There’s No Such Thing as Qualitative Sustainability

Thinking green is just not enough

It was one of those classic moments where the irony just seemed too severe to be unplanned. I was riding my bike to work when I passed a parked vehicle and noticed a remarkable bumper sticker. I still regret not taking out my phone and snapping a picture; because I did not, I can only paraphrase what this bumper sticker promoted. The sticker said something akin to “we don’t use plastic bags” and featured an image of a reusable canvas shopping bag. And — oh yeah, did I mention? — it was firmly affixed to the bumper of a large sport utility vehicle.

As a trained ecologist who thinks and teaches about the sustainability of our civilization, I instantly identified the potential for irony. That irony can be illuminated by asking a very simple question: how many miles would someone have to drive this vehicle before any benefit from forsaking the use of plastic bags would be “over-ridden” by the impacts associated with driving a large, fossil-fuel-intensive vehicle? My suspicion is that a year’s worth of not using plastic bags probably would not even offset a short trip to the supermarket, and that is why I find the sticker ironic. But the truth is that my suspicion is no more than a hunch: I do not know the answer to the question that determines how ironic this sticker placement really was. To actually know how ironic that sticker might be, I cannot just think qualitatively: I need a quantitative estimate of the impact of both plastic bag use and sport utility vehicle use.

I live in Brooklyn, where if you find yourself in the right neighborhood there is no limit to where intentional irony might take you. Although I have no real basis for knowing the intentions of this vehicle’s owner, I somehow doubt that in liberal-minded Brooklyn this was an ironic attempt at making fun of the sustainability movement. And yet, in so many ways, earnest people advocating a more sustainable path end up producing a near-constant stream of these ironies. Nowhere is this tendency more apparent than in the design fields.

These days sustainability is a major agenda at most schools of design and architecture. Courses focus on using renewable and lower-impact materials, creating energy-efficient designs, and — to a lesser degree — on designing durable, timeless products. It is admirable that so many designers and architects have begun to confront the problematic side of their work, to look unflinchingly at the environmental impacts of their craft. But too frequently schools of design are more comfortable talking about the qualitative aspects of sustainability than looking at the hard numbers that allow us to determine whether a given design actually meets our goals for reducing impact.

It is not surprising that design often shies away from quantitative analysis of sustainability. After all, much of the value of design is unquantifiable: you cannot objectively measure what makes a building inspiring, a garment beautiful, or a piece of furniture appealing. Much of the design process is similarly based on qualitative decisions — what materials to use, what color palette to incorporate, what three dimensional shape to render — although increasingly these qualitative decisions are quantified by digital design software. Some might also suggest that there is enmity in the design fields towards quantitative thinking, although I think that this assessment reverses cause and effect. That designers are so good at qualitative thinking simply reflects that good design requires good qualitative decision-making. It is not at all surprising that when most designers thinking about making a “green design”, they begin by thinking qualitatively.

The tendency to think qualitatively about sustainability is not unique to the design fields: a fair amount of “green policy” is also rendered useless by relying solely on green logic rather than green calculations. In the United States, our support of corn ethanol provides an instructive example. Assessed qualitatively, biofuels seem like a really sustainable option: agricultural plants turn carbon dioxide in the atmosphere into liquid carbon-based fuels that supplant the use of fossil fuels. Logically, biofuels seem “carbon neutral”, which suggests that they are “green”: part of a sustainable economy, and worthy of the massive subsidies we provide to promote their production. But for most biofuels — and particularly for corn ethanol — the logic of qualitative sustainability fails to produce sufficient quantitative reductions in environmental impact. While it is true that the actual carbon dioxide produced by burning corn ethanol “comes from photosynthesis”, only considering this qualitative difference from conventional fuels fails to account for the full impacts of biofuel production and use. What about the greenhouse gas emissions associated with growing and harvesting the corn and processing it into ethanol? What about the impacts created by the intensive farming required to grow corn in suitable abundance? And what about the social costs of diverting food to fuel? When the full impacts of most biofuels are quantified, it is hard to argue that they represent a sustainable solution to the problem of burning fossil fuels (Bourne 2007, Biello 2011).

Another great example of the pitfalls of trying to use qualitative logic to chart a sustainable course has been brought to us by the local food movement. While it might seem that there is a coarse mathematical logic behind the idea that local food travels fewer miles and therefore lowers environmental impact, being “local” is only one of the qualities of food that we might assess quantitatively. The efficiency of agricultural production methods has a much greater influence on the environmental impact of food, as does the kind of food produced (plant versus dairy versus meat) and how we store and prepare our food. Because the local food movement focuses exclusively on one metric — the number of miles a given food product travels from “farm to table” — it fails to fully account for the relative impacts of foods of varying origin. This means that “being local” is in essence a qualitative description of a particular food product. Often eating local can cause greater impacts than “eating global”.

The problem with only thinking qualitatively about sustainability is that the natural world functions in quantitative rather than qualitative terms. Greenhouse gases in our atmosphere are critical for maintaining a sufficiently warm planetary climate, but in excess concentrations these same gases have the potential to cause mass extinction. That is to say that greenhouse gases have no inherent “quality”; what determines whether greenhouse gases foster life or threaten life is their quantity. Similarly, nutrients like phosphorus and nitrogen are critical to the functioning of all ecosystems, but produced in excessive quantities they can cause massive loss of ecosystem services. There is a critical fraction of wild populations (for example bluefin tuna, or Sumatran rhinos) that we can harvest for our own use, but any harvesting above this level leads to population collapse. Even toxic pollution can be considered quantitatively, as substantial risk only emerges when toxins reach critical concentrations. It is not coincidental that “ecology” and “economy” share the same latin root: both are means of keeping track of the transactions of a dynamic system, and both are fundamentally quantitative fields. To understand how our actions affect the sustainability of the ecological systems on which we depend, we need to assess our impacts quantitatively.

Natural scientists are beginning to recognize the public’s need to think more quantitatively about the impacts of human actions. Scientific data has been used to produce a variety of ecological footprint calculators, which allow individuals to consider whether their lifestyles are sustainable. Ecological footprints represent a quantitative assessment of whether our impacts can be sustained by the earth’s service-providing ecosystems. In a similar vein, many scientists have argued that there are “planetary boundaries” past which we cannot sustainably push the earth. To determine whether our activities will push past these boundaries, we must ask quantitative rather than qualitative questions¹.

To an optimist my “plastic-bag-free-SUV” might not seem so ironic. After all, isn’t it better to use canvas bags rather than plastic? If you presuppose that a vehicle must be driven, a product must be consumed, or a building must be built, making choices that seem sustainable becomes a whole lot easier. If you are going to drive your large sport utility vehicle no matter what, refusing to use plastic bags does represent a more sustainable lifestyle. The problem of course is that “more sustainable” is not always enough: if it turns out that the impacts of driving an SUV really are far greater than producing, using, and disposing of plastic grocery bags, then we will never attain a sustainable society by being content with “living greener”. Relativistic optimism turns out to be just a more sophisticated form of denial. The SUV versus bags dilemma serves as a metaphor for the larger problem of making hard choices about our most unsustainable social practices. As long as we don’t want to think about sustainability quantitatively, we can delude ourselves into thinking that “greener” practices are enough.

So what is a conscientious designer to do? Well, to start with, all designers should be familiar with the principle and practice of life cycle analysis, which provides a means of assessing the full impacts of a potential or actual design. Whereas I might use qualitative logic to argue that my design’s use of fast-growing bamboo makes it more sustainable, life cycle analysis would allow me to comprehensively compare the relative impacts of different prospective design materials. If you are going to claim that your design is “more sustainable”, you ought to be able to show quantitatively that it lowers impact in comparison to other designs. But this relativistic quantification is not enough because our society as a whole will not be sustainable unless we lower our impacts enough. Designers cannot simply design relative to the state of their craft. Instead, designers need to take on problems that are truly in need of fixing. This means that every aspiring designer of sustainable products — from sunglasses to skyscrapers — has to have a quantified sense of what human activities cause the greatest impact. Revolutionary sustainable design must not just reduce our impacts, but reduce our impacts to such a degree that our overall society will become sustainable.

Lurking behind these sometimes-complex issues is a reality that is scary to designers, producers, and consumers alike: there is an inherent sustainability in not making, in not consuming, in not doing. As members of a society that often conflates consumption with necessity, with pleasure, and — ultimately — with success, the “not doing” approach to sustainability is not something we want to hear about. We don’t know how to stop consuming, in large part because we have constructed an economy that does not know how to be successful by reducing consumption. In fact, our entire economy’s success is predicated on forever growing, a growth that means consuming more. Thinking quantitatively about impact and the sustainability of our impacts forces us to confront the fact that we don’t just need greener products: we also need a greener economy.

Design is a kind of policy: it is the precursor to changing the behaviors of both manufacturer and consumer. For design to promote a truly sustainable society, designers have to think quantitatively. They need to select targets for green design by considering what impacts of the designed environment create the greatest harm. They need to assure that their designs don’t just cause less harm, but only cause harm at an intensity that can be sustained by the natural world upon which we depend. And designers need to destroy a sizable bit of their own profession by working towards an economy that isn’t just about consuming greener products but also about consuming less. Once you force yourself to think quantitatively about sustainability, “thinking green” is simply not enough.

¹ Although I don’t get into this nuance in this piece, I do want to acknowledge that both “ecological footprints” and “planetary boundaries” are not just quantitative measures. Both ways of measuring impact reflect particular values, the most prominent of which is that we share the goal of not depleting the ecosystems on which we depend for various critical services. Any means of quantitatively analyzing behavior has to start with a declaration of values/goals. If we do not know what our goals are, we cannot calculate what actions are required to reach those goals. Luckily, there is general agreement on a basic definition (read: goal/value) of sustainability: that our use of ecosystems today should not compromise or diminish the capacity of future generations to enjoy similar use.