From San Francisco eastward, city and state elections hinge this year on how environmental policies have affected cities’ economies. Today, the New York Times analyzed Mayor Mike Bloomberg’s green accomplishments. The analysis withstands scrutiny. But it also hints at how here,  and everywhere, traditional urban politics make the sager or fairer urban economic choices harder to see.

How many “green jobs” has New York’s Michael Bloomberg created, or how many industries have grown from Gavin Newsom’s choice to ban plastic bags in San Francisco? Did New Jersey’s pursuit of an anti-sprawl regulatory plan aggravate its economic troubles? These are impossible questions to answer because the cost of environmental inaction amasses millions of disconnected decisions around the world that add up to define our atmosphere. And the payoff from environmental action comes thinly in higher property values and more productive workforces- all of which the climate-change ostriches can attribute to other factors. The real payoff comes in a planet that’s recognizably our planet in 2050.

In that light, new accounting systems like LEED 3.0 or the Living Buildings Challenge (which my pal Suzanne LaBarre covers incisively in this month’s Metropolis) make hardier scorecards than old political methods like jobs created or contracts signed. We should learn to forecast political outcomes in order to predict economic ones. And today’s assessment of Mayor Bloomberg’s green accomplishments in the Times works most instructively as a read on the guy’s strategic targets.

Global climate change makes all our investments even balder bets on an uncertain future. It makes sense to judge the stewards of our economy on how sensible their plans seem, however short their list of wins might look.