Climate Change and Mosquito-Borne Disease

Currently, world climate is in a warming phase that began in the early decades of the eighteenth century.Temperatures, at least in the Northern Hemisphere, are now broadly similar to what they were during the Middle Ages, in the centuries before the Little Ice Age (2).Awareness of this warming has led to a new preoccupation: concern that human activities may be affecting the natural climatic Global atmospheric temperatures are presently in a warming phase that began 250-300 years ago.Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases.Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges.However, the histories of three such diseases-malaria, yellow fever, and dengue-reveal that climate has rarely been the principal determinant of their prevalence or range; human activities and their impact on local ecology have generally been much more significant.It is therefore inappropriate to use climate-based models to predict future prevalence.