The suggested way of doing this would be a new, very fatal pandemic, so reports One America News (OAN)

Volcanologist and ultra-hysterical climate scientist Prof. Bill McGuire posted a comment on X: "If I am brutally honest, the only realistic way I see emissions falling as fast as they need to, to avoid catastrophic #climate breakdown, is the culling of the human population by a pandemic with a very high fatality rate."
Bill McGuire
© NoTricksZone
Reaction McGuire's comment came swiftly and harshly, so much you that McGuire took down the callous comment, claiming he didn't mean it and that readers misinterpreted the comment.

If anything, it tells us what kind of twisted fantasies are floating around in the heads of the members of the climate doomsday cult.