Wallace-Wells titles his first and longest chapter “Cascades,” and socially, politically, and scientifically, he continually depicts climate change as a series of cascades. The Syrian Civil War is perhaps the most illustrative example of this in that it involves a chain reaction of meteorological, economic, social, and political factors that have disrupted systems across the Western world. For example, decades of higher greenhouse emissions lead to increased desertification in the Middle East, which leads to multi-year droughts that the Syrian government fails to address through policy. These droughts exacerbate existing civil unrest in a country already divided along sectarian lines. Civil war breaks out, and a million refugees flood into Europe, inadvertently creating a cultural wedge issue on which far-right nationalists capitalize. Some of the more successful of these movements crack down on hard-fought democratic norms surrounding freedom of expression and freedom of the press. The surge of nationalism leads to isolationist trade policies that hurt domestic economies.

To say that climate change caused all that would be, even to the author, a gross oversimplification. However, the example underscores how quickly factors can conspire to remake the world in a series of cascades. In the case of the Syrian Civil War, the impact of a single, albeit devastating, drought is debatable.