Tropics at Peril: Changing Climate Redrawing the Map

Tropical forests are at risk of losing most of the plants and animals that now comprise their ecosystems, according to a new report from the Carnegie Institution on the effects of climate change and deforestation. In a sober appraisal of the future, the study says that the combined impact of climate change and spreading land use "represents one the greatest global change experiments on Earth today" - and not to our benefit.

Among other things, the report expects deforestation and logging to exact a higher toll on the world's humid tropical forests than previously reported. Carnegie researchers concluded that only 18% to 45% of the plants and animals found in these ecosystems "may remain as we know them today" by the year 2100.

The full study will be published in the August 5, 2010, issue of Conservation Letters.

More than half of all the plants and animal species are found in tropical forests. Greg Asner, who directed the Carnegie study, held out hope that the impact of deforestation could be ameliorated by better land management policies in areas of the world most vulnerable to the effects of climate change. He said that would help many species make the adjustment, or at least keep pace with climate change.

Among their conclusions:

• Climate change could alter two-thirds of the tropical forests in Central and South America
• Over 80% of the Amazon Basin could suffer changes in its biodiversity
• About 70% of Africa's tropical forest biodiversity is at risk
• The Congo: Between 35 percent and 74 percent of the forests in the region are threatened by logging and climate change.
• In Asia and the central and southern islands of the Pacific may fare better than other regions. Deforestation and logging, the primary drivers of changes in their local ecosystems, are down 22% in the last decade. Still, up to 77% of the area is at risk of biodiversity losses.