On Friday, the Paris Agreement on climate change went into force. It provides a framework for how the U.S., China, and dozens of other countries plan to cut carbon emissions and curtail global temperature rise. But will President-elect Donald Trump support it?
Back in May, Trump signaled he may withdraw the U.S. from the Paris agreement.
Gary Yohe, who studies economics and the environment at Wesleyan University, said it's unlikely such a move would happen overnight. "The agreement itself," Yohe said, "requires one year's notice of withdrawing ... and then three years of phasing out."
While Yohe said it's possible an executive order from Trump would push for an early withdrawal, he thinks any attempts to curtail the Paris agreement would likely also challenge parts of Obama's existing environmental policy, which could result in environmental advocacy groups suing the government under the Clean Air Act.
Such lawsuits, Yohe said, may temporarily delay executive action on the issue.
But Trump isn't in office yet. No orders have been issued, and his environmental policies are not clear.
Tony Leiserowitz, director of the Program on Climate Change Communication at Yale University, said what is clear is what Trump has said on Twitter and on the campaign trail.
"He's already called climate change a hoax. He's vowed to pull us out of this international agreement. He's vowed to end the Clean Power Plan -- Obama's signature effort to reduce CO2 emissions from power plants," Leiserowitz said.
"On the flip side, he also has said that he's going to call for a massive investment in the nation's infrastructure and it's not yet clear what that means," Leiserowitz said, "because some of the infrastructure that could include is, for instance, our clean energy sources ... he has said, he's not opposed to solar and wind, he just wants to basically develop all of our energy sources."
Meanwhile, world leaders continue to meet in Morocco to discuss the future of the Paris agreement.