Confronting climate change – considering potential impacts and

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Global Roundtable on Climate Change atColumbia University

11-12 May, 2005

Jerry M. MelilloThe Ecosystems Center

Marine Biological LaboratoryWoods Hole, MA

Human Health

Agriculture

Forests

Water Resources

Species and Natural Areas

Temperature

Precipitation

Sea Level Rise

Coastal Areas

Energy Demands

Transportation

POTENTIAL IMPACTS

Climate Changes

Health Impacts

• Weather-related mortality

• Air quality – respiratory illness

• Vector-borne diseases

Agricultural Impacts

• Changes in crop yields

• Increased spread of pests and vector-borne diseases

• Changes in irrigation demands

Forest Impacts

• Forest health and productivity

• Forest composition

• Geographic range

Water Resources Impacts

• Water supply• Water quality• Competition for

water

Impacts on Coastal Areas

• Erosion • Inundation of

coastal lands• Additional costs

to protect coastal communities

Hurricane categories

Vulnerable coastal areas for Manhattan based on about a 6 meter high flooding zone for the year 2100- simulation of Klaus Jacob, Lamont-Doherty

Potential urban impacts of coastal flooding

Species and Natural Areas

• Species migrations

• Loss of habitats and their species

Energy demands

• Heating demands reduced in some regions

• Cooling demands increased in other regions

Transportation

• Damage to infrastructure

• New opportunities

IGSM diagram

Joint Program on the Science and Policy of

Global Change

MIT Integrated

Global System Model (IGSM)

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Ref: R. Prinn et al., Climatic Change, 41: 469-546, 1999

Contact rprinn@mit.edu for citation permission

Ref: J. Melillo et al., Nature 363:234-240, 1993

CH4

-200 -100 0 100 200

( g CO2 –eq. m-2 yr-1 )

Current 2090s w CO2 fert.

2090s

High-latitude annual carbon budget

that considers both carbon dioxide and

methane

Conclusions

• Climate change will affect people and the ecosystems that support them throughout the world

• The impacts will be a mix of positives and negatives

• The magnitude of both beneficial and harmful impacts grows as the focus shifts to smaller regions, individual communities and specific activities or resources

Conclusions (continued)• Some of the most negative impacts are likely

to be in regions that can least afford adaptation strategies – e.g., small island nations, sub-Saharan Africa

• Many ecosystems are vulnerable to the projected rate and magnitude of climate change. Ecosystems such as alpine tundra and barrier islands are likely to disappear entirely in some areas. Other ecosystems may fragment.

• The goods and services lost through the disappearance or fragmentation of certain ecosystems are likely to be costly or impossible to replace.

Conclusions (continued)

• Climate change is likely to promote the release of carbon as CO2 and CH4 from the biosphere into the atmosphere, thereby accelerating the rate of warming and the intensification of the hydrologic cycle.