Global warming has been under way for at least 25 years, and there is strong evidence that it is largely man-made and is continuing. (Jenkins, Brooks, et al 18-49) A large part of the warming is due to the burning of fossil fuels and consequent increase of carbon dioxide in the atmosphere. Since heat-related deaths are generally much fewer than cold-related deaths, the overall effect of global warming on health can be expected to be a beneficial one. Inevitably, though, when it was recognized in the 1990s that global warming was under way, attention shifted from the hazards of cold to those of hot weather.
The main concern at first was that diseases transmitted by insects, such as malaria, would spread to cooler regions of the world and would become a problem there. Closer examination showed that this was unlikely to happen to a serious extent. Malaria, for example, was once prevalent in most of Europe and even in Russia but had already been eliminated. The main reason was that modern farming methods and changes in human living conditions had reduced the number of the mosquitoes that spread the disease and had reduced their access to people. From time to time, global warming, together with rapid air travel, is likely to cause new health problems from insect borne illnesses, such as the recent outbreak of West Nile Fever in New York. These should remain relatively easy to contain by measures such as spraying to kill mosquito larvae and preventing access of mosquitoes to infected patients.
A simple assessment of the immediate effect of rising temperature can be made on the assumption that particular degrees and patterns of heat or cold will continue to produce the same mortality rates as they did previously. Lack of daily statistics has prevented accurate assessment........
