models cannot be relied upon since, as the IPCC’s model inter-comparisons have demonstrated127, different models generate a wide diversity of regional climate projections for high CO2 futures. In some regions, the results of most models converge, giving a relatively high degree of confidence that regional projections are correct. However, in other regions, there is no agreement among climate model projections. No inter-comparisons have yet been carried out for SRM models, although one is currently underway for stratospheric geo-engineering with sulphate aerosols128. Owing to these modelling uncertainties, it is currently difficult to conclude with high confidence on how a uniform deployment of SRM might affect biodiversity and ecosystem services in a given region. However, a recent paper suggests that regional inequalities from SRM that results in uniform dimming may not be as severe as is often assumed129 (Section 4.1.3).

SRM would introduce a new dynamic between the heating effects of greenhouse gases and the cooling effects of SRM. The combination of changes – high CO2 and other greenhouse gases concentrations, unpredictably altered precipitation patterns, and in some cases more diffuse light, – would be unlike any known combination that extant species and ecosystems have experienced in their evolutionary history. However, it is not clear whether the environment of the SRM world would be more or less challenging for any particular species and ecosystems than that caused by the climate change that it would be seeking to counter (Section 4.1.3).

There are a number of other potential implications of SRM. As described in section 4.1.2, it introduces a new dynamic between the warming effects of CO2 and the cooling effects of SRM.

Figure 4.1: Temperature changes resulting from two experimental simulations

127 S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L Miller (eds) (2007) Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Cambridge, UK and New York, NY, USA.128 Ben Kravitz et al, 2011, The Geoengineering Model Intercomparison Project (GeoMIP), Atmospheric Science Letters. Available online at http://climate.envsci.rutgers.edu/pdf/GeoMIP10.1002-asl.316.pdf129 Moreno Cruz et al 2011

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Panels (a) and (b) show change in mean annual surface temperature and its statistical significance with twice the CO2 concentration of the pre-industrial era, and (c) and (d) show projected temperature change and its statistical significance with a uniform 1.84% reduction of insolation.

Figure 4.2: Precipitation changes resulting from two experimental simulations

Panels (a) and (b)show change in total annual precipitation and its statistical significance with twice the CO2 concentration of the pre-industrial era, and (c) and (d) show projected precipitation change and its statistical significance with a uniform 1.84% reduction of insolation.

4.1.2 Projected impacts of deploying a generic SRM technique on hydrological and nutrient cycles

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While modelling to date has generally indicated that climate-induced changes to precipitation are likely to be reduced under SRM deployment (compared with a 2xCO2 world130,131), it is hard to extrapolate what the implications would be for biodiversity and ecosystem services. Precipitation minus evaporation is a much more useful metric of biologically available water than is precipitation alone132,133, with soil moisture the key hydrological variable for healthy terrestrial ecosystems. Under SRM deployment, one might expect soil moisture to decrease as precipitation decreases, soil moisture to increase as insolation decreases (since evapotranspiration would be reduced), and soil moisture to increase as CO2 increases (since plants would use less water).

Combining these various observations leads to the conclusion that soil moisture would increase overall under SRM, assuming that CO2 levels continue to increase. Such a conclusion is extremely tentative however, given the lack of modelling and model inter-comparisons to date. Conversely, some modelling has indicated that soil moisture would probably decline in the tropics134,135. Changes in soil moisture have implications for terrestrial ecosystem services since they affect Net Primary Productivity (NPP)136,137.

SRM could have both predictable and unknown side effects on the atmospheric cycling of nutrients and their deposition138. It is not known whether SRM would counteract the changes to nutrient cycles expected in a 2xCO2 world. In the absence of any nutrient cycle modeling, it is impossible to predict with any degree of certainty what the consequent implications for biodiversity and ecosystem services might be.

4.1.3 Projected impacts of deploying a generic SRM technique on species and ecosystems

Reducing temperature through deployment of SRM might benefit those species identified in Chapter 3 as being particularly vulnerable to the negative impacts of increased temperature due to climate change, including for example: stranded species; species of arctic ecosystems, mountain ecosystems and the northern extreme of northern islands. Long-lived non-mobile species such as many k-strategist trees, which are poor at adapting to climate change, are also likely to be favoured. So too, potentially, are most species that reproduce slowly. It is plausible, although not yet known, that species with temperature-regulated sex determination might also do better under SRM deployment than under climate change alone.

Species that are particularly poor at adapting to climate change, and which might therefore benefit most from SRM deployment, are also those most at risk from sudden SRM termination (See section 4.1.5).

130 Caldeira, K, and Wood, L, 2008, Global and Arctic climate engineering: numerical model studies. Philosophical Transactions of the Royal Society A, doi:10.1098/rsta.2008.0132 131 A. Jones, J. M. Haywood and O. Boucher, 2010, A comparison of the climate impacts of geoengineering by stratospheric SO2 injection and by brightening of marine stratocumulus cloud, Atmospheric Science Letters, 12 (2): 176-183.132 G. A.Ban-Weiss and K.Caldeira, 2010, Geoengineering as an optimization problem, Environmental Research Letters, 5: 1-9.133 Steve Running and John Kimball, 2006, Satellite-based analysis of ecological controls for land-surface evaporation resistance, Encyclopedia of Hydrological Sciences, DOI: 10.1002/0470848944.hsa110.134 G. Bala, P.B. Duffy and K.E. Taylor (2008) Impacts of geoengineering schemes on the global hydrological cycle. Proceedings of the National Academy of Sciences of the United States of America, 105 (22): 7664-7669.135 H.D. Matthews and K. Caldeira (2007) Transient climate-carbon simulations of planetary geoengineering. Proceedings of the National Academy of Sciences of the United States of America, 104 (24): 9949-9954.136 A. Jones, J. M. Haywood and O. Boucher, 2010, A comparison of the climate impacts of geoengineering by stratospheric SO2 injection and by brightening of marine stratocumulus cloud, Atmospheric Science Letters, 12 (2): 176-183.137 H. D. Matthews and K. Caldeira, 2007, Transient climate-carbon simulations of planetary geoengineering, PNAS, 104: 9949-9954.138 B. Kravitz, A. Robock, L. Oman, G. Stenchikov and A. B. Marquardt, 2009, Sulfuric acid deposition form stratospheric geoengineering with sulphate aerosols, Journal of Geophysical Research – Atmospheres, 114. Available online at http://www.stanford.edu/~bkravitz/research/papers/aciddep/aciddepositioncorrected1.pdf

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Current species and ecosystems may not be adapted to living in novel environments resulting from global change. This is true both for a world of climate change (high temperatures, altered precipitation patterns, increased CO2 concentrations) or from a world of climate change masked by SRM (more diffuse light, altered precipitation patterns, high CO 2

concentrations).

Overall, if (i) the world behaves the way that it does in most climate models, (ii) there were no secondary socio-political feedbacks to consider and (iii) there were no serious additional side effects, then, in general, uniformly deployed SRM should significantly reduce the impacts of climate change on biodiversity relative to a high greenhouse gas world without SRM.

However, the climate model predictions are unlikely to reflect closely changes in the real world, particularly at fine spatial and temporal scales (annual to decadal), and SRM deployment would almost certainly entail secondary socio-political feedbacks, and have unexpected side effects.

4.1.4 Impacts of high CO2 under SRM

SRM does not seek to reduce the atmospheric concentrations of greenhouse gases, and the process of ocean acidification will therefore continue unabated. Indeed, it could be worsened139, since more CO2 will dissolve in the ocean if its surface temperature has been reduced by SRM (relative to a non-geoengineered world). Marine biodiversity will therefore continue to be vulnerable to the negative impacts of ocean acidification, as discussed in more detail in Chapter 3.

Likewise, SRM will not address the effects of high CO2 concentrations on terrestrial ecosystems, such as favouring some plant groups over others, while ecosystems that are already water stressed may continue to be so under SRM.

As such, SRM cannot be seen as an alternative to limiting greenhouse gas concentrations.

4.1.5 Rate of environmental change and the termination effect

It is not just the magnitude, nature and distribution of environmental changes (from climate change or from solar geo-engineering) that will affect biodiversity and ecosystem services, but also the rate at which the changes take place. In general, the faster an environment changes, the greater the risk to species140. SRM, if effective, could slow, halt or even reverse the pace of global warming much more quickly than emissions cuts (instantly versus decades or longer), notwithstanding potential side effects. Therefore, it could either be deployed at short order in order to counter imminent threats, or more gradually to shave she peaks off more extreme warming, in order to allow more time for species to adapt141.

However, in addition to the biological and ecological impacts of SRM identified above, there is an additional issue to consider when evaluating the general effects of all SRM techniques on biodiversity and ecosystem services: the so-called ‘termination effect’.

SRM would only offset global warming so long as it is maintained. The cessation of SRM would result in increased rates of climatic changes, in the absence of effective reductions of atmospheric greenhouse gas concentrations: all the warming that would have taken place over several decades might take place over a shorter period.

139 Turley C & Williamson P. 2012. Ocean acidification in a geoengineering context. Phil. Trans. Roy. Soc A. (in press)

140 Luis-Miguel Chevin, Russell Lande and Georgina Mace, 2010, Adaptation, plasticity, and extinction in a changing environment: towards a predictive theory, PLoS Biology, 8 (4): e1000357. doi:10.1371/journal.pbio.1000357141 Secretariat of the Convention on Biological Diversity (2009) Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Technical Series No.41. CBD, Montreal, 126 pp

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Rapid termination of SRM that had been deployed for some time, and was masking a high degree of warming, would almost certainly have large negative impacts on biodiversity and ecosystem services that would be more severe than those resulting from gradual climate change. SRM does not address the problem of ocean acidification because it does not address CO2 concentrations.

Without any opportunity for species and communities to adapt, many microbial organisms, plants, animals and their interactions could be affected: current rates of anthropogenic climate change are already altering, or are projected to alter, community structure 142, biogeochemical cycles143, and fire risk144. Very rapid warming from SRM termination could lead to similar problems.

4.2 Potential impacts on biodiversity of specific SRM techniques.

Thus far, this chapter has only addressed the very general effects on biodiversity that uniform dimming from SRM might have, which may not be achievable in practice. Now, the chapter looks at the potential benefits and drawbacks associated with three specific SRM techniques – stratospheric aerosol injection, cloud brightening and surface albedo enhancement – since these are the options most frequently proposed. The positive and negative impacts of space-based mirrors are expected to be similar to those of the generic SRM approaches described in section 4.1.

4.2.1 Potential impacts on biodiversity of stratospheric aerosol injection

In addition to the positive and negative impacts of generic SRM approaches described in section 4.1, this proposed SRM technique could affect atmospheric acidity, stratospheric ozone depletion, and the overall quantity and quality of light reaching the biosphere, with knock-on effects on biodiversity and ecosystem services. It is worth noting that any projected effects on biodiversity associated with atmospheric acidity and ozone depletion/UV radiation would not necessarily occur if aerosols other than sulphates were to be used for this SRM technique. However, other particles that have been suggested145, including nano-materials, might bring with them their own particular risks.

Increased acidity in the atmosphere

Use of sulphate aerosols would marginally increase the negative effects of atmospheric acidity, such as acid rain, with consequent impacts on ecosystems. However, the size of this effect might not be very large because the suggested quantities of sulphur required for this form of SRM would likely be less than 10% of the global deposition, and possibly as little as 1%146.

Ozone depletion and increased UV radiation

One proposed method of stratospheric aerosol injection would involve spraying sulphur dioxide to create sulphate aerosols. There is some evidence that an increase in sulphate levels in the stratosphere would lead to increased ozone depletion147, primarily in polar regions in springtime. This would, in turn, cause an increase in the amount of ultra violet (UV) radiation

142 G. Walther et al (2002) Ecological responses to recent climate change. Nature, 416: 389-395.143 R.G. Zepp, T.V. Callaghan and D.J. Erickson III (2003) Interactive effects of ozone depletion and climate change on biogeochemical cycles. Photochem. Photobiol. Sci., 5: 51-61.144 J. Pinol, J. Terradas and F. Lloret (1998) Climate warming, wildfire hazard, and wildfire occurrence in coastal Eastern Spain. Climatic Change, 38: 345-357.145 Keith, D.W. (2010). Photophoretic levitation of engineered aerosols for geoengineering. PNAS September 21, 2010 vol. 107 no. 38 16428-16431146 Kravitz, B., Robock, A., Oman, L., Stenchikov, G., & Marquardt, A. B. (2009). Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols. Journal of Geophysical Research-Atmospheres, 114, D14109.147 Robock, A. Marquardt, A., Kravitz, B., and G. Stenchikov. (2009). Geophysical Research Letters, Volume 36, L19703, Pages 1-9.

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reaching the Earth, which would affect some species more than others. Certain plants possess a protective layer on the upper surface of their leaves, making them less susceptible to UV damage. The ecological effects of increased UV radiation also depend on the percentage change in UV radiation under stratospheric aerosol injection, and on the spectral forms (UVA, UVB and UVC) likely to be most affected. Possibly, the increase in UV due to depleted ozone might be partially offset by the attenuation of UV by the aerosols.

The impact of stratospheric ozone injection on the amount of UVB radiation reaching the Earth’s surface (with consequent impacts on biodiversity and ecosystem services) is very difficult to predict.

Changes in the nature and amount of light reaching ecosystems

Stratospheric aerosols would decrease the amount of photosynthetically active radiation (PAR) reaching the Earth, but would increase the amount of diffuse (as opposed to direct) radiation. The effects that this would have would vary from ecosystem to ecosystem, and from species to species.

For example, the net efficiency of carbon fixation by the forest canopy is increased when light is distributed more uniformly throughout the canopy, as occurs with diffuse light. Diffuse light penetrates the upper canopy more effectively than direct radiation because direct light saturates upper sunlit leaves but does not reach lower leaves. It has therefore been suggested that effects of the (small) reduction in total PAR would be less than the effects of the increase in diffuse radiation giving a net improvement in photosynthetic efficiency, leading to increased primary productivity in terrestrial ecosystems overall. Such may have been the case following the Mt. Pinatubo eruption148, and during the ‘global dimming’ period (1950-1980)149.

However, the magnitude and nature of effects on biodiversity are likely to be mixed, and are currently not well understood. While the increase in diffuse light as a result of stratospheric ozone injection might increase gross primary productivity (GPP) in certain ecosystems, GPP is not necessarily a good proxy for biodiversity, and increases in GPP could be due to a few species thriving in more diffuse light. In addition, for ecosystems where total light availability is the major growth-limiting factor, the small decrease in total radiation could be harmful while the increase in diffuse radiation is of no net benefit.

Complicating this picture is the fact that aerosol-induced cooling would probably slow the rate of organic matter decomposition in the soil, and thus reduce the availability of nutrients to plants. Persistent nutrient limitations may alter plant responses to diffuse light. One further complication is that while diffuse light is better at penetrating the canopy, sunflecks (bursts of very strong light which penetrate the canopy and reach the forest floor) would be less intense with diffuse light as opposed to direct light150. Changes in the nature and amount of light reaching ecosystems may therefore affect community composition and structure. Analyses of effects of large-scale, aerosol-based SRM on marine photosynthesis have not been carried out; however, primary production in the upper ocean is closely linked to the depth of light penetration, that is greatest for direct sunlight151. Thus, ocean productivity could be expected to decrease.

4.2.2. Potential impacts on biodiversity of cloud brightening

148 Gu, L., Baldocchi, D.D., Wofsy, S.C., Munger, J.W., Michalsky, J.J., Urbanski, S.P. and Boden, T.A.  2003.  Response of a deciduous forest to the Mount Pinatubo eruption: Enhanced photosynthesis.  Science 299: 2035-2038.149 Mercado, L. M., et al. (2009), Impact of changes in diffuse radiation on the global land carbon sink, Nature, 458, 1014-1018, doi:10.1038/nature07949.150 F. Montagnini and C.F. Jordan (2005) Tropical Forest Ecology: The Basis for Conservation and Management. Springer, UK.151 Morel A. 1991. Light and marine photosynthesis: a spectral model with climatological implications. Progress

in Oceanography 26, 263-306

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While section 4.1 described the positive and negative impacts of SRM approaches which assumed uniform dimming, this proposed SRM technique does not cause uniform dimming. Therefore it could cause stronger regional or local atmospheric and oceanic perturbations with possibly significant effects on terrestrial and marine biodiversity and ecosystems. However, few models are available on the impacts of cloud brightening on biodiversity.

Cloud brightening is expected to cause localized cooling, the magnitude and effects of which are poorly understood.

Changes to regional precipitation regimes resulting from cloud brightening are expected to increase overland water flow and this may have significant impacts on terrestrial ecosystems.152 Other changes to local weather patterns may have impacts on biodiversity.

The high degree of localised cooling projected as a result of cloud brightening has been shown in some modelling studies to have knock-on effects on weather systems at different locations around the globe153 , such as the West African Monsoon and the El Niño Southern Oscillation. However, results are inconsistent across different studies, or are based on very different parameters (e.g. different spray patterns) and so are not directly comparable. This could have either positive or negative effects on biodiversity.

4.2.3. Potential impacts on biodiversity of surface albedo enhancement

The specific impacts of surface albedo enhancement on biodiversity and ecosystem services, over and above the impacts of generic SRM approaches involving uniform dimming are described in section 4.1, depend on what method is used. Surface albedo can be increased, for example, through whitening the built environment, use of crops with more reflective foliage, covering deserts (or other lands) with reflective material, and use of micro-bubbles in water bodies. The albedo of the surface ocean might be enhanced through the introduction of microbubbles (currently called ‘Bright Water’) with claims that the microbubbles are effective at reducing solar radiation even at parts per million levels154.

In general, if surface albedo changes were large enough to have an effect on the global climate, they would have to be deployed across a very large area – with consequent impacts on ecosystems, or would involve a very high degree of localised cooling.

For instance, covering deserts with reflective material on a scale large enough to be effective in addressing the impacts of climate change would probably have significant negative ecological effects155, for instance on species richness and population densities.

Introducing bubbles into large expanses of water bodies would probably have negative impacts on ocean biodiversity due to decreased light penetration, with possible impacts on currents and further knock-on impacts on local ecosystems.

Increasing crop albedo through use of crops with more reflective foliage would have unknown effects on biodiversity and ecosystems beyond those caused by the positive or negative impacts of localised cooling. However, if deployed very widely, this approach could result in increased monoculture.

Whitening the built environment would likely have no specific effects on biodiversity and ecosystems beyond those caused by the positive or negative impacts of localised cooling. While the total cooling effect would be moderate at best, local cooling of buildings may reduce energy use for air conditioning.

152 Bala, G., Caldeira, K., Nemani, R., Cao, L., Ban-Weiss, G. and Ho-Jeong Shin. (2010). Albedo enhancement of marine clouds to counteract global warming: impacts on hydrological cycle. Climate Dynamics, Online First.153 Jones et al, 2009; Latham et al, 2008, Rasch et al, 2009

154 Seitz R (2011) Bright water: hydrosols, water conservation and climate change. Climatic Change. doi:10.1007/s10584-010-9965-8155 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp

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The effects of local cooling are poorly understood. While a high degree of localised cooling might help local ecosystems that are being damaged by the effects of climate change, the ‘patchy’ nature of the cooling might change local systems more than the global warming that the schemes are seeking to address.156

156 For example, add reference to recent study on unclear results on urban albedo.

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CHAPTER 5: POTENTIAL IMPACTS ON BIODIVERSITY OF CARBON DIOXIDE REMOVAL GEO-ENGINEERING TECHNIQUES

5.1. General features of CDR approaches

5.1.1 Reducing the impacts of climate change

By removing Carbon Dioxide (CO2) from the atmosphere, CDR techniques are intended to reduce the concentration of the main causal agent of climate change and ameliorate ocean acidification.

By reducing the negative impacts of climate change and ocean acidification on biodiversity, (as summarised in Chapter 5) effective and feasible CDR techniques would be expected to have positive impacts on biodiversity. However, as noted in Chapter 2, these effects are generally slow acting. Moreover, several of the techniques are of doubtful effectiveness as described in section 5.2.

In addition, any positive effects from reduced impacts of climate change and/or ocean acidification due to reduced atmospheric CO2 concentrations may be offset (or, in a few cases, augmented) by the direct impacts on biodiversity of the particular CDR technique employed. These are reviewed in section 5.2.

5.1.2 Sequestration and storage

Carbon Dioxide Removal (CDR) geo-engineering approaches actually involve two steps:

(1) carbon sequestration or removal of CO2 from the atmosphere; and

(2) storage of the sequestered carbon.

In some biologically- and chemically-driven processes these steps occur together or are inseparable. This is the case in ocean fertilization techniques and in the case of afforestation, reforestation and soil carbon enhancement. In these cases, the whole process, and their impacts on biodiversity, are confined to marine and terrestrial systems respectively.

In other cases, the steps are discrete, and various combinations of sequestration and storage options are possible. Carbon sequestered as biomass, for example, could be either: dumped in the ocean as crop residues; incorporated into the soil as charcoal; or used as fuel with the resultant CO2 sequestered at source and stored either in sub-surface reservoirs or the deep ocean. In these cases, each step will have different and additive potential impacts on biodiversity and both need to be examined. In some of these cases, there will be separate impacts on marine and terrestrial environments. In the case of enhanced weathering also, there will be the impacts of mining of rocks and transport in terrestrial environments as well as proximate impacts in the ocean and/or on the land due to the geo-chemical impacts of the measure.

5.1.3 Impact on ocean acidification

While sequestration of CO2 from the atmosphere will reduce ocean acidification, this benefit may be compromised if, for example, the CO2 leaks into the ocean from geological storage sites or as a result of decomposition of ocean stored biomass.

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Table 5.1: Classification of CDR techniques and summary of impacts157 Technique(s) Location of side

effects other than CO2 removal

Ameliorates OA?

Nature of side effects on biodiversity other than CO2 removal

Capture Storage

1. Ocean Fertilization

direct external fertilization – Ocean – x(√?) Changes to phytoplankton productivity & diversity, food-webs and biogeochemical cycling; anoxia; acidification in deep sea

up/downwelling modification – Ocean – x(√?)

2. Enhanced weathering

Ocean alkalinity (ocean) – Ocean+ – √ Habitat destruction from mining and transportation on land; localized impacts of excess alkalinity at sea

Spreading of base minerals – Land+ – √

3. Terrestrial Ecosystem management

Afforestation – Land – √ Negative and positive impacts of land use change

Reforestation – Land – √ Generally positive impacts on forest ecosystems

Soil carbon enhancement – Land – √ Mostly positive impacts of soil carbon enhancements

4. Biomass Biomass Production Land Na Habitat change; carbon debt

Biofuels with CCS na Sub-S √ above + estimated small risk of leakage

Charcoal storage Land √ above + mostly benign but uncertain impacts on soil condition

Ocean biomass storage Ocean X (√?) above + damage to benthic environments; eutrophication

5. Air Capture Either Na √ Minor land cover changes; water use; energy use

6. CO2 Storage Ocean CO2 storage na Ocean X Damage to deep sea ecosystems; ocean acidification

Geological CO2 reservoirs Sub-S √ Estimated small risk of leakage

157 Refer to Table 2.2 for information on likely effectiveness of the technologies

+ Ocean alkalinity: will also have indirect impacts on land through mining and transport of materials.

+ Spreading of alkaline minerals: will eventually have impacts (largely positive) on oceans through run-off to oceans.

(√?) indicates possible small effect on ameliorating Ocean Acidification (OA)

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5.1.4 Land and ocean-based approaches and potentially vulnerable biodiversity

As noted above, and summarised in Table 5.1, some CDR approaches will impact terrestrial ecosystems, some marine systems and some both.

Ocean-based approaches and potentially vulnerable marine biodiversity

The impacts of ocean-based CDR will vary greatly according to techniques. Whilst one approach – ocean iron fertilization – has been relatively well investigated through small-scale experiments and models (with several reviews158,159), most other interventions remain theoretical.

The behaviour of marine ecosystems subject to perturbations is inherently difficult to model and predict due to the complex interactions between marine physical, chemical and biological processes, operating over a wide range of spatial and temporal scales.

Deep sea multicellular organisms have adapted to the energy-limited environment of the deep sea by limiting investment in reproduction, thus most deep-sea species produce few offspring. Deep-sea species tend to invest heavily in each of their eggs, making them large and rich in yolk to provide the offspring with the resources they will need for survival.160Due to their generally low metabolic rates, deep-sea fauna tend to grow slowly and have much longer lifespans than their upper-ocean cousins. For example, on the deep-sea floor, a bivalve less than 1 cm across can be more than 100 years old161. This means that populations of deep-sea species will be more greatly affected by the loss of individual larvae than would upper ocean species. Upon disturbance, recolonization and community recovery in the deep ocean follows similar patterns to those in shallow waters, but on much longer time scales (several years compared to weeks or months in shallow waters)162.

The deep sea and its sediments also contain high abundances of microbes (bacteria, archaea and protists) for which there is very little information available.

The numbers of non-microbial organisms living on the sea floor per unit area decreases exponentially with depth, probably associated with the diminishing flux of food with depth. On the sea floor of the deepest ocean and of the upper ocean, the fauna can be dominated by a few species. Between 2000 and 3000 m depth, ecosystems tend to have high species diversity, not counting the species present in the water column, with a low number of individuals, meaning that each species has a low population size163. The fauna living in the water column appear to be less diverse than that on the sea floor, probably due to the relative uniformity of vast volumes of water in the deep ocean.

Most experimental studies on CO2 (and pH) sensitivity of benthic and sediment-dwelling organisms have been carried on shallow-water species164 and, in fact, our knowledge of the 158 Secretariat of the Convention on Biological Diversity (2009). Scientific Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity. Technical Series No. 45. CBD, Montreal, 53 pp159 Wallace DWR, Law CS, Boyd PW, Collos Y, Croot P, Denman K, Lam PJ, Riebesell U, Takeda S and Williamson P. (2010) Ocean fertilization: A scientific summary for policy makers. IOC/UNESCO, Paris (IOC/BRO/2010/2)160 IPCC (2005a) IPCC Special Report on Carbon Capture and Storage, Summary Report for Policy Makers, 25 pp.161 Gage JD and Tyler PA (1991) Deep-Sea Biology: A Natural History of Organisms at the Deep-Sea Floor. Cambridge University Press, Cambridge, 504 pp.162 Smith CR and Demopoulos AW (2003) Ecology of the deep Pacific Ocean floor. In ‘Ecosystems of the Deep Ocean’, PA Tyler (Ed) Elsevier, Amsterdam, pp. 179-218.163 Snelgrove PVR and Smith CR (2002) A riot of species in an environmental calm: The paradox of the species rich deep-sea floor. Oceanography and Marine Biology, An Annual Review 40, 311-342; IPCC (2005a) IPCC Special Report on Carbon Dioxide Capture and Storage, Summary Report for Policy Makers, 25 pp.164 Andersson A.J., Mackenzie, F.T. & Gattuso, J.-P. (2011) Effects of ocean acidification on benthic processes, organisms and ecosystems. In: Ocean Acidification (Eds: J.-P. Gattuso & L. Hansson). Oxford University Press, p 122-153

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deep sea is still very limited with new species being discovered regularly165. Whilst cold-water corals currently living close to carbonate saturation horizons (2000m in the North Atlantic; 50-600m in the North Pacific) are likely to be especially vulnerable to CDR-enhanced deepwater pH changes, species living at greater water depths already experience relatively low pH (< 7.4, cf ~8.1 in the upper ocean)166, that will vary according to episodic inputs of organic material from the upper ocean167. Within sediments, pH can vary by more than 1.7 units within the top few millimetres or centimetres168, with sub-surface values being relatively insensitive to changes in the overlying seawater.

Land-based approaches and potentially vulnerable terrestrial biodiversity

Land-based CDR potentially covers a range of proposals, although (as noted in Chapter 2) there is currently disagreement as to whether processes such as bio-energy carbon capture and storage and changes in forest cover and land use should be considered as geo-engineering. In many cases, they replicate natural processes or reverse past anthropogenic changes to land and land use.

The level of information concerning some land-based CDR approaches (as broadly defined here) is relatively well-developed. For example, reforestation and restoration activities reverse previous human-induced land-use changes, and the implications of these activities on biodiversity, ecosystem services, surface albedo and local and regional hydrological cycles are reasonably well known. While there have been site-based assessments to measure the impacts of biochar on crop yield, nutrient cycles, water availability and other factors169, so far, no clear conclusions can be drawn. These studies do not necessarily equate to effectiveness and safety if such approaches are applied as geo-engineering interventions, since in some cases the scale of such interventions in order to affect climate change would be far greater than what has been studied thus far.

Because of the range of techniques that can be included under land-based CDR, it is difficult to identify ecosystems and species which will be most vulnerable to possible negative impacts. In discussions on biofuel production, however, Parties to the CBD identified a number of vulnerable components of biodiversity that should be considered in order to avoid significant negative impacts. These include: primary forests with native species; rare, endangered, threatened and endemic species, high biodiversity grasslands and peatlands and other wetlands170.

5.2. Projected impacts on biodiversity of individual Carbon Dioxide Removal approaches

5.2.1 Ocean Fertilization techniques

Ocean fertilization involves the addition of nutrients to the marine environment with the aim of enhancing the uptake of CO2 in the oceans through biological processes and the subsequent sequestration (long-term storage) of a portion of the additional organic carbon in the deep sea.

165 Hotspot Ecosystem Research on the Margins of European Seas (HERMES). List of publications. http://www.eu-hermes.net/publications_public.html166 Joint, I., Doney, S.C. & Karl, D.M. 2011 Will ocean acidification affect marine microbes? The ISME Journal 5, 1-7.167 Gooday, A.J. (2002) Biological responses to seasonally varying fluxes of organic matter to the ocean floor: A review. J. Oceanography, 58, 305-332.168 Widdicombe, S., Spicer, J.I. & Kitidis, V. (2011) Effects of ocean acidification on sediment fauna. In: Ocean Acidification (Eds: J.-P. Gattuso & L. Hansson). Oxford University Press, p 176-191.169 Major J, Rondon M, Molina D, Riha S and Lehmann J, (2010). Maize yield and nutrition during 4 years after biochar application to a Colombian savanna oxisol. Plant and Soil, Volume 333, Pages 117-128.170 Secretariat of the Convention on Biological Diversity. Report of the Regional Workshop for Asia and the Pacific on Ways and Means to Promote the Sustainable Production and Use of Biofuels. 2009

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This may be achieved through the external addition of nutrients or by modifying ocean upwelling and downwelling (section 5.2.1.2).

5.2.1.1 Direct external ocean fertilization techniques

This section considers direct ocean fertilization by adding external nutrients. Most attention has been given to iron, an element lacking in some ocean areas (primarily the Southern Ocean and equatorial Pacific), yet only required in small quantities as a micro-nutrient by marine organisms. Other approaches include manipulations to increase the internal (re-)supply of macro-nutrients such as nitrogen and phosphorus.

There have been 13 field experiments on ocean fertilization over the last 20 years, at the scale of 50-500 km2. Although not designed for geo-engineering purposes, these studies have addressed some of the uncertainties concerning the impacts of ocean fertilization on biodiversity171. The limited experiments conducted to date indicate that this is a technique of doubtful effectiveness, since much of the enhanced carbon uptake is returned to the atmosphere relatively rapidly rather than being sequestered in the deep ocean. The technical feasibility and the costs of monitoring and verification of long-term sequestration seem likely to be very high.

Changes in phytoplankton community structure and diversity and food webs

For ocean fertilization technique to work, biological primary production (photosynthesis by algae and bacteria) will increase, inevitably involving changes in phytoplankton community structure and diversity172,173, with implications for the wider food-web. Whilst the duration of those changes will depend on the fertilization method and treatment frequency, the desired outcome would be to closely mimic or enhance natural phytoplankton blooms.

More permanent changes are however likely if ocean fertilization is sustained, and carried out on a climatically-significant scale. Such changes may include an increased risk of harmful algal blooms, involving increased toxic diatoms174,175. In addition, if the supply of organic matter to deep sea sediments were significantly enhanced, that would lead to greater densities and biomass of benthos176.

Iron-induced increases in marine productivity and carbon uptake will only occur in those ocean regions where iron is currently lacking yet macro-nutrients are abundant, primarily the Southern Ocean and equatorial Pacific. However, increases in net primary productivity in these regions will be offset by decreases in adjacent areas (Figure 5.1) due to use of macro-nutrients as part of the fertilization process177.

171 Secretariat of the Convention on Biological Diversity (2009). Scientific Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity. Technical Series No. 45. CBD, Montreal, 53 pp. Wallace DWR, Law CS, Boyd PW, Collos Y, Croot P, Denman K, Lam PJ, Riebesell U, Takeda S and Williamson P. (2010) Ocean fertilization: A scientific summary for policy makers. IOC/UNESCO, Paris (IOC/BRO/2010/2)172 Boyd PW, Jickells T, Law CS, Blain S and others (2007) Mesoscale iron enrichment experiments 1993-2005: synthesis and future directions. Science 315, 612–617173 Boyd PW, Law CS, Wong CS, Nojiri Y and others (2004) The decline and fate of an iron-induced subarctic phytoplankton bloom. Nature 428, 549–553174 Trick CG, et al. (2010) Iron enrichment stimulates toxic diatom production in high-nitrate, low-chlorophyll areas. Proc Natl Acad Sci USA 107, 5887–5892. 175 Silver MW, Bargu S, Coale SL, Benitez-Nelson CR, Garcia AC, Roberts KJ, Sekula-Wood E, Bruland KW and Coale KH (2010) Toxic diatoms and domoic acid in natural and iron enriched waters of the oceanic Pacific. Proc Natl Acad Sci USA 107, 20762-20767.176 Wolff GA, Billett DSM, Bett BJ, Holtvoeth J, FitzGeorge-Balfour T, mFisher EH, Cross I, Shannon R, Salter I, Boorman B, King NJ, Jamieson A and Chaillan F (2011) The effects of natural iron fertilisation on deep-se ecology: The Crozet Plateau, Southern Indian Ocean. PLoS ONE 6(6) e20697 doi:10.1371/journal.pone.0020697.177 Gnanadesikan A, Marinov (2008) Export is not enough: nutrient cycling and carbon sequestration. Mar Ecol Prog Ser 364:289–294

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Fish stocks can be expected to generally increase in response to increased phytoplankton (and zooplankton) arising from ocean fertilization. However, they could also decrease in far field areas where primary production is reduced (Figure 5.1), and in response to altered water quality (increased anoxic zones and lower pH) in mid and deep water.

Ocean acidification

Although ocean fertilization may slow near-surface ocean acidification, it would increase acidification of the deep ocean178.

Figure 5.1. Changes in primary production after 100 years of global iron fertilization179

Projected increases (red, orange and yellow) and decreases (blue) in vertically integrated primary productivity (gC/m2/yr) after 100 years of global iron fertilization.

Changes in biogeochemical cycling

Ocean fertilization is expected to increase biogeochemical cycling in surface layers (including CO2 uptake and trace gas production) although the extent of long term CO2 drawdown is likely to be variable and difficult to quantify. This increase in biogeochemical cycling is expected to accelerate and enhance the remineralisation of sinking particles with an associated potential production of methane (CH4) and nitrous oxide (N2O)180. If released in any quantity to the atmosphere, these greenhouse gases could significantly reduce the effectiveness of ocean fertilization as a geo-engineering technique. Whilst enhanced dimethyl sulfide (DMS) emissions from plankton could be considered a ‘beneficial’, unintended outcome of ocean fertilization, due to albedo effects, the scale (and even sign) of this response is uncertain, and the overall linkage between DMS and climate is now considered relatively weak.

5.2.1.2 Ocean fertilization through modification of upwelling and downwelling

Artificial upwelling is an ocean fertilisation technique that brings cool, deep water (~200 – 1000 m) rich in nutrients up to the surface, for example through some type of pipe, to fertilise

178 Cao, L., and K. Caldeira (2010) Can ocean iron fertilization mitigate ocean acidification? Climatic Change, 99(1-2): 303-311179 Aumont O. & Bopp L. 2006. Globalizing results from ocean in situ iron fertilization studies. Global Biogeochemical Cycles, 20, GB2017, doi: 10.1029/2005GB002591180 Law CS (2008) Predicting and monitoring the effects of large scale ocean iron fertilization on marine trace gas emissions. Marine Ecology Progress Series 364, 283-288.

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the phytoplankton181. There have been some field experiments carried out in the Pacific Ocean182, 183.

The intended effects of artificial upwelling to stimulate phytoplankton growth and carbon uptake are essentially the same as for ocean fertilization above (section 5.2.1.1) and consequently will not be repeated here. However, there is a major problem with the concept, as the nutrient rich water brought up to the surface also contains high concentrations of dissolved CO2 derived from the degradation of organic material. The release of this CO2 to the atmosphere184, 185 would counteract most (if not all) of the potential climatic benefits from the fertilization of the plankton.

Upwelling in one area necessarily also involves downwelling elsewhere. Modifying downwelling currents to carry increased carbon into the deep ocean by either increasing the carbon content of existing downwelling or by increasing the volume of downwelling water has also been considered.

While the view of some authors186 is that “modifying downwelling currents is highly unlikely to ever be a cost-effective method of sequestering carbon in the deep ocean”, lower-cost structural approaches have recently been proposed.187 In order to estimate the number of such structures necessary to achieve global climate impact, the hydrodynamics and biogeochemistry of such systems would need further attention. However, it is likely to be high, covering a significant proportion of the ocean surface, since – as for other ocean fertilization techniques188 – the geo-engineering requirement is for long-term sequestration of anthropogenic carbon, not carbon uptake per se. In particular: i) if the increased phytoplankton growth is stimulated by nutrients from deeper water, such water will also contain higher CO2, thus no drawdown of atmospheric CO2 will be achieved; ii) there is considerable variability in the timescale of carbon re-cycling in the ocean interior, determining the rate of return of additional, biologically-fixed CO2 to the atmosphere and iii) enhancement of biological production at the scale required for climatic benefits is likely to significantly deplete mid-water oxygen, resulting in increased CH4 and N2O release. High costs are therefore likely to be involved in achieving reliable data on long term carbon removal (needed for international recognition of the effectiveness of the intervention), also in quantifying potentially counter-active negative impacts, over large areas (ocean basin scale) and long time periods (10-100 years).

5.2.2. Geo-chemical sequestration of carbon dioxide

181 Lovelock JE and Rapley CG (2007) Ocean pipes could help the Earth to cure itself. Nature 449, 403.182 Maruyama S, Yabuki T, Sato T, Tsubaki K, Komiya A, Watanabe M, Kawamura H and Tsukamoto K. (2011) Evidences of increasing primary production in the ocean by Stommel’s perpetual salt fountain. Deep-Sea Research I, 58, 567-574. 183 White A, Bjorkman K, Grabowski E, Letelier R, Poulos S, Watkins B and Karl D (2010) An open ocean trial of controlled upwelling using wave pump technology. Journal of Atmospheric and Oceanic Technology 27 (2) 385-396. 184 Oschlies A, Pahlow M, Yool A and Matear RJ (2010) Climate engineering by artificial ocean upwelling: Channelling the sorcerer’s apprentice. Geophysical research Letters 37, L04701.185 Yool A, Shepherd JG, Bryden HL & Oschlies A (2009). Low efficiency of nutrient translocation for enhancing oceanic uptake of carbon dioxide. Journal of Geophysical Research doi: 10.1029/2008JC004837.186 Zhou S and Flynn PC (2005) Geoengineering downwelling ocean currents: A cost assessment. Climatic Change 71 (1-2) 203-220.187 Salter S.H. (2009) A 20GW thermal 300-metre3/sec wave-energised, surge-mode nutrient-pump for removing atmospheric carbon dioxide, increasing fish stocks and suppressing hurricanes. Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden, 2009; p 1- 6.188 Wallace DWR, Law CS, Boyd PW, Collos Y, Croot P, Denman K, Lam PJ, Riebesell U, Takeda S and Williamson P. (2010) Ocean fertilization: A scientific summary for policy makers. IOC/UNESCO, Paris (IOC/BRO/2010/2)

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Carbon dioxide is naturally removed from the atmosphere by the weathering (dissolution) of carbonate and silicate rocks. However, the process of natural weathering is incredibly slow: CO2 is consumed at around one hundredth of the rate at which it is currently being emitted 189. It has therefore been proposed that, in order to constitute a significant means of combating climate change, the natural process of weathering could be artificially accelerated. There is a range of proposed techniques that include releasing calcium carbonate or other dissolution products of alkaline minerals into the ocean (section 5.2.2.1) or spreading abundant silicate minerals such as olivine over agricultural soils (section 5.2.2.2).

5.2.2.1. Enhanced ocean alkalinity

This proposed approach is based on adding the dissolution products of alkaline minerals (e.g. calcium carbonate and calcium hydroxide) in order to chemically enhance ocean storage of CO2; it also would buffer the ocean to decreasing pH, and thereby help to counter ocean acidification190.

Dissolution products of alkaline minerals could be released into the ocean through a range of proposed techniques: CO2-rich gases dissolved in sea water to produce a carbonic acid solution that is then reacted with a carbonate mineral to form calcium and bicarbonate ions191, 192,193; bicarbonate ions from the electrochemical splitting of calcium carbonate (limestone)194; or magnesium and calcium chloride salts from hydrogen and chlorine ions produced from the electrolysis of sea water to form hydrochloric acid which is then reacted with silicate rocks195.

Each of these techniques involve relatively large volumes, and operational proposals therefore envisage the addition of material through a pipeline into the sea or indirectly through discharge into a river. This limits the application of these techniques to coastal zones, thereby limiting the potential for rapid dilution and increasing the local impacts on ecosystems.

Other proposals involve the direct addition of limestone powder196 or calcium hydroxide197 to the ocean.

These latter approaches can introduce their material from ships which not only increases flexibility with the sites of application but also can achieve much higher dilution rates to minimise any short-term pH spikes.

Impacts of local excess alkalinity on marine biodiversity

189 IPCC (2005) Special Report on Carbon Dioxide Capture and Storage. Prepared by Working Group III of the Intergovernmental Panel on Climate Change. J.T. Houghton, Y. Ding, D.J. Griggs, M. Nouger, P.J. van der Linden and D. Xiaosu (eds). Cambridge University Press, Cambridge.190 Kheshgi H (1995)Sequestering atmospheric carbon dioxide by increasing ocean alkalinity. Energy 20 (9) 915-922.191 Rau GH and Caldeira K (1999) Enhanced carbonate dissolution: a means of sequestering waste CO2 as ocean bicarbonate. Energy Conversion and Management 40, 1803-1813.192 Caldeira K and Rau GH (2000) Accelerating carbonate dissolution to sequester carbon dioxide in the ocean: Geochemical implications. Geophysical Research Letters 27 (2) 225-228.193 Rau GH (2011) Co2 mitigation via capture and chemical conversion in seawater. Environmental Science and Technology 45, 1088-1092.194 Rau GH (2008) Electrochemical splitting of calcium carbonate to increase solution alkalinity: Implications for carbon dioxide and ocean acidity. Environmental Science and Technology 42, 8935-8940.195 House KZ, House CH, Schrag DP and Aziz MJ (2007) Electrochemical acceleration of chemical weathering as an energetically feasible approach to mitigating anthropogenic climate change. Environmental Science and Technology 41, 8464-8470.196 Harvey LDD (2008) Mitigating the atmospheric CO2 increase and ocean acidification by adding limestone powder to upwelling regions. Journal of Geophysical Research 113, C04028, doi: 10.1029/2007JC004373197 Cquestrate (http://www.cquestrate.com/)

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While the chemistry of the processes of enhancing ocean alkalinity is well understood, the impacts on biodiversity are not. In particular, the effects of enhanced Ca2

+ ions and dissolved inorganic carbon on biodiversity are not known adequately.

It is expected that the initial local spatial and temporal pH spike could be harmful to biodiversity; however, this impact is transient and can be minimised through rapid dilution and dispersion and in the case of particulate material, by controlling the dissolution rate of the substance through its particle size.

The state of knowledge is limited but impacts on ecosystem services are likely if the technique is carried out in continental shelf waters.

There are large unknowns associated with enhanced ocean alkalinity due to limited knowledge of biological impacts. In particular, no field experiments have been carried out and there are a limited number of theoretical papers available.

It is questionable whether any of the approaches above can be scaled-up sufficiently to make a difference to the global carbon budget without creating environmental impacts (both on land and at sea) due to the bulk of materials198 that would need to be involved. Although the quantities involved are large, enhancing ocean alkalinity using the dissolution products of silicate rocks, for instance, would sequester two CO2 molecules in the ocean for each silicate molecule mined. This compares favourably with the bulk of materials required for enhanced weathering techniques on land (see section 5.2.2.2), in which only one CO2 molecule would be consumed (and stored as a solid mineral) for each silicate molecule weathered.

5.2.2.2. Enhanced weathering of carbonate and silicate rocks

It has been proposed that the natural process of weathering could be artificially accelerated, for instance by reacting silicate rocks with CO2 to form solid carbonate and silicate minerals. One proposed method is to spread abundant silicate minerals such as olivine over agricultural soils199. It is estimated that a yearly volume of 7 km3 of such minerals (roughly twice the current rate of coal mining) would remove as much CO2 as we are currently emitting200.

Even if weathering reactions, such as those described above, were to initially take place in soils, the resultant chemicals would eventually be washed into the oceans. The impacts on biodiversity (many of them unknown) of increased concentrations of bicarbonate, calcium and magnesium ions, and hence enhanced ocean alkalinity, are outlined in section 5.2.2.1 and so are not repeated here.

Impacts on terrestrial biodiversity

The addition of rock dust to nutrient-deficient soils may increase the productivity of those soils, thereby reducing the incentive to convert previously non-agricultural land into agricultural land. However, in order to have a significant effect on the Earth’s climate, most enhanced weathering proposals would entail large-scale mining and transportation activities201, thus potentially exacerbating habitat degradation and loss which is already threatening numerous species.

Enhanced weathering techniques such as spreading olivine over fields would increase soil pH, with likely knock-on effects on vegetation and river ecosystems, and ultimately (as already discussed) on ocean biochemistry, as a result of terrestrial reaction products reaching the sea.

198

199 Schuiling and Krijgsman (2006) Enhanced weathering: an effective and cheap tool to sequester CO2. Climate Change, 74: 349-354.200 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp201 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp

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Despite confidence in the basic chemical ability of enhanced weathering to reduce atmospheric CO2 concentrations, research into the potential impacts of this geo-engineering technique on biodiversity and ecosystem services is currently severely limited. It is also unknown at present what impact the large-scale dispersal of rock dust might have on planetary albedo.

5.2.3. Restoration, afforestation, reforestation, and the enhancement of soil carbon

Although not always viewed as geo-engineering per se, familiar methods such as afforestation, reforestation, and the enhancement of soil carbon can play a small but significant role in moderating climate change202 through increasing carbon sequestration in natural and managed ecosystems (forests, plantations and agricultural lands).

Afforestation involves the direct and intentional conversion of land that has not been forested (for at least 50 years, for the purposes of the first commitment period of the Kyoto Protocol) into forested land, through planting, seeding and/or the promotion of natural seed sources by humans. Reforestation involves similar techniques, but is carried out on land that was previously forested but converted to non-forested land at a certain point in time (before 31 December 1989, for the purposes of the first commitment period of the Kyoto Protocol). Since both afforestation and reforestation result in increased forest cover, their potential impacts on biodiversity and ecosystem services are discussed collectively below. Restoration of some other ecosystems (marine as well as terrestrial), while making significant contributions to biodiversity, may also make additional though smaller contributions to reducing atmospheric CO2.

A related means of ecosystem carbon storage is the enhancement of soil carbon. This is achieved by improving land management practices; for instance, preventing captured CO 2

from reaching the atmosphere, and altering livestock grazing patterns so as to increase root mass in the soil.

Impacts on biodiversity

The impacts on biodiversity of ecosystem carbon storage depend on the method and scale of implementation. If managed well, this approach has the potential to increase or maintain biodiversity. However, if not managed well, it may result in the reduction of the distribution of certain biomes, the introduction of invasive alien species and the conversion of land use (e.g. from grassland to forest) and subsequent loss of species. Since afforestation, reforestation and land use change are already being promoted as climate change mitigation options, much guidance has already been developed. For example, the CBD has developed guidance to maximize the benefits of these approaches to biodiversity, such as the use of assemblages of native species and to minimize the disadvantages and risks203,204,205 such as the use of monocultures and potentially invasive species . The CBD is also developing advice for the application of REDD+ biodiversity safeguards (reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries).

In order to maximize biodiversity benefits, ecosystem storage should be based on an environmental impact assessment including impacts related to biodiversity and native species. Interventions should also incorporate resilience to anticipated climate change, and should

202 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp203 Secretariat of the Convention on Biological Diversity. 2009. Connecting Biodiversity and Climate Change Mitigation and Adaptation. Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Montreal, Technical Series No. 41, 126 pages. 204 Secretariat of the Convention on Biological Diversity (2003). Interlinkages between biological diversity and climate change. Advice on the integration of biodiversity considerations into the implementation of the United Nations Framework Convention on Climate Change and its Kyoto protocol. Montreal, SCBD, 154p. (CBD Technical Series no. 10).205 CBD COP decision VI/22 Annex and X/33 paragraph 8(p) –ADD additional decisions providing guidance.

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prioritize climatically-appropriate native assemblages of species. Where such recommendations have not been heeded (e.g. in reforestation projects using non-native eucalyptus in Madagascar), the result has often been monoculture plantations which are unable to support viable population of endemic species206.

Impacts on ecosystem services

Increased soil carbon can increase the amount of water retained in the soil, thereby increasing the resilience of ecosystems and potentially mitigating the water-depleting effects of climate change in arid areas. In addition, increased soil carbon has the potential to enhance crop productivity. This may reduce the incentive to convert previously non-agricultural land into agricultural land, and could therefore help to safeguard biodiversity/gene benefits. As demonstrated by a watershed scale study in Oregon, USA, increasing carbon storage through the introduction of land-use policies can be beneficial to a wide range of ecosystem services207. Moreover, several regional studies have demonstrated that benefits to ecosystem services such as water regulation, biodiversity conservation, and agriculture, can result from integrated land-use planning that delivers enhanced CO2 sequestration208.

However, it is worth noting that while increasing the amount of water retained in the soil as a result of increased soil carbon may have positive effects in certain areas; in other areas, increased water retention could lead to more anoxic conditions.

Moreover, the potential for enhanced soil productivity could lead to adverse ecosystem impacts since productivity would probably be enhanced to a greater extent in fast growing species. This could lead to shifts in ecosystem composition, interactions between species, and food webs. The potential for increased nitrogen deposition would also affect the cycling of nutrients.

Risks and uncertainties

Large-scale increases in forest cover can have an impact on both planetary albedo and the hydrological cycle, and can create a protecting buffer for neighboring ecosystems against floods and other environmental perturbations. Newly created forests are also likely to emit volatile organic compounds (VOCs), which increase the concentration of cloud condensation nuclei and therefore affect cloud formation. However, the combined effects of increased forest cover on the hydrological cycle209, planetary albedo and cloud cover, and the knock-on impacts on biodiversity and ecosystem services, are currently not well understood. This is an area for which further research and assessment are required210.

As for soil carbon, it will be necessary to determine whether its enhancement leads to anoxic conditions and methane release in all instances, and if not, which types of soil carbon best enable these adverse side effects to be avoided. It is also currently unclear how a change in soil carbon might affect the community of species dependent on a particular area of soil, and whether biodiversity/gene benefits would ultimately increase or decrease.

206 J. Ramanamanjato and J.U. Ganzhorn (2001) Effects of forest fragmentation, introduced Rattus rattus and the

role of exotic tree plantations and secondary vegetation for the conservation of an endemic rodent and a small lemur in littoral forests of southeastern Madagascar. Animal Conservation, 4(2): 175-183.207 E. Nelson, G. Mendoza, J. Regetz, S. Polasky, H. Tallis, D.R. Cameron, K.M.A. Chan, G.C. Daily, J. Goldstein, P.M. Kareiva, E. Lonsdorf, R. Naidoo, T.H. Ricketts and M.R. Shaw (2009) Modelling multiple ecosystem services, biodiversity conservation, commodity production, and trade-offs at landscape scales. Frontiers in Ecology and the Environment, 7: 4-11.208 The Royal Society (2001) The role of land carbon sinks in mitigating global climate change. Policy document 10/01. The Royal Society, London.209 Arora V.K. & Montenegro A. 2010. Small temperature benefits provided by realistic afforestation efforts.

Nature Geoscience, 4, 514-518; doi: 10.1038/ngeo1182

210 L.M. Russel et al. (2011). Ecosystem Impacts of Geoengineering: A Review for Developing a Science Plan. Submitted to Ambio 20 June 2011.

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5.2.4. Carbon sequestration and storage in biomass.

Biomass approaches to carbon dioxide removal involve two steps: biomass production (section 5.2.4.1) and biomass storage of disposal (section 5.2.4.2).

5.2.4.1. General issues on biomass production

Biomass-based approaches are based on the assumption that biomass production is either carbon neutral or results in very low greenhouse gas emissions. However, recent work 211,212

shows that this assumption could be seriously flawed and that, in fact, biomass production could incur a carbon debt of several decades or centuries.

Habitat loss

Production of biomass for carbon sequestration on a scale large enough to be climatically significant would likely entail large changes in land use leading to the significant loss of biodiversity habitats directly, or indirectly as biomass production displaces food crops, which, in turn, leads to encroachment into natural areas. These effects are similar to those resulting from expansion of biofuels.213,214,215. For example, a recent assessment of global “biochar” potential (see section 5.2.4.2.2) indicates that sequestering 12% of annual anthropogenic greenhouse gas emissions would require 556 million hectares of dedicated biomass plantations, much of it through the conversion of tropical grasslands216. Besides the impacts on biodiversity, these land use changes would entail net greenhouse gas emissions due to land use change217,218. The production of biomass on previously degraded areas, if well-managed, may be conducted in a way that delivers biodiversity benefits. However, even here, greater benefits in terms of both biodiversity and net greenhouse gas reductions may be achieved through restoration of natural habitats on these lands. 219,

A 2009 study220 modelled the environmental consequences of an ambitious global cellulosic biofuels program up to 2050. The study looked at two scenarios: one in which there were no restrictions on deforestation and in which any land would be available for biofuel production

211 IAASTD: http://www.agassessment.org/docs/SR_Exec_Sum_280508_English.htm212 T.D. Searchinger et al (2009) Fixing a critical climate accounting error. Science, 326: www.princeton.edu/~tsearchi/writings/Fixing%20a%20Critical%20Climate%20Accounting%20ErrorEDITED-tim.pdf

213 Righelato, R and Spracklen, DV. (2007) Carbon Mitigation by Biofuels or by Saving and Restoring Forests? Science 317 (902), 902.214 Searchinger, T, Heimlich, R,. Houghton, R. A., Dong, F. Elobeid, A., Fabiosa, J., Tokgoz, T., Hayes, D., and Yu, T. (2008) Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change. Science. Published on-line 7 February 2008. Available from http://www.sciencemag.org/cgi/content/abstract/1151861215 Fargione, J., Hill, J., Tilman, D., Polasky, S. and Hawthorne, P. (2008). Land Clearing and the Biofuel Carbon Debt. Science, 319(5867), 1235 - 1238. Available from http://www.sciencemag.org/cgi/ content/abstract/1152747.216 D. Woolf et al (2010) Sustainable biochar to mitigate global climate change. Nature Communications 1, Article 56.217 Searchinger, T, Heimlich, R,. Houghton, R. A., Dong, F. Elobeid, A., Fabiosa, J., Tokgoz, T., Hayes, D., and Yu, T. (2008) Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change. Science. Published on-line 7 February 2008. Available from http://www.sciencemag.org/cgi/content/abstract/1151861.218 Fargione, J., Hill, J., Tilman, D., Polasky, S. and Hawthorne, P. (2008). Land Clearing and the Biofuel Carbon Debt. Science, 319(5867), 1235 - 1238. Available from http://www.sciencemag.org/cgi/ content/abstract/1152747.

219 Righelato, R and Spracklen, DV. (2007) Carbon Mitigation by Biofuels or by Saving and Restoring Forests? Science 317 (902), 902.220 J.M. Melillo et al (2009) Unintended Environmental Consequences of a Global Biofuels Program. Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change, Report No. 168: www.calepa.ca.gov/cepc/2010/AsltonBird/AppAEx13.pdf

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as long as it was economically viable ('deforestation scenario'), and the other in which the conversion of natural forests and other 'unmanaged land' was limited to recent regional land conversion rates ('intensification scenario'). The study concluded that the more optimistic 'intensification scenario' would see the loss of 3.4 million km2 of grasslands currently used for grazing, 38% of the natural forest cover and 38% of wooded savannah in sub-Saharan Africa based on 2000 figures. In Latin America, the same scenario would be associated with the loss of 20% of natural forests and savannah in Latin America.

Other impacts on biodiversity Proposals for carbon sequestration of carbon as crop residues in the ocean (see section 5.2.4.2.3) envisage the removal of some 30% of crop residues from agricultural systems221. This is likely to have negative impacts on productivity, biodiversity, and in particular soil quality.

There are clear trade-offs between optimizing land for bioenergy crop yield and for biodiversity benefits; where monocultures and invasive alien species are employed in the production of biofuels the projected impacts on biodiversity are negative. If however, native assemblages of species are planted on degraded land and managed in a sustainable manner, benefits may be positive.

Bioenergy Carbon Capture and Storage (BECCS)

Bioenergy carbon capture and storage (BECCS) combines existing or planned technology for bioenergy/biofuels and for carbon capture and storage (CCS). It involves harvesting biomass, using it as a fuel, and sequestering the resulting CO2.222

Issues related to bioenergy production are covered above. Issues related to carbon capture and storage are addressed in section 5.2.5

5.2.4.2. Storage of carbon sequestered in biomass

5.2.4.2.1. Charcoal production and storage (“Biochar”)

“Biochar” involves the production of black carbon from biomass (charcoal), usually through pyrolysis (decomposition in a low- or zero-oxygen environment), and its storage in soils or elsewhere for up to thousands of years223. Issues related to the production of biomass for charcoal production are covered under section 5.2.4.1, while issues related to the storage of charcoal in soils are addressed here.

Charcoal production and storage can help to slow the increase in atmospheric CO2

concentrations since it circumvents the natural process of biomass decomposition by micro-organisms, which returns carbon to the atmosphere. Laboratory incubation and modeling studies have shown biochar to be inherently stable and resistant to such decomposition224, due to the bonds between its carbon atoms being much stronger than those in plant matter. However, the assumption that black carbon is inherently stable is challenged by the results of

221 Strand S.E. and Benford G. (2009) Ocean sequestration of crop residue carbon: Recycling fossil fuel carbon back to deep sediments. Environmental Science and Technology 43, 1000-1007.222 Gough, C. and P. Upham (2011). "Biomass energy with carbon capture and storage (BECCS or Bio-CCS)." Greenhouse Gases: Science and Technology 1: 324-334 DOI: 10.1002/ghg.34223 K. Spokas (2010) Review of the stability of biochar in soils: predictability of O:C molar ratios. Carbon Management, 1(2): 289–330.224 C. Cheng et al (2008) Stability of black carbon in soils across a climatic gradient. Journal of Geophysical Research, 113, G02027.

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some field trials which have shown biochar impacts on soil carbon and soil carbon sequestration to be unpredictable and not always positive even over a short time-span225,226.

Impacts of charcoal storage in soils on biodiversity and ecosystems

There is a wide variety of raw materials (feedstocks) for creating charcoal – such as wood, leaves, food waste and manure – and various conditions under which pyrolysis can take place. These variations, combined with the diversity of soil types to which biochar can be added, mean that the impacts of biochar on soils, crop yields, soil microbial communities and detritivores are also highly variable227. In addition, the impacts of biochar on mycorrhizal fungi are not yet fully understood228.

As with increased soil carbon (discussed above), biochar could increase the amount of water retained in the soil, thereby enhancing the resilience of ecosystems and potentially mitigating the water-depleting effects of climate change in arid areas. However, while increasing the amount of water retained in the soil as a result of biochar may have positive effects in some areas, in other areas increased water retention could lead to more anoxic conditions.

Moreover, the deposition of biochar in a suitable terrestrial location is likely to require considerable transport, burying and processing, which could compromise the growth, nutrient cycling and viability of the ecosystems involved229.

There is a great deal of uncertainty surrounding the impacts of biochar on biodiversity and ecosystem services due to a lack of published research on biochar. Compounding this limitation is the fact that many field trials have relied on charcoal produced by wildfires rather than by the modern method of pyrolysis proposed for biochar geo-engineering230.

There is also considerable uncertainty surrounding the long-term effects of biochar on soil productivity. Published field trials show that applying the same type of biochar at different rates in the same region can have impacts on crop yields which vary from negative to neutral to positive, even over a short time period231.

5.2.4.2.2 Ocean biomass storage Ocean biomass storage (for example, proposals called CROPS – “Crop Residue Oceanic Permanent Sequestration”), involves the deep ocean sequestration of terrestrial crop residues on or in the seabed232, 233. These proposals suggest that up to 0.6 Gt C (30% of global annual crop residues of 2 Gt C) could be available sustainably, deposited in an annual layer 4m deep in an area of seabed of ~1,000 km2. However, a sustainable annual sequestration rate below 1 Gt C/yr makes it unlikely for CROPS alone to make a significant contribution to mitigating

225 Fate of soil-applied black carbon: downward migration, leaching and soil respiration, Julie Major at all, Global Change Biology, Volume 16, Issue 4, April 2010; Long term effects of manure, charcoal and mineral fertilization on crop production and fertility on a highly weathered Central Amazonian upland soil, Christoph Steiner et al, 2007, Plant Soil DOI 10.1007/s11104-007-9193-9 226 Nitrogen Retention and Plant Uptake on a highly weathered central Amazonian Ferralsol amended with Compost and Charcoal, Christoph Steiner et al, J. Plant Nutr. Soil Sci. 2008, 171, 893–899227 J.E. Amonette et al (2009) Characteristics of biochar: microchemical properties In J. Lehmann and S. Joseph (eds) Biochar for Environmental Management, Earthscan.228 D.D. Warnock et al (2007) Mycorrhizal responses to biochar in soil: concepts and mechanisms. Plant Soil, 300: 9–20. 229 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp230 S. Shackley and S. Sohi (eds). An Assessment of the Benefits and Issues Associated with the Application of Biochar to Soil. UK Biochar Research Centre.231 H. Asai et al (2009) Biochar amendment techniques for upland rice production in Northern Laos, 1. Soil physical properties, leaf SPAD and grain yield. Field Crops Research, 111: 81-84.232 Metzger R.A. and Benford G. (2001) Sequestering of atmospheric carbon through permanent disposal of crop residue. Climatic Change 49: 11–19.233 Strand S.E. and Benford G. (2009) Ocean sequestration of crop residue carbon: Recycling fossil fuel carbon back to deep sediments. Environmental Science and Technology 43, 1000-1007.

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climate change70.Potentially, charcoal (“biochar”) or other organic remains could also be deposited on the seabed. It seems unlikely that deposition on the seabed would be the most effective use of those residues (e.g. it would seem more useful to use them in BECCS).

Issues related to the production of biomass or crop residues are covered under section 5.2.4.1, while issues related to the ocean storage of the biomass are addressed here.

It should be noted that this technique may well be covered by the existing category of wastes ‘Organic material of natural origin’ in Annex I of the London Protocol and ‘Uncontaminated organic material of natural origin’ in Annex I of the London Convention.234

Impacts on biodiversity

Where crop residues are deposited as ballasted bales, it is likely that there will be significant physical impact, of a relatively local nature, on the seabed due to the sheer mass of the material. In addition, there may be wider chemical and biological impacts through reductions in oxygen and potential increases in H2S, CH4, N2O and nutrients arising from the degradation of the organic matter.

The degradation of crop residue bales is likely to be slow due to the ambient conditions of low temperature and limited oxygen availability; the apparent lack of a marine mechanism for the breakdown of ligno-cellulose material; and the anaerobic conditions within the bales235. While, it can be argued that potential impacts could be reduced if deposition occurred in areas of naturally high sedimentation, such as off the mouths of major rivers (e.g. Mississippi) 236, many such areas are already susceptible to eutrophication and anoxia from existing anthropogenic, land-derived nutrient inputs. These effects are likely to be worsened if increased use of inorganic fertilizer is needed to replace the nutrients removed in the crop residues.

The type of packaging would also be significant when assessing potential impacts as its permeability to water and gases has the potential to influence the flux of substances into the near seabed waters. If the bales are buried within the sediment, then impacts on near seabed waters are likely to be significantly reduced; additional manipulations would, however, almost certainly have cost implications.

The addition of significant amounts of organic matter to the deep sea floor could lead to greater densities and biomasses of benthic organisms over a long period in the locations where the crop residues are deposited, a perturbation from the natural state.

The limited knowledge of ecosystem services from the deep sea combined with limited understanding of the impacts of ocean biomass storage lead to a lack of understanding about its impacts on ecosystem services. However, if done in the shallower end of the water depths suggested (1000 – 1500 m), its impacts on ecosystem services could be more significant since this is just within the range of deep sea fisheries. Whilst the area directly affected could be relatively restricted (on a global scale), larger-scale and longer-term indirect effects of oxygen depletion and deep-water acidification could be regionally significant if there is cumulative deposition of many gigatonnes of organic carbon to the seafloor, and most of this is eventually decomposed.

There are large unknowns due to limited knowledge as indicated above. No field experiments have been carried out and only a few peer-reviewed papers on the proposed technique have 23476 International Maritime Organization (2010) Marine geoengineering: types of schemes proposed to date, Scientific Group of the London Convention 33rd meeting, Scientific Group of the London Protocol 4th meeting. Available online at http://www.imo.org/blast/blastDataHelper.asp?data_id=27646&filename=13.pdf )

235 Strand S.E. and Benford G. (2009) Ocean sequestration of crop residue carbon: Recycling fossil fuel carbon back to deep sediments. Environmental Science and Technology 43, 1000-1007.236 Strand S.E. and Benford G. (2009) Ocean sequestration of crop residue carbon: Recycling fossil fuel carbon back to deep sediments. Environmental Science and Technology 43, 1000-1007.

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been published. Furthermore, while there is a lot of knowledge about the impact of organic enrichment on continental shelf environments, it is unclear whether this is easily translated into the very different deep sea environment.

5.2.5 Carbon Dioxide Capture and Storage

5.2.5.1 Carbon Dioxide Capture from Ambient Air

Air capture is an industrial process that captures CO2 from exhaust streams or the ambient air and produces a pure CO2 stream for use or disposal. Three main technologies are being explored for doing so: adsorption of CO2 onto solids, absorption into highly alkaline solutions, and absorption into moderately alkaline solutions with a catalyst. The main problem is the high energetic cost. The technical feasibility of air capture technologies is in little doubt and as already been demonstrated (e.g. in the commercial removal of CO 2 from air for use in subsequent industrial processes). However, no large-scale geo-engineering prototypes have yet been tested. Given the high net CO2 emissions that would results from air capture that was powered by fossil fuels, it would appear that the system would only be viable if a geographically isolated non-carbon power source was available.

Capturing CO2 from the ambient air (where its concentration is 0.04%) is much more difficult and energy intensive than capturing CO2 from exhaust streams of power stations where the CO2 is about 300 times of magnitude higher. A recent study suggests that the energetic and financial costs of capturing CO2 from the air are likely to have been underestimated previously, therefore placing the viability of this approach in doubt. Such approaches are discussed extensively in Chapter 6 of the IPCC Special Report on Carbon Dioxide Capture and Storage237.

This section focuses only on the step of capturing CO2 from the air. Storage of the CO2 so-captured is considered in section 5.2.6.

Small land-use requirements

Negative impacts on biodiversity through habitat loss due to land-use conversion could be relatively small for this family of technologies, since air capture systems have a land-use footprint that is hundreds or thousands of times smaller per unit of carbon removed than that of biomass-based approaches.238

Fresh-water use

Some proposed methods of air capture have a high requirement for fresh water, which is already a scarce resource. Furthermore, the disposal of captured CO2, and the potential for leakage, might also impact terrestrial and marine ecosystems (as discussed in section 5.2.4.2).

5.2.5.2. CO2 storage techniques

CO2 that has already been extracted from the atmosphere by other geo-engineering techniques (e.g. air capture) must be stored either in the ocean or in sub-surface geological reservoirs. Such approaches are discussed comprehensively in Chapter 6 of the IPCC Special Report on Carbon Capture and Storage239.

5.2.5.2.1 Ocean CO2 storage

237 IPCC IPCC (2005b) IPCC Special Report on Carbon Capture and Storage, Cambridge University Press, 431 pp.238 The Royal Society (2009) Geoengineering the Climate: Science, Governance and Uncertainty. RS Policy document 10/09. The Royal Society, London, 82 pp239 IPCC IPCC (2005b) IPCC Special Report on Carbon Capture and Storage, Cambridge University Press, 431 pp.

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The main variants of ocean CO2 storage involve either adding CO2 to middle/deep ocean waters or putting CO2 in depressions in the seabed to form lakes/pools240, 241. It has also been suggested to deposit solid CO2 blocks in the sea242; inject liquid CO2 a few hundred metres into deep-sea sediments at greater than 3,000 m depth243, displace the methane by CO2 in methane hydrates on continental margins and in permafrost regions244; or discharge liquid CO2

mixed with pulverized limestone at an intermediate depth of greater than 500 m in the ocean245. However, the economic viability of these methods has not been assessed, and none would permanently sequester the CO2 since it will eventually return to the atmosphere over century-to-millennial time scales depending on where it was introduced. So whilst they could help in buying time, it would be at the expense of future generations.

Disposal of CO2 into the water column, on or in the seabed (other than in sub-seabed geological formations), is not permitted under the global instruments of the London Protocol 1996 and is explicitly ruled out under the regional OSPAR Convention covering the north East Atlantic region. The situation under the London Convention 1972 is currently unclear.

Impacts on biodiversity and ecosystem services

Ocean CO2 storage will necessarily alter the local chemical environment, with a high likelihood of biological effects. Knowledge available for surface oceans indicates that effects on mid-water and deep benthic fauna/ecosystems is likely on exposure to pH changes of 0.1 to 0.3 units, primarily in marine invertebrates and possibly in unicellular organisms246. Calcifying organisms are the most sensitive to pH changes; they are however naturally less abundant in deep water, particularly if calcium carbonate saturation is already <1.0 (i.e. CaCO3 dissolves, unless protected).

Total destruction of deep seabed biota that cannot flee can be expected if lakes of liquid CO 2

are created. The scale of such impacts would depend on the seabed topography, with deeper lakes of CO2 affecting less seafloor area for a given amount of CO2. However, pH reductions would still occur in large volumes of water near to such lakes247, and mobile scavengers are likely to be attracted (and themselves deleteriously affected) by the scent of recently-killed organisms248.

Ecosystem services from the deep seabed are generally of an indirect nature, relating to nutrient cycling and long term climate control. However, all deep water does eventually return to the surface and/or mix with the rest of the ocean. The use of the deep sea for large-scale CO2 storage will therefore eventually reduce ocean pH as a whole, with potential effects greatest in upwelling regions (currently highly productive and supporting major fisheries).

The chronic effects of direct CO2 injection into the ocean on ecosystems over large ocean areas and long time scales have not yet been studied, and the capacity of ecosystems to compensate or adjust to such CO2 induced shifts is unknown. Several short-term and very

240 Nordhaus, W.D. (1975) Can we control carbon dioxide? IIASA-Working Paper WP-75-63, June 1975.241 Marchetti C (1977) On geoengineering and the CO2 problem. Climatic Change 1:59–68242 Murray CN, Visintini L, Bidoglio G and Henry B (1996) Permanent storage of carbon dioxide in the marine environment: The solid CO2 penetrator. Energy Conversion and Management 37 (6-8) 1067-1072.243 House K Z, Schrag D P, Harvey CF and Lackner KS (2006) Permanent carbon dioxide storage in deep-sea sediments. PNAS 103 (33) 12291-12295.244 Park Y, Kim D-Y, Lee J-W, Huh D-G, Park K-P, Lee J and Lee H (2006) sequestering carbon dioxide into complex structures of naturally occurring gas hydrates. PNAS 103, 12690-12694.245 Golomb D and Angelopolous A (2001) A benign form of CO2 sequestration in the ocean. Proceedings of the 5th

International Greenhouse Gas Technology Congress, CSIRO Publ, 463-468.246 Gattuso J.-P. & Hansson L. 2011. Ocean Acidification. Oxford University Press247 IPCC (2005b) IPCC Special Report on Carbon Capture and Storage, Cambridge University Press, 431 pp.248 Tamburri M.N., Peltzer E.T., Friederich G.E., Aya I., Yamane K. & Brewer P. 2000. A field study of the effects of CO2 ocean disposal on mobile deep-sea animals. Marine Chemistry 72, 95-101.

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small field experiments (litres) have, however, been carried out, e.g. on meiofauna249, and peer-reviewed literature on potential CO2 leakages from geological sub-sea storage250 is also relevant.

It is expected that, where CO2 storage in sub-seabed geological formations is authorized pursuant to a permit under the London Protocol, that information on the leakage and potential impacts will be reported and amassed over time.  It should also be noted that the injection into the water column of CO2 would generally be considered to be disposal at sea from a ship, platform or other structure at sea and would not be allowed under the London Protocol.

5.2.5.2.2. CO2 storage in sub-surface geological reservoirs

CO2 storage in sub-surface geological reservoirs is already being implemented at pilot-scale levels, and has been used industrially as part of enhanced oil recovery. Based in part on this experience, the risks are generally regarded as low. However, leakage from such reservoirs could have locally significant biodiversity implications.251

5.6. Sequestration of other Greenhouse Gasses

This report focuses on the removal of carbon dioxide from the atmosphere but there are some indications that other greenhouse gasses could also be removed although there is currently no supportive peer reviewed literature available on such proposals.

249 Barry J.P., Buck K.R., Lovera C.F., Kuhnz L., Whaling P.J., Peltzer E.T., Walz P. & Brewer P.G. 2004. Effects fo direct ocean CO2 injection on deep-sea meiofauna. J Oceanography, 60, 759-766250 IPCC (2005b) IPCC Special Report on Carbon Capture and Storage, Cambridge University Press, 431 pp.251 Wilson E.J., Johnson T.L. and Keith D.W. 2003. Regulating the ultimate sink: managing the risk of geological CO2 storage. Environ Sci Technol 37, 3476-3483.Oruganti, Y. and Bryant, S. (2009) Pressure build-up during CO2 storage in partially confined aquifers. Energy

Procedia, 1(1): 3315-3322.

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CHAPTER 6. SOCIAL, ECONOMIC, CULTURAL AND ETHICAL CONSIDERATIONS OF CLIMATE-RELATED GEO-ENGINEERING

6.1 Introduction

Climate change is likely to have serious impacts on biodiversity, ecosystems and associated ecosystem services. The social, economic and cultural implications of un-controlled climate change and continued degradation of ecosystems should not be underestimated (see chapter 3).

Similar to the discussion on the impacts of climate change on biodiversity, the social, economic and cultural considerations regarding geo-engineering have significant inter- and intra-generational equity issues.

Geo-engineering proposals are likely to meet not only support, but also opposition, especially considering the present divergence of opinions about potential risks and benefits. All new technologies or techniques are embedded in a wider social context and have social, economic and cultural impacts that might become apparent only once they have been employed. However, due to its intentionality and its potential impacts, geo-engineering raises issues beyond technical scientific assessments. Nuclear power, genetically modified organisms (GMOs) and nano-technologies have shown the importance to connect scientific research to a wider social context.

The Conference of the Parties, through its decision X/33 requested the Executive Secretary to identify social, economic and cultural considerations associated with the possible impacts of geo-engineering on biodiversity.

In this chapter, we discuss a number of social, economic and cultural aspects of geo-engineering, and the role of indigenous groups and local communities in the context of geo-engineering and biodiversity. The first parts deal with social, economic and cultural issues that are relevant for geo-engineering in general.252 The ambition here is to put geo-engineering technologies in a wider social context, and to highlight social, political, economic and cultural issues that ought to be of interest for the Parties of the CBD, and the readers of this report. The second part of the chapter has an explicit focus on potential social concerns associated with different geo-engineering proposals and technologies and their impacts on biodiversity.

6.2. Available information

Assessing the social, economic and cultural impacts of geo-engineering technologies as they relate to biodiversity is an important, yet difficult task considering the current state of knowledge and the lack of peer-reviewed literature on the topic. It should be noted that there is a lack of published academic studies that specifically address the issue. It has also been questioned whether peer-reviewed literature can adequately reflect indigenous knowledge; knowledge which is often as much a process of knowing as it is a thing that is known, and so does not lend itself to the practice of documentation253. This is particularly worrisome considering the role these communities play in actively managing ecosystems, sometimes through an active application of local ecological knowledge that has evolved during considerable time frames through co-management processes and social learning254.

Some work on this matter has been conducted within the framework of CBD activities on biodiversity and climate change, including through the workshop on opportunities and

252 We acknowledge that this first part extends beyond the explicit mandate of the group, but has been included to put the technologies in a wider social context, as well as to respond to comments on earlier drafts of this report.

253 A. Agrawal, 1995, Indigenous and scientific knowledge: some critical comments, Indigenous Knowledge and Development Monitor, 3 (3): 3-6. F. Berkes, 2008, Sacred Ecology, 2nd edition, Routledge, New York, USA.254 Berkes, F., J Colding and C Folke (2004). Navigating Social-Ecological Systems – Building Resilience for Complexity and Change. Cambridge University Press, Cambridge. 397 pp.

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challenges of responses to climate change for Indigenous and local Communities, their traditional knowledge and biological diversity held the 25 - 28 March 2008 in Helsinki, Finland255, as well as through the consideration of the role of traditional knowledge innovations and practices during the second Ad hoc Technical Expert Group on Biodiversity and Climate Change256, however further work remains to be done. In addition, there is a growing literature on social dimensions of geo-engineering257, including examples of social perceptions from historic efforts to engineer the climate and other large-scale planetary processes258. Issues related to geo-engineering ethics, governance and socio-political dimensions have also been discussed within the geo-engineering research community, as exemplified by the Oxford Principles259 and the subsequent Asilomar principles.

It should also be noted that there is very little information available about the perspectives from indigenous peoples and local communities, especially among developing countries within geo-engineering discussions.260 The CBD Secretariat has initiated a process to bring in the views of indigenous communities, and the results will be presented in a separate report.261

6.3 General social, economic and cultural considerations

There are a number of social, economic and cultural considerations from geo-engineering technologies that may emerge, regardless of the specific geo-engineering approach considered. These considerations are not necessarily unique for geo-engineering, but have clear parallels to on-going discussions on social dimensions of climate change, emerging technologies, and complex global risks. It should be restated that this is not intended to be a complete all-encompassing analysis of costs and benefits, but should rather be seen as social, economical and cultural issues of potential concern. In addition, social perceptions of risks in general, are highly differentiated across social groups, and highly dynamic262, and pose particular socio-political challenges in settings defined by complex bio-geophysical

255 Opportunities and challenges of responses to climate change for Indigenous and Local Communities, their Traditional Knowledge and Biological Diversity. 25 - 28 March 2008 - Helsinki, Finland. Meeting report: http://www.cbd.int/doc/meetings/cop/cop-09/information/cop-09-inf-43-en.pdf; Meeting documents: http://www.cbd.int/doc/?meeting=EMCCILC-01256 Secretariat of the Convention on Biological Diversity (2009) Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Technical Series No.41. CBD, Montreal, 126 pp257 Stanford Journal of Law and Science, special issue 2009: Barrett, Schelling, Victor, Gardner REFS258 Fleming, James Rodger. 2006. “The Pathological History of Weather and Climate Modification: Three cycles of promise and hype,” Historical Studies in the Physical Sciences 37, no. 1 (2006): 3-25. http://www.colby.edu/sts/06_fleming_pathological.pdf Fleming, James Rodger. 2011. “Iowa Enters the Space Age: James Van Allen, Earth’s Radiation Belts, and Experiments to Disrupt Them,” Annals of Iowa 70 (Fall 2011), in press.259 Rayner, S., Redgwell C., Savulescu, J., Pidgeon, N. and Kruger, T. (2009) Memorandum on draft principles for the conduct of geoengineering research. House of Commons Science and Technology Committee enquiry into The Regulation of Geoengineering. The call by the American Geophysical Union Policy Statement on Geo-engineering the Climate System for “coordinated study of historical, ethical, legal, and social implications of geo-engineering that integrates international, interdisciplinary, and intergenerational issues and perspectives and includes lessons from past efforts to modify weather and climate”, is nevertheless still relevant in this context. AGU Position Statement. Geoengineering the Climate System. Statement adopted by Council 13 December 2009. Adopted from the statement written by the American Meteorological Society and adopted by the AMS Council on 20 July 2009: http://www.agu.org/sci_pol/positions/geoengineering.shtml.260 However, public engagement initiatives have now been piloted in the developed world, as a means of gauging public opinions on geo-engineering, see Ipsos MORI, 2010, Experiment Earth? Report on a Public Dialogue on Geoengineering. Available online at http://www.nerc.ac.uk/about/consult/geoengineering-dialogue-final-report.pdf261 UNEP/CBD/SBSTTA/16/INF/30: Impacts of climate related geo-engineering on biodiversity: views and

experiences of indigenous and local communities and stakeholders.

262 Kasperson, R. E., Renn, O., Slovic, P., Brown, H. S., Emel, J., Goble, R., Kasperson, J. X., et al. (1988). The Social Amplification of Risk: A Conceptual Framework. Risk Analysis, 8(2), 177-187. doi:10.1111/j.1539-6924.1988.tb01168.x

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interactions.263 This complicates any projection of how the general public, non-governmental organizations and governments would perceive any experimentation and deployment of geo-engineering technologies.

6.3.1 Ethical considerations

Humanity is now the major changing force on the planet, a new geological era proposed as the “Anthropocene”.264 This shift has important repercussions, not only because it forces us to consider multiple and interacting global environmental changes,265 but also because it opens up difficult discussions on whether it is desirable to move from unintentional modifications of the Earth system, to an approach where we intentionally try to modify the climate and associated bio-geophysical systems to avoid the worst outcomes of climate change. Hence, the very fact that the international community is presented with geo-engineering as a potential option to be further explored is a major social and cultural issue.

Geo-engineering poses numerous ethical challenges. It also requires the international community to resolve the conflicting objectives of avoiding the effects of global climate change vis-à-vis avoiding the risks of geo-engineering.

Although some upstream public engagement on geo-engineering has been trialled266,267 current discussions on geo-engineering are often based on technical approaches whose implications are not readily understood nor easily assessed268. There is a growing discussion and literature on ethical considerations related to geo-engineering, including issues of “moral hazard” 269; intergenerational issues of submitting future generations to the need to maintain the operation of the technology or suffer accelerated change270; the possibility that development and uses of geo-engineering techniques are perceived to be threatening by governments 271; as well as the question of whether it is ethically permissible to remediate one pollutant by introducing another272.

6.3.2 Unintended consequences and technological lock-in

Technological innovation has in very many ways helped to transform societies and improve the quality of life, but not always in a sustainable way.273 Failures to respond to early 263 Galaz, V., Moberg, F., Olsson, E.-K., Paglia, E., & Parker, C. (2011). Institutional and Political Leadership

Dimensions of Cascading Ecological Crises. Public Administration, 89(2), 361-380. doi:10.1111/j.1467-9299.2010.01883.x

264 Crutzen et al 2011

265 Rockström et al 2009, ”A Safe Operating Space for Humanity”, Nature; Steffen, W., Persson, Ã…., Deutsch, L., Zalasiewicz, J., Williams, M., Richardson, K., Crumley, C., et al. (2011). The Anthropocene: From Global Change to Planetary Stewardship. Ambio. doi:10.1007/s13280-011-0185-x

266 Ipsos MORI, 2010, Experiment Earth? Report on a Public Dialogue on Geoengineering. Available online at http://www.nerc.ac.uk/about/consult/geoengineering-dialogue-final-report.pdf267 Karen Parkhill and Nick Pidgeon, 2011, Public Engagement on Geoengineering Research: Preliminary Report on the SPICE Deliberative Workshops [Technical Report], Understanding Risk Group Working Paper, 11-01, Cardiff University School of Psychology. Available online at http://psych.cf.ac.uk/understandingrisk/docs/spice.pdf268 Ipsos MORI, 2010, Experiment Earth? Report on a Public Dialogue on Geoengineering. Available online at http://www.nerc.ac.uk/about/consult/geoengineering-dialogue-final-report.pdf269 Alan Robock, 2008, 20 Reasons Why Geoengineering May Be A Bad Idea, Bulletin of the Atomic Sciences, 64 (2): 14-18. Available online at http://www.thebulletin.org/files/064002006_0.pdf270 Gardiner, Stephen M. (2011). “Some Early Ethics of Geoengineering the Climate: A Commentary on the Values of the Royal Society Report”, Environmental Values, Volume 20, Number 2, May 2011 , pp. 163-188.271 Fleming, James (2010). Fixing the Sky272 Hale, B. and L. Dilling (2011). “Geoengineering, Ocean fertilization, and the Problem of Permissible Pollution”, Science, Technology and Human Values, 36(2): 190-212.273 Westley, F., Olsson, P., Folke, C., Homer-Dixon, T., Vredenburg, H., Loorbach, D., Thompson, J., et al.

(2011). Tipping Toward Sustainability: Emerging Pathways of Transformation. Ambio. doi:10.1007/s13280-

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warnings of unintended consequences of particular technologies have been documented 274. The possibilities of unintended side effects in the large-scale application of geo-engineering techniques is an often-raised concern in the literature and general debate especially for Solar Radiation Management (see chapter 4). The concept of ‘technologies of hubris’ has been introduced, calling for an increased balance between the concept that technology can solve problems and the concern over whether technological approaches are the best option when considering social and ethical considerations275.

An additional issue that has been raised is the possibility of technological, political and social “lock in” - that is the possibility that the development of geo-engineering technologies also result in the emergence of vested interests and increasing social momentum. It has been argued that this path dependency could make deployment more likely, and/or limit the reversibility of geo-engineering techniques.276

6.3.3 Governance and legal considerations

Issues related to geo-engineering governance and regulation have gained increased prominence in the literature.277 It should be noted that the challenges for regulation and governance of geo-engineering include the variety of evolving technologies as well as their different stages of development – ranging from theory to modelling, to sub-scale field testing, and large scale deployment278. Governance structures also need to provide different functions ranging from ensuring transparency, participation, containing risks, the coordination of science, bridging the science-policy divide, and create structures to secure funding279.

These issues, along with precautionary principle/approach and human rights approaches, are discussed in detail in a parallel legal study assumed in line with CBD Decision X/33 entitled “Regulatory Framework of Climate-related Geo-engineering Relevant to the Convention on Biological Diversity”, and are therefore not explored in detail here.

6.3.4 Societal distribution considerations

Geo-engineering could raise a number of questions regarding the distribution of resources and impacts within and amongst societies and across time. First, access to natural resources is needed for some geo-engineering. Competition for limited resources can be expected to increase if geo-engineering technologies emerge as a competing activity for land or water use. For example, possible competition for land as a result of land based albedo changes, or land based CDR will reduce land available for other uses such as the production of food crops,

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274 Harremoës, P., & Agency, E. E. (2001). Late lessons from early warnings: the precautionary principle 1896-2000 (pp. 1-211). Office for Official Publications of the European Communities.

275 Sheila Jasanoff. Technologies of Humility: Citizen participation in governing Science. Minerva, 2003. http://sciencepolicy.colorado.edu/students/envs_5100/jasanoff2003.pdf276 Royal Society (2009, pp.39, 45). See also literature on socio-technical regimes e.g. Arthurs, BA (1989).

”Competing technologies, Increasing returns and lock-in by historical events”, The Economic Journal, 99: 116-131.

Geels, F. (2004). From sectoral systems of innovation to socio-technical systems- Insights about dynamics and change from sociology and institutional theory. Research Policy, 33(6-7), 897-920. doi:10.1016/j.respol.2004.01.015

277 Royal Society (2009), Macnaghten, P., & Owen, R. (2011). Good governance for geoengineering. Nature, 479, 2011; Reynolds, J. (2011). The Regulation of Climate Engineering. Environmental and Resource Economics, 3, 113-136.GAO

278 Blackstrock, J., N. Mooore and C. Kehler Siebert (2011). Engineering the Climate – Research questions and policy implications. UNESCO-SCOPE-UNEP Policy Briefs. November 2011.

279 Bodansky 2011

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medicinal plants or the exploitation of non-timber forest products. These competing demands for land use can increase social tensions unless addressed by national and local institutions280. In addition, changes in land use may impact indigenous people’s cultural and spiritual values of natural areas, sacred groves and water shades281.

These issues could also be relevant in the marine environment where experimentation or deployment of geo-engineering proposals such as ocean fertilization could impact traditional marine resource use282,283,284,285 The use of the deep water as reservoirs for storage of CO 2 or biomass, as well as for ocean fertilization, would also use ocean space. To the extent that most of these activities would happen on the high seas, there are unlikely to raise significant distributional issues as a social consideration.

Enhanced weathering on land however will have clear local impacts as it requires large mining areas and associated transport infrastructure. In addition, the mineral resources required will only be available in certain locations, therefore reducing the opportunity for choosing between alternative sites. Based on historical experience, large mining activities could have serious social implications. In addition, land space is needed for weathering to happen.

Second, the distribution of impacts of geo-engineering are not likely to be even or uniform as are the impacts of climate change itself. Regarding impacts on climate, this appears to be mainly an issue arising from SRM. Regarding other impacts, CDR could have local and possibly also regional impacts that could raise distributional issues. Such impacts are explored below in this chapter. Where distributional effects arise, this raises questions about how the uneven impacts can be addressed for instance through proper governance mechanisms.

Third, as with climate change, geo-engineering could also entail intergenerational issues. As a result of possible technological “lock in”, future generations might be faced with the need to maintain geo-engineering measures in general in order to avoid impacts of climate change. This mainly has been identified as an issue for SRM. However, it is also conceivable that CDR-techniques entail similar “lock in” effects depending on emission trajectories. Conversely, it could be argued that not pursuing further research on geo-engineering could limit future generations’ options for reducing climate risk.

6.3.5. Political considerations

There are also a number of social and political considerations to bear in mind especially when considering SRM. In an international context, countries and societies will have to dealing with the possibility of unilateral pursuit or deployment of geo-engineering. In cases in which geo-engineering experimentation or interventions have (or are suspected to have) transboundary affects or impacts on areas beyond national jurisdiction, geopolitical tensions

280 Trumper, K. et al. (2009). The Natural Fix? The role of ecosystems in climate mitigation. UNEP rapid response assessment. UNEP, Cambridge, UK281 UNFF “Cultural and Social Values of Forests and Social Development”. UN Economic and Social Council. E/CN.18/2011/5. New York, 2011.282 Glibert, P M. (2008). Ocean urea fertilization for carbon credits poses high ecological risks. Marine pollution bulletin, 56(6), 1049-1056.283 IMO 2007. Convention on the Prevntion of Marine Pollution by dumping of wastes and other matter, 1972 and its 1996 Protocol. Statement of concern regarding iron fertilization of the oceans to sequester CO2. http://www.whoi.edu/cms/files/London_Convention_statement_24743_29324.284 Sedlacek, L., Thistle, D., Carman, K.R., Fleeger, J.W and Barry, J.P. 2009. Effects of carbon dioxide on deep-sea harpacticoids. ICES International Symposium – Issues confronting the deep oceans, 27 – 30 April, 2009, Azores, Portugal.285 OSPAR, 2007. OSPAR Decision 2007/1 to prohibit the storage of carbon dioxide streams in the water column or on the sea-bed. Available at www.ospar.org/v-measure /get_page.asp?

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could arise regardless of causation of actual negative impacts, especially in the absence of international agreement.286.

Furthermore, some civil society organizations have expressed opposition to geo-engineering experiments and deployment287,288,289. Tensions could also increase in cases where geo-engineering technologies are combined with biotechnology (such as albedo enhanced crops) and nanotechnology (under consideration for aerosols) and where actors are perceived to have ulterior motives. Polarization of the debate could prove detrimental to political decision-making.290

6.4. Specific social, economical and cultural considerations of geo-engineering technologies as they relate to biodiversity

Climate change is expected to result in altered ecosystems consisting of new assemblages of species291, and therefore affect biodiversity in ways that are relevant for all sort of local uses of land-based and marine ecosystems, and their associated ecosystem services. Reducing the impacts of climate change through geo-engineering interventions may in theory address the loss of ecosystems upon which traditional knowledge is based. On the other hand, deployment of geo-engineering interventions may itself alter ecosystems (see examples below), resulting in this impact being offset or eclipsed292. This however, is highly dependent on the geo-engineering technology of interest, how they are deployed, and the institutions (local and national) in place.

In addition to the social considerations that generally arise from geo-engineering, in this section we briefly elaborate social, economical and cultural considerations that result specifically from geo-engineering’s impacts on biodiversity.

6.4.1 Geo-engineering, and indigenous and local communities and stakeholdersDecision X/33 calls for the integration of the views and experiences of indigenous and local communities and stakeholders into the consideration of the possible impacts of geo-engineering on biodiversity and related social, economic and cultural considerations. Integrating such views is important as indigenous peoples and local communities, especially in developing countries, tend to be among the populations whose livelihoods are most reliant upon biodiversity resources. In addition, disadvantaged users of ecosystems and their associated ecosystem services, are at constant risk of losing out in conflicts related to local

286 The Royal Society (2009). Geoengineering the climate. Science, governance and uncertainty. London, 82 pages, Scott Barrett (2008). “The Incredible Economics of Geoengineering”, Environ Resource Econ (2008) 39:45–54; Jason J Blackstock and Jane CS Long (2009). “The Politics of Geoengineering”, Science, Vol. 327 no. 5965 p. 527;287 ETC Group, 2011, Open Letter to IPCC on Geoengineering. Available online at http://www.etcgroup.org/upload/publication/pdf_file/IPCC_Letter_with_Signatories_-_7-29-2011.pdf288 Karen Parkhill and Nick Pidgeon, 2011, Public Engagement on Geoengineering Research: Preliminary Report on the SPICE Deliberative Workshops [Technical Report], Understanding Risk Group Working Paper, 11-01, Cardiff University School of Psychology. Available online at http://psych.cf.ac.uk/understandingrisk/docs/spice.pdf289 Poumadère, M., R. Bertoldo, J.Samadi (2011) "Public perceptions and governance of controversial technologies to tackle climate change: nuclear power, carbon capture and storage, wind, and geoengineering", Climate Change. Advance Review DOI: 10.1002/wcc.134.290 Bodle, Ralph, "International governance of geoengineering: Rationale, functions and forum", in: William C.G.

Burns (ed.), Geoengineering and climate change, Cambridge University Press (submitted February 2011; forthcoming 2012)

291 John Williams and Stephen Jackson, 2007, Novel Climates, No-Analog Communities, and Ecological Surprises, Frontiers in Ecology and the Environment, 5 (9): 475-482. Available online at http://www.frontiersinecology.org/paleoecology/williams.pdf292 H.D. Matthews and S.E. Turner (2009) Of mongooses and mitigation: ecological analogues to geoengineering. Environmental Research Letters, 4 (4), 045105.

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resources, have less of a voice in decision-making at all levels, and may have less knowledge of regulations and policies to support their interests293,294.

The issue here is as much about physical resources, as about cultural uses and worldviews associated with ecosystems and their management such as forest taboo systems in Madagascar295, and the unique cultural features of Balinese water temples296.

All forms of environmental change – resulting from geo-engineering or not – have local implications for livelihoods and ecosystem services. In fact, the Second Ad hoc Technical Expert Group on Biodiversity and Climate Change concluded that indigenous people will be disproportionately impacted by climate change because their livelihoods and cultural ways of life are being undermined by changes to local ecosystems297. As such, if geo-engineering can reduce the negative impacts of climate change, without effecting more environmental change than that which is avoided, geo-engineering could contribute to the preservation of traditional knowledge, innovations and practices.

On the other hand, there is considerable uncertainty concerning the impacts of any environmental change on indigenous peoples and local communities since most such impacts are difficult to predict with current modelling capabilities298. Furthermore, there is the risk that geo-engineering, in some instances, could effect change far more rapidly even than climate change itself299.

In order to ensure that the impacts of geo-engineering on indigenous peoples and local communities are adequately considered and addressed, there is a role for such stakeholders in various phases of geo-engineering research, ranging from theory and modelling, technology development, subscale field-testing; and potential deployment. The participation of indigenous peoples and local communities could hence be included in all parts of research development, especially in cases where technological interventions are projected to have impacts for biodiversity and ecosystem services.

Guidelines for the consideration of the views and knowledge of indigenous peoples and local communities have already been proposed by the Second Ad hoc Technical Expert Group on Biodiversity and Climate Change with regards to climate change300. These guidelines (see box 1) may be useful to consider by scientists and national governments alike when assessing the social, economic and cultural impacts of geo-engineering.

As noted above, the CBD Secretariat has initiated a separate process to bring in the views of indigenous communities, and the results will be presented in a different report.301 293 Trumper et al. 2009:49-50294 Bridging Scales and Epistemologies: Linking Local Knowledge and Global Science in Multi-Scale Assessments Conference; Alexandria, Egypt  · March 17-20, 2004, under the title: “Learning from the Local: Integrating Knowledge in the Millennium Ecosystem Assessment". Available at: http://www.millenniumassessment.org/documents/document.349.aspx.pdf295 Tengö, M., K. Johansson, F. Rakotondrasoa, J. Lundberg, J-A Andriamaherilala, J-A Rakotoarisoa and T. Elmqvist (2007). Taboos and Forest Governance: Informal Protection of Hot Spot Dry Forest in Southern Madagascar. Ambio, Vol. 36, Issue 8, pg(s) 683-691.296 Lansing, S. (2006). Perfect Order – Recognizing Complexity in Bali. Princeton University Press, Princeton.297 Secretariat of the Convention on Biological Diversity. (2009) (a). Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Montreal, Technical Series No. 41, 126 pages.298 Robock, A. Bunzl, M. Kravitz, B. Georgiy L. Stenchikov, A Test for Geoengineering? Science 29 January 2010: Vol. 327. no. 5965, pp. 530 - 531299 The Royal Society, 2009, Geoengineering The Climate: Science, Governance and Uncertainty, The Royal Society, London, UK.300 Secretariat of the Convention on Biological Diversity. (2009) (a). Connecting Biodiversity and Climate Change Mitigation and Adaptation: Report of the Second Ad Hoc Technical Expert Group on Biodiversity and Climate Change. Montreal, Technical Series No. 41, 126 pages.301 UNEP/CBD/SBSTTA/16/INF/30: Impacts of climate related geo-engineering on biodiversity: views and

experiences of indigenous and local communities and stakeholders.

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Box 1: Activities to promote the consideration of the views of indigenous peoples and local communities:

Promote the documentation and validation of traditional knowledge, innovations and practices. Most knowledge is not documented and has not been comprehensively studied and assessed. Therefore there is need to enhance links between traditional knowledge and scientific practices.

Revitalize traditional knowledge, innovations and practices on climate change impacts on traditional biodiversity based resources and ecosystem services through education and awareness-raising, including in nomadic schools.

Explore uses of and opportunities for community-based monitoring linked to decision-making, recognizing that indigenous people and local communities are able to provide data and monitoring on a whole system rather than single sectors based on the full and effective participation of indigenous and local communities.

6.4.2 Social, economic and cultural considerations of Solar Radiation Management techniques

As with climate change, solar radiation management is expected to impact weather patterns with implications for ecosystem productivity and associated livelihoods. Any shifts of temperature and changes to the hydrological cycle might affect local and indigenous communities, especially those dependent on provisioning ecosystem services such as food, energy. Cultural services such as ceremonies that follow planting and harvesting seasons in most rain fed agricultural regions (e.g. Nigeria and Ghana302,303) could also be affected by rapid changes in hydrological regimes.

On the other hand, since SRM theoretically has the potential to target regional climatic changes304 (for example, in the Arctic), local approaches may address climate change sufficiently to preserve threatened traditional livelihoods. However, a number of uncertainties regarding the impact of SRM for instance on food security, ecosystem productivity and associated issues remain. Some approaches suggest changing the albedo of agricultural land, and it is unknown what the impact will be on productivity305. As another example, some projected increases in crop productivity due to changes in diffuse insolation306 are expected although this increase may be either offset or enhanced by regional changes in precipitation which will impact rainfed agriculture and traditional pastoral livelihoods with effects likely to be positive in some areas and negative in others 307,308.

302 Orkwor, G. C., Asiedu, R. and I. J. Ekanayake, 1998. Food Yams. Advances in Reasearch. IITA and NRCRI, Nigeria, 249 pp.303 IITA 2010. Research to nourish Africa. R4D Review. http://r4dreview.org/2010/04/yam-festival.304 Rasch, P.J., Latham, J., and C.C. Chen. (2009). Geoengineering by cloud seeding: influence on sea ice and climate system. Environmental Research Letters, Volume 4, Pages 1-8.305 Ban-Weiss, G.A. and K. Caldeira (2010). Geoengineering as an optimization problem. Environmental Research Letters, Volume 5, Pages 1-9.306 Keith, D.W. (2010). Photophoretic levitation of engineered aerosols for geoengineering. PNAS Volume 107, pages 16428-16431.307 Latham, J., Rasch, C., Chen C., Kettles, L., Gadian, A., Gettelman, A., Morrison, H. and K. Bower. (2008). Global temperature stabilixation via controlled albedo enhancement of low-level maritime clouds. Philosophical Transactions fo the Royal Society A, Volume 366, Pages 3969-3987.308 Ridgwell, A. and J.S. Singarayer. (2009). Tackling Regional Climate Change by Leaf Albedo Bio-engineering. Current Biology, Volume 19, Pages 146-150.

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Stratospheric aerosols would adversely affect ground-level astronomical observation and as well as satellite-based remote sensing of Earth. They may also make skies whiter (less blue) though the expected magnitude of this effect is not clear309.

6.4.3 Social, economic and cultural considerations of Land Based Carbon Dioxide Removal techniques

Land based CDR poses uncertain impacts for ecosystem productivity and associated livelihoods. Some models project increased ecosystem productivity310 which may lead to increased food production while increased carbon and nutrient content in soils may increase yields311 although the long term impacts are unknown.

The large-scale implementation of “artificial trees” could compromise locally significant features, or degrade whole culturally significant landscapes and with possible parallels to the debate over wind farms. These are also likely to be associated with noise associated with wind currents or machinery, depending on the deployment. Concerns have also been raised on about whether CDR-interventions of this form could deplete local freshwater supplies, and negatively impact local freshwater biodiversity.

Large-scale afforestation also implies changes on landscapes that are likely to have both positive and negative impacts on biodiversity, ecosystems services and their uses. Besides from the possibility of competing land uses (mentioned above), altered landscapes imply habitat fragmentation and/or loss. Some of these concerns could also apply to reforestation in certain circumstances.

Furthermore, it has been suggested that some land based CDR approaches could make use of genetic modification of organisms and / or monoculture hybrid crop breeding312 which may have a negative impact on traditional crop varieties and non-target species including those of cultural / medicinal importance. Where such approaches are considered, the safe handling of such materials, including through the provisions set out in the Cartagena Protocol on Biosafety313 apply.

6.4.4. Social, economic and cultural considerations of Ocean Based Carbon Dioxide Removal techniques

The impacts of ocean based CDR are likewise faced with regional disparities and uncertainties. Some activities to enhance ocean alkalinity could negatively impact marine and coastal species of cultural importance, other impacts, such as disruptions to fisheries due to changes in marine food chains, are likely to be positive in some areas and negative in others314. In addition, some consequences of ocean fertilization can have unpredictable far field effects, so distant ecological and human communities can be affected. There is also a suggested risk of toxic blooms but ocean fertilization is probably a less significant driver compared to others such as land-based nutrient inputs.

309Solar radiation management: the governance of research. The Royal Society. http://www.srmgi.org/files/2012/01/DES2391_SRMGI-report_web_11112.pdf

310 Woodward, I., Bardgett, R.D., Raven, J.A., and A.M. Hetherington. (2009). Biological Approaches to Global Environment Change Mitigation and Remediation. Current Biology, Volume 19, Issue 14, R615-R623.311 The Royal Society (2009). Geoengineering the climate. Science, governance and uncertainty. London, 82 pages.312 Vandana Shiva, 1993, Monocultures of the Mind: Perspectives on Biodiversity and Biotechnology, Third World Network, Penang, Malaysia.313 Cartagena Protocol on Biosafety. http://bch.cbd.int/protocol/314 Secretariat of the Convention on Biological Diversity. (2009) (b). Scientific Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity. Montreal, Technical Series No. 45, 53 pages.

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CHAPTER 7. SYNTHESIS / CONCLUDING REMARKS

This study has reviewed the range of geo-engineering techniques (Chapter 2), reviewed the projected impacts of climate change on biodiversity (Chapter 3) and also considered the impacts of geo-engineering techniques on biodiversity (Chapters 4 and 5). Based on the information in those chapters, this chapter (section 7.1) provides a concise review of how the drivers of biodiversity loss under the scenarios of (i) rapid and significant reduction in greenhouse gas emissions; and (ii) deploying geo-engineering techniques to address climate change, against a baseline scenario of taking no action to reduce climate change.

The chapter also includes remarks on the importance of scale (section 7.2) and highlights key areas where further knowledge and understanding is required (Section 7.3) 7.1. Changes in the drivers of biodiversity loss

As noted in Chapter 1, the direct drivers of biodiversity loss are habitat conversion, over-exploitation, the introduction of invasive species, pollution and climate change.

Also as noted, at a global scale, the largest driver of terrestrial biodiversity loss has been, and continues to be, land use change. In the oceans, overexploitation has also been a major cause of loss. Climate change is rapidly increasing in importance as a driver of biodiversity loss. However, the drivers of loss vary among ecosystems and from region to region.

In the baseline scenario described in Chapter 3, that is, in the absence of action to reduce greenhouse gas emissions, climate change poses an increasingly severe range of threats to biodiversity and ecosystem services resulting from changes in temperature, precipitation and other climate attributes, as well as the associated phenomenon of ocean acidification. The impacts are exacerbated by the other anthropogenic pressures on biodiversity (such as over-exploitation; habitat loss, fragmentation and degradation; the introduction of non-native species; and pollution) since these reduce the opportunity for gradual vegetation shifts, population movements and genetic adaptation. In addition, climate change is projected to actually increase some of the other drivers, for example by providing additional opportunities for invasive alien species.

Under this baseline scenario of taking no action to address climate change, the climate change driver will increase substantially.

Under the scenario of addressing climate change through a rapid and significant reduction in greenhouse gas emissions, there would be a transition to a low-carbon economy in both the way we produce and use energy and the way we manage our land. Measures to such effect could include: increased end use efficiency; the use of renewable energy technologies alongside nuclear and carbon capture and storage; and ecosystem restoration and improved land management. These measures would substantially reduce the adverse impacts of climate change on biodiversity. Generally, most other impacts on biodiversity, mediated through other drivers, would be small (e.g. use of nuclear power to replace fossil fuels) or positive (e.g. avoided deforestation, ecosystem restoration). Although some of the climate change mitigation measures have potential negative side-effects on biodiversity (e.g. bird kill by wind farms; disruption of freshwater ecosystems by hydropower schemes) these can be minimized by careful design. Overall, climate change mitigation measures are expected to be beneficial for biodiversity and the provision of ecosystem services.

Under this scenario therefore, the climate change driver will be very much reduced. Land use change would also likely be significantly reduced relative to the baseline scenario. Pollution and invasive species are expected to be somewhat reduced compared to the baseline, while there are few reasons to expect significant differences in overexploitation.

A third scenario involves deploying geo-engineering techniques to address climate change in the absence of significant emission reductions. Under such a scenario, some of the negative

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impacts of climate change on biodiversity could be reduced, provided that the techniques prove to be feasible and effective. At the same time, most geo-engineering techniques would have potential negative impacts on biodiversity. The net effect on biodiversity will vary depending on the techniques employed and are difficult to predict. The techniques are associated with significant risks and uncertainties.Under this scenario, the climate change driver would be expected to be significantly reduced, compared to the baseline scenario of taking no action, for some or all aspects of climate change and/or their impacts. For several techniques (e.g. surface albedo and afforestation) there would likely be increases in land use change compared to the baseline scenario, though this driver would likely be unaffected for some other techniques. For some techniques (e.g. afforestation) there could be an increased risk from invasive species compared to the baseline, though this could be avoided through good design. Some other techniques (e.g. aerosols, ocean fertilization) may lead to a small increase in pollution compared to the baseline. There are few reasons to expect significant differences in overexploitation compared to the baseline scenario.

7.2. The question of scale and its implications for feasibility and impacts of geo-engineering techniques

The study describes a large range of potential impacts of geo-engineering techniques on biodiversity and large uncertainties associated with these. To have a significant impact on reducing climate change, geo-engineering techniques need to be deployed on a large scale, either individually, or in combination. In most cases the risks associated with the techniques are very much dependent upon the scale at which they are deployed. In fact, some of the techniques (e.g. whitening of the built environment; afforestation; biomass production) are benign at a small scale, but scaling up is either difficult or impractical (e.g. spatial extent of the built environment is limited) or associated with large negative effects (afforestation – as opposed to reforestation – or biomass production on a very large scale could have significant adverse effects on biodiversity via land-use change).

7.3. Gaps in knowledge and understanding

The report recognizes many areas where knowledge is still very limited. These include (i) how will the proposed geo-engineering techniques affect weather and climate regionally and globally; (ii) how do biodiversity and ecosystems and their services respond to changes in climate; (iii) the direct effects of geo-engineering on biodiversity; and (iv) what are the social and economic implications.

In addition, there is very limited understanding among stakeholders of geo-engineering concepts, techniques and their potential impacts on biodiversity. There is also as yet little information on the perspectives of indigenous peoples and local communities and other stakeholder on geo-engineering, especially in developing countries. Considering the role these communities play in actively managing ecosystems, this is a major gap.

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ANNEX I. SUMMARY OF SELECTED DEFINITIONS OF CLIMATE-RELATED GEO-ENGINEERING

1. Convention on Biological Diversity – Decision X/33

Technologies that deliberately reduce solar insolation or increase carbon sequestration from the atmosphere on a large scale that may affect biodiversity (excluding carbon capture and storage from fossil fuels when it captures carbon dioxide before it is released into the atmosphere)

http://www.cbd.int/climate/doc/cop-10-dec-33-en.pdf

2. Intergovernmental Panel on Climate Change – Fourth Assessment Report

Technological efforts to stabilize the climate system by direct intervention in the energy balance of the Earth for reducing global warming

http://www.ipcc.ch/pdf/glossary/ar4-wg3.pdf

3. Intergovernmental Panel on Climate Change – Third Assessment Report

Efforts to stabilize the climate system by directly managing the energy balance of the Earth, thereby overcoming the enhanced greenhouse effect

http://www.ipcc.ch/pdf/glossary/tar-ipcc-terms-en.pdf

 

4. The United Kingdom of Great Britain and Northern Ireland

Activities specifically and deliberately designed to effect a change in the global climate with the aim of minimising or reversing anthropogenic (that is, human made) climate change

http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/221/22102.htm

5. The United Sates House of Representatives Committee on Science and Technology

The deliberate large-scale modification of the Earth’s climate systems for the purposes of counteracting [and mitigating anthropogenic315] climate change

Hearing on November 5th, 2009 - Geoengineering: Assessing the Implications of Large-Scale Climate Intervention

6. The Royal Society

The deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change

Geoengineering the Climate: Science, governance and uncertainty. September, 2009

7. The National Academy of Science

Options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry

315 Added in the Report by the Chairman of the Committee on Science and Technology ‘Engineering the Climate: Research Needs and Strategies for International Coordination – October, 2010’.

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http://books.nap.edu/openbook.php?record_id=1605&page=433

8. The Australian Academy of Science

A branch of science which is focused on applying technology on a massive scale in order to change the Earth's environment

http://www.science.org.au/nova/123/123key.html

9. The ETC Group (Non-governmental Organization)

Intentional, large-scale manipulation of the environment by humans to bring about environmental change, particularly to counteract the undesired side effects of other human activities

http://www.etcgroup.org/en/materials/issues

10. The Asilomar Conference Report: Recommendations on Principles for Research into Climate Engineering Techniques

Deliberate steps to alter the climate, with the intent of limiting or counterbalancing the unintended changes to the climate resulting from human activities.

http://www.climateresponsefund.org/images/Conference/finalfinalreport.pdf

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