Some things are so big you don’t see them, or you don’t want to think about them, or you almost can’t think about them. Climate change is one of those things. It’s impossible to see the whole, because it’s everything. It’s not just a seven-story-tall black wave about to engulf your town, it’s a complete system thrashing out of control, so that it threatens to become too hot, too cold, too dry, too wet, too wild, too destructive, too erratic for many plants and animals that depend on reliable annual cycles. It affects the entire surface of the Earth and every living thing, from the highest peaks to the depths of the oceans, from one pole to the other, from the tropics to the tundra, likely for millennia — and it’s not just coming like that wave, it’s already here.