3-3: Global Change and Human Health

Human health is affected in a variety of ways by global change of the kind we have discussed in blocks 1 and 2. Many of these effects are not directly relating to warmer temperature, for instance, but indirectly through other components of natural systems, such as the spread of malaria-carrying mosquitoes. Paul Epstein of Harvard University is a noted scholar on this topic, and his article in CONSEQUENCES is a very good one.

One area sometimes considered outside the realm of climate and therefore not considered by Epstein is human impact of ozone depletion and increased UV radiation. A brief summary of these effects is given in the series of images associated with this unit. A photo taken recently by a friend visiting family in Australia shows "shade sails" which are being constructed over many public areas such as swimming pools (as in the photo) and parks as protection from UV radiation. The public media in Australia recently reported that there are 370,000 new skin cancer cases each year in Australia, which has a population of 20,100,000. Doing the math you find that one of every 54 Australians will get skin cancer this year. Another way of looking at this (approximately) is that after 54 years everyone has it. The standard school uniform for children includes a wide brimmed hat.

Why is the rate of getting skin cancer so high in Australia? The hole of stratospheric ozone depletion over the South Pole is large enough and drifts away from the polar region enough to leave portions of Australia unprotected from the lethal UV radiation from the sun. Although skin cander occurrence in the US is far lower, you should learn to recognize the signs.

The most recent and comprehensive study of the impacts of climate change on human health has been published by the US Global Change Research Program. This comprehensive assessment is not required reading.