It is easy to go see climate talks at Berkeley and as a social scientist I have to say that they usually make me uncomfortable. If you go to an astronomy or physics talk, nobody bats an eyelash when people question the evidence for, say, Dark Energy. (Criticizing the idea that speed of light sets an absolute limit on velocity definitely will encounter resistance, but I’ve seen that done also.) This pattern of evidence and push-back has been going on since universities rejected scholasticism back in the 1100s. It’s a pleasure to watch.
To an outsider, at least, the climate talks feel different. True, speakers can and often do criticize the evidence. But they invariably begin and end with the disclaimer that “Of course global warming is happening.” Partly, I suppose, this is about not wanting to be misunderstood in a subject where obscure research sometimes ends up in the newspapers. But it’s pretty obvious that there there are social pressures at work inside the university too. And that’s a pity. Investigators shouldn’t care what the answer is. (None of us can really meet this standard, of course, but it’s inspiring to see people try.)
So yes, I was disappointed by the e-mails. And no, they aren’t damning to the point where we should toss out the evidence and start over. Given that social pressures had so visibly crept into the process, they just aren’t that surprising. Still, it’s good for the public to feel disappointment and even to say so. That’s what keeps all of us honest.
Can we run the global warming debate better next time? There are several problems that here. The first and biggest is that society wants binary judgments — Does global warming exist or not. Humans are notoriously uncomfortable with probabilities. Science, on the other hand, is about evidence. And the evidence is never 100%.
The other problem is that global warming is a tough subject. Physics works best for problems where the number of inputs is small and small inputs have small effects. Climate physics is remarkably difficult by that measure. We probably understand the interior of the Sun — or even dark energy — better than we do climate.
Society’s insistence on certainty — maybe zero, maybe 100%, but nothing in the middle — is a psychological fact. But it is also the wrong way to do policy. If the chances of global warming were only, say, 78%, that would not absolve us of the obligation to consider the probabilities and act accordingly. And indeed, there is an enormous literature on decision-making under uncertainty.
Global warming won’t ever be “proven” in this 100% sense. All the same, it has arrived and needs to be dealt with. As the old aphorism would have it, “You can ‘t win, you can’t break even — and you can ‘t get out of the game.”