Lomborg, global warming, and opportunity costs

I've not read Bjorn Lomborg's new book (nor his previous one), but I have read enough of what he has written to suspect that some of those who are ridiculing one of his arguments don't understand it. For example, Bob Park of the American Physical Society's "What's New" writes:

Bjorn Lomborg's "Cool It: The Skeptical Environmentalist's Guide to Global Warming" is out. Well, yes it is getting warmer he finds, but aside from polar bears, it just means more beach weather. We've got bigger problems, he says. Instead of spending all that money trying to prevent warming, let's focus on making everyone rich so they can all buy air conditioners.

P.Z. Myers at Pharyngula writes:

He also has a bad argument about relative spending: he suggests that spending on climate change would reduce spending on other pressing issues, like the fight against malaria. It's a bad choice. Malaria research is already underfunded — it's a third-world disease, don't you know, one that mainly affects those tropical countries, so the wealthy western nations typically don't prioritize it very highly. We don't take our big pots of money and allocate it into aliquots appropriate to the world's needs already, so for an economist to sit there and pretend that climate research is a drain on tropical disease research is comical. Especially since he seems unaware of how one feeds into the other. Hey, if the world warms up, tropical diseases will creep northward into Europe and North America, and then we'll be fighting the economic effects of both direct effects of climate change and new diseases.

But as I understand it, Lomborg is making a simple point about opportunity costs--that money spent on climate change mitigation can't be spent on other things, and that it would be better off spent on things like fighting malaria (which I'm sure he would agree with Myers is underfunded, since it's #4 on the Copenhagen Consensus 2004 list of "very good projects" to spend money on), because the amount of benefit received for each dollar spent is so much greater.

To make the same point--I have looked into putting solar cells on my house, both to reduce my carbon footprint and my long-term energy costs, but I've decided against it because even with the tax incentives and my power company's willingness to subsidize half the cost, it's still not cost-effective. (I'm hoping new solar cell technologies will improve efficiency and lower cost so that I will be able to become less dependent upon the electrical grid). Instead, I've spent much smaller amounts of money that have had far more bang for the buck, replacing my incandescent lights with CFLs (though LEDs and other new promising technologies are on the way as better sources of light), adding insulation, and improving the efficiency of my air conditioning units through regular maintenance. These things I've done not only have an impact on my energy use and climate change, they are things which provide me with direct economic benefit as well--thus these are things that rational people will be doing independently of government regulation and spending.

Lomborg--or at least the Copenhagen Consensus--is not saying that climate change deserves no attention. The premise of the Copenhagen Consensus is that if the world spent an additional $50 billion over the next five years to address ten categories of global challenges (one of which is climate change), how would that money best be spent to provide the greatest net benefit. That seems to me to be an entirely worthy effort, and this kind of cost-benefit calculation should be given greater weight in public policy decisions. Instead, however, most politicians like to make arguments based on the assumption that any law, regulation, or government spending that saves even one life (or prevents one child from seeing something offensive) is worth doing, whether or not that generates enormous opportunity costs.

My personal behavior--and I suspect that of those criticizing Lomborg on this point--demonstrates that I don't consider climate change my number one priority. In my case, I live in a large house that uses a lot of electricity, I travel frequently by plane, I drive a car instead of using public transportation, I eat meat instead of being a vegetarian like my wife. Each of these things causes, directly or indirectly, an increase in carbon dioxide emissions over the alternatives.

UPDATE (December 16, 2008): I just came across this description of Lomborg's overall behavior with respect to the climate change debate, which I think is likely accurate.