David R. Henderson recently wondered what’s so special about current global temperatures, such that moderate warming will allegedly prove so damaging? After all, there have been larger swings in global temperatures in the past.
In the comments, the popular answer was that humans have adapted to the current climate. Thus, if the global average temperature that will in fact be achieved in the year 2100, had been the norm for thousands of years, then that would be one thing, but since people have settled in particular areas and adopted particular agricultural techniques etc., an increase to this (projected) temperature could be very harmful.
The major problem with this type of argument is that it ignores how much time people will have to adapt. I saw a funny stand-up bit where the comic said something like, “You know what the people on the coast should do when the sea level starts rising?” And then he took a big step backwards, on the stage.
Adaptation is the only strategy that is guaranteed to be part of the world’s climate strategy. Using the most comprehensive set of data files ever compiled on mortality and its determinants over the course of the 20th century, this paper makes two primary discoveries. First, we find that the mortality effect of an extremely hot day declined by about 80% between 1900-1959 and 1960-2004. As a consequence, days with temperatures exceeding 90°F were responsible for about 600 premature fatalities annually in the 1960-2004 period, compared to the approximately 3,600 premature fatalities that would have occurred if the temperature-mortality relationship from before 1960 still prevailed. Second, the adoption of residential air conditioning (AC) explains essentially the entire decline in the temperature-mortality relationship. In contrast, increased access to electricity and health care seem not to affect mortality on extremely hot days. Residential AC appears to be both the most promising technology to help poor countries mitigate the temperature related mortality impacts of climate change and, because fossil fuels are the least expensive source of energy, a technology whose proliferation will speed up the rate of climate change. [Bold added.]