Climate change and malaria: exploring the risks.

That the enhanced greenhouse effect may prove to influence human health will come as no surprise. One of the potential health consequences is a change in distribution patterns of vector-borne diseases. In tropical countries, such diseases are a major cause of illness and death. One of the most important vector-borne diseases in the world is malaria, which is associated with one of four species of parasite and transmitted by a mosquito vector. Climatic conditions, and temperature in particular, directly influence mosquito development, feeding-frequency and longevity of the mosquito, as well as the time in which the parasite develops inside the mosquito. Other environmental factors such as vegetation and breeding sites are indirectly influenced by climate conditions. In order to assess the impact of an anthropogenic climate change on the transmission of malaria, an integrated assessment model has been developed. In this integrated model, the direct effects of a change in temperature and precipitation on the transmission potential of a mosquito population is assessed by means of the vectorial capacity. The effect of a human-induced climate change on human health is evaluated by assessing the change in malaria prevalence and disease burden. A sustainable development index, which is an aggregate of an environmental pressure indicator, a health indicator and a socio-economic development indicator is introduced and discussed. Such an index can be used to determine whether future projections are sustainable.