There is this TED talk going around, in which the idea of a sustainability metric gets some fire. I thought of course of the DOM, although that’s a slightly different idea, and which I’ll come back to in a bit. But first I want to address the talk itself, which both Grist and the Atlantic appear to have bought wholesale. Words like ‘meaningless’, ‘ridiculous’, and ‘absurdity’ are not just hyperbolic, I’d say, but entirely misplaced. In his talk, Kaufman offers a few arguments that might seem to support the absurdity of a sustainability metric, but I think they all fail.
Kaufman mentions, for example, that there are literally hundreds of candidate metrics on offer. But it doesn’t follow that the idea of a metric is absurd, only that (at best) coming up with a good one is hard. And he smirks at the fact that the businesses involved—from ag producers to Wal-Mart—seem to think that the right yardstick is ultimately money. Which is, of course, a problem; nobody should think that economic measures track sustainability. But again it doesn’t follow that a sustainability metric is absurd, only that (at best) interested businesses aren’t necessarily credible agents for producing one. And then there’s the lament that
Our generation has fallen in love with the meta, with the virtual, with the hyper, with the derivative product, with the indexical. But you know what? When we’re talking about food as an index, we’re no longer talking about food.
Which is just staggeringly dumb: there is no reason to think “the meta” et al belong in one box together; or that our generation is the first to “fall in love” with these, whatever that means; or, more to the point of this post, that talking about e.g. food indexes isn’t a way of talking about food. If you’re a wheat farmer and I tell you about the price of wheat futures, we are talking about the price of wheat futures. A sustainability metric is indeed an abstract device, but it doesn’t on that ground alone fail to be informative. (Of course a bad metric would fail to be informative, but not merely on account of its abstractness.)
The place where I think Kaufman gets at the real difficulty with designing a sustainability metric is when he makes the point that a metric has to treat a variety of properties as commensurable. Diesel energy, pesticide use, synthetic fertilizer costs and so on all have to be converted to numbers and then weighted to yield a single number. But because that number is supposed to be an evaluation of sustainability, the whole process of quantifying and weighting treats each component as a value that can be traded off against the others. Creating a metric for food sustainability thus means deciding, for example, how many gallons of diesel it’s worth burning to conserve 100 gallons of water; and likewise for all other factors relevant to sustainability.
This might be an intractable problem. It’s possible that, in principle, the panoply of “green” values is simply incommensurable, and hence that any attempt to weigh them against each other is going to fundamentally misrepresent the facts. But I don’t think this possibility should deter us.
There’s an old joke about a mathematician and a sailor at a bar. The mathematician decides to prove to the sailor that, try as he might, he (the sailor) will never be able to kiss the girl at the other end of the bar. For to get to her, he first has to walk halfway there, and from there has to walk half the remaining distance, and so on. The sailor will only ever get halfway to the girl, in a kind of reverse Zeno paradox. So the mathematician presents this proof to the sailor, who mulls it over and then says “Sure, but you still get close enough for a kiss.”
The metaethicist, like the mathematician in the joke, might be able to give an argument for the incommensurability of values. But a sustainability metric that treats those values as commensurable might still get us close enough for a kiss; even a crude metric could still improve consumers’ decision-making. As Barath wrote:
Can there be a good single metric that can measure everything we care about—the things that make human life good? Probably not. But maybe we can try for less bad.
Maybe it’s absurd to aspire to a perfect measure of sustainability; maybe not. But that shouldn’t stop us from trying to create a decent one.