"Even though it will disappoint many of you, the evidence is that you have a very bright future." This is how I finished my presentation at American University, eliciting a few chuckles from the audience. On a more serious note, I asked the students to consider a radical proposition: Economic growth and technological progress are not enemies of the environment but are perhaps its best friends, since they allow us to reduce humanity's footprint on the natural world. High tech agriculture boosts farm productivity, which means a cheaper food supply and more land spared for nature. Better sewage treatment means that our rivers and streams can run freer of pollutants. Catalytic converters on cars and better filters on power-plant smokestacks have greatly reduced smog, smoke and soot in the air. But only rich societies can afford to pay for these. In the end, the best environmental program of all is the promotion of prosperity.