AP Associated Press - Dec. 7, 2009 

WASHINGTON - The Environmental Protection Agency took a major step Monday toward regulating greenhouses gases, concluding that climate changing pollution threatens the public health and the environment.

The announcement came as the Obama administration looked to boost its arguments at an international climate conference that the United States is aggressively taking actions to combat global warming, even though Congress has yet to act on climate legislation. The conference opened Monday in Copenhagen.

The EPA said that the scientific evidence surrounding climate change clearly shows that greenhouse gases "threaten the public health and welfare of the American people" and that the pollutants - mainly carbon dioxide from burning fossil fuels - should be regulated under the Clean Air Act.

The Obama administration has announced that rather than wait for Congress to act, it has authorized the Environmental Protection Agency to move forward on enacting new regulations on greenhouse gas emissions emitted from hundreds of power plants and large industrial facilities.