I have been meaning to write something about this ever since Jim Manzi linked to Indur Goklany's Cato paper climate change a couple weeks ago and wrote that "before anybody gets on a high horse about how CO2-laden economic development is such a threat to the poor of the developing world, he really ought to have a response to this analysis." So, in the interest of scrambling back atop the high horse, let me say a couple of things about Goklany's analysis (PDF).
The Goklany paper makes two basic arguments. The first is that we are not net necessarily better off with a cooler and poorer world than a richer and warmer world. Our money might be better spent adapting to the changing climate and sustaining growth, rather than changing mitigating the effects of climate change and reducing growth. The second argument is that the problems that global warming creates for the developing world pale in comparison the problems created by more predictable issues, like basic population growth. If that's true, why devote scarce resources to a comparatively small problem?
The paper is worth a read, no doubt about it. But I have four issues with it:
(1) Goklany's analysis does not extend beyond the 21st century. This is a problem for two reasons. First, climate change has no plans to close shop in 2100. Even if you believe GDP will be higher in 2100 with unfettered global warming than without, it's not obvious that GDP would be higher in the year 2200 or 2300 or 3758. (This depends crucially on the rate of technological progress, and as Goklany's paper acknowledges, that's difficult to model.) Second, the possibility of "catastrophic" climate change events -- those with low probability but extremely high cost -- becomes real after 2100.
(2) Goklany's estimates are based on global aggregates that hide the unequal distribution of the climate change burden. Yes yes, I know Manzi will say that's not decisive: As long as global GDP is higher, we can redistribute our way out of the problem more effectively tomorrow than we can today. I would be more comfortable with that debate if I thought vast international restributions ofincome in the name of global equity were more likely tomorrow than they are today.
(3) Along those lines, I'm suspicious of the ethical calculus that says we should not focus on one large global problem because larger global problems might exist. That kind of moral math rarely corresponds to the political reality. (Do you think the average congressperson opposed to Waxman-Markey has trouble sleeping at night over new cases of malaria or global hunger?) Nor does it correspond to the historical responsibility: Industrialized nations are more responsible for the global problems created by climate change than the problems of population growth.
(4) I think Goklany is a bit picky and choosey with the evidence. I always feel uncomfortable making this kind of argument, since empirical disagreements tend to make important differences of worldview look like abstruse technical quibbles. I also like the Goklany paper a lot. But in this case it's hard to resist.
To take one example (of several), Goklany's hunger estimates rely heavily on those published by Global Environmental Change (GEC), which he uses to make the argument that "the world will be better off in 2085 with respect to hunger than it was in 1990 despite any increase in population." But the GEC produced two estimates of hunger and climate change -- one that assumes the benefits of co2 fertilization and one that does not. Goklany picks the former estimate (I have no idea why), despite the fact the GEC says the effects of climate change "will fall somewhere between" the two.
That probably looks like an abstruse technical quibble, but it isn't, and I've got a chart to prove it:
Right then, back on the high horse: if you embrace anything other than the most Pollyanish co2 fertilization estimate -- the one that Goklany uses in his Cato paper -- we will be living in a world in which climate change puts tens of millions of additional people at risk of starvation by 2085.
Photo: This farmer is from Bangladesh, and Syed Touhid Hassan's Flickr photostream.