Footprints and Debt

by Kevin S. Baldwin

With the recent global economic troubles, bail-outs of various kinds, and hand-wringing about passing financial debt onto future generations, it seems like as good a time as any to think about other debts that may be at least as important. Don't get me wrong: I too am concerned about the long term implications of deficit spending by national, state, and local governments, but believe these may be overshadowed by what we are doing to the natural world.

BiocapacityNearly 20 years ago, Mathis Wackernagel and his collaborators began formulating a measure of human impact on the earth's ecosystems. Eventually they arrived at an index called the “ecological footprint,” which summarizes food and fiber production, animal feed, timber harvest, fishing, infrastructure, and fossil fuel consumption and expresses this in “global hectares.” Thus a typical American would require nearly 10 global hectares in order to be supplied with all goods and services (Note how this compares to the global average of nearly 2.0 gha ecological footprint).

Using the index of ecological footprint, Wackernagel et al. 2002 estimated that humans crossed the threshold of sustainability into unsustainability around 1980 (see figure).

More recent estimates place our consumption of the earth at 150% of its biological capacity. In other words, we have been in ecological overshoot for three decades. Imagine having a retirement account that yielded 5% per year, while you spent 7.5% of it annually. Probably not a good idea if you have just retired and want to maintain a certain standard of living for two or three decades. Not so bad if you are clearly nearing the end of your life and can't take it with you; but truly a terrible idea if you are planning to bequeath an inheritance that would be the sole source of income for your descendants!

Many fiscal conservatives insist that deficit spending is immoral yet don't seem to mind that we are blowing through environmental capital/principal at an ever increasing rate. Conversely, many greens focus on the environment but tend to overlook deficit spending especially as it relates to issues of social justice and income redistribution. So we have this interesting situation in which groups that tend to be polar opposites are making the same arguments about debt in two different spheres. The result is that we will be leaving our children with the worst of both: high fiscal debt and degraded ecosystems. How then to reconcile these views?

The idea of a triple bottom line was first developed in the early 1990's by Elkington and promoted the three P's: Planet, People, and Profit or three E's: Ecology, Equity, Economy. Taking these three things into account for our decision-making process may help to bridge the chasm between the financial and natural worlds. Ecology and Economy have the same etymological roots after all! Until then, I will be more willing to discuss deficit spending with people when they acknowledge ecological overshoot.


Elkington, J. 1997. Cannibals with Forks: the Triple Bottom Line of 21st Century Business. Capstone.

Wackernagel et al. 2002. Tracking the ecological overshoot of the human economy. PNAS. 99 (14) 9266-9271.