A mad Scientist/Super Villain who's plan for world domination is to decrease/move/get rid of a lot of the greenhouse gases, bringing the earth back closer to an ice age-like environment. They, having planned ahead, had already created a safe haven against cold temperatures and had already recruited those looking for that as henchmen.
Well... That WAS the plan.
They are thwarted by Global-warming.
(Bonus Points if they are praised a hero for the work they've done reversing the effects of global warming and providing homes for the homeless.)