How does climate change affect human health?
There is consensus that population health is influenced by a multitude of factors. Chief among these are environmental factors, in particular climate change. The United Nations estimates that 1 in 4 deaths worldwide is now related to environmental risks.
Maria Neira, Director of the Department of Public Health, Environment and Social Determinants of Health at the World Health Organization, stresses that “it has never been clearer that the climate crisis is one of the most urgent health emergencies we all face”.
Climate change affects human health by altering the severity and frequency of existing problems already affected by climate or weather factors and creates unforeseen challenges.
Climate impacts manifest themselves in different ways and have a significant impact on people, damaging their physical and mental health. According to the United Nations, environmental factors claim the lives of some 13 million people each year. Changing weather patterns are increasing the number of diseases and extreme weather events are increasing deaths and making it more difficult to maintain health systems.
Greenhouse gas concentrations are increasing as a result of human activities such as fossil fuel burning and deforestation, causing global temperatures to rise, amplifying extreme heat events, leading to more frequent and stronger heat waves, intensifying the likelihood of heat stroke and heat exhaustion, as well as aggravating pre-existing medical conditions.
Exceptionally high global temperatures were recorded in 2023, as can be read in the Global Climate Highlights 2023 report presented by the Copernicus Programme.
This report shows that 2023 was the hottest year on record, with global temperatures close to the 1.5°C limit, exceeding that of 2016. It also shows that every month from June to December 2023 was warmer than the corresponding month of any previous year.
Climate impacts also lead to extreme weather events such as hurricanes, tsunamis, severe storms, floods, and prolonged droughts, which are becoming more frequent and intense, and are among the reasons for the global increase in hunger and malnutrition.
In addition, climate change could alter the geographic ranges of insect vectors such as mosquitoes, which could lead to an increase in vector-borne diseases such as malaria, dengue fever, Zika and West Nile fever. And the growth of environments favourable to the proliferation of infectious diseases, such as waterborne diseases.
Among the negative impacts of climate change is the deterioration of air quality, which is already considered the 4th leading cause of global mortality, aggravating existing respiratory problems, and contributing to the development of lung and cardiovascular diseases. It should be noted that, according to the WHO, 12.6 million people die each year, 24% of all deaths worldwide, from environmental causes. Nearly half of all environmental deaths are due to air pollution.
As well as impacting physical health, climate change has consequences for mental health. Extreme weather events can cause trauma and stress. Concern about climate change and its future effects can contribute to anxiety and depression, a direct consequence of the growing awareness of the climate crisis and its impact on our lives.
But who is at risk?
We all face the risk of health impacts associated with climate change. However, some people face greater risks than others because of differences in the hazards to which they are exposed, their sensitivity to them and their capacity to adapt.
It also emphasises that different health impacts do not occur in isolation, as people may face multiple hazards at the same time.
The Intergovernmental Panel on Climate Change (IPCC) report states that around 3.5 billion people, almost half of humanity, live in areas highly vulnerable to climate change.
Exposure to hazards is related to the contact between a person and one or more climate change stressors. In this sense, poor or low-income populations are more vulnerable, as they may be more exposed to hazards due to socio-economic factors, e.g. lacking the resources to have air conditioning in their homes and are more likely to be exposed to extreme heat. But also, occupational groups, people working outdoors, who are more frequently or more intensely exposed, for example, to heat or insects. And also, residents of certain locations, i.e. people living in places more prone to droughts, floods or storms, such as those living off the coast, who are more exposed to rising sea levels.
In terms of hazard sensitivity, we refer to the degree to which individuals or communities are affected, adversely or beneficially, by their exposure to climate variability and change. Pregnant women have greater health risks, such as extreme heat or certain infectious diseases, and their own physical and mental health may affect that of their baby. Children are more susceptible to respiratory diseases than adults, due to their low body weight, high levels of physical activity and still-developing lungs. People with pre-existing health problems, such as asthma, are especially sensitive to air quality, and people with diabetes or other chronic diseases have more difficulty regulating their body temperature and are more sensitive to extreme heat.
Adaptability, which refers to the ability of individuals or communities to adjust to climate change, take advantage of its opportunities or respond to its consequences, includes older people, people with disabilities and indigenous people.
In addition to being physiologically more sensitive, older populations may have limited capacity, for example, to protect themselves during a heat wave. Persons with disabilities face greater challenges in preparing for or responding to extreme weather events. For example, emergency or evacuation instructions are often inaccessible to people with visual, hearing, or cognitive disabilities. Indigenous populations, whose livelihoods depend on locally produced food, are affected by changes affecting the safety, availability and nutritional value of some foods and medicinal plants.
Thus, in the knowledge that climate change will continue to affect health risk, there is a need to move towards better understanding and adaptation to climate change, as well as to work to combat and mitigate practices that exploit extreme weather events and strengthen community health systems.
Links:
- European Environment Agency – https://www.eea.europa.eu/publications/harm-to-human-health-from-air-pollution
- European Environment Agency – https://www.eea.europa.eu/publications/air-quality-in-europe-2022/air-quality-in-europe-2022
- European Environment Agency – https://www.eea.europa.eu/publications/air-quality-in-europe-2022/health-impacts-of-air-pollution
- European Environment Agency – https://www.eea.europa.eu/publications/harm-to-human-health-from-air-pollution
- European Environment Agency – https://www.eea.europa.eu/pt/highlights/as-mortes-prematuras-devido-a
- European Environment Agency – https://www.eea.europa.eu/publications/air-quality-in-europe-2022/air-quality-in-europe-2022
- European Environment Agency – https://www.eea.europa.eu/publications/air-quality-in-europe-2022/health-impacts-of-air-pollution
- Copernicus – https://climate.copernicus.eu/global-climate-highlights-2023
- European Commission – https://ec.europa.eu/commission/presscorner/detail/en/IP_23_5951
- European Commission – https://climate.ec.europa.eu/climate-change/consequences-climate-change_pt
- European Commission – https://essenciadoambiente.pt/combate-alteracoes-climaticas-combate-desinformacao/)
- European Commission – https://essenciadoambiente.pt/a-poluicao-e-o-cancro-da-mama-ligacoes-perigosas/
- Essência do Ambiente – https://essenciadoambiente.pt/oms-impacto-ambiental-em-destaque-dia-mundial-saude/
- Essência do Ambiente – https://essenciadoambiente.pt/revive-impacto-ambiente-saude-populacao/
- Essência do Ambiente – https://essenciadoambiente.pt/18-milhoes-criancas-expostas-residuos-eletronicos/Expresso – https://multimedia.expresso.pt/059_cheias_fenomenos_extremos/
- United Nations – https://news.un.org/pt/story/2023/12/1825322
- United Nations – https://news.un.org/pt/story/2023/11/1822877
- United Nations – https://news.un.org/pt/story/2023/11/1823697
- United Nations – https://news.un.org/pt/story/2022/02/1781142
- RTP – https://ensina.rtp.pt/explicador/alteracoes-climaticas/
- Intergovernmental Panel on Climate Change (IPCC) – https://www.ipcc.ch/report/ar6/syr/
- European Youth Portal – https://youth.europa.eu/get-involved/sustainable-development/what-climate-change_pt
- SIC – https://sicnoticias.pt/mundo/2024-01-09-2023-e-o-ano-mais-quente-de-sempre-com-temperatura-global-proxima-do-limite-de-15C-1e192515
- Sábado – https://vidasustentavel.sabado.pt/alteracoes-climaticas/alteracoes-climaticas-em-que-medida-afetam-a-nossa-saude/