The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert

Crutzen wrote up his idea in a short essay, “Geology of Mankind,” that ran in Nature. “It seems appropriate to assign the term ‘Anthropocene’ to the present, in many ways human-dominated, geological epoch,” he observed. Among the many geologic-scale changes people have effected, Crutzen cited the following:

In a recent paper in the journal Nature, researchers calculated that the weight of human-made objects, which includes everything from our houses and cars to asphalt and heavy machinery is now equal to or greater than all the world’s biomass. This is yet another sign that we have entered the Anthropocene.