Solar Power Footprint
See it? That little black square in the middle of Saudi Arabia? It's 231 kilometres on a side, covering some fifty-three thousand square kilometres. That's the total area of solar panels needed to supply global electricity needs at its current rate of consumption, some 2 trillion Watts. Calculated by Professor Raymond Pierrehumbert of Chicago University, in an open letter that corrects global-warming denying innumeracy in Superfreakonomics.
(via Carl Zimmer)