Could Obama have done more? Sure. But he did pass the first ever federal limit on carbon pollution, helped forge an international climate agreement, directed his EPA to noticeably increase fuel efficiency standards for vehicles, and preserved 260 million acres for future generations by designating 19 national monuments for public use.
In contrast, Trump has rolled back Obama's anti-pollution legislation, withdrawn from that international climate agreement, reversed the heightened EPA standards, and begun selling our National Parks to miners.
There is absolutely no comparison, and to pretend otherwise is absurd.