the impact is dwarfed by the 92 percent decline in the decadal death toll from natural disasters since its peak in the 1920s. In that decade, 5.4 million people died from natural disasters. In the 2010s, just 0.4 million did.28 Moreover, that decline occurred during a period when the global population nearly quadrupled.

While global sea levels rose 7.5 inches (0.19 meters) between 1901 and 2010,30 the IPCC estimates sea levels will rise as much as 2.2 feet (0.66 meters) by 2100 in its medium scenario, and by 2.7 feet (0.83 meters) in its high-end scenario. Even if these predictions prove to be significant underestimates, the slow pace of sea level rise will likely allow societies ample time for adaptation.

We have good examples of successful adaptation to sea level rise. The Netherlands, for instance, became a wealthy nation despite having one-third of its landmass below sea level, including areas a full seven meters below sea level, as a result of the gradual sinking of its landscapes.31 And today, our capability for modifying environments is far greater than ever before. Dutch experts today are already working with the government of Bangladesh to prepare for rising sea levels.32

When it comes to food production, the Food and Agriculture Organization of the United Nations (FAO) concludes that crop yields will increase significantly, under a wide range of climate change scenarios.37 Humans today produce enough food for ten billion people, a 25 percent surplus, and experts believe we will produce even more despite climate change.38 Food production, the FAO finds, will depend more on access to tractors, irrigation, and fertilizer than on climate change, just as it did in the last century. The FAO projects that even farmers in the poorest regions today, like sub-Saharan Africa, may see 40 percent crop yield increases from technological improvements alone.39

Has anyone done a study of food production at four degrees? I asked. “That’s a good question. I must admit I have not seen a study,” said Rockström, who is an agronomist. “It seems like such an interesting and important question.”63 In fact, scientists have done that study, and two of them were Rockström’s colleagues at the Potsdam Institute. It found that food production could increase even at four to five degrees Celsius warming above preindustrial levels.64 And, again, technical improvements, such as fertilizer, irrigation, and mechanization, mattered more than climate change. The report also found, intriguingly, that climate change policies were more likely to hurt food production and worsen rural poverty than climate change itself. The “climate policies” the authors refer to are ones that would make energy more expensive and result in more bioenergy use (the burning of biofuels and biomass), which in turn would increase land scarcity and drive up food costs. The IPCC comes to the same conclusion.