I have to chuckle at this one, Is Environmentalism A Religion?
To just phrase the question that way suggests a worldview that answers the question before it is asked.
Compare: Is free-market capitalism a religion?
We don't get to ask that, because - let me see if I can paraphrase the NRO clip just right - "the putatively non-prescriptive ethics of capitalism's 'laws' are being taught given to children in kindergartens, schools, and colleges all over the world."
And, before you jump all over me for being a snarky socialist commie subversive (or "anti-business, anti-America"), none of which apply, go have a look at the case of, say, General Electric versus the Hudson River ...
The question then becomes, "Is Environmentalism just another word for Responsibility?"