The Intergovernmental Panel on Climate Change (IPCC) recently cautioned that mounting temperatures could reshape the spatial distribution of certain infectious disease vectors. The report stressed that the effects would be mixed and varied and could include changes in the "range and transmission potential of malaria in Africa."
Stephen Morse, a professor at Columbia University, noted at the 107th General Meeting of the American Society for Microbiology that "environmental changes have always been associated with the appearance of new diseases or the arrival of old diseases in new places." David Rogers of Oxford University, who also spoke at the meeting, explained that the diseases that are most likely to be affected by environmental changes are those carried by insects and ticks. What isn't clear, he added, is whether the diseases would increase or decrease, an uncertainty he ascribed to the lack of a thorough analysis of historical disease record and the need for present-day ground-based surveillance and good predictive models.
Based on current and projected figures, Morse predicted that rising global temperatures would exert a profound impact on the spread of malaria by facilitating the migration of disease vectors, such as mosquitoes, to altitudes that had originally been too cold to support them. "One of the first indicators of rising global temperatures could be malaria climbing mountains," says Morse.
In addition, the expansion of the tropical airmass around the Earth's equator could result in more areas losing their seasonality, potentially extending the longevity of influenza and the flu season and rendering it a year-round event outside of the tropics. Joan Rose of Michigan State University warned that extreme weather events would lead to more disease by putting water supplies at risk. Most countries' drinking and wastewater infrastructures have already experienced tremendous wear and tear due to the combined effects of hurricanes, tornadoes and other high intensity weather events, and, more worryingly, are now seeing the re-suspension of pathogens from sediments and the enhanced mixing of untreated sewage and water supplies. This has caused the displacement of large populations to temporary shelters and will likely continue in the near future.
Discussing the potential effects of global warming on agriculture, Morse noted that "if agriculture in a particular area begins to fail due drought, more people will move into cities." He continued, cautioning that "high population densities, especially in developing countries, are associated with an increased transmission of a variety of diseases including HIV, tuberculosis, respiratory diseases (such as influenza) and sexually transmitted diseases."
See also: ::World Health Organization: Preventing Disease Through Healthy Environments, ::IPCC on Latin America: Land Drought and Coastlines Floodings are on the Menu, ::Roasted World: The IPCC Second Course Is Served, ::Palm Carbon Up, Cap & Trade Down, ::World Bank Reports Carbon Market Trends, ::Planktos, Inc. "Seeds of Iron " to Mitigate Climate Change, ::Guardian's Climate Change Adverts, ::Scary New British Report on Climate Change