WASHINGTON – President Donald Trump is keeping a signature campaign promise to boost the coal industry, but environmentalists say the energy plan his administration rolled out Wednesday would lead to premature deaths,increase the risk of lung disease and hasten climate change.

The Affordable Clean Energy (ACE) rule, an amendment to the Clean Air Act, is likely to extend the lives of potentially scores of aging coal-fired power plants across the country whose carbon emissions are blamed for contributing to global warming.

It replaces the Clean Power Plan, President Barack Obama's aggressive strategy to confront climate change that never took effect after the Supreme Court prevented its implementation in 2016.

Obama's approach sought to shutter dozens of coal-fired power plants by forcing utilities to cut down on emissions of carbon, sulfur dioxide and nitrogen oxide that contribute to global warming.

Many of those plants are likely to operate longer under the Trump administration rule because it gives states and utilities flexibility to design a plan that proponents say will keep energy costs for coal plants and consumers low while gradually reducing carbon emissions.

Environmental Protection Agency Administrator Andrew Wheeler unveiled the ACE rule during a news conference at agency headquarters attended by coal miners, congressional lawmakers and energy industry representatives.

Under ACE, states have three years to submit a plan to limit greenhouse gas emissions to the EPA for review. The agency estimates that 600 coal-fired electric generation units at 300 facilities nationwide will be covered by the rule though officials could not say how many of them would run longer as a result.

The new rule, Wheeler said, "gives states the regulatory certainty they need to continue to reduce emissions and provide affordable and reliable energy to all Americans."

Opponents argue it does little to confront the escalating dangers posed by climate change and will allow power plants to keep spewing air pollutants, such as soot, that lead to asthma and other lung-related diseases.

“As rising temperatures, surging seas and record-breaking natural disasters ravage communities everywhere, the Trump Administration continues to ignore science and put the interests of polluters ahead of the American people," House Speaker Nancy Pelosi, D-Calif., said in a statement shortly after the proposal became public.

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Environmental groups and some states vowed to sue to stop the plan's implementation, just as opponents of Obama's Clean Power Plan did successfully four years ago.

"Like so many other Trump regulatory rollbacks, these new (ACE) rules will hit the wall in the courts," David Doniger of the Natural Resources Defense Council (NRDC) wrote. "NRDC, joining forces with state, environmental, and business allies, will challenge the Clean Power Plan repeal and the Dirty Power Plan replacement – and we expect to win."

Trump has made reviving the coal industry a signature plank of his "Make America Great Again" agenda. He is withdrawing the United States from the Paris Agreement to lower carbon emissions and has repeatedly questioned the science – some of it from his own administration – confirming the evidence of a warming planet and the threat that poses.

The issue could be a factor in the 2020 election in swing states, such as Ohio and Pennsylvania, where coal is still mined.

Labor Department statistics show that the industry workforce has risen slightly under his administration after hitting a low in 2016, Obama's last year in office.

Obama's Clean Power Plan was finalized in 2015, mainly targeting coal-fired power plants that account for nearly 40% of U.S. carbon dioxide emissions. It remains on hold under a Supreme Court stay, pending the outcome of a legal challenge from states.

Mandy Gunasekara, who worked on the ACE proposal as a top official in the EPA until leaving the agency in February, said ACE has a better chance of improving air quality than the Clean Power Plan because it's more likely to survive a court challenge.

"For all the fanfare around the CPP, it achieved a total number of zero emission reductions due to Supreme Court intervention," said Gunasekara, who runs a nonprofit group called Energy45 to promote Trump's energy policies. "ACE establishes a cooperative framework whereby the federal government works alongside state government to advance environmental goals. For any honest environmentalist, this (is) something to be celebrated."

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The new rule lists six technologies that coal-fired plants can use to lower emissions, including ways of modernizing facilities to improve efficiency. It does not allow plants to count emissions reductions achieved through carbon capture technology. It does not permit carbon trading or carbon pricing, methods pushed by environmental advocates as more effective.

Even if it survives a court challenge, the Trump proposal might not do much to help an industry that's been buffeted by economic and political forces.

Coal-fired plants across the country have been closing regularly over the past decade and dozens more are scheduled to close by 2030. This month, former New York City mayor and environmental activist Michael Bloomberg pledged $500 million as part of an effort to shutter every coal-fired power plant in the USA.

Conrad Schneider, advocacy director for the Clean Air Task Force, an environmental organization, said the Trump rule is misguided not only because it promotes bad policy but because the industry doesn't even want it.

"It contemplates investing more money in old, dirty coal plants," he said. "The one thing they chose to base this rule on is the one thing that no one is doing. Nobody is putting money into old coal plants right now."