In the 20 years that we’ve known about this problem, we’ve steadily burned more coal and gas and oil. Just the opposite: in the 20 years that we’ve known about this problem, we’ve steadily burned more coal and gas and oil, and hence steadily poured more carbon dioxide into the atmosphere. We need to change our habits—really, we need to change our sense of what we want from the world. Which leads to the next necessity:We need to stop insisting that we’ve figured out the best way on Earth to live. We need that kind of community to slow down the environmental changes coming at us, and we need that kind of community to survive the changes we can’t prevent.