The idea of “nature” went out with the twentieth century. Part of the reason is physical: It keeps getting harder to distinguish the natural world from everything else. Between 1950 and 2015, nitrogen synthesized for fertilizers rose from less than 4 million tons annually to more than 85 million, and plastics production increased in weight from under 1 million tons to over 300 million. A 2017 study estimated the mass of the global “technosphere,” the material habitat that humans have created in roads, cities, rural housing, the active soil in cropland, and so forth, at 30 trillion tons, some five orders of magnitude greater than the weight of the human beings that it sustains. That is approximately four thousand tons of transformed earth per human being, or twenty-seven tons of technosphere for each pound of a 150-pound person.

Another reason is growing understanding that “nature” is always political. The meaning and value of the non-human world are always partly human creations, involved in gender, race, imperialism, capitalism—all of them offered up as “natural.” In my writing on ecology, law, and politics, I’ve written about living “after nature,” meaning, once we understand humans as thoroughly involved in the materiality and meaning of the world. This might seem to mean living against nature or without a nature. But here I would like to make a different point, one with many sources including Rousseau and Marx. Humans do have a nature, but a dynamic one: our nature is to create ourselves by creating the material and political worlds in which we live together. Humanity is the political animal, the species that explicitly makes its own rules and institutions. And in ecological and material terms we are an infrastructure species.

When I say infrastructure, I mean it in a few ways. First is the classic sense of the word: roads, rails, and utility lines—artificial systems that are open to most or all and enable people to reach one another for communication or other cooperation. Second, I mean those immaterial systems of interconnection and cooperation that do the same kind of work, such as the law of contract and, more generally, the market—which both economists and lawyers know is always built in a legal framework. Although this second type of infrastructure may be immaterial, its effects are very material: it produces the economics of the global carbon cycle, the food system, and everything else that is remaking the world. Third is the basic domains and cycles of the natural world: the global atmosphere, the water cycles and the waterways that it passes through, the soil and its fertility. These, too, are infrastructure: the conditions of all human action and interaction. Human activity increasingly shapes them and will do so even more intensively.

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