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ANNEX 2. IDENTIFY THE ENVIRONMENTAL CONSEQUENCES OF FARMING SYSTEMS OVER THE PAST 50 YEARS AND THEIR LONG-TERM SUSTAINABILITY

In this report we begin by summarising the broad impacts of agriculture on the wider environment. We then provide more detail on the priority areas: greenhouse gas (GHG) emissions, air and water quality, water resources and soil degradation, all of which need to be assessed when evaluating the sustainability of agricultural systems. We also summarize the interaction between agriculture and land use change (LUC), including ecosystem services and biodiversity. Finally we summarize the main environmental impacts of the farming systems identified in Task 1.

Summary of findingsThe environmental impacts of farming systems over the past 50 years and their long-term sustainability have been evaluated with respect primarily to their impact on a range of environmental factors.

All farming systems may have adverse impacts on the environment; while it might be assumed that intensive systems have the greatest adverse environmental impact this is not always the case. Intensive production tends to emit less GHG per t of produce. This is mainly because intensive systems may use inputs more efficiently but also because intensive systems are not usually encroaching upon natural ecosystems and do not lead to indirect emissions from LUC. Intensive farming is also less likely to lead to land degradation since greater crop yields return more organic matter to land, hence better maintaining soil organic matter (SOM) and soil structure. Inputs of manures and fertilizers maintain soil fertility. However, intensive farming has greater impacts on local water and air quality and also makes greater use of water resources, principally via the need for irrigation water and also, to a much lesser extent, as a consequence of draining wetlands. The adverse impacts on air and water quality tend to result from intensive agriculture emissions being concentrated and causing point source pollution.

The key concerns for each farming system are:

Intensive arable The major environmental impacts of intensive arable farming are a reduction in water quality and emissions of N2O arising from applications of fertilizer-N. However, in many EU countries inputs of fertilizer-N, the major source of emissions of N2O and NO3, have stabilised while yields of the major arable crops have continued to increase.

Intensive dairy farmingIntensive dairy production is a significant source of GHG but productivity can increase without corresponding increases in emissions. Large herd sizes and concentrations of livestock within small areas pose serious concerns for their impacts on water and air quality. In addition, indirect LUC may be stimulated by demand for ingredients such as soya or cassava for concentrated feeds.

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Intensive livestock farming Intensive livestock farming poses similar problems to those of dairy farming.

Intensive horticulture. As horticulture, particularly vegetable production, becomes more specialised and intensive the large fertilizer applications required and intensive cultivation are likely to increase local water pollution.

Extensive beef and sheep grazing Extensive livestock production is a significant source of the GHG CH4 and a driver to LUC. In addition, soil nutrient supplies can be depleted leading to a cycle of further extensification and demand for LUC to create new pastures.

Wetland rice cultivation Irrigated rice cultivation is a major source of CH4 but changes to production methods are forecast to lead to no net increase in CH4 emissions to 2030 despite forecasts of substantial increases in production. However, rice cultivation is likely to continue to be a major source of N2O and NH3.

IrrigatedWithout significant improvements in water use efficiency it will be difficult to greatly increase production from this farming system. In some regions maintaining current production may be difficult.

Smallholder rain-fed humid Climate change is forecast to reduce rainfall in several of the regions which depend upon rain-fed smallholder production. Substantial areas are also prone to land degradation. Unless inputs can be made available to improve productivity and management to avoid degradation, there will be pressure for LUC.

Smallholder rain-fed highland This farming type is particularly vulnerable to soil erosion. Dixon et al. (2001) suggest that this system has great potential for intensification, by using soil restoration methods and improved water management techniques. However, this may compromise the sustainability of the system itself.

Smallholder dry and cold These systems often have low productivity due to environmental constraints including nutrient poor soils, low temperatures and lack of rainfall. This low input of precipitation explains the need for additional water abstraction in these areas, leading to water stress.

Dualistic mixed Heavy demand for water in some areas is diminishing water resources while a combination of increased agrochemical inputs and decreased water flows is reducing water quality. In some areas soil reserves of P and K are not being maintained.

Fisheries The loss of mangrove swamps to shrimp farming has had major adverse effects on coastal environments. The majority of sea fisheries are over-exploited and it may prove difficult to maintain current production.

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1. Impacts of agriculture on the environmentAgriculture has changed the environment since the first farmers modified the existing habitat to cultivate crops and suppress competition from other plants and grazing by animals. As human populations have increased so has the replacement of natural ecosystems by agriculture. Of the world’s fourteen biomes, more than half have had 20-50% of their surface converted to croplands (Olson et al. 2001). Tropical dry broadleaf forest, temperate grasslands and flooded grasslands and savannas have had the greatest conversion to agriculture over the past 50 years. More than 50% of the global wetlands and 60% of major world rivers have been transformed or modified by humans over the past 100 years (Millennium Ecosystem Assessment 2005), reducing biodiversity through habitat flooding, disruption of flow patterns, and fragmentation of animal populations and travel corridors. Water abstraction from rivers in many regions of the world has significantly reduced flows and, in some cases, left some major rivers nearly dry.

As well as reducing biodiversity and modifying water supplies, the removal of plant cover and tillage of soil break down soil organic matter (SOM) and lead to substantial emissions of the GHG carbon dioxide (CO2). Breakdown of SOM, and release of CO2, may continue for decades after initial LUC and the process also releases nitrate (NO3) which can pollute watercourses. In recent years agricultural production has increased primarily through increased production per ha, reducing the pressure for LUC and consequent emissions of CO2 from soil. However, this has not eliminated the impact of increased agricultural production on GHG emissions. Increased production of arable and forage crops in many parts of the world has been made possible by increased use of mineral fertilizers, in particular N, and in the soil a proportion of that N is converted to the GHG nitrous oxide (N2O). The growing demand for livestock products has led to increases in emissions of the GHG methane (CH4) which arises primarily from enteric fermentation.

As agriculture intensifies soil quality can be reduced, in some cases leading to erosion, and further contamination of watercourses, and in extreme cases degradation such that the land can no longer be farmed. The input of agrochemicals and mineral fertilizers, especially nitrogen (N) can lead to further reductions in water quality due to increased NO3 leaching, phosphate (P2O5) enrichment and pesticides. Emissions to air may also be increased not only as N2O but also as ammonia (NH3). To be able to improve the sustainability of global production systems, it is necessary to first identify the environmental impacts of the systems.

1.1 Greenhouse gasesTable 1 below presents current estimates of CH4 emissions expressed per litre (L) of milk produced in different world regions. There are very large differences among regions and that greater productivity tends to emit less CH4 per L.

Table 1. Default CH4 in different regions, per L of milk yield, from IPCC 2006 table 10.11, dairy cattle

Enteric CH4 kg head-1 yr-1

Milk L head-1 yr-1 g CH4 L-1

NAFTA 121 8400 14.4EU 109 6000 18.2CIT 89 2550 34.9Oceania 81 2200 36.8

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Latin America 63 800 78.8N Africa, mid-East 40 475 84.2S Asia 47 900 52.2E and SE Asia 61 1650 37.0SS Africa 40 475 84.2

The above picture is not quite so straightforward as it appears. The output is per lactating dairy cow. The greater yielding cows tend to have a shorter lifetime, going through fewer lactations within that lifetime, and hence the ratio of replacement animals (followers) per dairy cow is greater. Since these followers produce CH4 as they mature (but before they start producing milk) they will indirectly contribute to the GHG burden of milk production. In addition, the move toward breeds suitable only for milk production lessens the opportunity for unwanted male dairy calves to be sold to beef producers for fattening, hence indirectly increasing the GHG emissions of beef production (Webb et al., 2009). Nevertheless, when the contribution of followers is taken into account the ranking of the above regions is unlikely to change significantly; production in the NAFTA and EU regions will emit less GHG per L milk produced than production in other regions. But the difference will not be as great as that produced by the simple estimate above.

Table 2 below presents default emissions for beef production in different regions.

Table 2. Default CH4 emissions from beef production in different regions, from IPCC 2006, beef cattle

Enteric kg CH4 head-1 yr-1

**meat kg head-1 yr-1

kg CH4 kg-1 meat

NAFTA *53 65 - 69 0.8EU 57 65 - 69 0.9CIT 58 45 - 67 1.3Oceania 60 20 - 23 3.0Latin America 56 13 - 19 4.3N Africa, mid-East 31 13 - 19 2.4S Asia 27 15 - 22 1.8E and SE Asia 47 15 - 22 3.1SS Africa 31 13 - 19 2.4

*Includes beef cows, bulls, calves, growing steers/heifers, and feedlot cattle.**Estimated from Bouwman et al. (2006)

These data also indicate that increased production of livestock products does not inevitably come at the price of increased emissions, albeit there is a general trend in that direction.

Table 3 presents average estimated N excretion for the main types of livestock in each region of the world. Emissions of N2O from manure management and following application of manures to land will be broadly in proportion to these estimates of daily N excretion. There is less variation in these estimates, which is partly due to their being expressed per day, and thus not taking account of the longer time to maturity in some regions. Such differences are found mainly with extensively-raised ruminants. Hence emissions of N2O per kg extensively-raised beef or lamb will be greater for produce raised in Africa, the Middle East and Latin America.

Table 3. Default N excretion, kg N (1000 kg animal)-1 mass day-1, from IPCC 2006 Dairy Beef Finishing pigs Sheep Buffalo Horses Layers Broilers

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NAFTA 0.44 0.31 0.42 0.42 0.32 0.30 0.83 1.10EU 0.48 0.33 0.51 0.85 0.32 0.26 0.96 1.10CIT 0.35 0.35 0.55 0.90 0.32 0.30 0.82 1.10Oceania 0.44 0.50 0.53 1.13 0.32 0.30 0.82 1.10Latin America 0.48 0.36 1.57 1.17 0.32 0.46 0.82 1.10N Africa, mid-East 0.70 0.79 1.57 1.17 0.32 0.46 0.82 1.10Sub-saharan Africa 0.60 0.63 1.57 1.17 0.32 0.46 0.82 1.10S Asia 0.47 0.47 0.42 1.17 0.32 0.46 0.82 1.10E and SE Asia 0.47 0.47 0.42 1.17 0.32 0.46 0.82 1.10

The other major source of GHG emissions from agriculture is N2O arising following application of mineral-N fertilizers. The current IPCC default emission factor (EF) is 1.0% of applied N. Although there is evidence of emissions being more or less than this default depending upon soils and subsequent weather conditions, several factors control N2O emissions and these will broadly correlate with applications of N fertilizer. Hence productions systems such as the high-input systems used in the EU, and increasingly China and parts of India, will emit much more than extensive systems in other regions. However, since yields in regions such as NW Europe are larger than in many other areas N2O emissions per kg of output will not be in proportion to overall N2O emissions.

As indicated above, GHG emissions, primarily in the form of CO2, arise when land is converted to agriculture. While soils under well-managed agricultural grassland may contain amounts of carbon similar to some natural ecosystems, soils under tillage will contain less (Guo and Gifford, 2002). However, when evaluating fluxes of CO2 to the atmosphere, it needs to be remembered that only considering changes to soil carbon takes no account of changes in above ground carbon stocks which may be greatly reduced by land use change. The current estimate of total carbon storage, both SOC and above ground, is c. 360 t/ha for Brazilian rainforest (IPCC, 2006) and hence conversion to either grassland or arable will lead to significant emissions of CO2.

1.2. Water and Air QualityWith respect to broader environmental impacts of N, in particular NO3 leaching and NH3 volatilization, Bouwman et al. (2006) report some differences among regions in the efficiency with which applied N is used, as reflected in the recovery of N as a % of inputs (nitrogen use efficiency: NUE). For most regions NUE for 1995 was reported as c. 50%, but only c. 40% for E Asia and 78 and 108% respectively for SE Asia and SS-Africa. Forecasts for 2030 were between c. 60 and 70%, but are rather less for E Asia (42%) and more for CIT (83%), SE Asia (90%) and SS-Africa (131%). The latter figure is a cause for concern. While a relatively large NUE indicates that losses of N to the environment are relatively small, some losses, especially of NO3

leaching and denitrification in humid areas, are unavoidable and even in a sustainably fertilized system NUE would be expected to be < 100%. If N removal in crops is exceeding inputs it means there is a net loss of N from the soil-crop system potentially leading to a reduction in soil fertility. The forecast increase in NUE suggests these problem of nutrient depletion will increase. In turn declining soil fertility is likely to increase pressure for clearance of forests and savannahs for agricultural production.

The small NUE for E Asia is due to the prevalence of paddy rice cultivation from which emissions of N are particularly large. Emissions of NH3 being increased by the high pH of these systems while waterlogging leads to intense denitrification, albeit the predominant loss is as molecular N (N2) which does not harm the

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environment. Emissions of NH3 are particularly large in China, and some CIT due to the use of the fertilizer ammonium bicarbonate (AB) (Cai et al., 1998). In their projections of fertilizer-N use to 2030, Bouwman et al. (2005) assumed 90% of the AB used in China would be substituted by urea, hence greatly reducing, but by no means eliminating, emissions of NH3.

1.3. Water resources Views have been put forward that current patterns of water extraction are close to what can be sustained, or may be exceeding it. Some major rivers no longer reach the sea including the Indus, Rio Grande, Colorado, Murray-Darling and Yellow rivers. This is at least partly due to extraction for cereal production.

Freshwater fish populations are in decline. According to the World Wide Fund for Nature (WWF, 2003), fish stocks in lakes and rivers have fallen roughly 30% since 1970. This is a bigger population decline than that suffered by most forms of wildlife. Half the world’s wetlands, in one estimate, were drained, damaged or destroyed in the 20th century, mainly because, as the volume of fresh water in rivers falls, salt water invades the delta, changing the balance between fresh and salt water. On this evidence, there may be systemic water problems, as well as local disruptions.

1.4. Soil degradationA UNEP survey (cited in Smeets et al., 2004) on soil degradation reported that the rate of soil erosion is 10 to 20 times the renewal rate in temperate regions and 20 to 40 times the same rate in the tropics. This results in an annual worldwide loss of cropland of between 5 and 12 million ha per year. Deforestation is thought to be responsible for 43% of the total erosion and overgrazing and mismanagement for 29% and 24% respectively (Smeets et al., 2004).

Despite this, in many parts of the world such as northwest Europe, soils have been cultivated for over two millennia and are more productive than ever. This production is largely dependent on inputs of mineral fertilizers and other agrochemicals, but the production of high yielding crops may lead to substantial returns of organic matter to soils, helping to maintain soil structure. This has led to the view being put forward that regions such as Europe, with fertile and stable soils, equitable climate and in consequence large yield potentials, have a duty to optimize food production to reduce the burden on pristine ecosystems and less resilient soils in other parts of the world.

1.5. Land use change, ecosystem services and biodiversityEcosystem services (ES) may be defined as 'the benefits of nature to households, communities, and economies.' (Boyd and Banzhaf, 2006). Clearly the continued provision of ES requires the natural ecosystem to remain intact, and hence changes in land use from natural ecosystems to agriculture reduces the provision of ES. It is presumed that increased food production is better achieved by increased production on existing agricultural land than by converting natural systems. The Millennium Ecosystem Assessment has categorised ecosystem services into the four general areas of support, regulation, provision, and cultural services, shown in Table 4 below. Each general area is sub-divided into increasingly detailed roles that support human society.

Table 4. Categories of ecosystem services (Millennium Ecosystem Assessment)Support Provision Regulation CulturalNutrient Cycling Food Climate Regulation Aesthetic

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Soil Formation Fresh Water Flood Regulation SpiritualPrimary Production Wood and Fibre Disease Regulation Educational

Fuel Water Purification Recreational

These ecosystem services depend on all of the component ecosystem species within: plants provide primary production and food for herbivores, soil invertebrates aerate the soils and recycle nutrients, bacteria and fungi decompose plant and animal litter, birds distribute seeds of plants and so on. All of these roles are interlinked among the thousands or millions of species that inhabit an ecosystem.

There is increasing evidence that high levels of biodiversity may act as “insurance” that buffer ecosystem services from environmental change. Therefore maintenance of species composition and abundance is essential to maintaining the ecosystem services upon which humans depend. Loss of biodiversity is directly associated with habitat change, climate change, invasive alien species, overexploitation and pollution (MEA 2005). The effects of this loss are particularly pronounced in areas that have been deforested or where wetlands have been drained. Key impacts here include loss of ecosystem services that act as natural breaks on flooding and erosion, as well as release of carbon stored in soils. Some of these changes are irreversible, particularly deforestation in areas that are vulnerable to desertification. These are crucial differences to the impact of deforestation in temperate and tropical regions. Unlike the deciduous forests of temperate regions, tropical rain forests are not easy to regenerate once lost.

2. Identification of environmental impacts of production systems and their long-term sustainabilityIn our assessment of the potential environmental impacts of providing food security by 2030 we will focus on the evaluation of the necessary changes to farming practice with respect to their impacts on:

GHG emissions;air and water quality;water resources;soil sustainability; LUC, including biodiversity.

The impacts outlined in this report range from those which are local, which is usually the case for soil erosion and water pollution, those which are transboundary, such as emissions to air, and global impacts such as emissions of GHGs. We also make a distinction between direct and indirect LUC. Direct LUC arises when a farming system expands into land that had not previously been used for agriculture, for example, cultivating savannah to grow sugar cane. Indirect LUC arises when a change in one farming system, which arises without increasing the farmed area of that system, promotes indirect LUC by increasing demand for inputs sourced from elsewhere. An example of this is the impact, on Amazonian rainforests, of increased demand from Asia for soybeans to feed livestock (World Development Report, 2008). It is important to remember the global footprint of a system, taking into account production, distribution and consumption of goods, and not just the direct impacts felt in the immediate environment.

This study intends to evaluate production systems in light of the following criteria:

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1. Can production be maintained into the future without causing irreparable damage to the means of production? For example, is the rate of soil loss or salinisation likely to lead to degradation?

2. Can production be maintained into the future without reliance on inputs which will not be available in the foreseeable future? For example, the use of fossil water from aquifers which are being depleted faster than the rate of replenishment.

3. Can production be maintained within the existing cultivated area without the need for continual encroachment on uncultivated land?

4. Can production be maintained into the future without having a negative impact on the income generation capacity of the farmers?

The sustainability of the production systems outlined in Task 1 was assessed according to the extent to which they comply with the above criteria.

We summarize below, for each region in turn, the main environmental impacts that have been identified from each farming system. In addition, we draw upon projections made by the Intergovernmental Panel on Climate Change (IPCC) in its 4th Assessment Report (IPCC, 2007) in order to consider how each production system might be affected by a changing climate.

2.1 NAFTA and EUThese regions are reported together as their farming has much in common particularly with respect to the impacts on the environment.

2.1.1 Intensive arableEnvironmental impacts

Production of carbohydrate and protein kg/ha/year

Cereal yields (2005)

In the United States – 6.45 t/ha In Canada - 3.03 t/haIn UK – 7.23 t/haItaly – 5.43 t/haNetherlands – 8.15 t/ha

Rain-fed or irrigated

In these regions the great majority of production is rain fed.

Emissions to water (nitrate, phosphate, biological oxygen demand)

In some countries fertilizer application has been applied in excess, outstripping the soil’s capacity to hold nutrients and make these available to crops. NO3 and P2O5 can be leached to ground and surface waters (Breeuwsma and Silva, 1992). To give an idea of potential run-off to water, the following figures from WRI (2009) show fertilizer consumption in selected countries where intensive arable farming is a major farming system:

Fertilizer use is very high in the US where 25.278 * 10^6 t of nutrient were used in 2005 (WRI, 2009). This equates to 109 kg/ha (WRI, 2009) (This also applies to the intensive livestock and arable farming in NAFTA.)

Canada used 17.870 * 10^5 t of nutrient fertilizer in 2005 (WRI, 2009), with an intensity of 53.7 kg/ha.

In the UK in 2005, 1,502 kg * 10^6 of fertilizer was used. This is a high level of fertilizer in line with Canada (WRI, 2009). The intensity of use in 2005 was

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287.5 kg/haThis represents an intensive production system.

Nitrate concentrations exceed the guide level of 25 mg/l in 85% of farmland in the EU. However, a combination of reduced prices for produce, increases in prices of fertilizers, and measures such as the EU Nitrates Directive have reduced such losses in recent years. Nevertheless, the application of fertilizers to maintain current yields will inevitably lead to some leaching.

Extensive use of pesticides can initiate a negative feedback loop – as herbicides remain in the soil where crop rotations and fallow periods are short, crop yields can be reduced. This also lowers the ability of soil to remove pollutants thereby inhibiting the migration of pollutants to nearby water bodies (Zaldis et al., 2002).

ADAS (2002) suggest that using less pesticide can increase arable crop yields when compared with high input production. A recent study by Young et al (2001) found that for yields of 66 crops grown in low input production systems, average gross margin was 2%, equivalent to £12 per hectare, greater than gross margins for the high input system. However, where herbicide inputs were reduced, weed burden increased in some cases. Conversely, cutting N fertilizer application by 50% reduced gross margins by 9%, equivalent to £64 per hectare, emphasizing the importance of N and a more strategic approach to cutting its use. The success of this low input system will vary depending on soil and crop types.

Emissions to air (GHGs, NH3, NOx, non-methane VOCs)

The main issues are N2O and NH3 from N fertilizer and CO2 from cultivation; emissions of the latter are few from long-term arable soils but there will still be net emission from former grassland soils.

Soil erosion, soil degradation or desertification

Agriculture has become more intensive with widespread use of heavy machinery, fertilizers, pesticides, and large-scale irrigation. As a result of changing agricultural practice, crop choice and higher water consumption, land desertification is occurring along with soil salinisation and salt water intrusion in countries around the Mediterranean Basin including western Greece, Tunisia and Lebanon (Zalidis et al., 2002).

Biological degradation of soils can be attributed to many agricultural practices. Particularly in Mediterranean countries, soils are low in organic matter which leads to reduced soil fertility and damaged structure due to reduced root penetration, soil moisture content and permeability. In turn, erosion increases along with the rate of runoff, thus lowering biological activity (EEA, 1995).

Microorganisms assist in maintaining the water content of soils, promoting good soil structure and thereby reducing erosion. Many features of the intensive arable farming system cause disruption to microbes, including lower plant diversity above ground caused by tillage and extensive grazing of livestock (Christensen, 1989 and Boddy et al., 1988 in Zalidis et al., 2002).

In NAFTA, particularly the mid-west United States, significant damage to soils has occurred as a result of intensive cereal production. The nutrients provided by soil organic matter have been used by the cereal crops, making the soil less fertile and stable. As a result of this and the arid, windy environment, soil erosion has been significant.Farms in the mid-west can be thousands of acres in size, which can dwarf farms in some EU Member States. Wheat is grown widely and there are no annual rotations so inputs remain the same. This means the soils do not have a chance to recover and organic matter cannot be replenished. No livestock farming takes place, so there is no organic matter/manure to import to improve the soils.

Biodiversity Declining abundance of farmland plants and animals is a feature of intensive arable agriculture. For example, in arable areas in the UK, there is a lack of

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nesting sites available for lapwings and skylarks (Donald et al., 2001). However, the presence of over-winter stubbles is believed to attract skylarks back. Initial negative trends showed recovery of the birds with 10–20 ha of stubble per 1 km square. Thus, it is believed that agri-environment schemes which promote over-winter stubbles can help attract birds, thus helping to reverse current population declines (Gillings et al., 2004).

Biotic and abiotic soil processes are affected by extensive pesticide use. This influences the role of soil as a service provider: as a habitat for soil and other biota, reducing resilience, converting nutrients and toxicants and protecting surface and groundwater from pollutants (Zaldis et al., 2002)

Forestry/LUC/agro forestry

In NAFTA and EU countries deforestation for agriculture is now uncommon and some countries are increasing native wooded areas through planting.

Climate change impacts for this system

The effects of climate change and increased CO2 in the atmosphere are projected to result in increases in crop productivity in some parts of Europe, with wheat yields increasing from 37 % under the B2 scenario to 101% under the A1 scenario by 2050 (IPCC, 2007). It is suggested that crops currently grown largely in southern Europe such as maize, sunflower and soybeans will become viable for growing further north or at higher-altitude southern areas (Audsley et al., 2006). However, some productive lands are at risk of inundation by rising sea levels and yields in some of the most productive areas may be reduced by increased temperatures and drought stress. In contrast many of the areas of Europe in which crop yields have potential for increase are dominated by sandy soils of only moderate yield potential and are unlikely to be able to fully make up any shortfall in production.

Yield increases are expected to occur largely in northern Europe. , For example, wheat yields are forecast to increase by between 2% and 9% by 2020, +8 to +25% by 2050 and +10 to +30% by 2080 (IPCC, 2007) while sugar beet yields are expected to rise by between 14% and 20% during the next forty years in England and Wales (IPCC, 2007).

The greatest yield reductions in all crops are expected in the Mediterranean, the southwest Balkans and in the south of European Russia (Olesen and Bindi, 2002; Alcamo et al., 2005; Maracchi et al., 2005). In southern Europe, general decreases in yield (e.g., legumes, range: -30 to + 5%; sunflower, range: -12 to +3% and tuber crops, range: -14 to +7% by 2050 and increases in water demand (e.g., for maize +2 to +4% and potato +6 to +10% by 2050) are expected for spring sown crops (IPCC, 2007).

In North America, rain-fed agricultural yields are set to increase early in the 21st century. However, coastal vulnerability in North America may increase with disruption to transport and infrastructure on the Atlantic Coast as sea level rises and tidal surges increase.

Current water stresses in Australasia are likely to be compounded from the 2020s onwards.

Key pointsThe major environmental impacts of intensive arable farming are a reduction in water quality and emissions of N2O arising from applications of fertilizer-N. However, in many EU countries inputs of fertilizer-N, the major source of emissions of N2O and NO3, have stabilised while yields of the major arable crops have continued to increase. Hence in regions where soil and water are not limited it is possible that crop yields can continue to increase without commensurate increases in emissions.

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2.1.2 Intensive dairy farmingEnvironmental impacts

Production of carbohydrate and protein kg/ha/year and productivity

In NAFTA and EU 27, highly productive commercialized dairy sector feeding high quality forage and grain. Average milk production: NAFTA - 8,400 kg head-1 yr-1; EU - 6,000 kg head-1 yr-1

Countries in transition - commercialised dairy sector feeding mostly forages, 2,550 kg head-1 yr-1.Oceania - commercialised dairy sector based on grazing, 2,200 kg head-1 yr-1

In New Zealand, dairy cattle numbers increased to 5.6 million in 2008, up 6 % from the previous year (New Zealand Government, 2009).


In addition to groundwater pollution by NO3 and P2O5 as a results of application of mineral fertilizers and livestock manures, surface water often becomes directly polluted when manures are applied to wet soils and run-off occurs. The true problem of surface and groundwater pollution from farming (dairy and other) has not been thoroughly investigated in all EU countries (EC, 2000).

Similar to arable farming, the following figures from WRI (2009) give an indication of fertilizer use in countries with heavy involvement in dairy farming.

Fertilizer use is very high in the US where 25.278 * 10^6 t of nutrient were used in 2005 (WRI, 2009). The intensity of use in 2005 was 287.5 kg/ha,UK: 1.502 * 10^6 t which is a high level of fertilizer use. This equates to an intensity of 287.5 kg/ha (2005) (WRI, 2009).

Defra (2009) give the following figures for fertilizer use on grasslands (kg/ha) in the UK:Total N – 65Total P – 14Total K2O – 18


Nitrous oxide – emissions arise from manure fertilizer application to pasture; deposition of manure and urine by animals (greater in intensive systems than extensive systems) and from the storage of manure in stall-feeding systems such as the feedlot system.

Perhaps the main problem is that of NH3 which is produced at all stages of manure management. This is an increasing cause of concern in the US and Canada has led to the introduction of the EU National Emissions Ceilings Directive and. Ammonia emissions are highest in intensive systems from manure storage and application to arable land.

Dairy production has an indirect impact on CO2 and N2O emissions due to the energy consumed to produce feed concentrates and forage as well as that used in housing systems (EC, 2000).

The majority of CH4 is produced by enteric fermentation. A projected shift towards in-house feeding in grazing systems is likely to increase storage of manure in a liquid or waterlogged form, and this is the main source of CH4 emissions from manure.

Soil erosion/soil degradation/desertification

Soils under grass are generally protected from soil erosion while the addition of organic matter in manure and excreta improves soil quality.

The major concern is that some feed concentrates contain phytotoxic heavy metals including copper, zinc and cadmium which can all build up in soils.

High stocking rates can lead to greater soil compaction around gateways and water troughs as cattle trample the land, thus reducing infiltration and increasing runoff and erosion from these areas (EC, 2000)

Biodiversity Pastures maintained and cut for silage or grazed intensively are less biodiverse than traditional hay meadows.

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Succession of meadows by scrub and woodland, decline in open grassland and field boundaries, degradation of hydro geological systems.

Vet medicines may persist in dung, affecting its fauna and potentially populations of birds which feed on these invertebrates.

Invasive species and decline in species diversity as a result of increased fertilizer use (N&K), silage, less grazing.

Changing intensity of production in traditional farms may lead to lower complexity and stability of food webs, especially in river-based and mixed Mediterranean systems (EC, 2000)


Deforestation for agricultural cultivation is now uncommon and some countries are increasing their wooded areas. Indirect LUC may be stimulated by demand for ingredients such as soya or cassava for concentrated feeds.


Rising frequency and intensity of heat waves in Europe may threaten the health and wellbeing of livestock reared indoors and outdoors. This may lower forage crop productivity to the extent that they are not suitable for livestock at current stocking rates without irrigation (IPCC, 2007);

Coastal vulnerability in North America, disruption to transport and infrastructure on the Atlantic Coast as sea level rises and tidal surges increase;

Current water stresses in Australasia are likely to be compounded from the 2020s onwards.

In North America, rain-fed agricultural yields are set to increase early in the 21st century. Having been exposed to extreme weather events during the past decade, this system, along with intensive arable and livestock, is well adapted to cope with a changing climate. For instance, diversification of crops and business has taken place, as well as improved soil and water conservation. This highlights the resilience of the system to moderate potential damage from climate change (IPCC, 2007).

Key pointsForecasts indicate that intensive dairy production can be more productive without emissions of GHGs increasing in proportion. Effective measures to reduce emissions of NH3 have been developed and are being implemented in some countries. However, continued increases of herd sizes and concentrations of livestock within small areas pose serious concerns for the impacts on water and air quality.

2.1.3 Intensive livestock farmingEnvironmental impacts


In New Zealand, beef cattle numbers fell to 4.1 million in 2008, down 6% on the previous year (New Zealand Government, 2009).

NAFTA: separate beef cow herd, primarily grazing with feed supplements seasonally. Fast-growing beef steers/heifers finished in feedlots on grain.

To calculate meat production per carcass – total meat production/total number of animals. Figures are for total cattle stocks – may include dairy but can’t get separate figures. All figures from WRI (2009).

Canada: 4.493*109 t/14.830*106 heads = 303 kg/carcass

EU 27: dairy cows also used for beef calf production. Very small dedicated beef cow herd. Minor amount of feedlot feeding with grains.

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France: 5.206*109 t /19.418*106 = 268 kg/carcass

Countries in transition: separate beef cow herd, primarily grazing. Minor amount of feedlot feeding with grains. Separate beef cow herd, primarily grazing rangelands of widely varying quality. Growing amount of feedlot feeding with grains.

Romania: 1.003*109 t /2.862*106 = 350.5 kg/carcassCroatia: 120.499*109 t /483*106 = 249.4 kg/carcass

Pigs and poultry livestock convert plant protein to animal protein much more efficiently than ruminants.

In Australia in 2003-2004, there were 2.553*106 pigs. Average slaughter weight was 72.7 kg/head, representing a 0.5% share of the world total for pig meat production (Australian Government, 2009)

In the United States in 2007, there were 8.9 billion birds at a value of $43 billion (USDA, 2009)

Irrigated or rain fed

Largely rain fed.


The intensive raising of livestock may give rise to disposal problems for manure. Where the ratio of land available to livestock manure is small there are likely to be considerable problems with water quality, nitrate pollution, eutrophication and direct contamination by run-off. Examples of areas affected include the Flemish region of Belgium, much of the Netherlands and the Po valley in Italy. These problems are not simply related to the size of the enterprises. In densely populated areas where relatively few livestock are raised by farming families the overall burden of manure per ha may still exceed the amount that can be re-cycled effectively.

In addition to groundwater pollution by NO3 and P2O5 as a result of application of mineral fertilizers and livestock manures, surface water often becomes directly polluted when manures are applied to wet soils and run-off occurs. The true problem of surface and groundwater pollution from farming (dairy and other) has not been thoroughly investigated in all EU countries (EC, 2000).

Feedlots are very intense sources of NH3, but tend to be less polluting to water.

In NAFTA, water pollution concerns largely relate to the use of N and P in ground and surface waters. In much of the United States, the emphasis is on effects of P on water quality, however, arid areas of the western United States are more concerned about soil salinity. Many regions of the world have greater restriction of N than P with respect to water quality (Powers and Angel, 2008).

In the South China Sea region, livestock are reported to be a major inland source of phosphorous and nitrogen contamination, thereby leading to biodiversity loss in marine ecosystems (FAO, 2006).


When emissions from land use and land use change are included, the livestock sector accounts for 9% of CO2 deriving from human-related activities, but produces a much larger share of even more potent GHGs. It generates 65% of human-related N2O, which has 298 times the Global Warming Potential (GWP) of CO2. Most of this comes from fertilizer-N and manure applications to land and from excreta deposited directly to pastures during grazing. Livestock production accounts for 37% of all human-induced CH4 (25 times as warming as CO2), which is largely produced by the digestive system of ruminants, and 64% of NH3, which contributes significantly to acid rain.

Some estimates indicate that the livestock sector generates more GHG emissions

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as measured in CO2 equivalent – 18% – than transport.

Per kg of N excreted emissions of NH3 (ammonia) are much greater from livestock raised entirely indoors than from livestock which spend much, or all of the year outdoors (Webb et al., 2005).

Nitrous oxides emissions arise from manure fertilizer application to pasture, deposition of manure and urine by animals (higher in intensive systems than extensive systems) and from the storage of manure in stall-feeding systems such as the feedlot system.

Stall-feeding is a very intense source of methane. A projected shift towards stall-feeding in grazing systems is likely to increase storage of manure in a liquid or waterlogged form, and this is the main source of methane emissions from manure.

In NAFTA, concerns over air and water quality have largely been related to N and P. Air emission concerns include N and sulfur. Lately, states are addressing emissions of volatile organic compounds (Powers and Angel, 2008).


Herds cause wide-scale land degradation, with about 20% of pastures considered as degraded through overgrazing, compaction and erosion. This figure is even higher in the drylands of US and Australia where inappropriate policies and inadequate livestock management contribute to advancing desertification (FAO, 2006).

Biodiversity Declining livestock density in the English, Welsh and Scottish uplands, caused as a result of CAP reform, is affecting biodiversity of these grazing areas and environmental support schemes are being used to reduce further destocking.

The intensive farming of livestock produces concentrated waste which, if near populous (e.g. urban) areas can lead to the spread of disease including avian influenza and tuberculosis (WDR, 2008).

Pastures managed and cut for silage or grazed intensively are less biodiverse than traditional hay meadows.

Succession of meadows by scrub and woodland, decline in open grassland and field boundaries; degradation of hydro geological systems.

Vet medicines may persist in dung, affecting its fauna and potentially bird populations who use this.

Invasive species and decline in species diversity as a result of increased fertilizer use (N&K), silage, less grazing.

Changing intensity of production in traditional farms lead to lower complexity and stability of food webs, especially in river-based and mixed Mediterranean systems (EC, 2000).

Moderate intensity of grazing in the Great Hungarian Plain stimulates growth of vegetation (Horvath et al., 2009).


Livestock now use 30% of the earth’s entire land surface, mostly permanent pasture but also including 33% of the global arable land used to producing feed for livestock.

A recent study (Morton et al., (2006) reported annual destruction of the Amazon rainforest to be positively correlated with the market price for soya, which is a major ingredient of pig and poultry feeds.


As a result of the increasing frequency of heatwaves, heat stress in Britain is expected to increase the risk of mortality of pigs and broiler chickens produced in intensive livestock systems (Turnpenny et al., 2001). The rate of livestock diseases, such as bluetongue, may also rise.

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Increased frequency of drought along the Atlantic coast for instance in Ireland, may lower forage crop productivity to the extent that they are not suitable for livestock at current stocking rates without irrigation (Holden and Brereton, 2003, FAO, 2003a).

Coastal vulnerability in North America, disruption to transport and infrastructure on Atlantic Coast as sea level rises and tidal surges increase;

Current water stresses in Australasia are likely to be compounded by 2020s and 2050s;

In North America, rain-fed agricultural yields are set to increase early in the 21st century

Key pointsForecasts indicate that intensive livestock production can become more productive without corresponding increases in GHG emissions. Effective measures to reduce emissions of NH3 have been developed and are being implemented in some countries. However, continued increases in herd sizes and concentrations of livestock within small areas may pose serious threats to water and air quality. Indirect LUC may be stimulated by demand for ingredients such as soya or cassava for concentrated feeds.

2.1.4 Intensive horticulture – all worldHorticulture means the production of vegetables and of top (orchard) and protected fruit. Vegetable production generally requires cultivation and fertilizer inputs while fruit, much of which are perennial crops, requiring little cultivation and less fertilizer. However, some annual fruit crops may be grown under protection, such as in glasshouses or polytunnels.

Environmental impactsProduction of carbohydrate and protein kg/ha/year and productivity

Agricultural production of roots and tubers ranges from 13.983 t/ha in Romania to 41.692 t/ha in the US in 2005 (WRI, 2009).

In the UK in 2007, total area planted with vegetables was 116,311 ha. Total area planted with fruit was 27,580 ha.

Total orchard fruit (apples, pears, plums) in 2007 - 18,016 ha planted;Total soft fruit - 9,418 ha planted (Defra, 2009).

In Indonesia, 2007, shallot production was 802,810 tonnes; cabbages 1 288 738 tonnes; potatoes 1 003 732 tonnes (Statistics Indonesia, 2009).

Irrigated or rain-fed

Horticulture is predominantly rainfed, but often supplemented by irrigation and for some crops in some countries may depend on irrigation


Water pollution from intensive vegetable production can be greater than from intensive arable crops. For example, while applications of N to cereals will not usually exceed 200 kg/ha/year, annual applications to brassicae can be > 300 kg/ha/yr. In addition, N recovery by vegetables is often much less than by cereals and some other major arable crops and much larger N residues are left in the soil after harvest. High fertilizer inputs combined with large-scale irrigation promotes nitrate leaching to surface and groundwater (EEA, 1995). However, the situation is very variable and some vegetable crops have fairly modest fertilizer requirements. Nevertheless, vegetable production requires more cultivation than that of combinable crops and N cycling is less efficient. The requirement for cultivation, and tendency to site vegetable production on light sandy soils, prone to erosion, may lead to direct pollution of watercourses

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from run-off.Emissions to air (GHGs, NH3, NOx, non-methane VOCs)

As a result of harvesting, poor application of nitrogen fertilizers and lack of soil drainage, base cations in soils are removed thus causing acidification particularly in Mediterranean soils. At the micro level, this leads to a reduction in soil fertility and the potential for aluminum movement (Zaladis et al., 2002).

The production of Mediterranean fruits and vegetables in heated greenhouses in the temperate zones may lead to very large GHG emissions per t of produce, with total GHG emissions being much greater than from imported produce despite large distances often involved (e.g. Williams et al., 2008).


Can be considerable and locally significant under intensive vegetable production.

Biodiversity The greater variety of crops grown, compared with arable production, and the perennial nature of some crops, offers greater potential for biodiversity. However, due to the needs for more intensive cultivation for vegetables, and greater pesticide inputs for all crops, this biodiversity potential may not be realised.


Production of tropical fruits can lead to rainforest destruction


The Mediterranean region can expect the greatest reductions of all crops, as well as the south-west Balkans and in the south of Russia (Alcamo et al., 2007; Maracchi et al., 2005). However in Germany, there may be an advance in the beginning of growing season for fruit trees (IPCC, 2007);

Australian temperate fruits and nuts are projected to be negatively impacted by warmer temperatures since they need to be exposed to colder temperatures in winter. In addition, crops which require irrigation may become more vulnerable as water stresses increase in the 2020s and 2050s.

A pest species, the Queensland fruit fly Bactrocera tryoni, could become a growing threat to southern Australia if temperatures warm by 0.5°C – 2.0°C, thus impacting apple, orange and pear growers.

In North America, rain-fed agricultural yields are set to increase early in the 21st century

Key pointsAs horticulture, particularly vegetable production, becomes more specialised and intensive substantial fertilizer applications to some crops and intensive cultivation are likely to increase local water pollution.

2.1.5 Extensive beef and sheep grazing – all worldEnvironmental impacts


Latin America: Commercialised dairy sector based on grazing. Separate beef cow herd grazing pastures and rangelands. Minor amount of feedlot feeding with grains. Growing non-dairy cattle comprise a large portion of the population. Average milk yield 800 kg hd-1 yr-1.

Africa and Middle East: Commercialised dairy sector based on grazing with low production per cow. Most cattle are multi-purpose, providing draft power and some milk within farming regions. Some cattle graze over very large areas. Cattle are smaller than those found in most other regions. Average milk yield 475 kg hd-

1 yr-1.

E and SE Asia: Small commercialised dairy sector. Most cattle are multi-purpose, providing draft power and some milk within farming regions. Small grazing population. Cattle of all types are smaller than those found in most other regions

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Average milk yield 1650 kg hd-1 yr-1.Thailand produces over 500 million tonnes of poultry worldwide in 2003. Implementing a zoning and tax system has controlled the spread of disease and helped reduced the intensity of poultry holdings in urban areas (WDR, 2008).


This system tends to be rain fed (Hamilton et al., 1996).


While emissions to water can still be significant, the intensity will be less than from intensive production due to the smaller inputs of fertilizer and reduced stocking density. Pesticide leachate to water tends to be minimal except where treatment for parasites is required.

Excessive leakage of nutrients creates problems for water quality in this system. Grazing animals produce faeces and urine which are lost through leaching. The higher the dietary crude protein and rumen solubility in feed, the greater the urine nitrogen losses (Hamilton et al., 1996).. Increasing intensification in Asia is leading to water pollution by nitrogen, phosphorous, cadmium, copper and zinc. Indeed, environmental concerns have largely been in relation to emissions from manure storage and application to water.


Emissions of NH3 from livestock decrease considerably as the ratio of time spent grazing to time spent within buildings increases (Webb et al., 2005). However, emissions of N2O will not be decreased as much as those of NH3, while emissions of CH4 a tend to be greater, since diets with greater proportions of forage tend to be less digestible, leading to greater emissions of CH4.

For sheep grazed land in New Zealand, 3.7 ± 2.2 kg N2O-N per hectare per year and 32.0 g N2O-N per hectare per day for pastures grazed by dairy cows (Saggar et al., 2007).

Grazing land acts as a sink for methane - 0.64 ± 0.19 kg CH4-C per hectare, higher in summer and lower in winter. In order to cut anaerobic N2O emissions, greater CH4 oxidation at the soil surface will be favoured (Saggar et al., 2007).


Grazing animals are known to speed up the nutrient recycling process and to redistribute nutrients. The nutrients input into this system tend to be controlled by the animal feeds used, thus the more feeds used, the greater the nutrient output (Hamilton et al., 1996).

In livestock, grassland, humid and temperature zones, manure is not a significant issue due to the low concentration of livestock on grazing land (Hamilton et al., 1996).

As woody vegetation is removed, incoming light increases, there is less interception of rainfall and reduced release of soil nutrients. As a result, understory forage production increases.

Biodiversity The density of livestock herds increases the likelihood of animal disease such as avian flu being spread, and poses a threat where they come into contact with human populations, particularly in east Asia (WDR, 2008).

Herds cause wide-scale land degradation, with about 20% of pastures considered as degraded through overgrazing, compaction and erosion. This figure is even higher in drylands where inappropriate policies and inadequate livestock management contribute to advancing desertification (FAO, 2006).


Trend is a shift away from extensive grazing to more intensive grazing in most developing countries. This is likely to lead to a return to forest cover and there is potential to increase grassland cover in China and parts of South America (FAO, chapter 12).

In developing countries, including much of Asia, livestock farming is growing in intensity, with a shift from dispersed production systems in rural areas to intensive, specialist production in urban areas (WDR, 2008).

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Increasing frequency and intensity of drought and heat waves in summer in Europe and Oceania may increasingly affect the health of livestock, as it does already in Australia. This is likely to reduce production and productivity (IPCC, 2007).

Conversely, there are likely to be fewer deaths of young lambs and calves as a result of milder winters in Australia and New Zealand, and possibly Europe too.

The range of the cattle tick (Boophilus microplus) is likely to move extend southwards on thus affecting a greater proportion of the Australian beef industry (IPCC, 2007).

Current water stresses in Australasia are likely to be compounded by 2020s and 2050s.In North America, rain-fed agricultural yields are set to increase early in the 21st century.

Key pointsExtensive livestock production is a significant source of the GHG CH4 and a driver of LUC. In addition, soil nutrient supplies can be depleted leading to a cycle of further extensification and demand for further LUC.

2.2 Developing countries

2.2.1. Wetland rice cultivationEnvironmental impacts


In 1999-2000, rice yields in India were 1.99 t/ha (Ministry of Agriculture, 2000). The average wheat production in India is in the region of 2.60 t/ha (Indian News, 2008).In China during the 1990s, rice yields were estimated at 5.95 t/ha, an increase of almost 100% since the 1960s (FAO, 2000a). In 2005, total grain yields in China were 426.613*103 t, or 5.17 t/ha. The average farm produces 3.39 t rice based on an area of 0.30 ha (IIASA, 2005).


Multiple rice crop systems are only found where rainfall is greater than 200 mm per month for at least 6 months per year.


Extensive use of nitrogen fertilizer and pesticides has led to nitrates being found in water and food at levels which exceed the tolerable level, particularly in the Punjab region of India (WDR, 2008).

According to WRI (2009), fertilizer consumption in India was 19.258 *106 tof nutrient.


Global rice production from wetland paddies contributes 6% of total global atmospheric CH4 emissions (Bouwman and McCarl, 2006). It is suggested that global rice production releases 0.13–0.89 t C per hectare per year (Ramsar, 1999). Over 90% of worldwide rice cultivation occurs in developing countries: it is predicted that global rice production will double between 1990 and 2050, therefore an increase in CH4 emissions can be expected if emissions are related to biomass (FAO, 2003b).


Rice-wheat systems in South Asia cover 12 m ha in the Indo-Gangetic Plain of India and Pakistan. Monoculture of rice in summer and wheat in winter has contributed to soil and water degradation, including soil salinisation, soil nutrient depletion and reduced organic matter (WDR, 2008). Main areas affected by salinisation include North East Thailand and the North China Plain and the unterraced slopes of China and southeast Asia are affected by erosion (Dixon et al., 2001).

Biodiversity In Asia, algal blooms and eutrophication are a result of fertilizer run off, thus destroying wetland habitats (WDR, 2008)

Forestry/LUC/

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agro forestryClimate change impacts for this system

The IPCC suggest that South East Asia is likely to see an increasing grain harvest under a changing climate. However, regional variations in the response of wheat, maize and rice yields to climate change projections could be significant (Parry et al., 2007).

The HadCM2 climate model projects that crop yields could increase by up to 20% in East and South-East Asia but could decrease up to 30% in Central and South Asia, taking into account any positive feedback from having extra CO2 in the atmosphere (IPCC, 2007).

Increased frequency and magnitude of forest fires in northern Asia as temperatures rise and drought increases;

Key pointsIrrigated rice cultivation is a major source of CH4 but changes to production methods are forecast to lead to no net increase in CH4 emissions to 2030 despite forecasts of substantial increases in production. However, rice cultivation is likely to continue to be a major source of N2O and NH3.

2.2.2 IrrigatedEnvironmental impacts


Based on the countries falling into the irrigated farming system, including Peru, Chile and Iraq, yields of cereal are presented based on WRI (2009) datasets.Peru: 3.54 t/haChile: 5.81 t/haJordan: 1.33 t/ha


Irrigated by definition.

Less than 4% of renewable water resources in Africa are used for farming;Barriers include a lack of finance and labour force to construct irrigation and the infrastructure needed. Also lack of agricultural technology, and access to markets (Hanjra et al., 2009)

Countries with the largest areas of irrigated land include (WRI, 2009)China – 54,596,000 haIndia – 55,808,000 haPakistan - 18,230,000 ha


Smallholder irrigated farming systems require large-scale irrigation schemes in comparison to the scale of the farming. Rising frequency of drought in arid regions, as a result of climate change, is a further stress factor to this farming system.

In Latin America, lower rainfall will cause serious water shortages, e.g. in Argentina, Chile and Brazil between 7 million and 77 million people could be affected by the 2020s (Parry et al., 2007).

Lake Chapala in central Mexico and Lake Chad in western Africa are both receding as a result of unsustainable irrigation (WDR, 2008).

In Sub-Saharan Africa, major investment in irrigation is required (Dixon et al., 2001).

Hydrological impacts include a 30m drop in water table level in the coastal aquifer Hermosillo, Mexico, as a result of water abstraction at a rate 3-4 times greater than recharge level. This leads to intrusion of saltwater, leading to relocation of farms.

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Around 40% of irrigated land in arid Asia is affected by salinisation including Pakistan and the Aral Sea basin (WDR, 2008). The result of this is loss of productivity and land that can support agriculture.


Greenhouse gases from irrigation schemes will contribute to a high level of emissions.

In rice production, emerging trends involve lower consumption of irrigated water. Diversification of crops and intensification of the system by using water more efficiently under high yield levels mean the GHG budget is changing. Methane emissions are lower. However Nitrous oxide emissions are greater. Soil organic carbon and therefore CO2 emissions make this system less sustainable (Wassmann et al., 2006).

Soil erosion/soil degradation/ desertification

Under this production system and each of the sub-systems (including maize mixed farming system, the cereal-root crop farming system and the highland temperate farming system) soil fertility is decreasing. As a result of increasing fertilizer costs, the application of fertilizers to maize and wheat has dropped. As such, those regions previously producing smallholder maize have had to grow local varieties without fertilizer application (Dixon et al., 2001).

In north Africa, the Nile Delta is affected by salinisation as a result of the reduced flow of the Nile since the completion of the Aswan High Dam, and southeast Nigeria and the Sahel are affected by erosion (Dixon et al., 2001).

Biodiversity Stress is exerted on river basins and their ecology and can lead to nutrient depletion and soil erosion, as well as loss of fish and other aquatic species. As a result, this threatens the nutritional value of this system’s outputs

Forestry/LUC/agro forestryClimate change impacts for this system

Africa is projected to experience an increase of 5 to 8% of arid and semi-arid land by the 2080s leading to reduced agricultural yields, increased desertification and drought;

Rise in number of people at risk of hunger in Latin America, from 5, 26 and 85 million in 2020s, 2050s and 2080s respectively;

Increased frequency and magnitude of forest fires in northern Asia as temperatures rise and drought increases;

This system is likely to be put under pressure from water shortages in coming years. For instance, gross per capita water availability in India will drop from around 1820 m3/yr in 2001 to as low as around 1140 m3/yr in 2050 (IPCC, 2007).

Key pointsWithout significant improvements in water use efficiency it will be difficult to greatly increase production from this farm type. In some regions maintaining current production may be difficult.

2.2.3 Smallholder rain-fed humidEnvironmental impacts


In East Africa, cassava yields range from 6600 kg per head per year to 12700 kg per head per year. Maize yields range from 700 kg to 1400 kg per head per year (Fermont et al., 2008).

These yields are very small, given the large area of land which Sub Saharan Africa covers at 2,429,569 ha (WRI, 2009).

Yields of cereal in countries under this farming system range from:

Ethiopia: 1.24 t/ha

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Uganda: 1.70 t/haKenya: 1.32 t/ha

Based on WRI (2009)Irrigated or rain-fed

At present little irrigation is required as climates have abundant rainfall. However, under a changing climate, yields in rainfed farming systems could decline, threatening the achievement of the Millennium Development Goals of ending poverty and hunger, as well as achieving environmental sustainability.(Millennium Development Goals, 2005).Smallholder farmers are at most risk from the impacts of climate change, which include increased risk of crop failure; greater livestock disease and therefore lower prices for produce; rising dependency on aid and a decline in human development indicators including health and education (Ifid, 2008).


Losses of 17.3 kg N per hectare per year, 5.3 kg P /ha per year and 7.1 kg /ha per year have been seen for cereals, supporting the low yields of Ethiopian production systems.

Leaching losses of K and N were greatest under permanent crop production, at a rate of 41.1 and 21.3 kg /ha per year.


Greenhouse gas emissions are likely to be low since irrigation use is low, fertilizer use is low, e.g. In Venezuela, fertilizer use was 372.6 kg * 10^6 in 2006. This represents a low level (127.2 kg/ha)of fertilizer use. (WRI, 2009)

Soil erosion/soil degradation/ desertification

Much of Sub-Saharan Africa is covered by this farming system (FAO, 2003b). Here, the WDR (2008) estimate that productivity losses are in the region of 1% or less each year; in areas of extensive production including Kenya, Ethiopia and Uganda, this is higher. One estimate puts land degradation in the Nyando River Basin in Kenya at 56%.

Pressure on land is low with an average of 2.5 persons per cultivated hectare. However, land degradation is high due to wind and water erosion, particularly in the Sahel Desert and Sub-Saharan Africa which are covered largely by the smallholder rain fed humid system. Here overgrazing of pastoral lands is also high (WDR, 2008).

Biodiversity Kaihura and Stocking (2003) published a book on the agricultural biodiversity of smallholder farms in East Africa. They found that agricultural uniformity is increasing, however, many farmers are promoting patchwork land use including annual cropping, orchards, forest, fallow, home garden, and hedges)

In Yunnan, China, for example, some farmers are expanding home gardens on to former rice paddy terraces to produce vegetables, medicinal plants, and fruits for sale. Maize fields are being replanted with native tree species as forestry.


In western Africa, the Amazon and southeast Asia, deforestation is occurring rapidly in tropical areas (WDR, 2008). There is little forest cover left in West Africa and population is growing (Dixon et al., 2001).


Ifad (2008) suggest that the smaller, poorer farmers could be affected worst by climate change. If emissions do not change and a ‘business as usual scenario’ exists, agricultural productivity may drop by 10 to 25% by 2080. For some countries, yields in rainfed agriculture could decrease by up to 50%.

Sea level rise and coastal inundation by end of 21st Century in Africa;It is projected that in Latin America, lower rainfall will cause serious water shortages, e.g. in Argentina, Chile and Brazil between 7 million and 77 million people could be affected by the 2020s;Rise in number of people at risk of hunger in Latin America, from 5, 26 and 85 million in 2020s, 2050s and 2080s respectivelyCurrent water stresses in Africa are likely to be compounded by 2020s and 2050s.

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Key pointsClimate change is forecast to reduce rainfall in several of the regions which depend upon rain-fed smallholder production. Substantial areas are also prone to land degradation. Unless inputs can be made available to improve productivity and management to avoid degradation, there will be pressure for LUC.

2.2.4 Smallholder rain-fed highlandEnvironmental impacts


Winter wheat has a seeding rate of 171 kg/ha.In the Gansu Province of China, farmers tend to have an average of 1.7 pigs per household. Donkeys are used for transportation of produce and labour purposes, and sheep, goats and cattle are also kept.


Irrigation is limited to 0.6 million ha; main crops produced are subsistence winter wheat in areas of higher rainfall, and subsistence spring wheat in lower rainfall areas.


Water pollution receives much attention in developing countries than in the EU and NAFTA. However, fertilizer use in this system is low due to the extensive nature of this farming system, its poorly developed infrastructure and lack of machinery for application. Therefore emissions to water will are also likely to be low.


Emissions are similar to those in smallholder rainfed humid production systems. Inputs are limited in terms of fertilizers, irrigation and energy, therefore emissions are likely to be low.

BiodiversitySoil erosion/soil degradation/desertification

There is substantial soil erosion on the Loess Plateau, China. Due to soil type, slope and rainfall, soil erosion here is greatest in China and in the world at 3720 t km-2 year-1, (Liu, 1999).

Uplands are more prone to water erosion where cultivated slopes are steeper than 10 to 30%, where soil conservation measures are absent and precipitation rates are high. Estimates of how much of this type of land is currently cropped cannot be made. Land pressure in South East Asia is caused by increasing population and has encouraged greater use of steep hill slopes for maize production, although in countries such as Bhutan and Nepal where there is little flat land left to cultivate, there is little choice over where cultivation can take place. Erosion occurs at a rate of 20,000 to 50,000 kg per hectare per annum in fields and 200,000 kg per hectare per annum in highly degraded watersheds (Dixon et al., 2001).

Biodiversity In many upland areas, forest cover has been reduced as cultivation expands across the slopes. Combined with thin and infertile soils, there is not much to support a wide range of biodiversity.


Dixon et al (2001) suggest that this system has great potential for intensification, by using soil restoration methods and improved water management techniques. However this may compromise the sustainability of the system itself.


Again, smallholder farmers are likely to be negatively impacted by climate change as they are least able to afford to adapt to the consequences.

As glaciers melt at an increased rate, glacial floods will increase in frequency, slopes will become less stable and river flows are likely to decrease.

It is thought that agricultural productivity in Asia will decline as a result ofrising temperatures, increasing severity of drought, flooding and soil degradation;

Landslides are expected to become more frequent and theecology of mountain and highland systems in Asia is predicted to be altered (IPCC, 2007).

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Key pointsThis farming type is particularly vulnerable to soil erosion.

2.2.5 Smallholder dry and coldEnvironmental impacts


Crop farming is subsistence based; surplus yields are sold if it is likely that the following harvest will be good (Ncube et al., 2009). In semi-arid Zimbabwe, yields range from 820 kg pearl millet, 150 kg sorghum and 30 kg maize per farm per annum on a better resourced farm, to 320 kg pearl millet, 40 kg sorghum and 10 kg groundnut on a poorly resourced farm (Ncube et al., 2009).

Irrigated or rain fed

Irrigation is used widely; for example, in Pakistan, 18,230 thousand ha of land are irrigated. In Kazakhstan, 3,556 thousand ha of land is irrigated (WRI, 2009).


Lack of rainfall means groundwater irrigation is used heavily in the Middle East and South Asia, areas dominated by this farming system. Groundwater use is high compared to the land under cultivation (WDR, 2008). In future, food needs must be met through improved water efficiency (WDR, 2008). Almost 20 million hectares of land requiring irrigation are located in Kazakhstan, Kyrgiz Republic, Tajikistan and Uzbekistan (Dixon et al., 2001).

Areas experiencing water stress in major river basins have been identified in recent research (Smakhtin et al., 2004 in WDR, 2008). Overexploited areas include areas which are covered largely by smallholder dry and cold farming systems. This supports the fact that such systems often have low productivity due to environmental constraints including nutrient poor soils, low temperatures and lack of rainfall, for instance in North Africa, parts of South Asia (India) and Central Asia (Fermont et al., 2008; Tittonell et al., 2008; Ncube et al., 2009). This low precipitation explains the need for additional water abstraction in these areas, leading to water stress.


Where there are negative nitrogen balances caused by low fertilizer input, which is common in sub-Saharan Africa, leaching into water tends not to be problematic (FAO, 2003b). In semi-arid Zimbabwe, better-resourced farms use 2000-5000 kg manure per season and medium resourced farms use less manure (1000 kg to 0 kg) (Ncube et al., 2009). China, however, is the world’s largest consumer of nitrogen fertilizer with applications of around 600 kg/ha (Lin, 2009).

Part of this large input of N is due to the type of fertilizer used, predominantly ammonium bicarbonate (NH4HCO3). This fertilizer dissolves to produce a high pH solution in which much of the N is in the form of NH3 and is readily lost (up to 50%) as gaseous NH3 (Cai et al., 1998). The authorities are aware of this problem; however, the manufacture of NH4HCO3 is a significant industry, at one time employing c. 500,000 people, and hence the replacement of these plants with the manufacture of alternatives will be a long-term process.


Overgrazing and land degradation is high in the Middle East and Central Asia. Figures for soil degradation tend to be rare and where they do exist, cause debate (WDR, 2008). In the regions of Indus, Tigris and the Euphrates river basins in South and west Asia, salinisation is a major problem. The foothills of the Himalayas are affected by erosion.

Soil erosion is the main cause of soil nutrient depletion, which can be compounded by limited fertilizer application or a lack of organic manure or fertiliser being applied. For instance in Ethiopia, nutrient depletion occurs at the rates of 122 kg N ha yr-1, 13 kg P ha-1 yr-1 and 82 kg K ha-1 yr-1 (Haileslassie et al., 2004). This system tends to have a very high population pressure on natural resources, particularly around Turkey and Central Asia (Dixon et al., 2001).

Biodiversity As a result of stress on river basins and increasing salinisation, there has been a rise in disease carrying pathogens in eastern Africa, in countries including Ethiopia, Somalia, Kenya.


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Sea level rise and coastal inundation is projected by the end of the 21st Century in Africa.

It is projected that an annual increase of 25% in peak discharge could be experienced in Bangladesh, thus aiding the productivity of the farming systems (Parry et al., 2007).

Current water stresses in Africa are likely to be compounded by 2020s and 2050s.

Africa is projected to experience an increase of 5 to 8% of arid and semi-arid land by the 2080s leading to reduced agricultural yields, increased desertification and drought.

Increased frequency and magnitude of forest fires in northern Asia as temperatures rise and drought increases.

Key pointsThese systems often have low productivity due to environmental constraints including nutrient poor soils, low temperatures and lack of rainfall; for instance, in North Africa, parts of South Asia (India) and Central Asia. This low precipitation explains the need for additional water abstraction in these areas, leading to water stress.

2.2.6 Dualistic mixedEnvironmental impacts


A study by Pretty et al., (2006) suggests that within the dualistic mixed farming system, 537,311 farmers have adopted agricultural sustainable technologies. This equates to 26,846,750 hectares under sustainable agriculture, and has resulted in a 76.5 % increase in yields.


In Haryana, India, there is inadequate irrigation as a result of declining water tables and poor discharge from tubewells. Water supply from canals is also not sufficient and ground water is of poor quality (Indian Council of Agricultural Research, 1998).


Nitrates are exceeding ambient levels in waters (Singh, 2000).


Pretty et al (2006) suggest that the dualistic mixed production system has the potential to sequester 0.32 t C per hectare per annum. This is a total of 8.03 Mt C per year, the largest figure of all production systems.

It is suggested that decomposition in drained peatlands in southeast Asia emits between 355 and 874 Mt/y CO2 per year (Hooijer et al., 2006). This problem has arisen because of palm oil production, an important crop in the dualistic mixed production system in parts of Brazil, Ecuador and the Ivory Coast, as well as in the smallholder rainfed humid production system.

Biodiversity In Indonesia the rapid expansion of palm oil production (Elaeis guineesis) has led to intense international concern about its wide-scale environmental impacts. Indonesia is experiencing unprecedented rates of deforestation, with associated loss of biodiversity and damage to ecosystem services. Palm oil plantations currently occupy about 6 * 106 ha in Indonesia.


The impact of grazing on soil organic carbon in the Cerrado is less than on forest. Maquere et al. (2008) reported that total C stocks to 1 m depth under pastures that had been established for 20 and 80 years were numerically greater than, albeit not significantly different to, total SOC to 1 m of native Cerrado. The total SOC estimated, at 84 t/ha, was greater than the default value of 66 t/ha for Brazilian savannah cited by IPCC (2006).

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In 1980, soil phosphorous content was declining on a more widespread basis. The area of soil with a low N content only increased from 89 to 91%. Soils with high K content have dropped from 91% in 1980 to 61% in 1995. The wheat–rice rotation disrupts soil nutrient balance causing soil infertility and a lack of zinc and copper (Singh, 2000).


Deforestation is a major problem associated with cattle ranching in Latin American countries including Guyana, Venezuela and Ecuador, where it is projected that by 2012, more than 80% of land will be used for pasture. Tree species including large leaved mahogany are also threatened (FAO, 2002)


In Latin America, lower rainfall will cause serious water shortages, e.g. in Argentina, Chile and Brazil between 7 million and 77 million people could be affected by the 2020s;

Current water stresses in Africa are likely to be compounded by 2020s and 2050s;

Rise in number of people at risk of hunger in Latin America, from 5, 26 and 85 million in 2020s, 2050s and 2080s respectively

Key pointsHeavy demand for water in some areas is diminishing water resources while a combination of increased agrochemical inputs and decreased water flows is reducing water quality. In some areas soil reserves of P and K are not being maintained.

2.3 Fishing and aquaculture, including coastal artisanalEnvironmental impacts


The Asia-Pacific region produces most of the world’s share of fish, both from aquaculture and fisheries (91 and 48% of total world production, respectively). This totalled 46.9 million tonnes from aquaculture and 44.7 million tonnes from capture fisheries in 2002.

Small fish species, damaged catch and young fish targeted are often referred to as 'trash fish'. They have a low market value. Increasingly, this 'trash fish' is used as fish meal in aquaculture and also as livestock feed, thus increasing demand and placing greater pressure on fish stocks (FAO, 2005). Nitrogen is reported to be the main limiting nutrient for primary production in coastal areas (Wu, 1995).

During the 1990s, between 28 and 33 million tonnes of fish were used each year for the production of fishmeal and oil and these fish were mainly landed by marine capture fisheries. The capture of pelagic fish off the west coast of South America contracted as a result of theEl Niño phenomenon, as did the production of fishmeal in the world; in 1998 only 23.9 million tonnes of fish were reduced to fishmeal and oil. By 1999 this figure increased again to 30 million tonnes or almost 24 % of total world catch of fish, representing a return to a more normal level as a result of the recovery of fishing in South America (Dixon et al., 2001)


European salmonid farms which use artificial feed can expect to lose 52-95% of N and 82% of P to the environment through excretion of ammonical-N and urea, food wastage and faecal production. Most food is wasted by open sea cage culture which use trash fish as feed, followed by pond culture using moist feed and lastly raceways which use dry feed (Wu, 1995).

In previous years, tributyltin (TBT) was used to control fouling of fishing vessels. However, due to its toxicity, the use of TBT has been banned in most countries.

Marine fish farming tends not to lead to eutrophication.In the water surrounding fish farms, dissolved oxygen levels are lower and biological oxygen demand and P, organic and inorganic N and total C are higher

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(Wu, 1995). Indeed, fish farming raises sediment oxygen demand by between 2 and 5 times of sediments in non-fish farming areas.


European salmonid farms which use artificial feed can expect to lose between 80 and 84% of C through wastage of feed and respiration by fish (Wu, 1995).

Biodiversity Deep sea fishing can threaten other vulnerable marine species including delicate cold water corals and sponges, sea-bottom seep and vent habitats that contain unique species, and features like underwater seamounts which support sensitive species (FAO, 2008a).

As a result of conversion for fish and shrimp farming, mangrove habitats have suffered. Asia has lost more than 1.9 million ha as a result of land use conversion whilst north and central America and Africa have lost in the region of 690 000 and 510 000 ha respectively in the past 25 years. Indonesia, Mexico, Pakistan, Papua New Guinea and Panama experienced the largest losses of mangroves during the 1980s, with. Around one million hectares were being lost in total in these five countries. Vietnam, Malaysia and Madagascar, which all support coastal artisanal production systems, suffered major area losses in the 1990s and between 2000 and 2005 (FAO, 2008b).

A global assessment by the FAO found that 3.6 million hectares of mangrove forests have been lost since 1980. It was suggested that Asia had suffered the greatest loss, with a total of 1.9 million hectares being destroyed because of land use change. However, it is believed that the rate of loss is slowing down from a loss of 187,000 hectares in the 1980s to 102,000 hectares in the early 2000s (BBC, 2008).

Mangrove loss is a serious social., environmental and economic concern for many developing countries. Mangroves play a key role in protecting coastlines and moderating monsoonal tidal floods and tsunamis. The United Nations suggest that mangroves can absorb between 70 and 90 % of the energy of a normal wave (FAO, 2008c). In addition, they are host to a wide variety of wildlife and estuarine and near-shore fisheries. As a result, the degradation of this vital ecosystem service will mean terrestrial and aquatic production is reduced, and wildlife habitats are lost. Furthermore, the environmental equilibrium of coastal forests which protect inland agricultural crops and villages will be upset.

Shrimp trawling tends to have a negative impact on other marine biodiversity. The capture of young valuable fish before they have the chance to reproduce threatens the sustainability of fish populations; extensive removal of non-targeted species such as sea turtles threatens marine ecosystem biodiversity and can thereby impacting on the fishery’s productivity (FAO, 2006b).

However, fish species can be used as bioindicators to detect signs of pollution in coastal waters (Wu, 1995).

At risk species include white abalone, barn door skate and large coral reef fishes. As a result of intensive fishing, genetic diversity is lost and the adaptability of species is reduced. Key threats include habitat destruction, pollution and climate change (Dixon et al., 2001).


The north-east Atlantic marine ecoregion is suggested to be highly vulnerable to climate change, particularly for marine fish and shellfish species (Baker, 2005). Rising temperatures impact the productivity of fisheries in the North Atlantic. Species distribution patterns will change, with greater production in northern waters and a decreases in southern waters (IPCC, 2007);

As a result of rising atmospheric temperatures, primary productivity could reduce in the tropical oceans. These oceans are particularly vulnerable since East Asia and South-East Asia provide one quarter of the world’s total tuna population,

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particularly the skipjack tuna (IPCC, 2007).

In China, marine fishery is threatened by overfishing, pollution, eutrophication and red tides. Ribbon fish and large and small yellow croakers could be impacted by climate change.

Key pointsThe loss of mangrove swamps to shrimp farming has had major adverse effects on coastal environments. The majority of sea fisheries are over-exploited and it may prove difficult to maintain current production.

3. Case studies3.1 Environmental impacts of beef production in BrazilIn Brazil, there has been widespread degradation of the main pasture type, the Cerrado (Cezar et al., 2001). Barcelos (1996) estimated that about 80% of pastures in central Brazil were in some state of degradation. One feature of this is depletion of P reserves in the soil, which are historically low in much of Brazil (Butterworth, 1985). There is also a need to replace the native flora with more productive forages. Cezar et al. (2001) described how some native pastures used to support stocking rates of 0.5 animal units/ha (450 kg liveweight/ha) but now support only 0.2. Plans have been made to improve large areas of pasture, although it is not clear how far and how quickly this has progressed. Pasture restoration implies cultivation, reseeding with more productive species and fertilizing with P and K. One limit to this restoration is cost, which may be beyond the capacity of small farmers. Costs are relatively high because large areas typically need cultivating, but still only support relatively few animals. Brazil is not alone in facing such a problem of pasture degradation. In parts of northern Australia, some pastures are estimated to have only about 20 years more productive life left (Evans pers. comm., 2008). Nitrogen fertilizer does not seem to be needed because N fixation should occur through legumes and free-living soil bacteria.

However, this type of degradation, depletion of nutrients, can be reversed by the addition of mineral fertilizer. Moreover, the addition of P and K may initiate a beneficial cycle in which forage productivity, including that of forage legumes is increased, increasing stocking rates and hence returns of N, P and K to the soil in excreta.

Winter feeding is restricted mainly to urea and mineral supplements rather than the forage and concentrates that are used in Europe. This means stock gain weight in the wet season (summer) and may lose weight in the dry season.

The comparison of beef production in Brazil with beef production in the UK reported by Williams et al. (2009) highlights the large differences between the relatively extensive low-input pasture based system in Brazil and the generally more intensive systems in the EU and NAFTA countries. Emissions of GHGs at c. 32 t CO2-eqv. per t of meat at the farm gate are greater from the Brazilian systems than from UK production (c. 24 t CO2-eqv. per t of meat). The difference arises mainly because of greater emissions of enteric CH4, reflecting the relatively slow growth and reproductive rates of Brazilian cattle. To reach slaughter weight of c. 450 kg takes around 36 months in Brazil compared with 18-22 months for the UK. The Nellore breed that dominates in Brazil is, however, generally long lived and resilient. In both the EU and Brazil enteric fermentation is the largest source of GHGs from pre farm gate production. However, in the EU, substantial emissions also arise from the

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production of feed and the maintenance of grazed pastures, primarily from the manufacture of fertilizers and from subsequent emissions of N2O.

3.2 Meat production and the impact on rainforest and other natural ecosystemsSoya meal can be a significant component of poultry diets; Ferguson et al. (1998a; 1998b) examined diets containing c. 25-44% soya as a proportion of feed intake. In many feeds protein quality is low, in that the proteins have less than required concentrations of essential amino acids (EEA), and in order to supply the required amounts of these EEA more protein has to be supplied than the animal requires. A major reason for the inclusion of soya in the feeds of pigs and poultry is that, as well as having a high concentration of crude protein (CP; c. 35% of dry matter) soya also has high proportions of the EAAs needed by non-ruminants, in particular lysine.

The greatest reported association between meat production and rainforest loss is the indirect impact of the cultivation of soya to feed to livestock. The intensification and expansion of soya production comes at the expense of important regions of biological diversity. Soybean production has been identified as one of the leading causes of deforestation in Brazil’s forests, particularly the Mato Grosso seasonal forest ecoregion (Grau et al., 2005; Casson, 2003; Morton et al., 2006). Links have been between increases in the area under soybean cultivation and decreases in uncultivated land and biodiversity in the Cerrado and (more recently) rainforest. Evidence of these changes was obtained from statistical data from the Brazilian Government and FAO (USDA, 2005). The USDA has provided an analysis of historical soybean production in Brazil, which links soybean expansion firmly to the price commanded for soybean on the international market and increased profitability for Brazilian farmers (USDA, 2005). Some soybean producers clear forests themselves. Others buy the land from small producers, often colonists, who have already cleared it. These same small producers then move further into the frontier and clear more land. In addition to direct habitat conversion, soybean production in pristine areas also requires the construction of massive transportation and other infrastructure projects. Moreover, the infrastructure developments for soya production unleash a number of indirect consequences associated with opening up large, previously isolated environments to population migration and to other land uses. This infrastructure contributes directly and indirectly to habitat conversion. Casson (2003) also reports the displacement of smallholders by soybean plantations, causing them to migrate into the Amazon region where they clear forest for agriculture or cattle ranching (for domestic consumption).

Soya production in the Cerrado is estimated to lead to average soil losses of 8 tonnes/hectare/year (Fritsche et al., 2006); loss of SOC is a serious problem in the soya-producing areas of Brazil due to the warm climate and dry winters.

Nevertheless, it must be recognised that the expansion of soya production is mainly due to demand from Europe and elsewhere for animal feed. Moreover, since poultry raised in the EU are fed amounts of soya similar to those fed to poultry in Brazil, and much of the soya imported into the EU originates in Brazil, there is little or no reason to suppose that poultry production in Brazil is any greater driver of soya cultivation than poultry raised in the EU. The key driver here is not the country of origin of poultry and other meat products but the growing global demand for meat.

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3.3 The environmental impacts of palm oil productionPalm oil is the most produced and traded of all vegetable oils. The oil palm (Elaeis guineensis) is grown in regions of high rainfall within 10o of the equator. It is grown for its oil, which has been used as an ingredient for cooking in Africa for hundreds of years. A different type of oil can also be obtained from the kernel of the palm fruit, which is used as a basis for soap and oleochemicals, and is the traditional export to the European market. Finally, the residues from processing (around 70% of the harvested matter) can be used; the empty fruit branches are used as mulch for soil and the fibrous expeller burnt to produce heat (and power) for the oil extraction process. The nutshells, which are rich in silica, can also be used for road surfaces.

Table 11. Summary of oil palm properties. The table below is mainly focussed on large-scale plantations in Asia. However, oil palms are also grown in Africa, where small and medium scale planting is common.

Palm oil Both palm oil and palm kernel oil are produced. The former is used as cooking oil; the latter as a feedstock for oleochemicals.

Rainfall requirements (mm/y)

Usually grown in areas of high rainfall. There are records of irrigation in Africa.

Growth conditions High demand for nutrients. On most soils fertilizer is required to obtain reasonable yields. Nutrient demand is less in Africa than in South East Asia. Pesticides seldom used. According to Fairhurst and Mutert (1999) ‘well-managed palm oils sequester more carbon per unit area than tropical rain forest. About 25% of the harvested biomass may be returned to the field as a nutrient rich mulch’.

Economic life Perennial Yields (tons/ha/y) 12.24 t/ha (fruit) 3-4 t/ha (palm oil) and 0.5 t palm kernel oil/ha, but higher

yields are thought to be obtainable.AdvantagesCo-product Co-products include the empty fruit branches which can be used as fodder or

fibre for paper and particle board; the shells, used as road cover and the palm kernel expeller, used as a fuel or fertilizer.

Areas where palm oil is grown.

Grows within regions 10o from the equator. Malaysia, Indonesia, Nigeria, Thailand, Colombia, Cote D’Ivoire, Ecuador.

Issues Deforestation to establish palm oil plantations. Soil erosion and degradation from traditional planting methods (best practice can reduce these problems). Effluents from processing (which can be treated). Animal-human conflict, particularly elephants and orang-utan. Soil conservation required on hilly areas.

Fairhurst and Mutert 1999; Wahid et al., 2004

Processing results in considerable quantities of high organic strength effluent. At large scale it is cost effective to treat this through a combination of anaerobic and aerobic digestion to produce a treated effluent that can be discharged to local watercourses. However, at smaller scales this is not feasible. According to the FAO (undated) ‘environmental awareness of the operators in this industrial area is low. Traditional processors simply return liquids to the surrounding bushes. In intermediate technology mills sludge from the clarifying tanks are carried in buckets or rudimentary gutters to sludge pits dug in nearby bushes. When the sludge pit begins to give off a bad odour, the pit is filled in and another one dug for the purpose. Charcoal from cooking fires is dumped into the pits to absorb some of the odour.’

Table 12. Key factors and impacts of palm oil productionKey Indicator

Key factor Impact Key indicator and score

Land use Deforestation Clearance of jungle (Ardiansyah, Certification scheme such as RSPO are

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change 2006).Illegal logging occurs in 37 of the 41 national parks in Indonesia (UNEP 2007).

setting out principles for development including no deforestation.There are general moves to ensure protection of high conservation value forests and national parks.Sustainability certification schemes generally suggest use of degraded land rather than forests. Support for the international “Forest Law enforcement and Governance” (see UNEP 2007.) Strengthen international programmes of law enforcement against illegal logging, including support from Interpol.Strengthen surveillance and intelligence units (UNEP 2007)

No deforestation

There are national moves in Indonesia to ensure that current concessions are properly planted and that sustainable practices are adopted.

Biodiversity management

Deforestation Decreases in biodiversity due to clearance of forest (WWF 2003). Fragmentation of high conservation value forests. Specific species mentioned: Orang-utans; Sumatran elephant; Sumatran tiger and rhinos, due to conflict with humans1. Uncontrolled fires due to deforestation contribute to the elimination of species rich habitat (WWF 2003).Drainage of peatlands results in habitat and biodiversity loss.

Expansion and infrastructure support for “ranger quick response units” to patrol sensitive habitats (UNEP 2007).Creation of buffer zones for wildlife.Use of “flying squads” to drive elephants away from plantations.Training manuals for small farmers. (Ardiansyah 2006).Ban practice of slash and burn for forests.Policies to conserve peat lands and stop peat land draining and burning.Sustainability policies in countries that form major markets for palm oil.

Agricultural practice

Use of pesticides and herbicides in combination with monocultures restricts biodiversity further.Decrease of biodiversity due to monocultures.

Good agricultural management to decrease use of pesticides and herbicides.Use of buffer zones to increase habitat for wildlife.Land management, integrated pest management, waste management

Drainage of wet lands

Flooding down stream of drained and degraded peat lands in Indonesia, resulting from drainage and compaction of peat lands and loss of forest (ref: note 2 below).In dry periods drained peat lands result in low water flow and lower water table, and may result in fires.Salt water intrusion as a result of drainage of peat lands.

Improved water management in peatland plantations, embedded in water management master plans for peatland areas.Forest conservation and drainage avoidance in remaining peat swamp forests.Restoration of degraded peatland hydrological systems and peat swamp forests (Hooijer et al., 2006). International recognition of the problem and an internationally recognised peat land conservation and management system.

Water use Oil palm is only grown in areas of high rainfall. Generally the impact on water use is not high.

Water pollution from run off

Leaching of pesticides and agrochemicals can be significant.

Monitor status of surface and ground water.Good agricultural management to decrease use of pesticides and herbicides.

Water Large scale High organic strength effluents (palm Ensure that better water treatment practices

1 UN report (2007) The Last Stand of the Orang-utan: State of Emergency: illegal logging, fire and palm oil in Indonesia’s national parks. This report found that forests in Indonesia and Malaysia are being felled so quickly that 98% could be gone by 2022. See: www.unep.org/grasp/docs/2007Jan-LastStand-of-Orangutan-report.pdf ) 700,000 ha of tropical forest in Malaysia have been cleared for palm oil production and around 2 Mha of palm oil plantations in Indonesia have been planted on forest land (0317). The lowlands of Sumatra and Kalimantan are considered to be among the most species rich on earth. There are also potential impacts in parts of Africa, Papua New Guinea, Columbia and Ecuador where palm oil plantations are under consideration. Lowland forest clearance in Indonesia is thought to result in loss of 80% of species (WWF 2003).

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http://www.unep.org/grasp/docs/2007Jan-LastStand-of-Orangutan-report.pdf


Pollution from processing.

oil mill effluent, POME) can be treated by anaerobic and aerobic treatment at large-scale. There is evidence in Indonesia that the effluent is not treated and results in water pollution and fish kill.In Africa large-scale Government plantations are being split up into smaller units, where funds for efficient processing are not available.

are introduced and water pollution law are enforced. Use of POME as animal protein (Wahid et al 2004).

Small and medium scale

Smaller and medium scale producers do not have the means to treat effluents, which results in local water pollution.

Develop better practice for small and medium-scale producers.

Soil health Deforestation or drainage of peat land

Development of acid sulphate soils in coastal areas as a result of drainage of peat lands.Loss of soil organic carbon as a result of deforestation.

Forest conservation and drainage avoidance in remaining peat swamp forests.Restoration of degraded peatland hydrological systems and peat swamp forests.

Development on degraded land

Planting oil palm on degraded or abandoned land should increase organic matter in soil and improve soil health, once the crop is established.

Erosion Plantations planted down slope on hills have been shown to encourage erosion.Once plantations are established soil erosion potential decreases.

Ensure oil palms are only planted on suitable aspect. The impact of erosion from plantation roads needs to be addressed.

Effects on food crops

Currently the expansion of palm oil in the Far East appears to be at the expense of tropical forest or peatlands rather than the displacement of food production. However, there has been little work on the displacement of indigenous populations from these regions and whether or not their food supply has been affected. Palm oil is an important food in Africa and Asia. There are ambitious plans to use palm oil for biodiesel, which generally involve expanding plantations and improving efficiency of processing rather than switching from food to fuel.

There is little analysis on the potential for biodiesel production from palm oil to displace food production, as the production of biodiesel is still quite low. However, palm oil is an important food crop in the Far East. The use of OSR for biodiesel in the EU is causing increased demand for palm oil for food in the EU. The impact of this should be monitored.

Air emissionswhere forest fires occur

Forest fires Forest and land fires to clear jungle, cause “hazes” in South East Asia (Ardiansyah 2006)

Zero burning policies.Prosecute deliberate starting of forest fires.Zero burning practices add to land-clearing costs by US$50-150 per ha (WWF 2003).

GHG emissions

From forest and other habitat clearance.

Drainage and burning of peat land to create new land for palm oil plantation releases CO2 to the atmosphere (Wetlands International). Figure: 600M t/year C released. “Production of 1 tonne of palm oil causes a CO2 emission between 10 and 30 tonnes through peat oxidation (assuming production of 3 to 6 tonnes of palm oil per hectare, under fully drained conditions, and excluding fire emissions)."( Hooijer et al., 2006).)Fires generate an estimated 1,400M t of CO2 /year.

Policies to prevent the use of vulnerable and high conservation value habitats and the fragmentation of such habitats.

GHG Emissions

Use of co-products

The Palm oil processing industry can be very efficient at the use of co-products: empty branches can be used as mulch; secondary oil is used for soap; fibrous expeller is used as a fuel

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for the processing plant (and is also exported to the UK for use in co-firing) and the palm nut shell is used in roads for the plantations. Co-products are also used as an animal feed. This use improves the GHG balance from biofuels production from palm oil. If there is no carbon emissions from land use change then emissions savings of about 35% can be realised.

Overall policies

Many of the more sustainable policies and practices are too expensive or difficult for small-scale producers.

Develop and share sustainable palm oil practices, with big companies sharing information with smallholders and funding of initiatives by co-operatives of smallholders.

3.3.1 Growth in production and consumption.FAO (2003b) data indicates ‘growth in oil crops, vegetable oils and products has been the fastest growth of all sub-sectors of global agriculture in recent times. Food demand in the developing countries accounted for half the increases in world output of the last two decades, with output measured in oil content equivalent. China, India and a few other countries represented the bulk of this increase. Strong demand for protein products for animal feed was also a major supporting factor in the buoyancy of the oil crops sector. The rapid growth of this sector reflects the synergy of the two fastest rising components of the demand for food: food demand for oils, favouring the oil palm and for livestock products favouring soybeans.’ The oil palm produces large yields of oil/ha compared with other crops and the seeds can be stored for a relatively long time. As a result they can be transported long distances and pressed elsewhere. In addition palm oil has good properties for both the food and oleochemical sectors. These factors, together with its relatively cheap cost are responsible for the increase in popularity of this crop.

Growth in oil palm production (in million tonnes of oil equivalent) rose from 2.1 Mt in 1964/66 to 21.6 Mt in 1997/99 and continues to rise (37.6 Mt in 2006/7). The main countries in which oil palm is grown are: Malaysia (51%); Indonesia (34%); Thailand (3.2%) Nigeria (2.6%) and Colombia (2.5%). African production tends to be at a small or medium scale, with relatively inefficient processing; production in Asia is at all scales including large plantations scale, with much more efficient processing.

It is estimated that 11 Mha of oil palm is planted world wide, approximately 6 Mha in Indonesia. There have been rapid increases over the past 25 years and more increases are planned. It is expected that Indonesia’s oil palm plantations will double in the next 20 years (Casson, 2003; Ardiansyah, 2006). In Indonesia production is planned in Kalimantan (up to 4 Mha) and Sumatra (Raiu, Jambi, Aceh, West Sumatra and Kalimantan).

The four main palm oil importers are China (imports total 5.6 Mt, 21% of total imports, up 0.6 Mt from 2005/06), the EU-25 (4.5 Mt, 17%, 4.1 Mt), India (3.8 Mt, 14%, 2.8 Mt) and Pakistan (1.8 Mt, 6%, 1.8 Mt). Palm oil is the world's most widely used oil, contributing to 32% of global vegetable oil consumption, and, of this, 74% of palm oil is used for food purposes. Currently some 24% of palm oil is used for industrial purposes. This includes uses in the chemical industry, washing and cleaning liquids, cosmetics and body lotions (Glastra et al., 2002). In recent years there has been an expansion in the proportion of palm oil used for industrial purposes, with only 16% being used in this sector a decade ago.

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3.3.2 Biodiesel productionThe use of palm oil for biodiesel production is relatively recent, and represents only 1% of biodiesel production at global level in 2006 (Thoenes, 2006). Most biodiesel is made from rapeseed oil (OSR) (84%), followed by sunflower oil (13%) and then soybean and other oils (2%). However, the use of OSR has a secondary effect on other oils. Because the EU is using so much OSR for biodiesel it has increased its imports of other oils (including sunflower and palm oil). Thoenes (2006) indicated that EU palm oil imports doubled during the 2000-2006 period, mostly to substitute for rapeseed oil diverted from food to fuel uses. The additional amount of oil that has been sourced for Europe’s food market is some 2.5 million tonnes/year, with a gradual increase since 2000. From 2000-2006 Europe’s palm oil imports doubled, as indicated above. This has had an impact on global plant oil prices. Thoenes (2006) estimates that imports of oils will increase by a further 1 and 1.5 million tonnes in the periods to 2010 and 2015 respectively.

There are indications that European producers may increase their use of palm oil if the recent high prices of OSR continue, as it is the cheapest suitable plant oil (although the price of palm oil has recently increased as well). Some analysts also point out that changes in US practices due to biofuels (planting maize rather than soy) has lead to decreased soy availability and increased demand for palm oil as a substitute (Times, 2008). This follows a long term decline in the palm oil price to 2005 (Thoenes 2006). In addition the Malaysian and Indonesian governments have announced plans to allocate 6 Mt of palm oil to biodiesel each year. This represents half their nation’s outputs (see below). In addition to the European production of biofuels, the UK Home Grown Cereals Authority (HGCA) states that ‘in Malaysia and Indonesia, the biodiesel sector is growing rapidly, driven by the low cost of the palm oil feedstock. This was part of the reason why, in mid-July, the two governments agreed a deal that limited annual palm oil usage in biodiesel to 12 Mt. Concerns have been raised that supplies of palm oil for food uses could be limited and that the destruction of large plantations of palm trees could reverse the carbon savings made from using biodiesel rather than conventional diesel. However, despite the new legislation, production of biodiesel in Malaysia and Indonesia is forecast at up to 0.13 Mt in 2006/07, with further increases expected in the next couple of seasons’. In addition, in 2003, Thailand launched an ambitious oil palm expansion (to cultivate an additional 800,000 ha over the next four years) in order to produce palm oil for biofuel production (FAO, 2003b).

There is some debate over what is causing the increase in deforestation of tropical rain forest in lowland Indonesia, which according to the FAO represents 17% of the global loss of rainforest between 2000 and 2005. There is no doubt that loss of rainforest can be correlated with the increase in oil palm plantations since the 1970s (see, for example, Brown and Jacobsen 2005, Greenpeace 2007, Nellerman et al. 2007). However, illegal logging and forest fires, which may or may not be a precursor to oil palm plantations are also blamed for deforestation. The Roundtable on Sustainable Palm Oil may ensure that palm oil is produced more sustainably in the future. This, however, will do nothing to prevent logging, illegal or otherwise. It is also difficult to provide statistics that clearly indicate whether illegal logging is directly or indirectly related to displacement of land use for palm oil production.

The above-soil carbon held in a mature oil palm plantation is only a small fraction of what old growth forests store. Primary forests in Indonesia have been found to hold 306 tonnes of carbon per hectare (t C/ha), whereas mature oil palm plantations hold 63 t C/ha (Boswell et al., 2007).

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3.4 GHG emissions from LUC in Latin AmericaLand use changes and the effects on SOC have been studied in Brazil, especially in the Brazilian Amazon (e.g. Cerri et al., 2003, 2004, 2007 cite over 50 papers). Cerri et al. (2003, 2004, 2007) studied conversion of forest to pasture for cattle ranching using simulation models, including RothC and Century, and experimental measurements. They showed how conversion to pasture led to initial falls in SOC stocks in the top 20cm soil layers, but in the majority of cases this was followed by a slow rise to levels exceeding those under native forest. One exception to this pattern was a degraded pasture. They conclude overall that well-managed pastures can be useful in increasing SOC stocks after deforestation. In one study (Cerri et al., 2004) reported how pasture SOC recovered, after about 10 years decline, to the original SOC concentration in the top 0-20 cm layer, although loss of forest SOC continued, it was exceeded by the accumulation of pasture SOC. It cannot, however, be assumed that all conversion will be as well managed. It also needs to be remembered that these measurements of SOC take no account of the loss of C sequestered in forest vegetation, which is much greater than in the soil.

Calegari et al. (2008) reported how SOC in a once-forested part of Paranà, decreased for about 10 years when cultivated for arable crops. This was followed by increases in SOC at differing rates according to the management practices used over a 19-year period, particularly at different depths of soil. No tillage (NT) cultivation sequestered more SOC in the upper soil layer than conventional plough-based tillage (CT). Winter cover crops grown under no tillage cultivation was the most successful method of increasing SOC storage and was the only method that approached the original SOC content of forest soil and increased C storage at a rate of abut 1.2 t C ha-

1 year-1. Again, the possibility of restoring some lost SOC was demonstrated, but not all management practices necessarily operate as effectively. The potential for sequestration also varies with soil types, as some are more capable of protecting SOC from degradation than others. Moreover, such estimates of the impact of NT on SOC fail to recognise that increases in SOC concentrations take place only near the soil surface and that the SOC content of lower horizons may decrease (Gál et al., 2007)

The impact of grazing on SOC in the Cerrado is less than on forest. Maquere et al. (2008) reported that total C stocks to 1 m depth under pastures that had been established for 20 and 80 years were numerically greater than, albeit not significantly different to, total SOC to 1 m of native Cerrado. The total SOC estimated, at 84 t/ha, was greater than the default value of 66 t/ha for Brazilian savannah cited by IPCC (2006). This finding was consistent with the results of earlier studies cited in the paper. However, when evaluating fluxes of CO2 to the atmosphere, it needs to be remembered that only considering changes to SOC takes no account of changes in above-ground carbon stocks which may be greatly reduced by land use change. The current estimate of total carbon storage, both SOC and above-ground, is c. 360 t/ha for Brazilian rainforest (IPCC, 2006).

It is clear that land use changes contribute to the loss of stored C, either from soils or from wood that may be burned during deforestation. There is also the potential for some recovery from the use of pasture or better arable cropping practices. It is worth observing that UK soils generally lost SOC following the great increase in arable cultivation both during and after the Second World War. These changes should be approaching a new equilibrium about now, although the asymptote may take another 100 years or so to be reached.

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40

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http://earthtrends.wri.org/searchable_db/index.php?step=countries&cID%5B%5D=179&theme=8&variable_ID=196&action=select_years

http://www.cropscience.org.au/icsc2004/symposia/2/4/187_wahidmb.htm