[johncolanduoni]

You wouldn’t take someone who proposed any other climate intervention they wouldn’t commit to themselves seriously, would you?

[squeaky-clean]

Individual death is not the same as an extinction. And after doing so they wouldn't be able to spread their idea, they'd be removing themselves from any ability to intervene.

A more appropriate response that still points out their absurdity would be to ask why they aren't committing any mass murders.