One of the most pressing challenges that the United States—and indeed, the whole world—will face in the next few decades is how to alleviate the growing stress that human activities are placing on the environment. As a matter of fact, the consequences are just too great to ignore. Wildlife habitats are being degraded or disappearing altogether as new developments take up more land. Plant and animal species are becoming extinct at a greater rate now than at any time in Earth’s history. As many as 30 percent of the world’s fish stocks are overexploited. And it is obvious that the list goes on.