This story was originally published by Wired and has been republished here as part of the Climate Desk collaboration.

When President Donald Trump visited Pittsburgh last month, he complained about how the Paris climate treaty was unfair to the United States.

“I withdrew the United States from the terrible, one-sided Paris climate accord. It was a total disaster for our country,” Trump told a cheering crowd at a natural gas conference. “They were taking away our wealth. It was almost as though it was meant to hurt the competitiveness—really, competitiveness of the United States. So, we did away with that one.”

Well, not exactly. The U.S. is still a signatory to the landmark agreement signed by President Barack Obama in 2016, and on Monday the Trump administration began the process of withdrawing. It is the first day the administration could technically tell the United Nations secretary-general that the U.S. wants out. The withdrawal officially would go into effect Nov. 4, 2020, the day after the U.S. presidential election.

Ever since Trump started talking about leaving the Paris Agreement two years ago, the question has been what impact that will have on the health of the planet. Will countries stick to the deal and begin the slow march toward a carbon-free economy, or will they start firing up even more coal-fired plants and gasoline-powered cars?

In the short term, some experts say, the biggest loser may be the U.S. That’s because other nations are starting to realize there’s a lot of money to be made by developing renewable energy.

The other fear is that leaders of other big carbon-emitting nations will either follow Trump’s lead or fail to make the tough choices to meet their own 2030 carbon targets.

These nations are making money exporting solar panels, wind turbines, electric cars, and batteries for storing renewable energy to nations that have pledged to make the Paris goals. American green energy companies lag far behind, says energy economist Jonas Nahm, who splits his time between the Johns Hopkins School of Advanced International Studies in Washington and China’s Nanjing University. Even though China is the world’s largest emitter of CO 2 and other greenhouse gases, it also makes 60 percent of the world’s solar panels, one-third of the world’s wind turbines, and 70 percent of all lithium-ion batteries, he says. “China has invested heavily in combating climate change and it has a huge interest in moving forward even if the U.S. doesn’t,” Nahm says. “The U.S. is giving up a lever to push China to do more.”

The other fear is that the leaders of other big carbon-emitting nations will either follow Trump’s lead or fail to make the tough choices to meet their own 2030 carbon targets. Rob Jackson, who documents greenhouse gas emissions as chair of the Global Carbon Project, worries that Trump’s move sends a bad signal to wobbly countries like Brazil and Australia that have had a hard time meeting stated climate goals. “Paris is helping, but the world is slowing down,” says Jackson. “Part of that is the uncertainty we have introduced.”

Brazilian President Jair Bolsonaro is encouraging rainforest deforestation that contributes to climate change. In September, Brazil and the U.S. announced a $100 million fund for “sustainable development” in the Amazon, which is worrying environmental groups given Bolsonaro’s actions so far. Down under, Australian coal is fueling power plants in China, India, and Southeast Asia, while the nation’s domestic emissions reductions have barely made a dent in its stated Paris goals.

On a more positive note, individual U.S. states are bucking the White House. Already, 14 states that represent 40 percent of the population have pledged to make the Paris goals by 2025. Former California Gov. Jerry Brown signed an executive order last year to make the state’s economy entirely carbon-neutral and its electricity 100 percent renewable by 2045.

The Trump administration is fighting back with lawsuits against current Gov. Gavin Newsom and others over California’s agreement with the Canadian province of Quebec to form a trading system for carbon emissions. Under the Trump administration, the Environmental Protection Agency is also trying to block California’s tougher auto emissions standards, a fight that will likely end up in court as well.

Of course, figuring out how to measure each nation’s economic output, efforts to fight carbon emissions, and path toward meeting the Paris goals can be tricky. The U.S. is the world’s second-biggest emitter, but carbon emissions will drop slightly this year as coal plants continue switching to natural gas, according to the Energy Information Administration.

One worrisome trend is transportation, says Andrew Light, senior fellow at the World Resources Institute. While CO 2 emissions from private vehicles went down, emissions from the trucking sector went up in 2018, something Light calls the “Amazon effect” of more long-haul deliveries to satisfy online consumer demand. This boost in diesel trucking emissions “is a big problem but also a big opportunity,” says Light, who was a lead negotiator for the Obama administration on the Paris Agreement. He says the technology exists to replace diesel trucks with clean-burning electric or cleaner-burning natural gas vehicles.

Even with the efforts of California and other states, the U.S. is on target to reach only 17 percent of 2005 emissions rather than the stated goal of a 26 percent reduction by 2025.

Perhaps because he and so many other negotiators put so much time and effort into crafting the climate treaty back in 2015, Light remains optimistic that the international deal won’t be damaged by Trump. “The agreement itself is showing signs of resilience, despite what the president is doing,” he says. “The problem is that the U.S. is still the second-largest emitter in the world. U.S. states and cities can try to fill the gap, but there is only so much they can do.”

Light says the next U.S. president could jump back into the Paris climate treaty within 30 days of taking office. All that’s required is a new U.S. emissions target, and probably a whole lot of work.