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Nov 9, 2012

Climate science is Nate Silver and U.S. politics is Karl Rove | Grist



Throughout this long, crazy campaign, there’s been a tension simmering between empiricists like Nate Silver andSam Wang, who cited poll data showing Obama with a small but durable lead, and pundits who trusted their “guts” and the “narrative,” both of which indicated that Romney had all the momentum after the first debate.

In the face of model projections like Silver’s, Jonah Goldberg said that “the soul … is not so easily number-crunched.” David Brooks warnedthat “experts with fancy computer models are terrible at predicting human behavior.” Joe Scarborough said “anybody that thinks that this race is anything but a tossup right now is such an ideologue.” Peggy Noonan said that “the vibrations are right” for a Romney win. All sorts of conservative pundits were convinced the Romney campaign just feltlike a winner.

You know how that turned out. Jon Stewart put it way better than I could:

Empiricism won. It didn’t win because it’s a truer faith or a superior ideology. It won because it works. It is the best way humans have figured out to set aside their prejudices, their perceptual limitations, their cognitive shortcomings, and get a clear view of what’s to come.

As it happens, there’s another issue in American politics where empiricists are forecasting the future and being ignored. Here’s what the Nate Silvers of climate science are up to:


Looking back at 10 years of atmospheric humidity data from NASA satellites, [John Fasullo and Kevin Trenberth of the National Center for Atmospheric Research] examined two dozen of the world’s most sophisticated climate simulations. They found the simulations that most closely matched actual humidity measurements were also the ones that predicted the most extreme global warming.

In other words, by using real data, the scientists picked simulation winners and losers.

“The models at the higher end of temperature predictions uniformly did a better job,” Fasullo said. The simulations that fared worse — the ones predicting smaller temperature rises — “should be outright discounted,” he added.

The Washington Post spells out what that means:


That means the world could be in for a devastating increase of about eight degrees Fahrenheit by 2100, resulting in drastically higher seas, disappearing coastlines and more severe droughts, floods and other destructive weather.

Such an increase would substantially overshoot what the world’s leaders have identified as the threshold for triggering catastrophic consequences. In 2009, heads of state agreed to try to limit warming to 3.6 degrees, and many countries want a tighter limit.

This is in keeping with a recent report from PricewaterhouseCoopers [PDF], which showed that, to hold warming to that 3.6 degree target (2 degree Celsius), global average carbon intensity would have to decline by 5.1 percent a year, on average, between now and 2050. That rate of decarbonization has never been achieved, ever, for as long as we have records. It is, the report notes dryly, “highly unrealistic.” Even to limit warming to 7.2 degrees (4 degrees Celsius) would require nearly quadrupling the current rate of decarbonization. And at our current rate rate of decarbonization (1.6 percent) we are on track for a temperature rise of 10.8 degrees (6 degrees Celsius) by 2100.

Let’s be clear about this. Scientists consider 3.6 degrees catastrophic. There are serious scientists who doubt that human civilization can endure at all in the face of 7.2 degrees. And we are headed for 10.8.

In short, the Nate Silvers of climate science are forecasting a landslide — that is, humanity under a landslide of drought, floods, disease, and dislocation. They’re telling us that unless we change our campaign strategy, i.e., undertake rapid, large-scale efforts to mitigate and adapt to climate change, our chances of surviving and prospering are dim and getting dimmer.

We simply haven’t come to terms with what empirical science is telling us. The mainstream media hasn’t come to terms with it. Most public intellectuals have not come to terms with it. And almost no politicians have come to terms with it. (Republicans deny it, most centrists ignore it, and Dems mouth platitudes about it.)

We all sound like pundits, going with our “guts.” The science feels too scary, too abrasive, too implausible. The hippies out there protesting over climate change feel “unserious.” The notion that energy prices might have to rise or lifestyles change feels “alarmist.” We talk about climate, if we talk about it at all, in terms of these time-worn prejudices and outdated folk theories. We all sound like Peggy Noonan with her vibrations.

It’s our own version of “math you do as a Republican to make yourself feel better.” Call it math you do as an American to make yourself feel better.

This election is being hailed in many quarters as a triumph for Nate Silver and forces of empiricism. But on the biggest, most pressing risk facing the country, those involved in U.S. politics might as well be witch doctors. Or worse, Karl Rove.

It’s not a wise approach, because in the climate race, losses are permanent and irreversible. There will be no recount.