You can believe climate change is a serious problem without believing it is necessarily an extinction-level event. It is entirely possible that in the worst case, the human race will just continue into a world which sucks more than it necessarily has to, with less quality of life and maybe lifespan.

If you consider it to be halfway to that, it's still enough to reasonably consider an overriding concern compared to other things.

I never said I held the belief, just that it's reasonable

A set of beliefs which causes somebody to waste their life in misery, because they think doom is imminent and everything is therefore pointless, is never a reasonable set of beliefs to hold. Whatever the weight of the empirical evidence behind the belief, it would be plainly unreasonable to accept that belief if accepting it condemns you to a wasted life.

Why would it cause someone to waste their life in misery? On a personal level, for everyone, doom is imminent and everything is pointless - 100 years is nothing, we all will die sooner or later. On larger time scales, doom is imminent and everything is pointless - even if everything was perfect, humans aren't going to last forever. Do people waste their lives in misery in the face of that reality? Why would believing humans are likely to wipe themselves out due to climate change lead to misery?

If anything, avoiding acknowledging the reality and risk of climate change because of the fear of what it might mean, is miserable.

It's the premise from the article we're discussing, where believe in imminent doom makes life feel pointless and preempts anything good somebody could be doing with their life.

> These beliefs can make it difficult to care about much of anything else: what good is it to be a nurse or a notary or a novelist, if humanity is about to go extinct?

You can treat climate change as your personal Ragnarok, but its also possible to take a more sober view that climate change is just bad without it being apocalyptic.