I mean, the first amendment does specifically state that congress shall make no laws either forbidding, or more importantly in this case, compelling the establishment of a state religion. And currently, two things are obvious:
1. That belief in man-caused global warming is a religion.
2. That the high priests of that religion, Environmentalism, is attempting to compel, through "green-friendly" legislation, the entire nation to worship at Gaia's altar, whether they will or no.