I disagree with you. Of course, the movement exxagerates by taking the worst case szenario as granted. BUT that does not mean that this worst case szenario is not possible.
As extinction of the human kind is a possibility, we should apply the precautionary principle, and this means drastically limiting CO2 emissions.

And even if you disagree with that, also the most propable developments are bad enough. These are not lies, these are science. We have to do more, or we will pay for it and the price will be far higher than the costs of precautious actions now.

So while I appreciate your dedication to science, you're siding with the wrong people (science deniers) here. Weird.