In reaching to remain relevant, the environmental movement has had to change tactics. Back in the seventies, when America looked like China does today, environmental issues needed attention. But then we cleaned up the air and water. The skies and rivers went from brown to blue. As Greenpeace cofounder Patrick Moore explains, in order to stay relevant, environmentalists had to find new issues.For most of the last decade global warming has been their cause, and carbon—or burning fossil fuels—was vilified as the cause. This gave way to a whole new industry: green. Green energy would replace fossil fuels. Wind and...