CCers: humans cause climate change.
TM and HR: no you are wrong, it's the humans who are the problem
The overpopulation thing is the conservative's last bastion they're using to hide from the overwhelming evidence showing that they've been wrong for years.
Whenever they're asked what they actually want to do about it, they flounder around and mutter something vaguely incoherent about immigration.
It's simply a way of agreeing that humans are affecting the world's climate and resources, but also somehow ignoring the solutions they don't like.