Humanity spends a lot of time on the internet. Too much, probably. And every little Google search, Facebook message, and tweet uses some energy. All that Hulu uses a lot more. It's been clear that energy going to internet use is growing, but how does it compare to total energy use? If we really want to become sustainable, are we going to have to stop playing so much Words With Friends?

Well, maybe. But at least now we know that the internet accounts for less than 2 percent of the world's total energy use. That's still a pretty big amount. (The world uses A LOT of energy.) The internet consumes between 170 and 307 gigawatts, i.e. possibly as much as 250 flux capacitors. But computers are also getting more efficient all the time: The laptop I'm typing on uses substantially less energy to do tons more stuff than the room-sized computers that were the only computers just a few decades ago.