After reading Pentti Linkola's brand of eco-fascism (seen via Azizonomics (seen via Greenie Watch)):
"What to do, when a ship carrying a hundred passengers suddenly capsizes and there is only one lifeboat? When the lifeboat is full, those who hate life will try to load it with more people and sink the lot. Those who love and respect life will take the ship's axe and sever the extra hands that cling to the sides."
I relized that the best response is to quote from Bryan Caplan's discussion of Leninism
The key difference between a normal utilitarian and a Leninist: When a normal utilitarian concludes that mass murder would maximize social utility, he checks his work! He goes over his calculations with a fine-tooth comb, hoping to discover a way to implement beneficial policy changes without horrific atrocities. The Leninist, in contrast, reasons backwards from the atrocities that emotionally inspire him to the utilitarian argument that morally justifies his atrocities.