Throughout history, moderate warming has significantly contributed to enhanced living standards.
Hardly a month goes by without predictions that global warming will result in increased rates of disease, infections and deaths. The World Health Organisation (WHO) claims that some 150,000 deaths every year can be attributed to the effects of climate change. These assertions, however, are misleading on two counts.
First of all, most climatologists would agree that it is impossible to associate local climate fluctuations (let alone the flux of local disease levels due to environmental variability) to global average temperature (1). Moreover, every health expert knows only too well that the most significant risk to human health is not due to warmer temperatures, but to cold winters and cold stress. In Europe and Russia alone, more than 100,00 people die on average each year as a result of cold temperatures during the winter months.
Local, regional and global climates have changed throughout human history. Climatic downturns in the form of temperature decreases have been significant enough to cause agricultural disruptions, social disintegration and detrimental health effects, while warmer periods have had a considerably benign role in social, economic and technological progress (2). The modest warming over the past 150 years, for instance, has coincided with the most dramatic advances in technological and medical progress, human health and the doubling of life expectancy in large parts of the world.
Lamentably, many climate change researchers have exaggerated the potential health risks due to global warming. While magnifying the probable risks to health and mortality as a result of warmer temperatures, many underrate or simply ignore the possible heath benefits of moderate warming. This one-sidedness raises considerable ethical problems: promoting unfounded and inflated health scares in itself contributes to human anxiety and ill health. That is why a growing number of risk analysts object to such scare tactics – they point out that the detrimental affects of false or exaggerated health alarms and the resultant fears are much costlier than generally presumed. Fears can create a new risk for health, wellbeing and the stability of communities (3).
Thus, instead of adding to the hyperbole of dubious doom-and-gloom prophecies, it would be prudent to look at the factual evidence of climate-related health issues. A large number of studies show that urban populations in the USA and Europe have successfully adapted to recurrent extreme weather events and heatwaves. People who used to be much more weather-sensitive only 30 or 40 years ago have become less susceptible to extreme climate conditions and heatwaves due to improved medical care, increased access to air conditioning, and biophysical and societal adaptations (4).
These studies essentially falsify the contention that future warming will lead to a significant increase of heat-related mortality rates. In fact, some of Britain’s leading medical experts have calculated that a rise of the average temperature by two degrees Celsius over the next 50 years would increase heat-related deaths in Britain by about 2,000 – but would reduce cold-related deaths by about 20,000 (5). In other words, the decrease in the number of cold-related deaths would be much more significant (by a factor of 10) than the heat-related deaths due to rising temperatures. The potentially huge health benefits of moderate temperature increases have been confirmed by other researchers. They estimate that a warming of 2.5 degree Celsius would lower the annual death rate by 40,000 in the USA alone while reducing medical cost by almost $20 billion per year (6).
Over the past couple of decades, most Western countries have seen a significant decline in the mortality rate during heat stress events, even where stressful weather conditions have been on the increase. In fact, technological adaptation to climatic stress has accelerated to such an extent that heat-related mortality has become essentially preventable in large parts of the developed world. Given the accelerated economic growth and technological progress in the developing world, successful adaptation to increasing or decreasing temperatures will become a universal feature in the not too distant future.
People who are genuinely concerned about the impact of climate extremes on human health should focus their attention on the real evidence of temperature-related health problems and mortality, ie, the social scandal of hundreds of thousands of winter excess deaths each year, fatalities that are largely avoidable. Moderate warming, rather than threatening global disaster, has eased some of these climatic strains throughout history and has significantly contributed to enhanced living standards. There is no reason to believe that tomorrow’s hyper-complex societies won’t be able to cope with any climate changes nature may throw at us. While past societies were extremely vulnerable to climatic stress factors, high-technology cultures are much more sheltered from likely temperature changes as a result of technological adaptation and societal mitigation.