Climate warning - Greenhouse gases may cause severe floods, droughts

Publication: Weekend Nation / Extra
Paper Section And Page: 20
Paper Date: Fri, Dec 14, 2001

The National Academy of Sciences has released a report citing evidence that warming caused by greenhouse gases and other pollutants could trigger large, abrupt climate changes marked by periods of severe floods and droughts. A December 11 Press release said the new report by the National Academies' National Research Council provides a different view from recent climate change studies that have focused on the risks of a gradual rise in the Earth's temperature. Using historical observations and computer modeling analyses going back hundreds of centuries, the researchers found evidence that periods of gradual change in Earth's past were punctuated by episodes of abrupt change, including temperature changes of about ten degrees Celsius in only a decade in some places.

The researchers said examples of abrupt change in the past century include the United States Dust Bowl drought of the 1930s and the rapid warming of the North Atlantic from 1920 to 1930 ­ a warming that was accompanied by significant climate changes across the globe, including flooding and drought.

The committee that wrote the report added, however, that there is no need for undue alarm about the possibility of sudden climate change because societies have learned to adapt to these changes through the course of human history. It also emphasized that not enough is known about such events to accurately predict them, so surprises are inevitable. The committee said proactive policies might be beneficial regardless of whether abrupt climate change occurs, including reducing greenhouse gas emissions to slow global warming, improving climate forecasting, slowing biodiversity loss, and improving water, land and air quality. The entire report, entitled Abrupt Climate Change: Inevitable Surprises, can be found at the www.nap.edu.

The report was sponsored by the United States Global Change Research Programme, with additional support from the National Bureau of Economic Research Programme on International Environmental Economics at Yale University. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. (USIS)