I’m spending a large part of my day writing a book review of Daron Acemoglu and James A. Robinson’s Why Nations Fail. Given the main theme of the book, which I like to focus on in reviews, I can’t find a way to fit an interesting section they wrote on global warming. But it’s important enough not to ignore. So here’s the relevant excerpt, taken from a section sub-titled “The Long Summer”:

About 15,000 BC, the Ice Age came to an end as the Earth’s climate warmed up. Evidence from the Greenland ice cores suggests that average temperatures rose by as much as fifteen degrees Celsius in a short span of time. This warming seems to have coincided with rapid increases in human populations as the global warming led to expanding animal populations and much greater availability of wild plants and foods. This process was put into rapid reverse at about 14,000 BC, by a period of cooling known as the Younger Dryas, but after 9600 BC, global temperatures rose again, by seven degrees Celsius in less than a decade, and have since stayed high. Archaeologist Brian Fagan calls it the Long Summer. The warming-up of the climate was a huge critical juncture that formed the background to the Neolithic Revolution, where human societies made the transition to sedentary life, farming, and herding. This and the rest of subsequent human history have played out basking in this Long Summer.

That excerpt got me wondering: If this huge increase–15 degrees Celsius is 27 degrees Fahrenheit–was good for mankind, what degree of certainty can we put on the idea that another 2 or so degrees Celsius is really bad for mankind? I understand that you can’t extrapolate and I understand that past some point, there’s likely increasing marginal damage due to an extra degree. But a lot of damage? I’m skeptical.