What lucrative technologies? For the most part it seems like most of them are lucrative due to the government subsides that you can get by using them.
And no, we aren't going to spend more money on coal, no matter what Trump thinks or wants his supporters to think. That market heavily favors natural gas. And more than that, new power plants will be around for decades. One administration policy wish list isn't going to significantly change the long term risk of coal investment.
It was stupid of us not to sign the agreement, but lets not forget that the president doesn't have the legal authority to ratify it. Even with Clinton in office and a democrat held legislature, it's unlikely that the Senate would have given the go ahead. Which is dumb, because it's a non-binding agreement. No one actually has to do anything, but by not signing, we get to be the scape goat that everyone else points to deflect from their lack of progress. Literally every other country signed it, because there's no reason not to.
I mean, we are probably going to come pretty close to meeting our part of the agreement anyway, due to the expansion of natural gas plants.