More deaths due to climate change? Or maybe not.
Coverage of a paper just published by Journal of Epidemiology and Community Health included dramatic headlines such as the Guardian's Heat-related deaths in the UK will rise 257% by 2050 because of climate change. But a closer look at the numbers in the paper paints a rather different picture.
Figure 4 of the paper shows the number of deaths expected per 100,000 people in each category, and how the authors estimate this will change into the 2080s.
But the vertical axes for the two plots are different, and they should perhaps have been drawn like this.
Or even added in a 'combined plot' [added 6th February 2013]
This clearly reveals that, in terms of rate per 100,000, the decline in cold-related death rate easily outweighs the increase in the heat-related death rate. So overall, for any individual in the UK, the risk of a temperature-related death is expected to fall steadily due to climate change. Bring it on!
But since there are going to be more old people in the future, the absolute numbers of deaths is going to increase - and this number was emphasised by the authors and got the headlines.
The abstract of the paper includes the phrase "The increased number of future temperature-related deaths was partly driven by projected population growth and ageing." According to the projections in the paper, if the population make-up did not change, the overall mortality risk would go down. So it would have been more accurate to say "The increased number of future temperature-related deaths was wholly driven by projected population growth and ageing.".
But that is clearly not the message that the authors wanted to convey. It is unfortunate that this kind of presentation gives ammunition to those who say that the effects of climate change are being exaggerated.