Wednesday, June 17, 2009

White House says climate change damage has begun

Harmful effects from global warming already are happening and are worsening, warns the first climate report from Barack Obama's presidency in the strongest language on climate change ever to come out of the White House.

Global warming already has caused more heavy downpours, rising temperature and sea levels, rapidly retreating glaciers, longer growing seasons and altered river flow, according to the document released Tuesday by the White House science adviser and other top officials.

«There are in some cases already serious consequences,» report co-author Anthony Janetos of the University of Maryland told The Associated Press. «This is not a theoretical thing that will happen 50 years from now. Things are happening now.
The White House document, a climate status report required periodically by Congress, contains no new research. Instead, it focuses and organizes what has been covered in numerous scientific journals and piecemeal federal studies to paint a more cohesive, bigger and darker picture of global warming in the United States.

The «major disruptions» already taking place will increase as warming continues, the authors wrote. They project the average U.S. temperature could rise by as much as 11 degrees Fahrenheit (24 C) by the end of the century.

«Thresholds will be crossed, leading to large changes in climate and ecosystems,» the study said in one of its main findings, adding that it could affect the survival of some species.

For example in the past few decades, winters in parts of the U.S. Midwest have warmed by several degrees, and the time without frost has grown by a week, according to the report.

«We're already seeing impacts across the nation,» said co-author Virginia Burkett, coordinator of global change science at the U.S. Geological Survey. «The evidence is much stronger than it has been.

White House science adviser John Holdren said in a statement that the findings make the case for acting to slow global warming, both by reducing emissions and adapting to the changes that «are no longer avoidable.

«It tells us why remedial action is needed sooner rather than later,» Holdren said.

The report emphasized that water, either too much or too little, will continue to be a major problem in every region of the country.

«Water permeates this document,» Burkett said. She said the U.S. Southwest will get drier and hotter and that will be a crucial issue. The nearly 200-page report has chapters examining the effects of global warming in each region, as well as everything from health to transportation problems.

Federal law requires comprehensive reports on global warming's effects every four years. An environmental group sued to force the Bush administration to issue an early draft of this report last summer because one had not been written since 2000. Since that time, the language has become stronger, but mostly because of fresher research, scientists said.

«The emphasis has shifted from just looking at the physical climate science to adapting to change,» Burkett said in an interview.

U.S. Global Change Research Program: tinyurl.com/m4rdnp