Despite the fact that we are protected by a formidable combination of ozone, gravity, solar radiation, magnetic fields, and life-enabling gases, our atmospheric “living room” remains as fragile as a fish bowl—and as easily contaminated. The idea that our atmosphere could be changed—by us—is not something we have ever, in our entire history, had to consider seriously until a single lifetime ago, which is about as long as we have had to seriously consider the automobile.
