If you follow Carlin more closely you'd get it. Actually he is not arguing against climate change at all. In a bunch of videos he talks about this topic and his man point usually is:
- Who is in the end will suffer from this is the human species, if we continue like this we'll die out pretty soon (he'd actually like that) and then the eco system on our planet will recover and after some time, it will seem like humans never existed.
What he doesn't like is people being hypocrites about this topic.
As in, people complaining about these things but actually actively contributing to all this kind of stuff. That's probably why he had given up on our species quite a long time ago already.