WASHINGTON - The Biden administration on April 25 placed the final cornerstone of its plan to tackle climate change: a regulation that would force the nation’s coal-fired power plants to virtually eliminate the planet-warming pollution they release into the air or shut down.

The regulation from the Environmental Protection Agency (EPA) requires coal plants in the United States to reduce 90 per cent of their greenhouse pollution by 2039, one year earlier than the agency had initially proposed. The compressed timeline was welcomed by climate activists but condemned by coal executives, who said the new standards would be impossible to meet.

The EPA also imposed three additional regulations on coal-burning power plants, including stricter limits on emissions of mercury – a neurotoxin linked to developmental damage in children – from plants that burn lignite coal, the lowest grade of coal. The rules also more tightly restrict the seepage of toxic ash from coal plants into water supplies and limit the discharge of wastewater from coal plants.

Taken together, the regulations could deliver a death blow in the US to coal, the fuel that powered the country for much of the last century but has caused global environmental damage. When burned, coal emits more carbon dioxide than any other fuel source.

The new rules regarding power plants come weeks after the administration’s other major climate regulations to limit emissions from cars and large trucks in a way that is designed to speed up the adoption of electric vehicles. Transportation and electric power are the two largest sources in the US of the carbon pollution that is driving climate change.

US President Joe Biden wants to cut that pollution about 50 per cent from 2005 levels by the end of this decade, and to eliminate emissions from the power sector by 2035.

The coal industry in the US has been on a precipitous decline for more than a decade, as environmental regulations and a boom in natural gas, wind and solar power have made it more expensive to burn coal, and power generation has shifted towards those cheaper, cleaner sources of electricity. In 2023, coal-fired power plants generated 16.2 per cent of the nation’s electricity, according to the US Energy Information Agency, down from a peak of 52 per cent in 1990. There are about 200 coal-burning power plants still operating, with many concentrated in Pennsylvania, Texas and Indiana.

There are only a few ways to eliminate emissions from power plants that burn coal. The chief manner is carbon capture and sequestration, a process that traps emissions from a smokestack before they reach the atmosphere and then stores them. That technology is extremely expensive and not fully deployed at any American coal plant. Some researchers are exploring other technologies, such as converting coal plants to run on ammonia. But none of those have been widely implemented.

The limits on power plant emissions announced on April 25 would also apply to future facilities that burn gas, requiring them to capture their emissions or to use a fuel that is non-polluting. Gas-fired power plants that are currently in operation would be exempt.

“Today, EPA is proud to make good on the Biden-Harris administration’s vision to tackle climate change and to protect all communities from pollution in our air, water and in our neighbourhoods,” said EPA administrator Michael Regan. “By developing these standards in a clear, transparent, inclusive manner, EPA is cutting pollution while ensuring that power companies can make smart investments and continue to deliver reliable electricity for all Americans.”

Mr Manish Bapna, the president of the Natural Resources Defense Council, an advocacy group, declared that “the age of unbridled climate pollution from power plants is finally over”.

The EPA estimates that the rule controlling greenhouse gases from power plants would eliminate 1.38 billion metric tonnes of carbon dioxide between now and 2047, which is equivalent to preventing the annual emissions from 328 million gasoline-powered cars.

The agency estimates that the rule would cost industries US$19 billion (S$25.8 billion) to comply between now and 2047, but says the economic benefits during the same time period would be far greater. By stopping pollution from reaching the atmosphere, the regulation would help prevent US$270 billion in damage to the economy from floods, wildfires, droughts, supply chain disruptions and increased commodity costs linked to climate change, the EPA said.

The EPA expects the regulation would also prevent other pollutants, such as soot, from escaping into the air, resulting in US$120 billion in public health benefits between now and 2047. In 2035 alone, the agency projects that the rule will prevent up to 1,200 premature deaths, 870 hospital and emergency room visits, 360,000 asthma attacks, 48,000 school absence days and 57,000 lost workdays.

“Today is a good day for public health, particularly kids’ health,” said American Lung Association president and chief executive Harold Wimmer.

Republicans, electric utilities and the coal industry are likely to challenge the regulations. They argue they would decimate jobs, increase blackouts and drive up electricity costs.

“We think it’s completely unrealistic,” said Ms Michelle Bloodworth, the president and CEO of America’s Power, a coal industry trade group.

There are about 42,000 jobs linked directly to coal mining today, down from about 73,000 a decade ago, according to the US Bureau of Labour Statistics.

“This barrage of new EPA rules ignores our nation’s ongoing electric reliability challenges and is the wrong approach at a critical time for our nation’s energy future,” said Mr Jim Matheson, CEO of the National Rural Electric Cooperative Association, which supplies electricity to many of the nation’s rural and suburban communities. “It undermines electric reliability and poses grave consequences for an already stressed electric grid.”

Former president Donald Trump, who is campaigning to return to the White House, has said he would overturn the regulation if he defeats Mr Biden in November.

“I will cancel Biden’s power plant rule,” Trump said in a video address on his campaign website, adding that wind and solar energy “doesn’t work” because they are subsidised. That claim is false; fossil fuels receive billions of dollars annually in federal subsidies and wind and solar generate electricity more cheaply than oil, gas or coal, even without extra financial help.

Under the plan, coal plants that are slated to operate through or beyond 2039 must reduce their greenhouse emissions 90 per cent by 2032. Plants that are scheduled to close by 2039 would have to reduce their emissions 16 per cent by 2030. Plants that retire before 2032 would not be subject to the rules.

The ageing nature of the country’s existing coal plants means that many of the facilities could shut down before they would have to meet the most stringent limits. More than 200 coal plants have closed in the past decade, putting the average age of surviving plants at almost 50. The lifespan of an American coal plant is about 60 years, according to the US Energy Information Administration, and roughly one-quarter of the existing 200 plants are already slated to retire within the next five years.

The EPA originally planned to also limit emissions from large gas plants that are currently operating. But the agency dropped that strategy after pushback from some moderate Democrats and the gas industry. Environmental justice groups also worried that a crackdown on large gas plants would cause utilities to more frequently run smaller gas units, known as peaker plants, that are often located in poor and minority communities that are already overburdened with pollution.

Under the new regulations, future natural gas plants that generate electricity at the rate of at least 40 per cent of their maximum annual capacity would have to reduce their emissions 90 per cent by 2032. New gas plants that generate electricity at less than 40 per cent of their maximum annual capacity would be required to use low-polluting technology, such as energy-efficient turbines – but the standard would not be so stringent as to force those plants to install carbon capture and sequestration.

The EPA cannot legally require that electric utilities use a specific technology or fuel. Instead, it can set limits on emissions that are so stringent that in most cases, existing coal and new gas plants would have to install carbon capture technology or switch to a cleaner fuel.

Associate Professor Emily Grubert of sustainable energy policy at the University of Notre Dame said it was possible but unlikely that coal plants would be able to continue operating under the new regulations.

A utility that installs expensive carbon capture technology in an ageing coal plant would be unlikely to keep it running long enough to get a return on the investment, Prof Grubert said. “Practically speaking, you’re talking about adding a billion dollars of capital investment to a plant that was at end of life anyway,” she said.

Minnkota, an electric cooperative based in Grand Forks, North Dakota, is planning what is expected to be the largest carbon capture project in the world at its coal-fired power station. Known as Project Tundra, it is projected to cost between US$1.3 billion and US$1.6 billion and is designed to cut the emissions from a 450 megawatt lignite coal unit about 90 per cent.

Mr Mac McLennan, the CEO of Minnkota, said that even with the carbon capture technology, he was not fully certain his power plant would be able to keep operating under the new rules.

“It’s never captured a tonne of CO2 yet. It’s not even constructed yet,” Mr McLennan said, adding: “EPA has made assumptions based on no real operating experience.”

Mr McLennan said the utility started Project Tundra because it was preparing for a “carbon-constrained” world and that 42 per cent of its generating capacity was already supplied by renewable energy. But he also said that when it gets seriously cold in North Dakota, coal is the most reliable fuel source to keep the heat on.

Meanwhile, Ms Bloodworth said the EPA rules would exacerbate the challenges of a power grid that is already struggling to respond to surging demand for electricity.

The new regulations allow that in emergencies, such as responding to power outages in large storms, electric utilities could generate additional power from coal or gas plants without having to use carbon capture technology. And if a coal plant is scheduled to shut down by a certain date, but a state can demonstrate that its retirement would violate state rules on power reliability, the coal plant could be allowed to remain open for one additional year.

The crackdown on coal plants is nearly a decade in the making.

Former president Barack Obama tried to limit carbon pollution from coal-fired power plants, but his 2015 Clean Power Plan was blocked by the Supreme Court. The Trump administration then rolled back the rule and imposed its own plan to keep coal plants online longer.

In 2022, the Supreme Court found the EPA had the authority to regulate emissions, but it could not force a nationwide transition away from the use of coal. Instead, it allowed the government to pursue only narrower policies that regulate how individual power plants operate.

Ms Barbara Freese, the author of Coal: A Human History, noted the immense power the coal industry wielded for much of the last century. The industrial age, she wrote, “emerged literally in a haze of coal smoke”.

Ms Freese, an environmental attorney and former assistant attorney-general in Minnesota, said the industry’s decades-long campaign to question climate science and thwart regulation delayed action until now to tackle greenhouse gases from coal plants.

“It has put us years behind schedule,” she said, adding: “It is infuriating we had to wait this long.” NYTIMES