We've known about the dangers of climate change for 30 years now. Up until recently, our global and national CO2 emissions have been steadily increasing. This has happened through Democratic and Republican presidents, and Democratic- and Republican-controlled Congresses.
So the "problem" is not Trump per se, and it is not Republicans.
The "problem" is that we have an economic system and a political system that is dominated by small group of extremely wealthy people who profit immensely from fossil fuel production. They care more about continuing to profit from coal, oil and natural gas than they care what will happen to most human beings and other species on the planet at some unspecified time in the future. And most of our elected officials of both parties serve that wealthy few, which is why Clinton and the Democrats refused to give up on fracking.
The "problem" is not even average Americans driving around in their cars. People are willing to sacrifice if they are aware of the threat, and if they feel that the burdens are equally shared by industry. But we have a political leadership that would rather kick the can down the road than admit that we are on the brink of global disaster. Many industrialized countries are ahead of the US in planning and developing renewable energy, in part because their political systems are less corrupt than ours.
Even though global CO2 emissions have leveled out in the past few years, we have reached a point where positive feedback loops like natural methane releases and a largely ice-free Arctic cap will continue to accelerate the warming of the planet. Climate change is not happening in a linear fashion - it is constantly increasing in rate. The time for incrementalism and ignorance is long past. We need radical economic and political change if we have any chance of avoiding the calamity that is coming.