Trump is bad for the environment (then again, all Presidents have been bad for the environment--nobody has the balls to do what needs to be done), but there are some bright sides. If you look at environmental harms in dollar terms, climate change isn't actually the most harmful thing: http://www.sourcewatch.org/index.php/External_costs_of_coal.

Per kilowatt hour of coal-powered electricity, air pollution generates about three times more environmental externalities than the climate change effect. The effects of mining in Appalachia is significantly more harmful too.

Climate change is a sexy issue, but health damage from air pollutants tends to cause more actual health damage. Water pollution is a bigger issue too: http://blogs.timesofindia.indiatimes.com/toi-editorials/very.... Ideally we'd address all three, but as a practical matter no U.S. President will take more than symbolic steps towards fixing climate change anyway.