GLOBAL CLIMATE CHANGE: THE NATURE OF THE BEAST Rob Wolcott Bret O. Bergst World Resources Institute

CLIMATE CHANGE AND THE GREENHOUSE EFFECT Some of the infrared radiation passes through the atmosphere, and some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the Earth’s surface and the lower atmosphere. Some solar radiation is reflected by the Earth and the atmosphere Solar radiation passes through the clear Most radiation is absorbed by the Earth’s surface and warms it Infrared radiation is emitted from the Earth’s Surface The Greenhouse Effect This slide illustrates the Greenhouse Effect.

HUMAN ACTIVITIES HAVE CHANGED THE COMPOSITION OF THE ATMOSPHERE SINCE THE PRE- INDUSTRIAL ERA IPCC, 2001

CARBON DIOXIDE HAS TWO MAIN SOURCES 80 – 85% produced by recent fossil fuel use 15 – 20% results from changes in land use

PROJECTED CONCENTRATIONS OF CO2 DURING THE 21ST CENTURY ARE TWO TO FOUR TIMES THE PRE-INDUSTRIAL LEVEL IPCC, 2001

CHANGES IN TEMPERATURE, SEA LEVEL AND PRECIPITATION WILL HAVE VARYING IMPACTS The change in sea level and temperature will have a number of biological and socioeconomic effects. IPCC, 2001

PROJECTED TEMPERATURES DURING THE 21ST CENTURY ARE SIGNIFICANTLY HIGHER THAN AT ANY TIME DURING THE LAST 1000 YEARS IPCC, 2001

LAND AREAS ARE PROJECTED TO WARM MORE THAN THE OCEANS WITH THE GREATEST WARMING AT HIGH LATITUDES Annual mean temperature change, 2071 to 2100 relative to 1990: Global Average in 2085 = 3.1oC

EXAMPLES OF VULNERABLE ECOSYSTEMS Polar Reduced sea ice Altered distribution of species Mainland Asia Poleward movement of southern boundary of permafrost zones Small Island States Threats to coral reefs, coastal ecosystems Threats to reef fish/fisheries North America Prairie wetlands, alpine tundra, cold water ecosystems ASIA Climate change increases threats to biodiversity from land-use/land-cover change, population pressure Risk to ecological security from sea level rise (mangroves and coral reefs) Poleward movement of southern boundary of permafrost zones AUSTRALIA/NEW ZEALAND Species with restricted climatic niches and unable to migrate may become endangered or extinct Freshwater wetlands in coastal zones are vulnerable Coral reefs, arid and semi-arid habitats in southwest and inland Australia, Australian alpine systems are vulnerable New Zealand ecosystems are vulnerable to accelerated invasion by weeds North America Unique natural ecosystems (prairie wetlands, alpine tundra, cold water ecosystems) will be at risk Sea level rise would result in enhanced coastal erosion, coastal flooding, loss of coastal wetlands, increased risk from storm surges Polar Ecosystems are highly vulnerable with low adaptive capacity Decreased extent and thickness of sea ice, permafrost thawing, coastal erosion, changes in ice sheets and ice shelves, altered distribution of species in polar regions Latin America Increase in rate of biodiversity loss Africa Exacerbation of desertification resulting in extinctions of plant and animal species Australia/New Zealand Coastal wetlands, coral reefs, arid and semi-arid habitats, alpine systems are vulnerable (Source: IPCC [2001])

PRECIPITATION RATES ARE CHANGING

Annual mean precipitation change: 2071 to 2100 Relative to 1990 SOME AREAS ARE PROJECTED TO BECOME WETTER, OTHERS DRIER WITH AN OVERALL INCREASE PROJECTED Annual mean precipitation change: 2071 to 2100 Relative to 1990

INITIALLY INCREASED AGRICULTURAL PRODUCTIVITY IN SOME MID-LATITUDE REGIONS & REDUCTION IN THE TROPICS AND SUB-TROPICS EVEN WITH WARMING OF A FEW DEGREES 2020s 2050s 2080s IPCC, 2001

INCREASED WATER AVAILABILITY IN SOME WATER-SCARCE REGIONS, AND DECREASED WATER AVAILABILITY IN MANY WATER SCARCE REGIONS IPCC, 2001

SEA LEVELS HAVE RISEN

Sea Level change is actually cased by a combination of factors. IPCC, 2002

MEAN SEA LEVEL IS PROJECTED TO RISE. 09 TO MEAN SEA LEVEL IS PROJECTED TO RISE .09 TO .88M BY 2100 WITH SIGNIFICANT VARIATIONS Estimates of Sea Level Change project a rise of .09 to .88m by 2100. There are significant variations depending on the type of area.

SEA LEVEL RISE AND HEAVY RAINFALL EVENTS WILL DRAMATICALLY IMPACT LOW-LYING DELTAIC AREAS This slide from UNEP/Grid shows the devastating overall effects of sea level rise on Bangladesh. The effects on this type of area would be enhanced because of the coastline characteristics.

CLIMATE CHANGE AND OTHER ENVIRONMENTAL ISSUES ARE ALSO INTER-LINKED IPCC, 2002