In a dark way it's probably for the best, because it probably galvanises climate opposition to him on a state/local/business level and makes his administration more isolated. It would probably have been more dangerous if he did the Japan/Australia solution of making frowny faces, saying "we are very concerned about climate change" and then doubling down on locking in future emissions while using the Paris agreement as a figleaf.
I mean, it's partially because trump is an idiot who doesn't know how to make alliances but the world has changed since a decade or so ago, when climate change was exclusively the preserve of a few rich European countries who were mostly going down symbolic, often wasteful routes anyway. Back then China was going on a coal bananza and it was basically assumed that India, SE Asia and Africa etc would be immediately following if they had any chance to develop (and there was a lot of resentment between developing and developed countries on the issue). With that sort of environment, there could easily be loose alliance developing of soft denialists - big Asian manufacturers like China, Korea and Japan; fossil fuel producers like Australia, Russia, Saudi Arabia and Canada; transitioning economies like Turkey, Indonesia and Vietnam that could ally with the Bush administration to stymie the half baked and often hypocritical initiatives of Europe. Nowadays though a lot of though has changed. Climate change is less of a "western issue" and awareness and activism has spread around the world, which means this is an issue that won't be put to bed by trump's pigheaded nature.
I really,
really hope you're right. There haven't been many reasons for optimism on climate change since... well, as long as I can remember, so I'll take what I can.