Whenever I give guest lectures or talks around campus I usually sneak in something about sustainability, just to bait the waters. If I’m lucky, I’ll get a nibble. Someone will walk up to me after class and ask: “How do you define sustainability?” My typical response is: “I can’t.” That usually generates a perplexed response: “Don’t you teach whole courses about sustainability? “
As most students rush off to another class or cup of coffee I explain to the few that remain that I can’t define sustainability because sustainability must be defined locally: by a people, in a place, at a time. What is deemed sustainable for one group of people in one place at one time probably won’t be sustainable for different people in a different place. Moreover, it probably won’t be sustainable for the same people in the same place at a different time. If the people decide they don’t want to act sustainably—whatever that means to them—then sustainability won’t happen. “Sustainability,” I state with some emphasis, “is both philosophical and procedural.” The philosophy helps people ask good questions about what to sustain and the process engages them in an adaptive and continuous journey towards a constantly evolving desired future that motivates their commitment and sacrifice.
Silence. Confused looks. A few people drift a way. I give the others a stare over the top of my glasses to try to reel them in just long enough to finish the mini-lecture. There are only four points I want to make, and I’ve already made point number 1: Sustainability requires a viable, local, democratic process.
Brundtland provides a good way to make point number 2. The Brundtland definition of sustainability is perhaps the most widely known and many people can paraphrase it: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” What often gets swallowed without digesting is the first phrase: meeting the basic needs of today. Many people alive today go without basic necessities, and to speak of sustaining those conditions is immoral. The Brundtland report, therefore, helps me make the point that sustainability is about ending poverty, which means sustainability is about economic growth, because no one has come up with a better way to reduce poverty and provide minimal levels of food, water, sanitation, and dignity than to build local economic and community capacity.
So once I get the questioner to wrestle with what at first seems a contradiction—sustainability means growth—I move on to the third philosophical point: What should a community sustain? What should it pass forward? Brundtland offers useful specifics about population, food, energy, biodiversity, urbanization, and ocean fisheries. But I remind the student that I think sustainability is constrained by people, place and time, so according to my philosophy, people must ask themselves what is sustainable in their place for the near and long term, not rely on a United Nations commission from afar.
For help making this point I turn to a classic debate between Nobel Laureate Robert Solow and, to my mind, one of the preeminent environmental philosophers of our day, Bryan Norton.
The debate, as you would expect, is rich and nuanced and requires some study. By now, I’m in a hurry; students for the next class are coming in and I need to get out of the way for their instructor, so I recommend two readings that do a much better job than I, and do so in an way that most people find accessible.
As I finish shutting down my computer and stuffing my briefcase with sundry notes and papers, I summarize the Solow/Norton debate: “It’s about the investments we make. Not your parents’ investments in stock markets, but the investments we as a society make with the profits we generate by consuming natural capital.”
Natural capital includes the ecosystem services that provide us water, oxygen, and other life support services. It also includes the reserves of gold, uranium, oil, and soil that fuel our economy and agriculture. As we convert natural capital into economic capital we can spend it all on trinkets and bobbles that give us a fleeting glimpse of happiness, or we can invest some significant portion of it in human and social capital that replaces the natural capital we used. That is, we can train engineers and biologists to invent new energy and food systems, we can fund the environmental protection agency to ensure clean air and water, and we can build energy efficient buildings, public transport, and water treatment infrastructures to sustain us into the future. As long as we replace natural capital with other capital, the people in future have the same, if not more choices than we have—sustainability.
But—and this is a critical but—not all natural capital is alike. We must not consume some natural capital, no matter how wealthy it will make us, because its absence starts ripples of change we can’t reverse, no matter how rich or smart we get. Some natural capital is irreplaceable, at least in the time span of a civilization. Species extinction, the ocean as a carbon sink, and fossil aquifers are examples. An observant student, if they all haven’t fled by now, will point out: “But isn’t that similar to what Brundtland recommended?”
“Yes, mostly,” I concede. “You are right, we pretty much know what sustainability is, and have for a long time. What we lack is the willpower to achieve it!” And that is point four. Science can help us see the challenges of becoming sustainable and the economy can build the capacities to resolve them, but nothing happens unless we possess the will to act.
By now we are exiting the classroom and dispersing into the currents of campus: “And you, good person, by sticking through to the bitter end of this blog, have demonstrated you have the will and tenacity to make a difference. Please do so!”
R. Bruce Hull, IV, Ph.D. is a professor in the College of Natural Resources at Virginia Tech practicing social ecology. His work focuses on healing forests fractured by pressures of urbanization and globalization. He is author and editor of over 100 publications, including two books: Infinite Nature (Chicago 2006) and Restoring Nature (Island 2000). He serves on the editorial advisory board for Gale’s GREENR environmental and sustainability studies web portal.
 As a place to start, Solow, Robert. 1991. Sustainability: an economist’s perspective (a talk delivered to Woods Hole). Norton, B. 1995. Evaluating ecosystem states: two competing paradigms. Ecological Economics 14: 113-127.