Happy Earth Overshoot Day!

There are many ways to compare humanity’s demands to the Earth’s ability to meet those demands. Scan the literature, and you’ll find plenty of approaches, and plenty of metaphors for what we used to call “The Limits to Growth.” Carbon budgets, temperature targets, and planetary boundaries all come to mind, as does the equity debate in the climate talks and, of course, the ecological footprint.

This (August 13) being 2015’s Earth Overshoot Day — the day on which, according the ecological actuaries at the Global Footprint Network, we’ve blown though 2015’s entire annual biocapacity budget — the footprint approach takes the spotlight. It’s earned the attention, for it’s a clever compromise between rigor and comprehensibility, and this is a rare thing indeed.

The power of the footprint approach is its flexibility, especially the way it scales. You can look at the planetary footprint of humanity as a whole — all our constructions, from wheat fields to weapons labs, taken together. Or you can talk about national footprints, wherein a country’s weight is compared to the biocapacity that lies within its borders, or, alternatively, to the footprints of other nations. Or you can talk about the footprint of a town, or a city, or a zipcode. You can talk of — and investigate — your own personal footprint. (Spoiler: Fly less!)

You can investigate footprints over time, in which case you’re going to be talking about ecological debts. You can even — and, alas, we do this far too seldom — talk about class footprints, by which, say, the weight of a nation’s elite is compared to the weight of its poor. You can aggregate people into groups, or you talk in per-capita terms. And the cool thing is that, in all these ways, the metaphor holds. You can be understood.

There are, of course, uses and abuses. This being Earth Overshoot Day, I can hardly fail to mention that the notion of “overshoot” has too often been used to carry water for reductionist forms of Malthusianism in which “overpopulation” dominates the stage, and hard thought about overconsumption and unjust distribution somehow never get equal time. On the other hand, we may have finally reached the point where we can leave this dismal history behind. As we do here: the “overshoot” of Earth Overshoot Day is not ideology, but rather methodology.

There’s much more to do, of course. In particular, there’s more to do on the distributional side of the footprint challenge. Oxfam tells us that, sometime in 2016, the “global one percent” — to richest hundreth of the human population — will own half of everything on the planet. The exact date when this great event takes place is not knowable — the data isn’t good enough — but it’ll happen soon. And the day it does will be at least as important as Earth Overshoot Day 2016.

Meanwhile, this is still 2015. The year of Pope Francis’ encyclical, and the year when Overshoot Day landed on August 13th. (Back in 2006, when Andrew Simms evidentally dreamt up the idea, it fell in October.) It’s also the year of the Paris climate accord, and next up on that agenda is fighting like hell to make sure Paris comes to something real. If we succeed, we won’t live to see the day when the annual overshoot moves forward into July. And then into June . . .

This is not someplace we want to go.