There are more habitable planets in our galaxy than humans living on planet Earth. But the nearest one is about 70 trillion miles away, which means that, for now, and for the foreseeable future, Earth is the only life-supporting rock hurtling through infinite space we’ll ever know. It’s really not the best idea to let it burn up–and key to keeping it cool are the massive rainforests of the Amazon. Sadly, we’ve had a hard time not cutting them down.