Reclaiming a Rigorous Definition of “Sustainability”

The latest issue of Frontiers in Ecology and the Environment features a great guest editorial by David N. Laband and David B. South entitled “Walking the talk on sustainability”. In this short piece, Laband and South make a point that is brought to light far too infrequently: that we use the word “sustainable” in a sloppy and disingenuous manner. Starting with the Brundtland Commission Report definition of sustainable development, the authors make the point that very few of the programs we call “sustainable” actually live up to this definition.

“Intergenerational Equity” is a really important concept for our times, one with equal applicability to our economic and ecological systems. To achieve intergenerational equity, it is critical that each generation leave in its wake a world that provides comparable resources to subsequent generations. For most of human history, one could argue that subsequent generations have been provided by their progenitors with greater resource supplies: through a combination of technological advance and geographical dispersal, our species now supplies itself with unthinkable abundance. But is this abundance of resources sustainable, and will future generations be the first to “live with less than their parents”?

Laband and South see that this kind of intergenerational decline is inevitable unless we radically shift our path. They correctly point out that much of the current abundance enjoyed by humanity comes through a really rapid depletion of non-renewable resources, most dramatically fossil fuels. At their current rate of exploitation, Laband and South see no more than sixty years’ worth of fossil fuels, suggesting that in only three to four human generations our species will have deprived its descendants of a supply of cheap energy. This radical intergenerational inequity is remarkable and quite scary.

According to Laband and South, to actually be “sustainable”, our fossil fuel supplies would have to be exploited at a rate twenty times lower than the current rate. This is an unimaginable change in efficiency, and suggests that no current plan to reduce fossil fuel should be granted the label “sustainable”. We just haven’t earned it yet, baby.

If non-renewable resources are being used in a way that is unfair to future generations, what of our renewable resources? Although they do not offer as concrete a set of calculations for ecosystem services such as marine fisheries, climate regulation by primary producers, or pollination, Laband and South point out that we are in the process of degrading these resources as well.

Someday we will run out of oil. I agree with Laband and South that the only fair way to exploit non-renewable resources is to drastically slow their depletion so that replacement technologies can be discovered and phased in to replace the value that these cheap sources of energy have provided over the past two centuries. But for the renewable resources that ecosystem services provide there is no excuse for allowing the steady supply to dwindle for future generations. Ironically, these two resource streams are interconnected: the faster we burn through our fossil fuel supply, the more rapidly we degrade and destroy the ecosystems that provide us with critical services. Real sustainability requires radical change.