Leaked report says climate scientists now see higher projected temperatures.

• Author: Ayres, Ed
• Position: Intergovernmental Panel on Climate Change revises forecast - Brief Article

* Leaked report says climate scientists now see higher projected temperatures: The Intergovernmental Panel on Climate Change (IPCC) has made two momentous revisions in its forecasts of global warming, according to a summary report that was distributed to the world's governments--and quickly leaked to reporters--in October. The panel has substantially raised its projections of the Earth's likely temperature increases over the next century, and it has become sharply more emphatic in its conclusion that human activities (as opposed to natural planetary cycles) are driving the increase. The IPCC, a U.N.-administered body composed of leading climate scientists from more than 100 nations, issued its first report projecting global warming and imputing anthropogenic (human) causality in 1992, and a second, stronger, report in 1995.

In its 1995 forecasts of temperature increase, the IPCC projected that the planet will warm by 1.8 to 6.3 degrees F. during the next century, but the new report revises that projection upward, to a range of 2.7 to 11 degrees. The revision is based on new evidence about the effects of sulfate pollution from factories and power plants. Sulfates have a cooling effect, which to some extent offsets the warming effect of the carbon dioxide...