Climate change is unlikely to kill everyone on earth. Other risks, such as an engineered pandemic, asteroid impact, or an AI apocalypse have the possibility of killing ~everyone. This is not saying that climate change is not a real issue.
The AIpocalypse seems incredibly unlikely. I'm a lot more worried about the nukes, and even if we end up with robotic overlords, I'd bet they'll be a whole lot better at administration than meat -admins have proven.
I'm with you on engineered superviruses. Feasible, likely, and incredibly high impact.
What I kind of keep coming back to is the risk profile of all this stuff. That magic vector of likelihood * impact. Global warming is happening now. And it's real bad - worse than I think we give it credit for.
What I worry about is that we're the proverbial frog in the pot. Things get just slightly hotter each year, so we'll miss it when we actually boil.
So what you're saying is that if a risk can totally upend our society, destroy most of our cities, make most of our farmland unusable, destabilize geopolitics in a way that's almost certain to lead to war between nuclear powers (who also have the ability to engineer deadly diseases), and massively disrupt every ecosystem on earth, and that there's enough evidence to say with almost complete certainty that this will come to pass without massive societal and political change and technological intervention... but it's unlikely to kill everyone... then it doesn't really deserve mention?
The cascading risks you mention are certainly real and serious, and are worthy of our best and urgent efforts to solve. Effective altruists are rightly concerned about these effects e.g. https://80000hours.org/problem-profiles/climate-change/
My comment was written with the summary of that article in mind (I didn't make this clear):
> Climate change is going to significantly and negatively impact the world. Its impacts on the poorest people in our society and our planet’s biodiversity are cause for particular concern. Looking at the worst possible scenarios, it could be an important factor that increases existential threats from other sources, like great power conflicts, nuclear war, or pandemics. But because the worst potential consequences seem to run through those other sources, and these other risks seem larger and more neglected, we think most readers can have a greater impact in expectation working directly on one of these other risks.
There is an excellent chapter on the existential risks associated with climate change in Toby Ord's book The Precipice, which you can get a free copy of at https://80000hours.org/the-precipice/
I know I'm jumping the gun just a little, but c'mon. An apocalypse list without climate?