On environmental issues, America is barely a nation. Under a single flag it uneasily accommodates a host of states pushing greenery at wildly different speeds. In the 1970s and 1980s, this multispeed environmentalism propelled America to a leadership position. The key was truly bipartisan legislation, which allowed Washington to craft a coherent national approach. In fact, most of the major U.S. environmental laws did not arise solely from the environmental left but were forged by centrist Republican administrations working closely with centrist and left-leaning Democrats. Republican President Nixon created America's pathbreaking clean air and water regulations; Republican George H.W. Bush updated the air rules to tackle acid rain and other pernicious long-distance pollutants. In his more moderate second term, Ronald Reagan was America's champion of the ozone layer and helped spearhead a treaty—probably the world's most effective international environmental agreement—that earned bipartisan support at home and also pushed reluctant Europeans to regulate the pollutants.
Ever since the middle 1990s—about the time that the U.S. government was shut down due to a partisan budget dispute—such broad coalitions supporting greenery have been rare. In the vacuum of any serious federal policy, for nearly a decade the greener coastal states devised their own rules to cut warming gases. The United States as a whole let its green leadership lapse. (At the same time, the project to create a single European economy has shifted authority in environmental matters from individual member states into the hands of central policymakers in Brussels, where a coterie of hyperrich and very green countries have set the agenda. Europe, long a laggard on environmental issues, is now the world leader.)