Environmentalism has plenty of buzzwords already–sustainability and resiliency come right to mind. Does it make sense to propose another? In a sense that is what we are doing by making habitability the focus of this blog. In this initial post I’d like to try to suggest why that theme is worth exploring—with the acknowledgment from the outset that its content is not well developed.

In a very obvious way discussions of the Anthropocene immediately raise the question of the future habitability of the planet. The Anthropocene idea was linked early to the idea of planetary boundaries, with the implication that if those limits are transgressed, altering the broad environmental parameters underlying current patterns of habitation, Earth may become a place that cannot support modern civilization—and in the extreme might cease to function as human habitat altogether. Even short of scenarios involving the extinction of human beings, the current concern that Earth is in the midst of the sixth great extinction event for non-human species likewise raises the question of the habitability of the Anthropocene. (Likewise the vehement responses to even the phrase “good anthropocene”—see the controversy over Andrew Revkin’s talk containing it.)

But the Anthropocene idea also points to a crucial recursiveness in the idea of habitation, which is linked also to the ancient idea of “second nature.” That idea, attributed to Cicero, expresses the idea that human beings themselves construct the basic conditions of their lives—the physical environment they inhabit (so fundamental and given as to be, in effect, nature) is the result of their transformation and exploitation of primordial materials and forces (so distinct from those as to be, in effect, a second thing). The Anthropocene seems like the fulfillment (for better or worse) of the idea of second nature: human activity has re-worked not just this or that landscape, but the entire planet. We recognize the recursiveness of habitation when we recognize that habitability is its product, not its precondition. That is, a place is made suitable for living by the activities of its inhabitants, who deliberately alter it to become suitable for the kind of habitation they require. This phenomenon, which has been called niche construction, appears to be quite general across organisms. Human beings are exceptional only for the extensiveness of their niche construction activities; that they engage in them is a core feature of their kinship with other forms of life. (See my post on niche construction theory.)

The dangers associated with the Anthropocene, of which climate change is perhaps most familiar, show that the recursion involved in habitation can lead to a vicious cycle, whereby patterns of habitation diminish habitability—in a painful irony, due in some measure to the ideals of habitability, i.e. the ideas about what constitutes a good form of life, which in turn influence the way people choose to live. (By way of a simplistic, strictly conceptual example: desire for comfort prompts the use of air conditioning, which drives demand for electricity, which drives fossil fuel consumption, which increases global temperatures, which increases use of air conditioning.) But a virtuous cycle is at least imaginable, where ideals of the good life inform ways of living that do not compromise habitat, and even perhaps improve habitability. What is not imaginable is that habitation has no effect on habitat. Thinking in terms of habitability thus helps makes vivid that, as I (along with Michael Ellis) have argued elsewhere, the question is not, how might we avoid the Anthropocene, but rather, which Anthropocene is it to be?

Now a defining (and obvious) feature of human habitation is that it is social, and cannot be understood apart from the structures and forces that characterize human society. It follows that thinking in terms of habitability encourages us to put social (including political and economic) explanations squarely in the center of accounts of anthropogenic environmental change as well as of the condition of human habitat. This is no doubt a truism for social scientists and humanities scholars. Perhaps, however, the habitability approach can aid with the emerging efforts to integrate those scholarly disciplines with the natural sciences, in the hopes of developing a holistic understanding of the interactions between human and natural systems. Those interactions take place at a full range of scales—from local all the way to the planetary level. Thus, thinking in terms of habitability might facilitate scholarly interactions across a range of disciplines, hopefully adding to the intellectually robust conception of the Anthropocene the world’s current circumstances demand.

I acknowledged at the beginning that the precise meaning of habitability is underdeveloped. I will close by reaffirming that acknowledgement: a goal for my contributions to this blog is not to present a worked-out theory, but rather to offer some conjectures and learn from responses, and other people’s posts. I expect that explorations, including suggestions for readings (see the Prospectus page), will follow both descriptive and normative tracks. That is, they might examine physical and social processes that people (and other species) rely on (or have relied on in the past) and construct (or have constructed) in order to inhabit the places they live across the globe. And they might also evaluate practices of habitation, making clear the standards of evaluation. For an advantage of the idea of habitability is that it encompasses both these dimensions: how people live, and why that way of living is good.