A Different Climate Change Apocalypse Than the One You Were Envisioning
Let’s say you are convinced that climate change is a huge threat and will have catastrophic consequences for humankind in the foreseeable future. How exactly do you envision that catastrophe playing out?
Most people I speak with, and most accounts I’ve read and seen, lean toward the apocalyptic. But what are the mechanisms by which disaster strikes? Where does it occur? Who is most likely to suffer?
According to a fascinating new working paper (abstract here; download available here) by Melissa Dell, Benjamin F. Jones, and Benjamin A. Olken, the answer to that last question may be an easy one: poor countries.
This answer may not surprise you very much, but Dell, Jones, and Olken have done a good job of showing the relationship between climate and the economy, and their paper may substantially inform the way that people — especially in the U.S. and other rich countries — consider the possible effects of climate change.
Here is the excellent first sentence of their paper:
Climate change may — or may not — be a central issue for the world economy.
Just in case it is, here is what they decided to do: take the historical temperature and precipitation data for every country in the world from 1950 to 2003 and combine it with the data for economic growth to see the overall effect that earlier climate change has had on economies.
The world has gotten a bit warmer and a bit drier over the past 50 years. The presumption is that it will get even warmer and drier over the next 50 years, so if economic changes from the past can be understood, perhaps future economic changes can be estimated. Here is the gist of their findings:
Our main results show large, negative effects of higher temperatures on growth, but only in poor countries. … In rich countries, changes in temperature have no discernible effect on growth.
What does this mean? Among other things, it may mean that many Americans — who are by definition rich — are worried about the wrong thing. Instead of thinking about weather apocalypses, they should instead be thinking about border invasions: the huddled masses from the poorest countries who will be seeking refuge as their own economies collapse. This would be Darwinism on the most epic scale imaginable — but instead of the finch with the shorter beak becoming extinct, it’ll be the poorest millions, or perhaps billions.
That, of course, is assuming the Earth keeps getting warmer and that warmer temperatures in fact disproportionately punish poor countries as Dell, Jones, and Olken suggest. (In an e-mail reply, they also raise an important caveat: “There are potentially other factors, such as sea level rise, which are outside the scope of our historical analysis.”) But in light of their compelling overview, it’s worth revisiting some other scholars’ work on the effects of climate change. For instance:
- Twenty-nine of 43 countries in sub-Saharan Africa experienced some kind of civil war during the 1980’s or 1990’s. The economists Edward Miguel, Shanker Satyanath, and Ernest Sergenti discovered that one of the most reliable predictors of civil war is lack of rain. If you have a largely agricultural economy, when the rain goes so does the agriculture, which makes political and economic breakdown much more likely.
In a rich country like the U.S., meanwhile, consider these findings from a pair of papers by Olivier Deschênes and Michael Greenstone:
- In the first paper, they use long-run climatological models — year-by-year temperature and precipitation predictions from 2070 to 2099 — to examine the future of agriculture in the U.S., and find that the expected rises would actually increase annual agricultural production — and therefore profits — by about 4 percent. Some states would be winners and other states losers but overall, climate change would be good for U.S. agriculture.
- In the second paper, Deschênes and Greenstone look at what a temperature increase means for mortality in the U.S., and find that the predicted climate change “will lead to an increase in the overall U.S. annual mortality rate ranging from 0.5 percent to 1.7 percent by the end of the 21st century.”
Sounds bad, yes? Think again: “These overall estimates are statistically indistinguishable from zero, although there is evidence of statistically significant increases in mortality rates for some subpopulations, particularly infants.”
In other words: the likeliest victims are, once again, the poorest people. Which means that if the relatively rich people who are currently most vocal about climate change are also the people who stand in the least danger, there may come a point where they realize that their concern is not so much an act of self-preservation as an act of altruism. Considering how impure much of our altruism is, that could be the most dangerous news of all.