By Matt Burdett, 28 February 2018
On this page, we look at the impacts of climate change on people and places, including health hazards.
It is important to recognise that the impacts on human health aren’t all negative. Benefits include fewer winter deaths in colder climates, and some marginal land that is currently hard to farm may be easier to grow crops on, so there might be better nutrition for some local scale groups.
However, the negative aspects are potentially very large. There are two main issues that will cause hazards to health:
- Direct weather related health problems such as flooding that contaminates water supplies
- Expansion of the areas in which disease-carrying insects can live
The World Health Organisation predicts that there will be an extra 250 000 deaths per year from 2030 to 2050 due to climate change (WHO, 2017), causing health costs of between US$ 2-4 billion/year by 2030 (WHO, 2017). Other impacts according to the World Health Organisation include:
- 300 million affected by worse respiratory diseases such as asthma due to increased pollen which occurs in higher temperatures
- Higher levels of malnutrition and hunger in areas where food production is reduced due to more difficult farming conditions
- Variable rainfall patterns and flooding will reduce water security, leading to an increase in diarrhoeal diseases. These environmental impacts are closely linked to temperature change with a resulting impact on hospital admissions as shown below:
- Sensitivity of diarrhoeal disease to meteorological conditions in Peru. Source: Checkley W et al. 2000, via UNFCCC.
Furthermore, the WHO (2017) identifies that patterns of infectious diseases will also change. Vector-borne diseases are those that are carried from person to person by a ‘vector’ such as a mosquito or water snails. As temperatures rise, these species breed more easily and can spread into new areas which were previously too cold for the vector species to survive. The result is a spread and intensification of the diseases that they carry. Common vector-borne diseases include dengue fever (see maps below) and malaria, both spread by a type of mosquito. Malaria alone is expected to kill an extra 60,000 people per year.
- Changing patterns of infectious disease: dengue transmission. Map A shows dengue fever transmission in 1990; Map B shows the projected transmission in 2080. Source: Hales S, de Wet N, Maindonald J and Woodward A. 2002.
- Climate Change and Malaria. The yellow areas incidicat climates currently suitable for the mosquitos that carry malaria, while red areas show the areas it might expand to by 2015. Source: Ahlenius, 2005.
Ahlenius, 2005. Climate change and malaria, scenario for 2050. www.grida.no/resources/7718 Accessed 28 February 2018.
Checkley W et al. 2000, via UNFCCC. Effects of El Niño and ambient temperature on hospital admissions for diarrhoeal diseases in Peruvian children. Lancet. 355: pp.442–450. Accessed via UNFCCC [United Nations Framework Convention on Climate Change], 2018. Climate Change Impacts Human Health New UN Report Highlights Risks, Opportunities and Solutions. http://newsroom.unfccc.int/unfccc-newsroom/climate-change-impacts-human-health/ Accessed 28 February 2018.
Hales S, de Wet N, Maindonald J and Woodward A. 2002. Potential effect of population and climate changes on global distribution of dengue fever: an empirical model. Lancet. 360: pp.830–834. Accessed via UNFCCC [United Nations Framework Convention on Climate Change], 2018. Climate Change Impacts Human Health New UN Report Highlights Risks, Opportunities and Solutions. http://newsroom.unfccc.int/unfccc-newsroom/climate-change-impacts-human-health/ Accessed 28 February 2018.
WHO [World Health Organisation] 2017. Climate change and health. http://www.who.int/mediacentre/factsheets/fs266/en/ Accessed 28 February 2018.
Societal impacts of climate change: Health hazards: Learning activities
- Identify the two main ways in which human health can be affected. 
- How many extra deaths does the WHO predict will occur due to climate change? 
- How much extra money does the WHO predict will need to be spend on health due to climate change? 
- Explain the link between temperature and water-borne diseases. 
- What is a vector-borne disease? 
- Describe the current extent of malarial regions worldwide. 
- Describe the possible extent of malarial regions worldwide by 2050.
- Explain why malaria may affect more people in future. 
Produce a presentation about this issue to show to a non-specialist. Anticipate the questions they might have and ensure that key terminology is clearly explained.