When Donald Trump takes office, he'll be the only head of state in the world to deny that climate change is real. He has promised to "cancel" the global climate agreement made in Paris, get out of other environmental laws, and revive the dying coal industry.
It's not clear how much of this will actually happen. Withdrawing from the Paris agreement would require a complicated process that could take more than three years, since it's already gone into effect. But because country commitments in the agreement aren't legally binding, Trump could just decide not to honor them.
The U.S. has promised to reduce climate emissions by up to 28% (below 2005 levels) by 2025. As the second largest polluting country in the world, after China, America's commitment is a critical piece of the Paris agreement.
Trump can attempt to reverse the Clean Power Plan, though that would also require lengthy court battles and a new regulatory proceeding. But he can slow the plan down, and can say he's not going to enforce it. Executive orders and executive actions—like President Obama's moratorium on coal leases on federal land—would be easier to overturn.
It's possible he'll change his mind, since he isn't deeply ideological. But even if he doesn't do the maximum amount of damage possible, it's also very unlikely that he'll do what's needed to mitigate the worst effects of climate change. Even meeting the Paris agreement, scientists say, wouldn't go quite far enough.
The good news: Businesses, along with state and city governments, can help fill at least some of that gap and drive climate action themselves. And that's already happening.
"We've got hundreds of CEOs and hundreds of the world's biggest businesses fully committed to act on climate, both the risks and opportunities," says Nigel Topping, head of a climate coalition called We Mean Business. "They're working in a context where their competitors are all going in the same direction because of Paris and local regulations. I think largely the course has been set by major businesses."
Last week, Walmart announced a new target to cut its emissions in line with the Paris agreement, making an 18% reduction in its own operations by 2025. All of its suppliers will also be encouraged to also reduce emissions, helping the company reduce emissions in its supply chain by a gigaton.
It's one of hundreds of major corporations to commit to climate action. Many, like Apple, Facebook, and General Motors, have committed to transitioning to 100% renewable energy (by 2015, Apple had already reached 93% renewable energy). That offsets a large amount of power that otherwise might have come from fossil fuels, and it's also beginning to reshape how state governments think about their power grids.
"If you're the governor of a state and you want companies to build plants and run facilities, and you know they're committed to 100% renewable energy, it changes the politics of renewable portfolio standards," says Topping. "That's jobs and it's tax. It's a political decision, not an environmental one."
The business and finance communities may also resist a push for more support for the coal industry from Trump. "The fact of the matter is, I don't think coal is really cost-competitive anymore," says Ken Berlin, president and CEO of the Climate Reality Project, Al Gore's organization dedicated to fighting climate change. "I don't know if any American bank would finance another coal plant. I think the day of coal is really coming to an end, unless [Trump] figures out a way to give it subsidies, which I think he'd probably have a very hard time justifying."
Trump may also change his mind about coal if he listens to experts. "The coal industry is dying globally, so to invest federal money in trying to revive a dying industry—rather than trying to invest in communities that have worked in coal for generations to reskill and retrain for transition—would be a bad business decision," says Topping.
Some U.S. states are also leading on climate policy. California, which was first to pass a law putting a limit on climate pollution a decade ago, strengthened its commitment this year. By 2030, the state will reduce pollution 40% below 1990 levels. Governor Brown has led a global effort to get states to commit to keeping global warming below two degrees Celsius.
Cities—where half the world's population now lives—are also leading in climate action. While positive federal policy would help cities, it isn't necessary for progress. "About half of the actions that could be taken in any given city are under the direct control or influence of the mayor," says Mark Watts, the executive director of C40, a network of the world's largest cities whose mayors have committed to act on climate. In the U.S., the list includes New York City, Los Angeles, Chicago, Houston, Philadelphia, San Francisco, and others.
Every two years, C40 reports, the number of specific actions cities have taken to tackle climate change has doubled. "Partly that's because of a huge amount of collaboration between big cities that has stimulated each of them to be more ambitious about climate action, because they're copying things that have been done successfully elsewhere already," says Watts.
That momentum isn't likely to shift much even with an anti-science administration. "I don't think we're going back to a situation that we were 20 years ago with George Bush, where if the American president isn't willing to take action on climate change, then it stops it elsewhere in the world," he says.
Taken together, action from businesses, cities, and states could help the U.S. keep moving (slowly) in the right direction. "There's a lot of things that can be done to continue making at least enough progress so that we have a chance by 2025 to meet our commitment," says Berlin. "Assuming we can start reversing what he's doing in 2018 or 2020."
Correction: This article originally implied that all Walmart suppliers would also have to reduce their emissions by 18%. The program, however, is voluntary. Additionally, We Mean Business was referred to as UK-based, but it is a global organization.