Project 2025—the controversial 922-page conservative playbook for the next presidential administration—includes extreme proposals on everything from abortion to child labor laws. It also calls for stopping the “war on oil and natural gas” with a long list of anti-climate actions, beginning with eliminating clean energy incentives.

In a new analysis, researchers from the nonpartisan energy and climate policy think tank Energy Innovation calculated what it would mean for the climate if a Trump administration managed to implement all of Project 2025’s energy proposals. Then they compared that to what could happen if Kamala Harris wins the next election and continues the climate progress that started under the Biden administration.

Current climate policy has “put the United States within striking distance” of Biden’s goal to cut the country’s emissions in half by 2030, Energy Innovation’s CEO Anand Gopal said in a press conference. The next president’s choices could either make it possible to achieve that goal, and hit next zero emissions by 2050, or could dramatically increase emissions. “The U.S. faces a fork in the road starting in January of 2025 with two climate and energy policy pathways that are highly divergent,” Gopal said.

Ambitious current climate policy

Two years ago, Biden signed the Inflation Reduction Act (IRA), the most ambitious climate law ever passed in the U.S. (Vice President Harris cast the tie-breaking vote.) In the first year after the law passed, utilities announced $270 billion in new renewable energy projects. Millions of Americans have already claimed $8.4 billion in clean energy and efficiency tax credits for their homes. Along with the Bipartisan Infrastructure Law and CHIPS Act, the IRA has also helped create more than 334,000 jobs, Energy Innovation calculates.

The Biden administration has also set new fuel-efficiency standards for vehicles, strict emission limits for power plants, and put a long list of other climate policies in place, including a plan for a national network of EV chargers.

To be on track for the goals of the Paris climate agreement, the next president will need to do even more, including helping factories electrify and setting even stricter standards for clean energy. Under what Energy Innovation calls a “continued climate leadership” scenario, it’s possible to reach the goal of cutting emissions in half by 2030 (compared to 2005 levels). The scenario would lead to a 70% reduction in emissions by 2035, and net zero by the middle of the century.

Project 2025’s climate impact

Project 2025, by contrast, proposes repealing most of the Inflation Reduction Act and Bipartisan Infrastructure Law. That includes tax credits for clean-energy and zero-emission cars, among many other incentives. The plan also proposes increasing natural gas exports, expanding oil and gas leasing, and repealing energy-efficiency standards. It calls for weaker fuel economy standards for vehicles. It says that the EPA shouldn’t regulate greenhouse gases.

Trump has tried to distance himself from Project 2025, which was put out by the conservative Heritage Foundation. But many of the authors were part of his previous administration, and there’s little sign that he disagrees with the plan’s basic approach to energy. (In his previous administration, 64% of the proposals in a document from the same group were ultimately implemented.)

Energy Innovation’s analysis looks at what would happen if the entire Project 2025 playbook for energy succeeds. Emissions, unsurprisingly, would be much higher. Between 2025 and 2050, the U.S. would emit an extra 76 billion tons of CO2 compared to the “continued climate leadership” scenario. Thousands more Americans would die prematurely from air pollution each year. Project 2025 would also increase electricity prices and reliance on gas. Collectively, by 2050, households would spend around $147 billion more each year than under the pro-climate pathway. Millions of jobs would be lost. The GDP would be $320 billion lower per year in 2030, and $130 billion lower each year by 2050.

“I think putting the numbers to it is really striking,” says Lena Moffitt, executive director of the climate advocacy group Evergreen Action. “I already knew the difference was vast between the two futures we face, but this is jaw-dropping.”

Project 2025 “will cost us millions of jobs, hundreds of millions of dollars in GDP, our place as a global leader in the clean-tech and energy transition, and it will literally cost people their lives,” she says. “We are at a precipice where this is an election of geologic consequences . . . we’re facing irreversible tipping points in the next few years. Who is president in this next term will, in many ways, determine our collective fate. And these numbers show that.”