Overall, Diamond’s latest book lacks the strength of Guns, Germs and Steel. With statements about getting to things later laced throughout the text, he seems rushed. His discussions about societies that executed face-plants are quite interesting, but the picture he paints of the underlying forces leaves something to be desired. Given that my research relates to this line of thought, many of his observations were not new for me. Injunctions to curb and halt population growth, prevent deforestation and avoid farming marginal land did not surprise me. Most failed civilizations deforested marginal land to feed unrestrained population expansion.
After identifying the positive feedback loop, one must identify the governing negative feedback loop(s) that failed in each instance. It is not sufficient, for example, to tell Brazilian soybean farmers with growing families to stop slash and burn agriculture in the Amazon because their new plots of marginal land will be exhausted in 5 years. They have families to feed, and the ever-growing Chinese population is willing to pay for soy. While informing the farmers might help, changes in societal and economic signals would prove more effective. For instance, strong societal traditions of small families working ancestral plots of land discourages slash and burn agriculture, and placing a high economic value on the rainforest (natural capital) discourages destroying it. Diamond does not explore such signals at length. He repeatedly mentions the importance of adjusting social values but stops short of discussing the important question of how.