The Math of Catastrophe

In the 1960s, the Soviet climatologist and mathematician Mikhail Budyko set out to investigate the potential future of a planet on the brink of nuclear Armageddon. He started by looking some 600 million years into the past. Back then, some scientists claimed, the ancient planet was an iced-over snowball. Most researchers considered that a crackpot theory. Ice over the equator? Please.

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