Forest forecast

Posted: 1 August 2000

The Intergovernmental Panel on Climate Change, made up of more than 2,500 of the world's leading scientists, has concluded that "forests are highly sensitive to climate change" and that up to one third of currently forested areas could be affected in some way.

Conservation of forest habitats in a rapidly warming world is likely to be hardest in the places where these ecosystems are fragmented, polluted or under development pressure, says Nigel Dudley and Adam Markham for the World Wide Fund for Nature (WWF) Climate Change Campaign. Global warming will alter the ability of trees to survive, and may force species to disperse and shift their ranges far faster than they are able to, thereby disrupting existing ecosystems. As climatic zones change, habitats may move geographically, move to different altitudes, break up or be lost entirely. Warmer temperatures increase the rate at which trees use water, and if not balanced by increased precipitation, warming can directly threaten forest survival, particularly where tree species are already living at the edge of their ecological tolerances. Hopefully, as some scientists suggest, the increased carbon dioxide in the atmosphere may partially offset this effect by increasing the efficiency with which trees use water. Warmer conditions may also increase the threat from pests and diseases. For example, scientists in Alaska have concluded that 20 million hectares of forest there is suffering from an unprecedented attack by spruce budworms as a result of the recent extraordinary string of warm years.

Contact: Andrew Kerr - Public Affairs Manager
WWF Climate Change Campaign.
Tel/Fax: (+31 20) 676 9058