Aaron Bernstein, MD, MPH, has written an interesting perspective on Vector that details some of the negative health effects of global climate change. For example:
The very gases that cause climate change, and in particular CO2, cause other health problems for kids. Take allergies. CO2 stimulates pollen production from some of the most allergenic plants around, like ragweed. If greenhouse gas emissions continue unabated, we can expect each ragweed plant to boost its pollen production -- already estimated to have doubled since the Industrial Revolution -- by a further 50 percent or more by 2100. Warming has also promoted an earlier start to spring and a later finish to fall that have translated into a longer allergy season and more days of misery for allergy sufferers.
Bernstein is a faculty member at Harvard Medical School's Center for Health and the Global Environment. The rest of his entry is worth reading.