By Deborah Zabarenko, Environment Correspondent
WASHINGTON (Reuters) - The U.S. Environmental Protection Agency found that climate-warming greenhouse gases, including carbon dioxide, pose a danger to human health and welfare, a White House website showed on Monday.
EPA's proposed "endangerment finding," sent to the Obama administration on Friday, could pave the way for U.S. limits on emissions that spur climate change.
"I think it's historic news," said Frank O'Donnell of the environmental group Clean Air Watch. "It is going to set the stage for the first-ever national limits on global warming pollution."
The substance of the proposal was not immediately made public but the White House Office of Management and Budget showed EPA sent a proposed rule for an "Endangerment Finding for Greenhouse Gases under the Clean Air Act."
An endangerment finding is essential for the U.S. government to regulate such climate-warming emissions as carbon dioxide under the Clean Air Act.
The environment agency had no comment on the endangerment finding, but no such finding is sent to the White House unless the EPA determines that human health and welfare are threatened.
The Supreme Court ruled in 2007 that the EPA has the authority to make these regulations if human health is threatened by global warming pollution, but no regulations went forward during the Bush administration.
Carbon dioxide, one of several so-called greenhouse gases that spur global warming, is emitted by natural and industrial sources, including fossil-fueled vehicles, coal-fired power plants and oil refineries.
An internal EPA document made public last year showed that the agency's scientists believed greenhouse pollution posed a health threat, but no official finding was ever accepted by the Bush White House.
President Barack Obama favors a market-based system that could limit carbon emissions and allow companies that emit more than the limit to trade allowances with those that emit less. Congressional Democrats also favor this kind of cap-and-trade plan to cut emissions.
This is in line with action the EPA took on March 10 by proposing a comprehensive U.S. system for reporting emissions of carbon dioxide and other greenhouse gases, a step toward regulating pollutants that spur climate change.
A carbon registry would affect fossil fuel suppliers, automakers and companies that emit at least 25,000 metric tons of greenhouse gases a year, the EPA said then.
The U.S. government already has statistics on emissions from coal-fired power plants.
(Additional reporting by Tom Doggett and Ayesha Rascoe; editing by Mohammad Zargham)