Climate Change and Human Health Impacts in the United States: An Update on the Results of the U.S. National Assessment

Ebi, Kristie L.; Mills, David M.; Smith, Joel B.; Grambsch, Anne

Vector-and rodent-borne diseases. In the HSA, Gubler et al. (2001) were uncertain about the cumulative impacts of climate change on vector-and rodent-borne illness because of limitations in the available climate models. Some of the climate scenarios projected that the temperature threshold for ticks that carry Rocky Mountain spotted fever in the southeastern United States could be crossed with increasing temperatures, potentially leading to more cases. Gubler et al. (2001) also expressed uncertainty about the impacts of climate change on rodent-borne illnesses because of a lack of available research and because of the potentially different impacts that could result from climate change as opposed to increased climate variability; the latter could result in population explosions and crashes that could increase disease risk. For mosquito-borne illnesses, Gubler et al. (2001) concluded that increasing average temperatures would generally reduce the U.S. population's susceptibility to epidemics, assuming increased amounts of time would be spent indoors in air-conditioned environments. However, Gubler et al. (2001) also noted that an increase in the frequency and severity of water-related extreme weather events (i.e., floods and hurricanes) could alter existing conditions governing human-mosquito interactions in large parts of the United States, potentially increasing mosquitohuman contact.