By Indur M. Goklany
In the run-up to the UN climate summit in September 2014, the World Health Organization (WHO) released, with much fanfare, a study that purported to show that global warming will exacerbate undernutrition (hunger), malaria, dengue, excessive heat and coastal flooding and thereby cause 250,000 additional deaths annually between 2030 and 2050. This study, however, is fundamentally flawed.
Firstly, it uses climate model results that have been shown to run at least three times hotter than empirical reality (0.15◦C vs 0.04◦C per decade, respectively), despite using 27% lower greenhouse gas forcing.
Secondly, it ignores the fact that people and societies are not potted plants; that they will actually take steps to reduce, if not nullify, real or perceived threats to their life, limb and well-being. Thus, if the seas rise around them, heatwaves become more prevalent, or malaria, diarrhoeal disease and hunger spread, they will undertake adaptation measures to protect themselves and
reduce, if not eliminate, the adverse consequences. This is not a novel concept. Societies have been doing just this for as long as such threats have been around, and over time and as technology has advanced they have gotten better at it. Moreover, as people have become wealthier, these technologies have become more affordable. Consequently, global mortality rates from malaria and extreme weather events, for instance, have been reduced at least five-fold in the past 60 years.
Yet, the WHO study assumes, explicitly or implicitly, that in the future the most vulnerable populations – low income countries in Africa, Europe, southeast Asia and the western Pacific – will not similarly avail themselves of technology or take any commonsense steps to protect themselves. This is despite many suitable measures already existing – adapting to sea level rise for example – while others are already at the prototype stage and are being further researched and developed: early-warning systems for heatwaves or the spread of malaria or steps to improve sanitation, hygiene or the safety of drinking water.
Finally, the WHO report assumes, erroneously, if the IPCC’s Fifth Assessment Report is to be believed, that carbon dioxide levels above 369 ppm – today we are at 400ppm and may hit 650ppmif the scenario used by the WHO is valid – will have no effect on crop yields. Therefore, even if one assumes that the relationships between climatic variables and mortality used by the WHO study are valid, the methodologies and assumptions used by WHO inevitably exaggerate future mortality increases attributable to global warming, perhaps several-fold.Unhealthy Exaggeration