The biggest challenge humanity faces this century is ensuring that the march of civilization does not degrade the global environment so much that we irreparably harm the planet on which our own survival depends. The advent of the Anthropocene—a new geological era in which humanity is the most important force shaping the biosphere—has revealed a fundamental contradiction between the Earth’s own integrated natural systems and a hopelessly fragmented international system. The former is an ecological and geophysical whole, as apparent in the famous “Earthrise” photograph taken by Apollo 8 astronauts on Christmas Eve, 1968. The latter is an artificial human […]