Computers, not for current reasons but because they're essential to prevent a collapse of civilization in the future. Computers may allow us to understand the earth's fickle climate and how it is affected by detours of the great ocean currents. These detours cause abrupt coolings within a decade that last for centuries, sure to set off massive warfare as the population downsizes to match the crop failures. "Natural" though these worldwide coolings have been in the past, with their forest fires and population crashes, they're not any more inevitable than local floods — if we learn enough about the nonlinear mechanisms in order to stabilize climate. Computer simulations are the key to a "preventative medicine" of climate, what may allow human scientific ingenuity to keep civilization from unraveling in another episode of cool, crash, and burn.
theoretical neurophysiologist on the faculty of the University of Washington School of Medicine