The Positive Side of Global Warming
The World Bank report on ‘climate change’ I wrote about yesterday produced reactions all over the world, and one of them, from Canada, was a reminder that while global warming has occurred over the past century, some of the consequences have been most positive for humanity.
My correspondent referred me to a study by Indur Goklany on the death rate from ‘extreme weather’ over the past 110 years. Goklany is a dissenter from the AGW orthodoxy, one who has served as an author and an expert reviewer for the IPCC, and was once the US delegate to the IPCC as well. I’ve come across his work in the public health field before.
Goklany reminds us that forecasts of increasing temperature are accompanied by warnings that we will also see more extreme weather events — worse droughts, more frequent and more intense storms, more devastating floods, and so on. As I wrote a little while ago, the doomsayers were quick to fasten on hurricane Sandy as exactly one of these ‘super storms’, though the history of these storms does not support that attribution.
So he set about exploring what has happened already across the planet during the period of increased global temperature that we have experienced since 1900, and treating the world as a whole, because heat somewhere is balanced by cold somewhere else, and deaths from summer temperatures might be balanced through fewer deaths in a warmer winter elsewhere. And like Roger Pielke Jnr and others who normalised the costs of disasters, so that we can compare two disasters at different times, Goklany looked at death rates, so that he could filter out the the effects of population growth.
There is a useful database for all this, maintained at the Catholic University of Louvain, and it contains more than 9000 weather events, droughts, floods, extreme temperatures, freak waves, bush fires and storms. For an event to have been included, it must have killed at least ten people, or affected at least 100, or caused a state of emergency or a call for international assistance. You would imagine that the numbers of such extreme events would have been smaller in the earlier 20th century, when news-gathering was much less comprehensive than it is now, and that is certainly the case: the number of extreme weather events in the database increases steadily as the 20th century advances. Moreover, there are now four times as many people on earth as there were in 1900.
So what did Goklany find? If he took all extreme weather events, then the numbers of deaths and the death rates have declined steadily since the 1920s. Droughts, the single most deadly category, caused great deaths and high death rates in the 1920s and 1940s, but have had little such effect recently. The same is true of floods, though here the worst decades were the 1930s and 1950s. Extreme storms have remained a problem throughout the past century and a bit, but death rates are down, as are total deaths — and the worst decade was the 1970s.
Goklany then divided the 100 years into two periods, the past twenty years, and the ninety before that — 1900-1989, and 1990 to 2010. For each category of extreme weather events save two there has been a striking reduction in deaths and death rates. Deaths caused by droughts have declined by 99.98 per cent, because we are much better at food production (helped more than a little by increased carbon dioxide in the air), while better communications enable us to move food quickly to where it is needed. The exception are deaths through storms, which have increased from the earlier to the more recent period, though the mortality rate has declined, and deaths through extreme temperatures, where the villain seems to have been the 2003 European heatwave, where there are various estimates of the number of deaths.
I think Goklany should be allowed his own conclusion: ‘the average annual death toll for 2001–2010 due to all weather-related extreme events was 38,321.19 By contrast, the World Health Organization (2002) estimates that in 2004 a total of 58.8 million people died worldwide from all causes, including 3.9 million from various kinds of accidents. 20 Of these, road traffic was responsible for 1.3 million deaths, violence (other than war) for 0.6 million, and war for 0.2 million. Thus, while extreme weather-related events, because of their episodic nature, garner plenty of attention worldwide, their contribution to the global mortality burden — 0.07% of global deaths —is relatively minor.’
What can we learn from this study? Goklany heads this part of the work ‘Wealthier is Safer’, and I agree with that message. We in the developed world have devoted a lot of time, energy and money to making our countries safer, and that has had a positive result. Even the developing countries have improved their food production as they grew wealthier. We are coping with extreme weather events much better than we are, say, with road safety. We have better warning systems, better emergency services, and better understanding on the part of those affected.
On the evidence, extreme storms are not increasing in frequency, and in any case we can deal with them. What we are not dealing so well with are the other causes of mortality. Goklany provides a list of 26 ‘risk factors’ showing the mortality for 2000 (the source here is the World Health Organisation in 2002). Heading the list are blood pressure, tobacco, cholesterol, ‘underweight’ and unsafe sex. Global warming came in at number 21.
Yes, extreme weather will remain a problem. We still have to learn how to stop people building in floodplains, and we don’t know how to manage increasing fuel load in our forests. But, again on the evidence, things are improving, not getting worse.
(Wealth and Safety: The Amazing Decline in Deaths from Extreme Weather in an Era of Global Warming, 1900–2010, by Indur M. Goklany, Project Director: Julian Morris, Policy Study 393, September 2011, published by the Reason Foundation)