Proponents of drastic curbs on greenhouse gas emissions claim that such emissions cause global warming and that this exacerbates the frequency and intensity of extreme weather events, including extreme heat, droughts, floods and storms such as hurricanes and cyclones. But what matters is not the incidence of extreme weather events per se but the impact of such events—especially the human impact. To that end, it is instructive to examine trends in global mortality (i.e. the number of people killed) and mortality rates (i.e. the proportion of people killed) associated with extreme weather events for the 111-year period from 1900 to 2010.
Aggregate mortality attributed to all extreme weather events globally has declined by more than 90% since the 1920s, in spite of a four-fold rise in population and much more complete reporting of such events. The aggregate mortality rate declined by 98%, largely due to decreased mortality in three main areas:
- Deaths and death rates from droughts, which were responsible for approximately 60% of cumulative deaths due to extreme weather events from 1900–2010, are more than 99.9% lower than in the 1920s.
- Deaths and death rates for floods, responsible for over 30% of cumulative extreme weather deaths, have declined by over 98% since the 1930s.
- Deaths and death rates for storms (i.e. hurricanes, cyclones, tornados, typhoons), responsible for around 7% of extreme weather deaths from 1900–2008, declined by more than 55% since the 1970s.
To put the public health impact of extreme weather events into context, cumulatively they now contribute only 0.07% to global mortality. Mortality from extreme weather events has declined even as all-cause mortality has increased, indicating that humanity is coping better with extreme weather events than it is with far more important health and safety problems.
The decreases in the numbers of deaths and death rates reflect a remarkable improvement in society’s adaptive capacity, likely due to greater wealth and better technology, enabled in part by use of hydrocarbon fuels. Imposing additional restrictions on the use of hydrocarbon fuels may slow the rate of improvement of this adaptive capacity and thereby worsen any negative impact of climate change. At the very least, the potential for such an adverse outcome should be weighed against any putative benefit arising from such restrictions.
The full study with diagrams is here, courtesy of the Reason Foundation. The press release, Extreme Weather Events Are Killing Fewer People Than Ever Before.