Former President Donald J. Trump has vowed to “cancel” President Biden’s policies for cutting pollution from fossil-fuel-burning power plants, “terminate” efforts to encourage electric vehicles, and “develop the liquid gold that is right under our feet” by promoting oil and gas.
Those changes and others that Mr. Trump has promised, if he were to win the presidency again, represent a 180-degree shift from Mr. Biden’s climate agenda.
When he was president, Mr. Trump reversed more than 100 environmental protections put in place by the Obama administration. Mr. Biden has in turn reversed much of Mr. Trump’s agenda.
But climate advocates argue a second Trump term would be far more damaging than his first, because the window to keep rising global temperatures to relatively safe levels is rapidly closing.
“It would become an all-out assault on any possible progress on climate change,” said Pete Maysmith, the senior vice president of campaigns at the League of Conservation Voters, an environmental group.
Senior Republicans don’t necessarily disagree. Michael McKenna, who worked in the Trump White House and is supporting Mr. Trump’s bid for a second term, said the approach to climate change would likely be one of “indifference.”
“I doubt very seriously we’re going to spend any time working on it,” Mr. McKenna said. To the contrary, he said, the Biden administration’s climate regulations would be “in trouble.”
Mr. Trump’s first term was marked by carelessness in its legal work, which led to some of his efforts to overturn Obama-era climate policies rejected by courts. Neil Chatterjee, chairman of the Federal Energy Regulatory Commission under Mr. Trump, said the former president’s team has learned from its past mistakes.
“It will be a far more organized and coherent legal and regulatory strategy if there’s a Trump 2.0,” Mr. Chatterjee said, adding, “These guys know what they’re doing now.”
Here are five of the most significant reversals a Trump administration could bring on climate.
1. Coal and Gas Power Plants
The fossil-fuel-burning plants that keep our lights on or power our heat and air conditioning are responsible for a quarter of the greenhouse gas emissions generated by the United States. Reducing them is key to Mr. Biden’s plan to tackle climate change.
Environmental Protection Agency regulations finalized on Thursday would force coal plants to either deploy technology to capture virtually all their emissions, or shut down. New gas plants constructed in the U.S. also would have to meet strict emissions standards.
The Biden administration estimated the rules governing coal plants would cut 1.38 billion metric tons of carbon dioxide between now and 2047, which is equivalent to preventing the annual emissions from 328 million gasoline-powered cars.
Mr. Trump has deployed a mixture of truth and falsehoods when describing this policy. He has said it will force coal plants to shut down, which is likely accurate. He also said it will force gas plants to close, which is not true. And he has said that renewable energy cannot keep the lights on, also untrue.
If elected, Mr. Trump said he will reverse the regulation on coal-burning electricity and “green-light the construction of hundreds and hundreds and hundreds of brand-new, beautiful power plants that actually work.”
2. Automobile Emissions Standards
Mr. Trump has spoken particularly aggressively about electric vehicles.
Transportation is responsible for another quarter of U.S. greenhouse gases, with cars and trucks making up the bulk. Mr. Biden has imposed limits on pollution from automobile tailpipes, rules designed to ensure that the majority of new passenger cars and light trucks sold in the United States are all-electric or hybrids by 2032.
Mr. Trump has said those regulations will lead to a “blood bath” in the U.S. economy, “kill” the auto industry and trigger an “assassination” of jobs. He has pledged to reverse them.
“That’s going to be the first order of business, to unwind all that,” Mr. McKenna said if Mr. Trump is elected. “I think everybody’s been pretty clear about that.”
3. The Inflation Reduction Act
The Inflation Reduction Act, which Mr. Biden signed into law in 2022, is the nation’s largest investment in fighting climate change.
It contains more than $370 billion in tax credits over 10 years to help shift the U.S. toward cleaner forms of energy, offering incentives to companies to make electric vehicles, batteries and to consumers to buy those vehicles, switch to solar energy and buy things like electric heat pumps to heat and cool their homes.
Mr. Trump, who has called the I.R.A. “the biggest tax hike in history,” is widely expected to try to gut much of the law.
Incentives for people to buy electric vehicles, which Mr. Trump has called “one of the dumbest” decisions he’s heard, would certainly be on the chopping block, Republicans said. So would measures to support businesses that install electric-vehicle charging stations.
Tax credits for solar- and wind-power, could be in the cross hairs of his administration, as could incentives for consumers to buy heat pumps or make their homes more energy efficient.
Yet even Republican opponents of the climate law acknowledge that undoing those tax incentives will be hard, in large part because many of the battery manufacturing facilities and new electric vehicle plants are being built in Republican districts.
“Unfortunately the wind and solar and EV guys have all got their hooks in red states, so clawing back that money is more difficult to do,” said Steven J. Milloy, a climate-change denialist who worked on Mr. Trump’s transition team in 2020. Still, Mr. Milloy said, a Trump administration could do a lot to slow down a transition to clean energy even if the tax breaks remains.
“What the I.R.A. doesn’t do is force anybody to approve wind farms or solar farms,” he said, adding, “I don’t see those getting approved under a Trump administration. I see extremely thorough investigations into whale deaths and other environmental problems.”
There is no evidence that offshore wind farms cause whale deaths. Mr. Trump has also railed against wind farms, saying falsely they cause cancer.
4. Oil and Gas Drilling
If he wins a second term, Mr. Trump has promised to “unleash domestic energy production like never before.” Primarily he is talking about coal, oil and gas, the three main fossil fuels.
While President Biden has certainly approved some big fossil fuel projects, like the enormous Willow oil development in the North Slope of Alaska, and the U.S. is producing more oil than any country ever, Mr. Biden has also tried to curb future development. His administration has approved the smallest offshore oil program in history. It has protected hundreds of millions of acres of wilderness from mining and drilling. Earlier this month Mr. Biden blocked oil and gas development within 13 million acres of wilderness in Alaska.
The U.S. is the world’s leading exporter of liquefied natural gas but the Biden administration has paused permits for new export terminals while the Department of Energy studies the effects of gas exports on national security, the economy and climate.
Mr. Trump has promised to immediately lift that pause and greenlight pipelines and other energy projects.
“We’re going to drill, baby, drill, right away,” Mr. Trump told supporters in January.
David Hayes, a former Biden administration climate adviser said he expects a Trump White House would revive drilling in the Arctic National Wildlife Refuge, the country’s premiere wildlife sanctuary. Mr. Biden canceled seven oil leases in the refuge last year.
“They’re going to look for symbolism, so they’re going to try to open other sensitive areas on public lands,” Mr. Hayes said of a Trump White House.
5. Global Climate Negotiations
The annual global climate summit convened by the United Nations is set to take place this year in Azerbaijan on Nov. 11, just days after the U.S. elections.
As president, Mr. Trump withdrew the United States from the Paris agreement, a 2015 accord in which all nations agreed to cut their greenhouse gases to keep global warming within relatively safe limits.
Mr. Biden returned the U.S. to the global deal on his first day in office and has pledged to cut U.S. emissions roughly in half this decade, and to stop adding greenhouse gases to the atmosphere before 2050.
Mr. Trump’s likely policies would add four billion tonnes of greenhouse gas emissions to the atmosphere, according to a study by Carbon Brief, a climate analysis site.
Many foreign leaders felt that the four-year absence of the world’s superpower during the Trump administration was a setback. They fear another American withdrawal would delay progress at a time when time is running short to avert the most catastrophic impacts from global warming.
Mukhtar Babayev, the incoming president of the November’s U.N. summit, has called on the U.S. to make good on its climate pledges, even if Mr. Trump wins in November, although he hasn’t mentioned Mr. Trump by name.