The effects of heat are amplified by stagnant air, high humidity and high levels of air pollution. As use of coal and oil generally results in significant emissions of local air pollutants as well as greenhouse gases, high levels of urban air pollution are likely to be associated with global warming. Infectious Diseases Vector-borne diseases are a major cause of illness and death in tropical countries. Rather than being transmitted directly from human to human, these diseases are transmitted by insects or other vectors. The IPCC concluded that In general, increased warmth and moisture would enhance transmission of these diseases.
Malaria is a central example.
About 300 million new cases of malaria occur each year. Temperatures above 64 F are required for the parasite to be actively infectious. Warmer temperature speed up the lifecycle of the parasite and increase infectiousness. Although this quantitative result must be viewed cautiously, and does not account for the potential for public health measures to mitigate the impact, it clearly indicates the magnitude of the potential impact of climate change on public health. Other types of infectious disease could also increase due to climate change.