It’s hard to find a corner of the globe where the aftershocks of Donald Trump’s surprise victory in the U.S. presidential election aren’t reverberating. They’re certainly being felt today in Marrakesh, Morocco, where negotiators from around the world are now gathered for the COP22 United Nations climate conference to hash out the details of the Paris Climate Agreement.

The 2015 accord, which was recently ratified by enough countries to become a binding international agreement, is the latest global effort to cut carbon emissions and stave off the worst impacts of climate change.

LISTEN: Trump Victory Casts a Shadow on Global Climate Talks

“There’s shock and trepidation about what’s going to happen to this global climate agreement and what role the U.S. will play,” says Susan Phillips, who’s covering the COP22 in Morocco for StateImpact Pennsylvania. “Remember—this is the first U.N. climate talks where there was an actual agreement. One hundred countries signed onto this and it was ratified before anyone expected it to be, so there was a lot of optimism here.”

Donald Trump’s victory changes all that. During the campaign, Trump said he would accelerate fossil fuel extraction, abandon Obama’s Clean Power Plan—which seeks to cut emissions from the electricity generation sector—and pull the U.S. out of the Paris agreement. Phillips says there’s little stopping him from getting a lot of that done.

“There’s nothing really in the agreement to hold them to their pledges anyway, so Trump could easily ignore whatever Obama pledged. And he could also appoint a Supreme Court justice who could overturn the Clean Power Plan.”

Phillips says this puts U.S. representatives at the conference in a difficult bind. One of the things negotiators are hoping to do in Morocco is flesh out how developed nations would financially help less-developed nations prepare for the impacts of climate change and cut their own carbon emissions.

“That could cost trillions of dollars. And, of course, the U.S. would be one of those contributors,” Phillips says. “So a lot of these least-developed countries are very concerned about what happened in the election.”

Some climate activists remain hopeful. They point to the fact that the rising cost of coal production and the falling price of renewables mean that market forces are likely pushing the world toward greener energy—though Phillips says that trend could decelerate under Trump.

“Pennsylvania is an interesting case, because you have this historical coal industry that’s been hurting, as natural gas development increases. And even Hillary Clinton said that natural gas should be a bridge fuel to renewables, so it’s not as if she was strongly anti-fracking. But I think before this election, I could pretty clearly tell you that coal production would decrease and natural gas production would increase—and possibly, renewable subsides would increase. But now, it’s really a question.”