Back on June 1 President Trump gave a speech (official transcript here) announcing that the United States will withdraw from the Paris Climate Accord, claiming that the agreement "disadvantages the United States to the exclusive benefit of other countries."
Of course, in reality, the agreement is entirely voluntary. Each country, including the United States, sets its own goals, and there is no penalty for missing them. We've been holding down carbon dioxide anyway, in large part because economic forces have pushed us in that direction. Natural gas is cheaper than coal and also releases less CO2 per unit of energy. Leakage of methane (CH4), a more potent greenhouse gas than CO2, remains a problem, but one that we should be able to mitigate. Extraction by hydraulic fracturing also leads (a bit indirectly) to earthquakes, which is a serious concern. But those problems exist with or without the Paris Accord.
The cost of solar electric power and wind power continues to drop to the point that they are already starting to be competitive with coal and jobs in those fields are soaring while jobs in coal mining have plummeted to just over 50,000, roughly on the order of the number of people who work at Disney World, I think. Out-of-work coalminers deserve help, but cutting regulations won't make a difference. The drop in demand for workers is a consequence of the relatively high cost of coal and especially the growth of automation in coal mining.
Overall there's no evidence the Paris Accord has hurt the U.S. economically, and mitigating global warming is to everybody's advantage, including our economic advantage.
Incidentally, Trump's withdrawal from the Accord won't actually take full effect until late 2020, after the next presidential election.
Perhaps the biggest strangeness in all this is that Trump has numerous times complained that Germany is out-competing us, and Germany is indeed an industrial and export powerhouse. But Germany's goals on greenhouse-gas reduction are stricter than those for the United States, and they're making a lot of progress toward them. For just one example, so far in 2017 Germany has produced more than a third of its electricity from renewable sources, more than double the level of the United States. Other categories of energy use, notably non-train transportation, are harder to convert to renewables, but they're making progress. Even China, partly as a result of its near-catastrophic problems with air pollution, is shifting away from fossil fuels.