Climate change will kill millions in the next ~40-60 years and if course isn't corrected 100s of millions will follow. Seems like it will do a pretty damn good job of killing us even if it fails to kill all of us.

I agree AGI would be horrendously dangerous and if achieved has a higher chance of complete extinction. However, we don't have AGI and it's still not clear we ever will.

I don't think it's likely, but climate change could easily wipe out humanity by exacerbating pre-existing geopolitical tensions. For instance, Pakistan and India famously share a river, and the treaty that governs its water rights was written with the assumption that the river wouldn't reduce in output. A sufficiently severe drought could cause a war between India and Pakistan, and both countries have nukes.

You could dispute that WW3 would cause human extinction, and while I'm not remotely certain of it I think that WW3 could cause extinction, if there's a sufficient combination of 1) climate collapse and 2) worldwide economic collapse that makes high-tech systems impossible to sustain.