A group of U.S. climate scientists is urging Congress to quickly pass a strengthened version of the House global warming bill, saying the legislation would provide a basis for stronger federal policies.

The letter [pdf] signed by 20 scientists says strong U.S. leadership is needed to avert a "rapidly developing global climatic catastrophe." The House climate and energy bill proposed by Democratic Reps. Henry Waxman of California and Ed Markey of Massachusetts offers a "powerful advance and must be enacted this year," it says, as a first step toward strong U.S. action.

"We're very encouraged that Congress is moving on legislation," said Michael MacCracken, chief scientist for climate programs at the nonprofit Climate Institute. "But a lot of what's happening in the discussions is that adjustments are being made, which is understandable, but in order to have an effect on climate we need to have really strong actions, and we don't want to just keep having it nibbled away."

The scientists also rebuked a widely held view that nations should strive to limit atmospheric carbon dioxide concentrations to 450 parts per million and limit the rise of global temperatures to less than 2 degrees Celsius.

"We and many others are of the view that these objectives are inadequate to sustain the integrity of global climate and to hold the risk of ruinous climatic change to an acceptably low level," the letter says.

Some scientists, including NASA climatologist James Hansen, have suggested that the world should cut atmospheric carbon dioxide levels to 350 parts per million -- below today's level of 385 ppm (ClimateWire, April 15). Hansen was not a signatory to this letter.

To achieve necessary cuts in greenhouse gas emission levels, the Waxman-Markey bill must be strengthened wherever possible and certainly not weakened before being passed into law, the letter says. And as Obama works to advance his health care reform agenda, the scientists are calling on the administration "to initiate an effort at least comparable in the area of climatic change."

Click here to read the letter.

Reprinted from Greenwire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500