For the public record, my full version is provided below.

A badly developed climate backgrounder

SIR — The Economist’s article, A bad climate for development (September 17), which also serves as a backgrounder for an online debate on climate change, is not only selective in the information it presents, it is riddled with speculation and unsubstantiated claims.

For example, its chart 3 presents portions of two of three panels in figure 2.1 of the World Development Report 2010.  But the panel that it chooses not to display shows that deaths from all climate related disasters have actually declined at least since 1981–85 despite (a) an enormous increase in the population at risk, namely, the world’s population, and (b) the fact that older data has a greater tendency to underestimate the number and casualties of extreme weather events. The original source of the data (Center for Research on the Epidemiology of Disasters, CRED) states that the increase in the data until 1995 “is explained partly by better reporting of disasters in general, partly due to active data collection efforts by CRED and partly due to real increases in certain types of disasters.”[1] They also state that they are unable to say whether the latter increases are due to climate change.

Secondly, the backgrounder cites estimates sponsored by the World Health Organisation and published in Comparative Quantification of Health Risks that attributed 150,000 deaths and a loss of 5.5m disability-adjusted life years — a measure of the global burden of disease — to climate change in the year 2000.  But these studies also show that at least twenty other risk factors contributed more to death and disease.[2] That is, there are many more important health problems facing the world than climate change.

Thirdly, the article goes on to claim that the indirect harm to public health from the impact of climate change on water supplies, crop yields and disease is “hugely greater.” But what’s the evidence for this?

In fact, access to safe water, improved sanitation, crop yields, and life expectancy has never been higher in the history of mankind.[3] This is true for both the developing and developed worlds. Much of this has been enabled, directly or indirectly, by economic surpluses generated by the use of fossil fuels and other greenhouse gas generating activities such as fertilizer usage, pumping water for irrigation, and use of farm machinery. And crop yields, in particular, are also higher today than ever partly because of higher concentrations of CO₂, without which yields would be zero.

Fourthly, the backgrounder claims that global warming is causing both droughts and floods. Regardless of whether this is the case, deaths from droughts have declined by 99.9% since the 1920s, and 99% from floods since the 1930s.[4] In fact, since the 1920s, average annual deaths from all extreme weather events have dropped by 95 percent while annual death rates, which factor in population growth, have been reduced by 99 percent.

One item, however, where I agree with the backgrounder is that projections of the future impacts of climate change are “no more than educated guesses” although, as Alexander Pope might have said, a little education is a dangerous thing.

[1] Revkin AC. 2009. Gore Pulls Slide of Disaster Trends. Dot Earth Blog. February 23, 2009. Available at http://dotearth.blogs.nytimes.com/2009/02/23/gore-pulls-slide-of-disaster-trends/. Visited September 10, 2009.

[2] Goklany IM. Climate change is not the biggest health threat. Lancet 2009; 374: 973-74.

[3] Goklany IM. The Improving State of the World: Why We’re Living Longer, Healthier, More Comfortable Lives on a Cleaner Planet (Cato Institute, Washington, DC, 2007).

[4] Goklany IM. Death and Death Rates Due to Extreme Weather Events:  Global and U.S. Trends, 1900-2006, in The Civil Society Report on Climate Change, November 2007, available at http://goklany.org/library/deaths%20death%20rates%20from%20extreme%20events%202007.pdf.