This idea that global warming could negatively impact the environment on its own is very tenuous. I see no evidence of that. Its as much psychological and social a phenomenon as anything else. They look for comfortable lies.
If you tell a scientist Look why are you making this stuff up, can’t you just stick to the data, well they get very upset. NGO’s that buy into the global warming thing, they benefit a lot in the sense that powerful interests that want to push things in that direction fund them.
You have this army of university scientists, and that have to pretend like they are doing important research without criticizing powerful interests in a real way. So what do they look for? They look for elusive sanitized things like acid rain, global warming. Its helps to neutralize any dissent.
H/t JM