Climate change is inextricably linked to health – and its serious worldwide adverse health outcomes are undeniable. Its direct health cost burden globally is estimated at between $2bn and $4bn a year by 2030.1
Healthcare providers and insurers need to understand this relationship to better support patients and customers, says James Sherwood.
Climate change describes long-term alterations in the average weather patterns affecting the Earth’s local, regional, and global climates. It is commonly measured as the average increase in our global surface temperature.
The world has reached approximately 1°C of global warming above pre-industrial levels. Projections show with high confidence that temperatures will be likely to rise 1.5°C between 2030 and 2052 if they continue to increase at the current rate.2
In the long term, the goal is to keep the increase in global average temperature to well below 2°C above pre-industrial levels.
Climate change is rapidly shaping the environment around us, including through rising temperatures and extreme weather events.
It is primarily driven by human activities, particularly fossil fuel burning which increases heat-trapping greenhouse gas levels in the Earth’s atmosphere causing surface temperatures to rise. These human-produced temperature increases are commonly referred to as global warming.3
The most significant impacts of climate change on health include:
Respiratory conditions and allergies
There is a direct link between the intensification of climate change and the worsening of existing respiratory conditions. Conditions of particular concern include asthma, respiratory allergic disease, chronic obstructive pulmonary disease (COPD) and respiratory tract infections.
Looking at current trends, we are likely to see more patients with these conditions, with the most vulnerable populations worst affected.
For example, the pollen season will get longer and more severe, meaning that patients may require medical assistance and treatment more frequently and for more extended periods of the year.
The growing incidence of wildfires may result in a local increase in disease burden after these events. Additionally, changes in the profile of respiratory conditions are expected to alter patterns of pharmaceutical use and result in greater use of medication.4
Extreme and prolonged heat and air pollution as a result of burning fossil fuels will lead to an increased risk of cardiovascular conditions, such as ischaemic heart disease, strokes, heart failure, arrhythmias and cardiac death.5,6
High temperatures will result in increased hospitalisations due to cardiovascular conditions such as myocardial infarction.7
Mental health can be impacted both directly through climate disasters and indirectly through the consequences of climate change. This can range from ecological anxiety to depression, post-traumatic stress and suicide.
It is estimated that, globally, as many as half of the people who survive extreme weather events experience adverse mental health outcomes.8
We need to recognise the impact that the overarching threat of climate change can have on mental health, leading to conditions such as ecological anxiety and ecological grief.
Changes in temperature and rainfall have altered the distribution of some water-borne illnesses and disease vectors. Diseases traditionally associated with tropical and subtropical regions are reaching new areas of the world because of climate change.
For example, viruses transmitted by mosquitos are anticipated to expand to North America and Europe as the continents become warmer, posing a threat to 49% of the world’s population by 2050.9
As such, there is a need for accurate forecasting and monitoring of climate change and its impact on infectious diseases.
As the skin is exposed to the environment, it is especially vulnerable to increased heat and humidity.
Some of the impacts of climate change on the skin are directly linked to extreme weather events, which will lead to an increase in skin infections, inflammatory skin diseases, and traumatic skin disorders.
Skin cancer rates may be affected by changes in temperature. Poland predicts an increase of 10% of skin cancer morbidity and 3% mortality by 2080.10
Protecting the most vulnerable
Older people are one of the most vulnerable groups to climate change and the associated increase in extreme temperatures and weather events. Both heat and cold exposure elevate their risk of cardiovascular and cerebrovascular deaths, as well as respiratory deaths and morbidity.
Extreme heat also has a negative impact on birth outcomes – length of gestation, birth weight, and stillbirth increase. Studies also present links between various pollutants and the development of autism and asthma in children.11
Understanding the scope and scale of impacts on pregnant women and new-born babies is an important first step to developing and implementing services designed to treat or prevent the impacts associated with climate change.
Compared with a future without climate change, the World Health Organization projected excess deaths for the year 2030: with 38,000 of these due to heat exposure in older people, 48,000 due to diarrhoea, 60,000 due to malaria, and 95,000 due to childhood undernutrition.12
Impact on healthcare delivery
The frequency and intensity of severe weather events will increase. In these circumstances, hospitals, clinics or care homes may be physically damaged or face power outages.
Roads may be flooded or destroyed, making it hard for emergency services to reach patients or for patients to come to healthcare professionals. Severe weather events anywhere around the globe can disrupt supply chains, thus impacting patient care and costs.
The longer-term migration and movement of people from regions affected by climate change may also pose a risk to healthcare systems in neighbouring countries which may not have sufficient capacity to support additional demand.
James Sherwood (right) is general manager, operations and healthcare management, Bupa
1. Climate change and health; World Health Organization; February 2018.
2. Global warming of 1.5°C; Intergovernmental Panel on Climate Change, 2019.
3. Global warming vs Climate Change, NASA Global Climate Change, 2022.
4. Potential Changes in Disease Patterns and Pharmaceutical Use in Response to Climate Change; Journal of Toxicology and Environmental Health; 2013.
5. Impact of climate and air pollution on acute coronary syndromes: an update from the European Society of Cardiology Congress 2017; Scandinavian Cardiovascular Journal; 2017.
6. The global threat of outdoor ambient air pollution to cardiovascular health: time for intervention; 2017.
7. Temporal trends of the association between ambient temperature and hospitalisations for cardiovascular diseases in Queensland, Australia from 1995 to 2016: A time-stratified case-crossover study; PLOS; July 2020.
8. Global climate change and mental health; Current Opinion in Psychology; April 2020.
9. Global expansion and redistribution of Aedes-borne virus transmission risk with climate change; PLOS; March 2019.
10. Climate Related Diseases. Current Regional Variability and Projections to the Year 2100; Quaestiones Geographicae 2018.
11. Towards a fuller assessment of benefits to children’s health of reducing air pollution and mitigating climate change due to fossil fuel combustion; Environ Res. 2019.
12. WHO – Quantitative risk assessment of the effects of climate change on selected causes of death, 2030s and 2050s; WHO report; 2014.