Forgive me for not seeming very upset that the US has pulled out of the Paris climate accord, but then I never took it seriously. It was a voluntary agreement with no teeth, doubly so in the US where Obama never even submitted it to the Senate for a ratification vote. (It would have gotten hammered.) It was simply a symbol of a worldwide elite consensus that human-caused climate change is a real danger.
So it was perfectly predictable that Donald Trump, a master of symbolism, would reject the treaty, metaphorically aligning himself with coal miners, oil drillers, factory workers, and guys who drive big trucks. If there is a consensus among the Davos set, the UN bureaucracy and the European Union Council, of course Trump wants to spit on it.
The difference to the climate future of the earth will be minimal, and so will the effect on the US economy and US "leadership."
Trump's fans will cheer him for it and his enemies will condemn him for it.
Trump's followers will credit him for any piece of economic good news and insist that it is better than Obama ever did even if that isn't so. Trump's opponents will blame him for any piece of bad news and say things were never that bad under Obama, even if that isn't so.
To get back to climate, you can expect that Trump's fans will attribute any good economic news over the next few years to his actions, including his rejection of the Paris treaty. Trump's enemies will attribute any bad economic news to the same causes, along with any bad environmental news.
Meanwhile the things that will actually determine the planet's climate future will continue to be the progress of solar cell and battery technology, fracking, offshore wind power, and a commitment by hundreds of millions of people around the world to reduce their carbon footprints.
Not that politics doesn't matter; governments can do a lot. But with a Republican Congress, there isn't much that Hillary or Bernie could have done to help, and even when he had a Democratic Congress Obama didn't manage to do very much. The biggest political issue right now is the rules governing how private solar panels will connect to the power grid, which is being fought out entirely at the state level.
Forget Trump. Forget Paris. Focus on putting in place technology that works.