> On top of that, climate change is a slow moving disaster, and we are typically good at mitigating long term changes (at least way better than urgent crises). Scientists calling for the end of the world at every opportunity will look ridiculous 100 years from now.

I wish I could share your optimism. Climate change may be a slow moving disaster, however it is more a "high latency" moving disaster. In the sense that once the symptoms start hurting us, it will not be possible to administer any control inputs that will effect the course of climate change within an acceptable period of time.

And while we may be good at mitigating long term changes, I think "existential crisis" kind of long term changes may not have any modes of mitigation that would be acceptable to the current generation of humans (like accepting that 90% of world population just won't have a chance of long-term surivival).