As the climate changes, the composition and distribution of ecosystems will alter and individual species will respond to the changes. Some species in ecosystems may become extinct.
Climate Zones
Groups of organisms will tend to move towards the poles as warming occurs. It is predicted that a warming of 2°C over the next 100 years would shift current climatic zones towards the poles by about 300 km. The ecosystems most at risk from global warming will include those that are presently subject to harsh climates.
These include:
• Tropical forest
• Coral reefs
• Deserts
• Polar (ice) regions
• Coastal marshes
• Mountains
• Low lying land
The occurrence of extreme events, such as flooding and drought in these environments, may become more likely.
Forests
Forests cover around a quarter to a third of the total land surface of the Earth. They are
essential for the maintenance of a stable global climate. Global warming will increase the risk of
forest fires as soils and plants will become drier. Changes in pest populations may also place stress on forests. Forests are known to strongly moderate local climates and use up carbon dioxide during photosynthesis, helping to remove some of the carbon dioxide released by
mankind. As forests are cut down, this potential is removed. Furthermore, forest clearance through burning releases a lot of carbon dioxide into the atmosphere.