WASHINGTON — The Obama administration on Monday will announce one of the strongest actions ever taken by the United States government to fight climate change, a proposed Environmental Protection Agency regulation to cut carbon pollution from the nation’s power plants 30 percent from 2005 levels by 2030, according to people briefed on the plan who spoke anonymously because they had been asked not to reveal details.
The regulation takes aim at the largest source of carbon pollution in the United States, the nation’s more than 600 coal-fired power plants. If it withstands an expected onslaught of legal and legislative attacks, experts say that it could close hundreds of the plants and also lead, over the course of decades, to systemic changes in the American electricity industry, including transformations in how power is generated and used.
It is also likely to stand as President Obama’s last chance to substantially shape domestic policy and as a defining element of his legacy. The president, who failed to push a sweeping climate change bill through Congress in his first term, is now acting on his own by using his executive authority under the 1970 Clean Air Act to issue the regulation.
Under the rule, states will be given a wide menu of policy options to achieve the pollution cuts. Rather than immediately shutting down coal plants, states would be allowed to reduce emissions by making changes across their electricity systems — by installing new wind and solar generation or energy-efficiency technology, and by starting or joining state and regional “cap and trade” programs, in which states agree to cap carbon pollution and buy and sell permits to pollute.
E.P.A. officials have said they hope the flexible approach will allow states to comply with the regulation more easily and cost-effectively, by adopting policies best tailored to regional economies and energy mixes. But industry groups planning to sue to block or delay the rule have said that approach makes the rule more legally vulnerable.
The details of the proposed regulation were first reported Sunday afternoon by The Wall Street Journal online.
Because burning coal is the largest source of the greenhouse gas emissions that scientists blame for trapping heat in the atmosphere and dangerously warming the planet, the rule is expected to have a powerful environmental impact. It comes on top of a regulation Mr. Obama issued in his first term that sharply increased the required fuel economy of vehicles, the second-largest source of carbon pollution in the United States.
Experts said that the new regulation would set the United States on track to meet its target set forth in a United Nations accord in 2009, when Mr. Obama pledged that the United States would cut its greenhouse gas pollution 17 percent from 2005 levels by 2020, and 83 percent by 2050.
On Sunday, environmental advocates praised the proposed rule for its breadth and reach while the coal industry attacked it as a symbol of executive overreach that could wreak economic havoc. Republican campaigns plan to use the rule to attack incumbent Democrats in this fall’s midterm elections.
“This momentous announcement raises the bar for controlling carbon emissions in the United States,” said Andrew Steer, president of the World Resources Institute, a Washington research organization, adding, “These new standards send a powerful message around the world.”
Scott Segal, a lawyer with the firm Bracewell & Giuliani, which represents coal companies and plans to sue over the rule, wrote in an email, “Clearly, it is designed to materially damage the ability of conventional energy sources to provide reliable and affordable power, which in turn can inflict serious damage on everything from household budgets to industrial jobs.”
Last week, the U.S. Chamber of Commerce issued a report warning that the rule could lower the gross domestic product by $50 billion annually.
The proposal to be unveiled Monday will be a draft, open to public comment, and is certain to set off a wave of lobbying from states, industry groups and environmentalists seeking to shape the final version of the rule. While there is no legal deadline for finalizing the regulation, Mr. Obama has directed the E.P.A. to issue the rule by June 2015 so that the administration can begin putting the program in place before he leaves office.
Nations around the world are closely scrutinizing the climate change rule and its prospects.
The timing of the rule signals that Mr. Obama may be more interested in achieving a legacy-making global deal on climate change than in short-term political concerns. While the rule could make things politically difficult for incumbent Democrats from coal states in November, it could make things easier for American climate change negotiators this fall at the United Nations General Assembly, where governments are expected to hold side meetings intended to forge a global climate change treaty that negotiators hope to have signed by 2015.
Over the long term, the United States has been the world’s largest emitter of carbon pollution, but today China is the largest, with India and other developing Asian countries poised to see an explosion in their carbon pollution in the coming years as millions of people join the middle class and begin enjoying cheap coal-fired electricity.
But China and India have resisted American pressure to cut their own carbon pollution because, they have said, the United States has no moral authority to push other nations to cut pollution when it fails to do so at home.
State Department climate negotiators hope that by bringing the new E.P.A. rule to the table, they will be able to demonstrate significant action and have fresh leverage to broker a deal.
“I fully expect action by the United States to spur others in taking concrete action,” Christiana Figueres, executive secretary of the United Nations Framework on Climate Change, said.
