It has been understood for a long time that climate impacts the patterns of infectious disease. Infectious diseases result from the transmission of agents such as bacteria or viruses, each of which have a relatively narrow envelope of climatic conditions (temperature etc.) in which they can exist and spread. Further, disease can be spread either directly from person-to-person, or with the assistance of a vector, such as mosquitoes in the case of malaria. Such vectors also operate within their own climate envelope. Changes to the climate will therefore result in changes to the geographical distribution of agents such as bacteria or viruses, as well as the vectors that transmit these agents. The WHO identify that in particular, climatic conditions strongly affect water-bourne diseases and diseases transmitted through insects, snails or other cold-blooded animals.
The WHO estimate that, between 2030 and 2050, climate change is expected to result in an additional c. 250,000 deaths per year from factors such as malnutrition, malaria, diarrhoea and heat stress. Further information is available at: the WHO website.
