WASHINGTON (AP) âÄî The EPA on Friday declared that carbon dioxide and five other greenhouse gases sent off by cars and many industrial plants “endanger public health and welfare,” setting the stage for regulating them under federal clean air laws. The action by the Environmental Protection Agency marks the first step toward requiring power plants, cars and trucks to curtail their release of climate-changing pollution, especially carbon dioxide from the burning of fossil fuels. EPA Administrator Lisa Jackson said while the agency is prepared to move forward with regulations under the Clean Air Act, the Obama administration would prefer that Congress addressed the climate issue through “cap-and-trade” legislation limiting pollution that can contribute to global warming. Limits on carbon dioxide and the other greenhouse gases would have widespread economic and social impact, from requiring better fuel efficiency for automobiles to limiting emissions from power plants and industrial sources, changing the way the nation produces energy. In announcing the proposed finding, Jackson said the EPA analysis “confirms that greenhouse gas pollution is a serious problem now and for future generations” and warrants steps to curtail it. While EPA officials said the agency may still be many months from actually issuing such regulation, the threat of dealing with climate change by regulation could spur some hesitant members of Congress to find another way to address the problem. “The (EPA) decision is a game changer. It now changes the playing field with respect to legislation,” said Rep. Ed Markey, D-Mass., whose Energy and Commerce subcommittee is crafting broad limits on greenhouse emissions. “It’s now no longer doing a bill or doing nothing. It is now a choice between regulation and legislation.” Sen. Barbara Boxer, D-Calif., chair of the Environment and Public Works Committee responsible for climate legislation, said EPA’s action is “a wake-up call for Congress” âÄî deal with it directly through legislation or let the EPA regulate. Friday’s action by the EPA triggered a 60-day comment period before the agency issues a final endangerment ruling. That would be followed by a proposal on how to regulate the emissions. The agency said in its finding that “in both magnitude and probability, climate change is an enormous problem” and that carbon dioxide and five other gases “that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act.” The EPA concluded that the science pointing to man-made pollution as a cause of global warming is “compelling and overwhelming.” It also said tailpipe emissions from motor vehicles contribute to climate change. The EPA action was prompted by a Supreme Court ruling two years ago that said greenhouse gases are pollutants under the Clean Air Act and must be regulated if found to be a danger to human health or public welfare. The Bush administration strongly opposed using the Clean Air Act to address climate change and stalled on producing the so-called “endangerment finding” demanded by the high court in its April 2007 ruling. The court case, brought by Massachusetts, focused only on emissions from automobiles. But it is widely assumed that if the EPA must regulate emissions from cars and trucks, it will have no choice but to control similar pollution from power plants and industrial sources. Congress is considering imposing an economy-wide cap on greenhouse gas emissions along with giving industry the ability to trade emission allowances to mitigate costs. Legislation could be considered by the House before the August congressional recess. In addition to carbon dioxide, a product of burning fossil fuels, the EPA finding covers five other emissions that scientists believe are warming the earth when they concentrate in the atmosphere: Methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). ____ On the Net: The Environmental Protection Agency: www.epa.gov