Climate Computer ModelsApril 8, 2010
The Washington Post has an article pointing out how the climate contrarian community has now focused heavily on the unreliability of computer models (as if this weren’t already the case).
It’s true, as they say, that climate models are only educated guesses… but educated guesses are, in many cases, the best we can do, and that alone isn’t a reason to discard them. I make educated guesses about how long to cook my dinner, for instance, just as I make educated guesses about the weather for the day, the reliability of bridges, and the likelihood of you having an ace in your hand. That information is invaluable to me, and I rely on it. I think Gavin puts it pretty well:
If policymakers don’t heed the models, “you’re throwing away information. And if you throw away information, then you know less about the future than we actually do,” said Gavin Schmidt, a climate scientist at NASA’s Goddard Institute for Space Studies.
“You can say, ‘You know what, I don’t trust the climate models, so I’m going to walk into the middle of the road with a blindfold on,’ ” Schmidt said. “But you know what, that’s not smart.”
More importantly, however, even though I rely on educated guesses, as well as all manner of scientific and non-scientific models, to help me make determinations about what I should do, I also make decisions about what to do independently of educated guesses and projected outcomes. In some cases, I make decisions about what to do with only a loose expectation or understanding of the impacts of my actions.
So, for instance, I can understand, more or less, that when an animal is raised on a factory farm, that it endures some substantial amount of discomfort, and may even endure some degree of suffering. Do I need to know the extent of this discomfort and suffering to make a determination about what to do? By my lights, not really. I just need to know that there is some morally significant discomfort and suffering, that a given threshold has been passed. This is enough to know that, arguably, I ought to change my behavior with regard to animals raised on factory farms. The models don’t actually matter so much.
What I’ve just given you is a considerably more consequentialist reason than one that I might normally give — I still need to know that there is suffering, for instance; and for the reason that there is this suffering, I therefore need to reevaluate my behavior — but it suffices to show that even reasoning along pretty strict consequentialist lines, hand-waving at the magnitude of discomfort and suffering is all that’s needed.
In the case of the climate, how much does it really matter if the climate goes up by one degree, up by ten degrees, or down by one degree? If human activity is having an effect on the climate, it seems reasonable to me that this matters, and that we ought to pay attention to this. The magnitude of the climate change — or what the models say — doesn’t affect the status of our requirement to do something about it.
Having said this, climate models do raise questions about the correct or effective anticipatory responses, but that’s a totally different question.