By the NRDC's count, environmental lawyers challenging the Bush EPA won 27 times and lost 11. Industry's win-loss ratio against Obama's EPA was 5 to 15. Walke says one reason is the U.S. Circuit Court of Appeals for the District of Columbia. That's where almost all clean-air lawsuits are litigated. He says it's a court that knows the Clean Air Act well and is committed to upholding it.
Even before Trump could change or rescind a regulation, though, there's a lot of red tape for a Trump EPA to get through. Says Walke: "They have to seek public comment, they have to make sure their actions are consistent with science and the law, founded upon studies that just cannot be made up by people who are climate deniers, for example."
So long-standing regulations are tough to overturn. But more recent ones may be vulnerable to congressional nullification.
Congress can invoke something called the Congressional Review Act. It gives Congress the power to rescind regulations within 60 working days of their enactment, if the president approves. So any regulation enacted 60 working days before Trump's inauguration could be vulnerable to the new Republican-led Congress. Several new rules, such as limits on methane emissions from oil and gas operations, fall in that category.
Trump's other big target is the climate deal agreed to in Paris last year. Nearly 200 countries set goals to reduce greenhouse gas emissions. Trump first said he wants to drop out. Then he said he is "open" to it.
"We do not know what the Trump administration is going to do" on the Paris deal, says Andrew Light, who helped negotiate the Paris deal for the U.S. State Department and is now with the World Resources Institute and George Mason University.
Trump has several options that would effectively pull the U.S. out of the Paris accord. If he does, Light's worried that the other big greenhouse gas emitter — China — could pull out, too. "If the United States is not on board and if China is not on board," he says, "then we're not actually going to achieve these goals" to reduce emissions.
Chinese diplomats have said their government would stick with the Paris deal even if the U.S. doesn't. But even if China does, its government could decide to downsize its emissions targets. And others might follow. "I think we will see a lot of countries begin to have an internal domestic debate," Light says, "about whether or not it still makes sense to hold onto and keep up the ambition they expressed at Paris in a world where potentially we could see the United States back down. And that's what really concerns me."
India is one example. Light notes that while the government is officially dedicated to working to slow climate change, some 300 million Indians lack electricity. "You really are talking about intense pressure for not only more solar," Light says, "but for a lot more coal, which will have a tremendous impact on the climate balance sheet for the entire planet."
In fact, several countries, including China, are planning to invest billions of dollars financing and building new coal-fired power plants in the developing world. The Obama administration has been trying to persuade them not to, but Light says a U.S. withdrawal from Paris might well scotch that effort.