Washington, DC:
The United States delivered a welcome boost on Monday to a pivotal climate conference by saying greenhouse gases blamed for global warming should be regulated as a health hazard.
The Obama administration's announcement came as delegates opened a meeting of 192 nations in Copenhagen with emotional appeals to leaders in Washington and elsewhere to take stronger action.
Such regulation by the US Environmental Protection Agency (EPA) would supplement the cap on carbon dioxide emissions being considered in the US Congress, effectively raising the US offer on emissions reductions in two weeks of hard bargaining in Copenhagen.
Under a Supreme Court ruling, the so-called endangerment finding is needed before the EPA can regulate carbon dioxide and five other greenhouse gases released from automobiles, power plants, and factories under the federal Clean Air Act.
"This long-overdue finding cements 2009's place in history as the year when the United States government began addressing the challenge of greenhouse-gas pollution and seizing the opportunity of clean energy reform," said EPA Administrator Lisa Jackson at news conference.
The announcement was delivered as the Obama administration looked to boost its arguments at Copenhagen that the United States is aggressively taking actions to combat global warming, even though Congress has yet to act on climate legislation.
The EPA signalled last April that it was inclined to view heat-trapping pollution as a threat to public health and welfare and began to take public comments under a formal rulemaking.
The action marked a reversal from the George W Bush administration, which had refused before leaving office to issue the finding, despite a conclusion by EPA scientists that it was warranted.
Business groups have strongly argued against tackling global warming through the Clean Air Act, saying it is less flexible and more costly than the cap-and-trade bill being considered before Congress.
Any regulations are also likely to spawn lawsuits and lengthy legal fights.
The EPA and the White House have said regulations on greenhouse gases will not be imminent even after an endangerment finding, saying that the administration would prefer that Congress act to limit such pollution through an economy-wide cap on carbon dioxide and other greenhouse gases.
Nevertheless, the EPA has begun the early stages of developing permit requirements on carbon dioxide pollution from large emitters such as power plants.
The administration also has said it will set the first-ever greenhouse gas emissions standards for automobiles and raise fuel economy to 35 miles per gallon by 2016 to reduce carbon dioxide emissions.
The EPA's readiness to tackle climate change is expected to give a boost to US arguments at the climate conference opening in Copenhagen this week, where the United States offer a provisional target to reduce greenhouse gases.
While the House has approved climate legislation that would cut emissions by 17 per cent by 2020 and about 80 per cent by mid-century, the Senate has yet to take up the measure amid strong Republican opposition and reluctance by some centrist Democrats.
Environmental campaigners in Copenhagen gave a broad welcome on Monday to news that America's Environmental Protection Agency had made the ruling regarding that greenhouse gases are endangering people's health and must be regulated.
Greenpeace USA spokesman Damon Moglen said the move would help Obama move ahead to curb climate change.
"The President doesn't need to wait for Congress. He can now use the EPA endangerment finding and the Supreme Court ruling that says the EPA can regulate greenhouse gases to move ahead and to really begin to bring down greenhouse pollution in our country."
Under a Supreme Court ruling, the so-called endangerment finding is needed before the EPA can regulate carbon dioxide and five other greenhouse gases released from power plants, factories and automobiles under the federal Clean Air Act.
The climax of the December 7-18 conference climax will come when President Barack Obama and more than 100 other national leaders arrive for the final hours of talks next week.
As the conference began, the European Union called for a stronger "bid" by the Americans, who thus far have provisionally pledged emissions cuts much less ambitious than Europe's.
Swedish environment minister Andreas Carlgren told reporters he would be "astonished" if Obama did not put more on the table.
Whether the prospect of EPA action will satisfy such demands - and what China may now add to its earlier offer - remains to be seen.
And success in the long-running climate talks hinges on more than emissions reductions.
Most important, it requires commitments of financial support by rich countries to help poor nations cope with the impacts of a changing global climate.
The focus in Copenhagen has fallen on individual countries' pledges of emission reductions, to be incorporated in some final agreement to succeed the Kyoto Protocol, whose modest emission cuts for 37 nations expire in 2012.
The EU has pledged an ambitious 20 percent reduction in gases by 2020, compared with 1990 levels, and 30 percent if other nations also aim high.
Japan has offered a 25 per cent cut against 1990, and Australia up to 25 per cent.
After eight years of inaction under the Bush administration, Obama has offered to reduce U.S. emissions by about 17 per cent by 2020 but against a later benchmark year, 2005.
Compared with 1990, that's only a 3 percent to 4 percent cut. Obama's offer had to be provisional, pending action in Congress.
Before the conference, developing countries, exempt under Kyoto, made their own offers: China said it would, by 2020, reduce gases by 40 per cent to 45 per cent below "business as usual" that is, judged against 2005 figures for energy used versus economic output. India offers a 20 per cent to 25 per cent slowdown in emissions growth.
Unlike industrialised nations, developing countries' targets are not expected to be made legally binding.