President Donald Trump has cast his shadow over the latest forecast on US greenhouse gas emissions. Reductions in planet-heating pollution are already expected to slow over the next decade, setting the US and the world back in efforts to stop climate change.

Here’s what could have been. Taking previous climate policies into account, research firm Rhodium Group forecast last year that US greenhouse gas emissions would fall by up to 56 percent by 2035. Alas, fortunes have changed. Following “the most abrupt shift in energy and climate policy in recent memory” during the first seven months of the Trump administration, according to a new Rhodium Group report published today, we can expect a significantly slower pace of progress — a 26–35 percent reduction in emissions over the next decade compared to pollution levels in 2005.

That falls far short of the action needed to stop global temperatures from rising, a problem that is already leading to more extreme weather and other climate-related disasters across the US. The gloomier outlook reflects obstacles the Trump administration has created for wind and solar energy in the US on top of sweeping efforts to wipe federal environmental protections off the books.

It’s been a whiplash change since 2024. Former President Joe Biden set a goal of slashing US greenhouse gas emissions by at least 50 percent this decade as part of the nation’s commitment to the global Paris climate agreement. The Inflation Reduction Act Biden signed into law in 2022 was projected to get the US most of the way to that goal, with generous tax incentives for carbon pollution-free energy and electric vehicles projected to shrink emissions about 40 percent by 2030. The Environmental Protection Agency under Biden also introduced policies to strengthen limits on pollution from power plants and transportation.

The EPA, meanwhile, no longer wants to regulate greenhouse gas emissions at all. In July, it proposed rescinding the landmark 2009 finding that allows the agency to regulate gases under the Clean Air Act because they endanger public health. The EPA says that if they finalize the rule change, which faces legal challenges, it would “repeal all resulting greenhouse gas emissions regulations for motor vehicles and engines, thereby reinstating consumer choice.”

Trump, after receiving tens of millions of dollars in campaign contributions from the fossil fuel industry, tapped a former oil and gas company executive, Chris Wright, to lead the Department of Energy. This week, Wright called efforts to reach net zero greenhouse gas emissions — which researchers have found needs to happen by the middle of this century to stop global average temperatures from rising much higher than they already are — a “colossal train wreck” and a “monstrous human impoverishment program.” The US, however, has managed to maintain economic growth while limiting greenhouse gas emissions. US greenhouse gas pollution was 17 percent lower in 2022 than they were in 2005, according to the EPA.

Rhodium Group’s emissions forecast includes a range of outcomes based on whether Trump’s proposed policies come to fruition, as well as other economic factors, including oil and gas prices and costs for clean energy technologies. Even without subsidies, renewable energy is still cost competitive with gas, Rhodium Group notes. Wind and solar and related energy storage projects make up a staggering 95 percent of new electricity generation capacity queued up to connect to power grids in the US. With electricity demand suddenly on the rise because of data centers, AI, and electric vehicles, utilities are racing to add as much capacity as they can. In short, renewables aren’t going away in this forecast and will continue to cut down US greenhouse gas emissions.

But that’s likely to happen at a slower pace as the Trump administration works to push the scales in favor of more fossil fuels to meet that growing electricity demand. US greenhouse gas emissions have shrunk by an average of 1.1 percent annually since 2005, according to Rhodium Group. In the firm’s most pessimistic scenario, that could fall in half to a pace of just a 0.4 percent reduction each year through 2040.