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What does climate change have to do with spreading disease? - OneSharedEarth
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How does climate change affect the spread and increase occurrence of disease across the world?
in Climate change by (410 points) | 139 views

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Climate change can influence spread of disease in many ways

  • As temperatures rise, mosquito season may become longer and spread to places that are currently relatively cold. The reproduction of bacteria like Salmonella also increases as temperature rises.
  • Flooding can increase the risk of gastroenteritis and diseases transmitted by rodents. Increased rainfall, flooding and humidity also creates more viable conditions for breeding of mosquitoes and other vectors.
  • Low rainfall in many places can lead to water scarcity, which may reduce hygiene practices thus leading to gastrointestinal illnesses.
  • Climate change can bring pressure on agricultural productivity, causing issues such as crop failure, malnutrition, starvation, increased population displacement, and resource conflict. These pressures can increase human susceptibility to infectious diseases.

Some projections of disease due to climate change

  • If global temperatures increase by 2 to 3°C, the population at risk for malaria is expected to increase by 3-7%. One example seen so far is the spread of malaria into highland regions of East Africa, where this disease previously did not exist.
  • By 2030 there is expected to be 10% more diarrhoea than there would have been with no climate change.
  • Projected geographic distributions of West Nile virus in North America show an expansion under future climate for 2050 and 2080.
  • More Mosquito Days Increasing Zika Risk in U.S.” (, 2016) found that since 1980, most major cities in the United States have seen an overall increase in days conducive for Asian Tiger Mosquitoes (Aedes albopictus), which is one of the species known to transmit the Zika virus.

Here are some of the diseases that can spread due to climate change - Malaria, Lyme disease, Yellow fever, Dengue fever, Zika virus, Chikungunya, West Nile virus, Cholera, Salmonellosis (Salmonella infection), Plague, Typhoid , African trypanosomiasis (sleeping sickness), Tick-borne encephalitis, Ross River fever, Arbovirus, Giardiasis (beaver fever)

See here for key studies that assess the relationship between extreme weather events and infectious diseases.



Wu X and others, “Impact of Climate Change on Human Infectious Diseases: Empirical Evidence and Human Adaptation” (2016) 86 Environment International 14

Shuman EK, “Global Climate Change and Infectious Diseases” (2010) 362 New England Journal of Medicine 1061

Burkholder B, “Climate Risk and Spread of Vector-Borne Diseases” (Climate Nexus, 2017)

Jordan R, “How Does Climate Change Affect Disease?” (Stanford Earth, 2019)

Derouin S, “What a Warming Planet Means for Mosquito-Borne Diseases” (Stanford Earth, 2017)

Harrigan RJ and others, “A Continental Risk Assessment of West Nile Virus under Climate Change” (2014) 20 Global Change Biology 2417

Lloyd S, Kovats R and Armstrong B, “Global Diarrhoea Morbidity, Weather and Climate” (2007) 34 Climate Research 119

Chretien J-P and others, “Global Climate Anomalies and Potential Infectious Disease Risks: 2014-2015” [2015] PLoS Currents

More Mosquito Days Increasing Zika Risk in U.S.” (, 2016)

by (550 points)
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Climate change will increase the occurrence of heat-related diseases and diseases carried by insects, as well as food-borne and water-borne diseases which thrive in warmer, wetter conditions.  

Rising global temperatures and increasing numbers of heat wave events will increase humanity’s vulnerability to heat-related diseases, such as heatstroke, heat exhaustion and cardiovascular disease. For example, on average, extreme heat kills more Americans every year than floods, hurricanes, lightning, and tornadoes taken together. 

Also, the climate becoming warmer and wetter will expand the range of insects that carry devastating infectious diseases, such as malaria and dengue fever, which will allow them to infect and kill more people each year. 


Climate Change and Health” (World Health Organization: WHO, 2018)

Heat-Related Deaths After an Extreme Heat Event — Four States, 2012, and United States, 1999–2009” (Centers for Disease Control and Prevention: CDC, 2013)

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