“Thou shalt not cut down trees” is pretty high up in the environmentalist handbook. Human development has done enough damage to the world, we often hear, leave the trees alone. And besides, they’re the ones dutifully soaking up the carbon dioxide and the floating particulates we pump into the air that can make us sick.

But there’s an uglier truth about wood. While we’re busy saving the trees in our back yard and our nature preserves, we’re not using any less wood. In fact, centuries after humans innovated beyond burning wood as the most efficient way to create energy, we’re using more than ever—nearly 4 billion cubic meters worth each year, in fact, or more than 50 percent of the