The FT has a long feature about the problems for human health caused by global warming. Although the article does mention a reduction in cold-related deaths, it plays the old Jedi mind trick and suggests that’s not an issue. In fact, it’s a massive issue.
It is likely that a warmer world will lead to more heat-related deaths, but likewise it will certainly see a reduction in cold-related deaths. These figures on both sides of this inequality vastly outweigh the numbers who might die as a result of any increase in vector-borne diseases (which isn’t really a warming issue anyway). Dr. Richard Tol calculates that each 1°C rise in global temperature would, for example, reduce cold-related deaths in North America by 64,000 each year, while increasing heat-related deaths by 14,000, making a net gain of 50,000 fewer human beings dying prematurely each year (at a mean value of life of $2 million, which is low for figures in the economic literature, this means a benefit to North America of $100 billion each year from a single degree of warming).
Although India would see a large increase in deaths from heat-related respiratory causes and Africa and the Middle East would see small net increases in temperature-related deaths, the world would benefit in total. According to Dr. Tol’s calculations, climate change would probably prevent half a million deaths around 2050. The sensitivities are highly uncertain, but by the year 2200, “climate change may help to avoid almost 2.5 million premature deaths, but also cause an additional 1 million deaths.”
We should also remember that in the United States, heat-related mortality has actually fallen even as urban temperatures have risen because of adaptation – more air-conditioing, better response techniques following the Chicago heat wave and so on.