Asking the Wrong Question on Global Climate Change:

Ellen Goodman writes today:

The climate is equally apparent in the struggle over what the Bush administration calls “climate change” — and everyone else calls global warming. The only way to justify doing nothing about global warming now is to deliberately muddle the science. It’s not an accident that Philip Cooney, the White House official caught editing reports on greenhouse gases, left for Exxon Mobil, which has indeed funded doubts.

Is it true that the only way to “justify doing nothing about global warming now is to deliberatly muddle the science”? I think the answer is quite plainly “no.” Even if it is true that global warming is occurring, this is only the first of many questions regarding whether we can justify doing nothing about global warming.

Embedded in Goodman’s assertion seems to be the implicit argument that if the scientific evidence shows that the global climate is warming, and if it is the result of human-induced factors, it follows that we must do something to try to reverse (slow?) global warming. Leave aside the scientific debate on the subject, and assume for a moment that the scientific predicate is correct. (the world is warming because of human influences). Even if this were true, the implicit syllogism still seems incorrect to me on several levels.

First, assume that the Earth were warming for wholly natural causes, and that the effect was as dire as the worst-case predictions under the current scenario–the apocalyptic stories we read of famine, pestilence, and natural disaster. Would the fact that this warming were “natural” make any difference at all with respect to whether we should do anything? The answer seems obviously no. We never stand by and simply permit wholesale disaster simply because the cause of the disaster is natural. Floods, hurricanes, cancer, smallpox, polio, starvation, wild animals, influenza, AIDS, etc.–all of these things are natural, yet that fact does not stand in our way of trying to alter nature to prevent their harm to humans. So, if global climate change is occurring, the quetion of whether we should do something seems largely irrelevant whether it is caused by humans or naturally-occurring.

So the real question to ask here is whether on net, the costs of doing something about global climate change outweigh the benefits of doing it. This is the same question we ask (or should ask) about every other intervention into nature–should we kill the parasites in water so that we can drink it, should we drain a mosquito-infested swamp to eliminate the risk of malaria, should we provide a vaccine to kill naturally-occurring smallpox. To imply that if the science shows we are changing the climate we must do something about it is as wrongheaded as it would be to say that if we are not contributing to global warming we should not do anything about it.

On the question of whether global warming would be a net benefit or detriment to the planet, the evidence I have seen to date suggests that it is inconclusive. There will be impacts on crop yields, growing locations, forests, energy consumption, etc., that cut in many different directions. The question of whether the warming will occur equally throughout the world, or whether it will occur more strongly in the coldest parts of the world appears to also be unsettled, and has powerful normative implications for policy. To get bogged down in the science, and especially in causal questions, seems to me to be largely beside the point.

Of course, this also shows why the “precautionary principle” is a non-starter as an intellectual construct. As I understand it, if the Earth was warming for natural causes and would nonetheless have the same effect as anthropocentric global warming, then the precautionary principle would tell us that we should not intervene to do anything about it, regardless of whether it might destroy us all. How can that possibly be an intellectually coherent position?

Moreover, note that like global climate change, economic growth is path-dependent, so that if we make ourselves poorer today, we will be forever poorer as a result, and as a result will have less of the good things in life that we acquire through wealth (health, education, medicine, safety, terrorism control). So some number of people will die either way.

I think we need to remind ourselves that the questions of whether the Earth is warming, and if so, why, are just the first question we need to ask ourselves. The real question is, if so, what should we do about it.

From what I can tell from reading the literature by Rob Mendelsohn and others, it is quite possible that based on the best predictions of global climate change over the next century at least, the net benefits of global warming may very well turn out to exceed the costs. (Beyond that time frame the predictions are largely irrelevant–recall that a century ago there were no cars, for instance, which should give us pause about the reliability of long-term models). But even if the benefits exceed the costs, there will be substantial distributional effects, primarily favoring wealthier countries that also tend to reside in more temperate climates (in part, the two are related, as the net beneficiaries of global warming also tend to have higher levels of economic productivity).

If this is true, I want to suggest one way we can think about this is the “Box 4” that is familiar to Property professors in teaching the Coase Theorem (Spur Industries v. Del Webb). This would be to recognize the right of the net “losers” of global warming as having suffered a global nuisance from the net “winners,” but to enforce it with a liability rule that entitles them to compensation, rather than a property rule that would entitle them to an injunction. The transaction costs seem too high to give them a property rule. Forcing the winners to pay compensation would also ensure that the net gains from global warming to the winners do in fact outweigh the net losses to the losers.

Update:

Glen Whitman has pointed out that I have incorrectly labeled this a “Box 4” problem, when, in fact, it is merely a traditional liability rule. Jonathan Adler has also noted that it might be fruitful to think about global climate change through the lens of a liability rule, rather than property rule, remedy (assuming, of course, that it is thought that a remedy or property right is appropriate in the first place). He also excerpts a comment from the Sierra Club’s Carl Pope on the liability rule idea (and responds) himself here.

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