Given that humans are tribal creatures, what made them leave their cradle? Why did they ever abandon their hunting and gathering mode of existence? How did the human population grow beyond the size comprehensible to an average human? Questions like these have been uppermost on my mind the last few days (“Tribe and Nothing but Tribe,” February 6, 2015). The agricultural revolution was the obvious culprit, of course. It brought the first population explosion and the sedentary way of life. But the loss of the earthly paradise is still remembered in the bible.

It did not take me long to remember that the agricultural revolution was underpinned by climate change. The current interglacial period is squarely behind it. Starting some ten-thousand years ago, it made the agricultural revolution possible. The growing population in turn led to slavery, feudalism, and capitalism in quick succession. What goes by the name of civilization evolved in just a few thousand years. The good weather was the end of hunting and gathering, as well as the tribe. It also brought the flooding of the Mediterranean caused by the melting of the ice caps. Once again, it is all in the bible.

To my surprise, yesterday evening I got an electronic-mail message from my No. 1 son, who sent me a link to an interview with Yuval Noah Harari, an Israeli historian. His recent book, Sapiens: A Brief History of Humankind (New York: Vintage Books, 2014), has become a bestseller. Amazingly, the interview revolves around the agricultural revolution. Harari is cited as saying that the scientific community acknowledges nowadays that it was not such a good idea. It made the human kind much more powerful, but the individual human being probably had a worse life than before. Precisely. He does not mention climate change that ushered the agricultural revolution, though. Nor the obvious fact that humans are climate slaves.