Thursday, August 18, 2011

The problem with global warming (or climate change)

I am pessimistic about our ability as a species to deal with the threat of climate change, and I think it's because this is an instance of a larger class of problems that we simply don't handle well.

Let me start by saying that I am not intending this to be a discussion of the science behind global warming. I have no particular scientific background in this area, and discussions/debates about this should really be limited to people who have that background. (I.e., being a politician makes you competent to discuss policy around global warming, but not to make pronouncements about whether or not it is real or man-made).

In any case, my point here does not depend on whether you believe climate change is real or not.

The usual tradeoff matrix for something like climate change is usually expressed something like this (AGW = "Anthropogenic Global Warming"):

AGW is real and bad AGW is bunk (or not as bad as feared)
We do nothingWe're hosed Hooray - we didn't hurt the economy
We do something meaningfulIt cost a lot, but we're saved We killed the economy for nothing

As a broad generalization, conservatives tend to look at the downside of the lower right quadrant, the upside of the upper right quadrant, and the uncertainty of the lower left and conclude that there is no point in taking aggressive action to fight climate change, while liberals tend to look at the downside of the upper left and the upside of the lower right and demand action.

This is a classic tradeoff matrix, of course. But the challenge with climate change that makes this sort of analysis vexing is that if we choose to address it, we end up "making the wrong bet".

(If you believe AGW is bunk, please suspend your disbelief for a moment and assume it is real for the sake of the argument below; I'm not trying to get you to change your mind, you can resume your AGW skepticism afterwards.)

First of all, given all the uncertainties around climate models, there is no way to know for sure if we were to over-invest. So we could end up putting a greater economic drag on ourselves than is necessary (either because we could solve the problem with less cost, or, more pessimistically, because it's all futile anyhow). Actually "could" is the wrong word - there is no way to accurately predict precisely how much would be the right amount of cost to successfully fight climate change, so we would necessarily miss the mark.

But there is a broader challenge: suppose that somehow that we were to nail it: we make whatever changes manage to stop climate change in its tracks. Then it turns out that there is no way to distinguish success in the lower left quadrant above (we defeated global warming) from the lower right quadrant (we wasted a lot of money on something that isn't real). The economic cost of fighting climate change will be relatively easy to measure, but the underlying climate change that didn't happen cannot be measured - suggesting (though not proving!) that AGW was bunk in the first place, or at least that the economic cost incurred to fight it was overkill. And since we can't do a controlled experiment (two earths, one with lots of CO2 and one without), we can't determine if we spent the right amount or if the threat was less than advertised.

As a result, I suspect that the debate about policy will inevitably creep over the line into an (inappropriate for politicians) debate about the underlying science. And the only way that this ultimately gets settled is if we find ourselves in the upper-left quadrant. In other words, we only react well to hard provable evidence; we don't have the tools to deal well with theoretical issues. That doesn't seem like the right way to resolve an issue like this.