Natural gas is clearly much cleaner than coal, and coal burning plants can be adapted, but over time additional solar, wind, hydroelectric, etc can pick up much of the load, and with better building practices we can use less power and actually reduce our needs. I can't say that we'll ever get fusion, which was thought to be a sure thing back when I was in engineering school roughly 50 years ago. Cancer was also certain to be cured by 2000 as well.
Fuel cells will almost certainly play a much greater roll using hydrogen and producing water. An article I recently read indicated that fuel cell based heavy trucks were being ordered in numbers far greater than similar electric vehicles that are being made available. Certainly it takes energy to create the hydrogen, but clean electricity can be the easiest source. Of course the network of hydrogen filling stations needs to expand, but I believe that's happening.
I'm sorry, but much of the world has legislated moving away from petroleum based transportation, Trump can insist on cars that use more fuel then previously established, but all the rest of the world is going the other way. I think it's time to join the rest of the world in building industries that improve our environment while meeting our needs rather than industries that increase the likelihood of accelerated global warming. The U.S. can be much better positioned to sell products around the world if those products are intended to make the world a better place.
Gary