While America was watching Donald Trump sweep the polls, climate representatives from over 200 countries saw America's commitments to international climate goals blow away. This week, climate negotiators—along with NGOs, journalists, and other observers—are gathered in Marrakesh, Morroco to flesh out the details of the Paris agreement, newly ratified and enacted by the United Nations to address climate change. And though Trump hasn't described his climate and energy policies in detail, he has made it clear that he will not honor promises the Obama administration made to combat the intensifying global warming catastrophe.

The Clean Power Plan. Tax breaks for renewable energy. Cabinet appointees and a Supreme Court seat. Trump has the power to drastically change US environmental policy—and as the soon-to-be-leader of the world's largest economy and second-largest greenhouse gas emitter, his decisions will change the math for other nations previously committed to climate regulations. Some will follow the US, and dial back (or abandon) their goals. Others will stay the course. And still others might double down on climate goals, potentially gaining global clout as a result. However the 45th president of the US proceeds, his decisions on climate will affect everyone on Earth.

Last November, after 21 years of annual negotiations, 196 nations agreed to a broadly-worded promise to limit global temperatures from rising 2˚C above pre-industrial levels-–and to aim for as close to 1.5˚C above those temperatures as possible. Scientists believe that if the world exceeds that 2 degree cap, the world will experience the very worst effects of climate change: stronger droughts, heat waves, storms, and famines. (Planet Earth has probably already blown past the 1.5˚C mark.)

The Paris document entered into force on November 4. "The goal of this Marrakesh meeting was to fill in all the blank spots in the Paris agreement, which is full of to-be-negotiated material," says Michael Wara, environmental policy expert at Stanford University. In particular, it left open questions like how countries would report their emissions to one another.

"The Paris agreement was designed to be durable and survive shifts in political currents," said Elliot Diringer1, executive vice president of the Center for Climate and Energy Solutions. Yet many global leaders have yet to confirm their commitment to the document in light of Trump's victory. Trump has called the Paris agreement a bad deal, vowing to pull out or renegotiate the US commitment.

If the president-elect reneges, the treaty requires four-year notice, during which time the US is still required to submit its annual emissions reports. And if the country honors that requirement, those reports will likely show a dramatic deviation from the Obama administration's goals of reducing greenhouse gas emissions by 26 to 28 percent from 2005 levels by 2025. Because Trump has also vowed to gut any environmental policies he feels are harmful to business.

The National Agenda

Front and center among those contested policies is the Clean Power Plan. The EPA regulation (which uses the Clean Air Act to force sweeping changes on the US power industry) is already in legal hot water, being contested in the DC circuit court from legal challenges brought by numerous states and industry groups. If the case wins, it could go to the Supreme Court for appeal—which, with a Trump-appointed 9th member, would probably shoot the thing down. But that could be moot, because Trump has stated in the past that he will simply force the EPA to kill the reg.

The Clean Power Plan isn't the only emissions-hammering tool Obama forged in his tenure. Earlier this year, the Obama administration amended its commitment to the Montreal Protocol, an international climate treaty originally signed in 1992, to address climate warming emissions emanating from refrigerators and air conditioners. These emissions—from chemicals called hydrofluorocarbons—don't really come from the US. But the US has promised to provide funds to developing countries that rely on HFCs to provide air conditioning to their impoverished citizens. If Trump refuses to ratify the amendment, it means the US won't contribute any funds. "It would mean that developing countries go down a path with cooling and refrigeration systems that will be really harmful to climate, and will be much more expensive to fix later," says Wara.

Certain cabinet appointments will also have a dramatic impact on the US's position on climate change. "Secretary of State, Energy, Interior," Wara lists off. "Whoever holds these and other key positions will shape domestic policy on environmental questions."

And then there's clean energy. Federal tax credits have buoyed the recent boom in solar and wind power, as well as electric vehicle adoption. Trump wants to cut corporate taxes, and the production tax credit and investment tax credit (which respectively subsidize solar and wind energy) are easy items to put on the chopping block. As is the electric vehicle tax credit, which gives $7,500 relief to anyone buying an EV. "I would be concerned that certain charismatic leaders of EV companies would be concerned about that credit, especially as they are rolling out the first generation of mass market EVs," says Wara. The Tesla Model 3 and Chevy Bolt, both due to hit the streets in late 2017, both have sub-$30,000 price tags partially through the beneficence of the federal government.

Global Impacts

Trump's global trade position could also hurt renewables. For example, solar energy is so cheap—$0.35 a watt, at the moment—because a lot of the hardware is manufactured overseas. Liberal trade agreements keep those costs low, but Trump sees many of these agreements as a threat to domestic production. Tariffs would make those components more expensive, and that added cost could get passed along to consumers. So goes renewable energy's competitiveness with fossil fuels.

But perhaps the most lasting change Trump could have on global climate would be to withdraw entirely from the UN Framework on Climate Change, which is the foundation for these annual meetings to discuss climate change. Even George W. Bush's administration—which relegated itself to observer status—didn't go that far. Any future president concerned with climate change could be hard-pressed to earn the UN's trust for readmission.

And by then, the world may have moved on. The Paris agreement was a signal from many countries that climate is of preeminent importance. The US's continued denial could ostracize the country from future dealings, and sideline it as a global leader. In particular, China came out early in its continued climate commitment. "They could adopt a leadership role, and it could be an opportunity for China to shape international regimes, not just on climate, but other things too," says Wara. Climate, like the atmosphere itself, is ubiquitous, and affects economics, politics, and trade.

No doubt US negotiators deployed by the Obama administration are trying to impress best case scenarios on their foreign counterparts in Marrakesh. If Trump follows through on his campaign trail rhetoric, America's brief stint of climate leadership is over.

1 Update 2:25pm ET 11/10/2016 - Previous version of this story mistakenly wrote Elliot's last name was Dillinger.