The Environmental Protection Agency has drafted a plan to eliminate all limits on greenhouse gases from coal and gas-fired power plants in the United States, according to internal agency documents reviewed by The New York Times.

In its proposed regulation, the agency argued that carbon dioxide and other greenhouse gases from power plants that burn fossil fuels “do not contribute significantly to dangerous pollution” or to climate change because they are a small and declining share of global emissions. Eliminating those emissions would have no meaningful effect on public health and welfare, the agency said.

But in the United States, the power sector was the second biggest source of greenhouse gases, behind transportation, according to the most recent data available on the E.P.A. website. And globally, power plants account for about 30 percent of the pollution that is driving climate change.

The E.P.A. sent the draft to the White House for review on May 2. It could undergo changes before it is formally released and the public is given the opportunity to offer comments, likely in June.

The proposed regulation is part of a broader attack by the Trump administration on the established science that greenhouse gases threaten human health and the environment. Scientists have overwhelmingly concluded that carbon dioxide, methane and other greenhouse gases from the burning of oil, gas and coal are dangerously heating the planet.

“Fossil fuel power plants are the single largest industrial source of climate destabilizing carbon dioxide in the United States, and emit pollution levels that exceed the vast majority of countries in the world,” said Vickie Patton, general counsel for the Environmental Defense Fund, an environmental group.

She called the proposed regulation “an abuse of the E.P.A.’s responsibility under the law” and added, “It flies in the face of common sense and puts millions of people in harms way to say the single largest industrial source of carbon dioxide in the United States is not significant.”

The draft reviewed by The New York Times said the agency “is proposing to repeal all greenhouse gas emissions standards for fossil fuel-fired power plants.” That would include Biden-era requirements that existing coal-fired units capture carbon pollution before it leaves the smokestack and store it, and that require some new gas plants use technologies that pollute less.

“We are seeking to ensure that the agency follows the rule of law while providing all Americans with access to reliable and affordable energy,” Lee Zeldin, the E.P.A. administrator, said in a statement.

Mr. Zeldin’s spokeswoman, Molly Vaseliou, declined to offer more information about the plan other than to say “the proposal will be published once it has completed interagency review and been signed by the administrator.”

The Trump administration is methodically uprooting policies aimed at curbing climate change, and the E.P.A. is at the epicenter of that effort. In recent weeks, Mr. Zeldin has shuttered offices responsible for regulating climate and air pollution, and has launched the repeal of more than two dozen regulations and policies.

The agency is feeling pressure from the White House to finalize its deregulations by December, according to two people briefed on internal discussions who spoke on the condition of anonymity in order to describe them. That would be an extraordinarily fast pace. Rewriting regulations can typically take more than a year.

One target is a 2009 E.P.A. finding that greenhouse gases endanger public health. That determination underpins most federal climate regulations, and repealing it would erase the agency’s legal authority to regulate carbon pollution from power plants, vehicles, oil and gas infrastructure and other sources.

Mr. Zeldin said deregulation would drive “a dagger straight into the heart of the climate change religion.”

In proposing to lift regulations on power plants, the E.P.A. points to the fact that the U.S. share of global power sector emissions represented about 3 percent of worldwide greenhouse gases in 2022, down from 5.5 percent in 2005. So, it argued, even if American power plants erased all their greenhouse gases from the power sector, the risk to public health would not be “meaningfully” improved.

But in the U.S., power plants were responsible for about 25 percent of greenhouse gas emissions in 2022. They emitted about 1.5 billion metric tons of emissions in 2023, which is more than the total greenhouse gas emissions produced by most countries.

Just a year ago, when the Biden administration announced tough new limits on pollution from existing coal-fired power plants as well as some new gas-burning plants, the E.P.A. said the restrictions would mean that by 2035 the nation would annually avoid up to 1,200 premature deaths, 870 hospital visits, 1,900 cases of asthma, 48,000 school absences and 57,000 lost work days.

Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University, noted that solving climate change means undertaking a large number of seemingly small measures, like curbing emissions from automobiles, oil and gas wells, air travel, landfills, buildings and more.

“Just because there are multiple contributors to a problem doesn’t mean we should excuse all but the top one,” Dr. Oppenheimer said. “Just because a polluter’s emissions are decreasing doesn’t mean that aren’t still far too high.”

Attorneys who represent utility companies said they agree that the sector is a small part of the global climate problem. “The argument is a solid argument,” said Jeffrey R. Holmstead, who served in the E.P.A. during both Bush administrations and now represents utility companies as a lawyer for the firm Bracewell.

But he wondered if it would hold up under a legal challenge. “I just don’t know if you’re contributing 3 percent of greenhouse gas emissions the court will say ‘that's not significant’ when there’s hardly anybody that contributes more than that.”

Only China releases more pollution from its power plants than the United States.

The E.P.A. plan is likely to face lawsuits once it is finalized. If it survives, it could block future administrations from regulating carbon dioxide emissions from power plants, eliminating a tool that Democratic administrations have relied on to tackle climate change. It also could make it easier to unravel other climate regulations, some experts said.

“If the administration is going to do this, it is the strategically smartest way,” said Jonathan Adler, a conservative law professor at Case Western University. “If they’re successful with regard to power plants, they’re pretty much going to be successful with everything else,” he said.