WASHINGTON — A coalition of 29 states and cities on Tuesday sued to block the Trump administration from easing restrictions on coal-burning power plants.
The lawsuit, led by New York’s attorney general, Letitia James, argued the Environmental Protection Agency had no basis for weakening an Obama-era regulation that set the first-ever national limits on carbon dioxide pollution from power plants.
That rule, the Clean Power Plan, required states to implement plans to reduce carbon dioxide emissions by 2022, and encouraged that to happen by closing heavily-polluting plants and replacing those energy sources with natural gas or renewable energy. Carbon dioxide released into the atmosphere is a major contributor to global warming because it traps the sun’s heat.
The lawsuit — by 22 states and seven cities including Massachusetts, California, Colorado, Wisconsin, North Carolina, Chicago and Miami — is the latest swing of the legal pendulum in a long-running dispute over how to regulate emissions from coal plants. Previously, Republican-led states and industry groups had sued to stop Mr. Obama’s Clean Power Plan from going into effect, and won a reprieve when the Supreme Court in 2016 temporarily blocked the Obama administration from imposing changes.
The new challenge, filed in the United States Court of Appeals for the District of Columbia, argues that the Trump administration’s replacement, known as the Affordable Clean Energy rule, ignores the E.P.A.’s responsibility under the law to set limits on greenhouse gases. It maintains that the new rule would actually extend the life of dirty and aging coal-burning plants, promoting an increase in pollution instead of curbing it.
It’s a legal battle that could again go all the way to the Supreme Court. This time, if justices ultimately decide in favor of the Trump administration and find the Clean Air Act does not allow the government to direct broad changes to the nation’s energy deployment, it could permanently weaken the United States’ ability to tackle its contributions to global warming.
“It would have a devastating effect on the ability of future administrations to regulate greenhouse gases under the Clean Air Act,” said Richard L. Revesz, a professor at New York University who specializes in environmental law. “It would essentially make it extremely difficult to regulate greenhouse gases effectively,” he said.
Michael Abboud, an E.P.A. spokesman, said in a statement that the agency does not comment on pending litigation. But he said of the A.C.E. regulations: “EPA worked diligently to ensure we produced a solid rule, that we believe will be upheld in the courts, unlike the previous Administration’s Clean Power Plan.”
Andrew Wheeler, the administrator of the E.P.A., announced the new rule in June at an event attended by coal-industry leaders, utility lobbyists and prominent deniers of climate change science.
Unlike the Obama-era Clean Power Plan, the Trump rule does not cap greenhouse gas emissions. Instead it leaves it up to states to decide whether, or if, to scale back emissions and pick from a menu of technologies to improve power-plant efficiency at the facility level.
Under the Clean Air Act, the E.P.A. is required to use the “best system of emissions reduction.” The Obama-era options included switching to cleaner energy sources like gas, solar or wind; putting a price on carbon dioxide emissions; or using technology that could capture and store carbon dioxide rather than releasing it into the atmosphere. The Trump-administration rule, by contrast, focuses solely on new efficiency measures for individual plants.
Mr. Wheeler argued that the Obama administration had overreached its authority with its rule and that the Trump administration’s plan was legally defensible. Mr. Obama’s Clean Power Plan was suspended by the Supreme Court in 2016 after challenges from 28 Republican-led states and several major industry organizations.
Those groups said Mr. Obama’s plan was unduly burdensome to utilities and too costly for consumers, a position that Mr. Wheeler also embraced. He maintained that A.C.E. would lead to a reduction of 10 million tons of carbon dioxide emissions and provide net benefits of $70 million each year. He also, however, said the new rule could lead to new coal plants being built.
Xavier Becerra, the attorney general of California, called the Trump administration’s rule “toothless,” described it as the “fossil fuel protection plan” and said the rule artificially narrows E.P.A.’s authority. “The Clean Air Act requires the E.P.A. to utilize the best system of emissions reduction that it can find. This rule does the opposite,” he said.
Ms. James said under the Trump administration’s suggested best system of reducing emissions, carbon dioxide pollution will come down only 0.7 percent more in the coming decade than it would if no rule existed at all.
Others joining the suit include Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Michigan, Minnesota, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont, Virginia, Washington, and the District of Columbia, as well as Boulder, Los Angeles, New York City and Philadelphia.
A coalition of environmental groups including the Natural Resources Defense Council, the Sierra Club and the Environmental Defense Fund are expected to file their own legal challenge this week.
Two leading public health groups, the American Public Health Association and the American Lung Association, have already filed suit to block the Trump administration plan.
The American Coalition for Clean Coal Electricity, a trade group that represents coal producers, last week filed a motion in support of the Trump administration. Michelle Bloodworth, the organization’s chief operating officer, said in a statement that she believes the E.P.A. has a “strong legal case” but added “we also want to help E.P.A. defend the new rule against others who prefer extreme regulation.”
For more news on climate and the environment, follow @NYTClimate on Twitter.