Healthcare systems face a growing burden from environmental hazards like air pollution and extreme weather events. As major contributors to greenhouse gas emissions, they are also seeking to reduce their carbon footprint.
National healthcare systems are the first in line when the health of the population is shaken by climate change and other environmental hazards. These include extreme weather events and elevated pollution exposure, which can affect people’s physical and mental health. The effects increase visits to accident and emergency (A&E) departments and put direct pressure on hospitals’ capacity to provide quality care.
At the same time, healthcare systems, such as the UK’s National Health Service (NHS), are large contributors of greenhouse gases and many other pollutants that directly affect health. For example, as the NHS is the biggest employer in the UK (and Europe), it is responsible for a high volume of commutes by its employees and patients. The healthcare sector also consumes tonnes of single-use products daily that need to be incinerated. This activity generates air and water pollutants directly harmful to individuals.
To minimise their negative impact on the environment while ensuring their resilience to change, healthcare systems need not only to be economically stable, but also socially and environmentally sustainable. The latter objective requires them to develop the ability to anticipate spikes in healthcare demand and shocks to supply, as well as ensuring that they lead by example and minimise their contribution to climate change.
How badly are healthcare systems affected by climate change?
The vulnerability of healthcare systems to environmental shocks has received increasing attention by researchers. The most common type of environmental shocks associated with climate change is extreme weather events, such as heatwaves and floods.
For example, one study in Germany estimates that extreme heat significantly increases hospitalisations and deaths across the healthcare system (Karlsson and Ziebarth, 2018). Most hospitalisations are associated with exacerbations of chronic illnesses such as respiratory or cardiovascular diseases.
With a growing older population and an increasing burden of non-communicable diseases, treating these shocks to the healthcare system is resource-intensive. More worryingly, some parts of the population are disproportionately affected. This is both in terms of individual vulnerabilities and since those that are the most deprived are often more likely to require hospital care. Research on the impact of temperature shocks in England over a decade illustrates that the most vulnerable groups are the elderly, children and the economically disadvantaged (Rizmie et al, 2021).
In addition to respiratory health effects, these groups are most likely to suffer from endocrine and metabolic diseases (such as obesity and diabetes) and injuries – putting pressure on hospital capacities. For example, on an extremely hot day, hospitals can see an increase of up to 26% in emergency hospitalisations for metabolic diseases and a 21% increase for infectious diseases, which are likely to be driven by a variety of heat stress body responses that increase vulnerability.
It doesn’t stop there. Temperature effects spread over time as they extend well beyond the day of the event. They can put the healthcare system under pressure for ten days after extreme heat (in the case of metabolic diseases). This can go up to 21 days for respiratory ailments exacerbated by cold weather.
The cumulative costs of extreme weather events for the NHS alone are estimated to be £20.8 million annually. To put things in perspective, the annual budget at Public Health England (PHE) for environmental hazards and emergency preparedness, which entails all environmental disasters and pandemic preparedness, was £18.2 million in 2017 (and has since been getting smaller). It currently costs more to treat a subset of health needs associated with one environmental shock than is being used to prepare prevention methods for all potential hazards.
Changes in air quality are associated with a changing climate and pollution emitted from economic activity. The total health and social care cost due to particulate matter and nitrogen dioxide was estimated to be £42.88 million in 2017 (Adomako-Mensah et al, 2020). Projecting no improvements by 2035, the direct health effects of air pollution could cost the NHS as much as £5.3 billion.
These are conservative estimates of the impacts of air pollution on the healthcare sector. The true cost is much larger when considering premature mortality, absenteeism and productivity losses. By achieving the World Health Organization’s (WHO) air quality recommendations, the UK economy could save £1.6 billion each year in working days gained and reduced mortality (CBI Economics).
A study in the UK that quantified the increased rates of daily A&E attendances associated with peaks of air pollution shows that these excess visits are observed at pollution levels much lower than the 2005 WHO air quality recommendations (de Preux et al, 2021, forthcoming). There are daily surges in emergency visits as soon as particulate matter and nitrogen dioxide levels peak, which happens frequently throughout the year in the largest cities.
Another extreme weather shock that affects the UK severely is flooding, with grave short- and long-term health impacts. Floods can devastate communities from structural damages to homes and property, as well as posing immediate health risks such as drowning, hypothermia and electrocution.
This damage displaces individuals and represents a threat to their economic stability. In addition, these traumatic events have been associated with increased risk of mental health symptoms – depression, anxiety and post-traumatic stress disorders – all of which have costly long-term consequences for the healthcare sector.
These examples of climate change impacts are the tip of the iceberg. Droughts, wildfires, increasing allergens and water contamination are associated with increased temperature variation, and they raise a range of health concerns in populations. Changing climates become conducive to a range of infectious diseases and pathogens, such as mosquito-borne diseases (Colón-González et al, 2018, 2021).
Beyond all this, the effects of climate change transcend borders. Severe weather conditions across the globe threaten agricultural and food production, the provision of healthcare goods and employment. Certain countries, largely in Asia and Africa but also Mexico and even the United States, will bear the brunt of these changes, forcing their populations to migrate to more hospitable temperatures. Receiving countries and their healthcare systems will need to be prepared.
All these factors gradually threaten the sustainability of healthcare systems. The NHS will not be spared by these long-term changes, with some of them already affecting the UK’s population.
Are healthcare systems just victims of climate change?
Far from it. The NHS represents 4-5% of the UK’s carbon footprint. Its emissions cost the NHS over £50 million a year in carbon permits – suggesting clear synergies to be achieved by reducing emissions.
The NHS is determined to do better. It has achieved a 26% reduction in greenhouse gases since 1990 (Tennison et al, 2021). In 2020, it became the world’s first national healthcare system to commit to becoming a carbon net-zero provider. It aims to achieve its ambitious targets with a series of measures around building improvements, renewable energy, electrifying the transport fleet and improving its staff’s transport choices. The supply chain also offers several opportunities (for example, local and recyclable products), being the largest carbon emitter in the delivery of care.
How can healthcare systems change?
A Guide for Health Leaders, published at the WISH 2020 Forum on Climate Change and Health encouraged more transparency and clear commitments from health leaders (Roland et al, 2020). This highlighted the co-benefits of greener provision of healthcare. But for these benefits and costs to be accounted for in future decision processes, they must be priced and valued in economic terms. Otherwise, they risk being acknowledged but not accounted.
Pricing carbon emissions in an economic evaluation that compares two treatments may change the cost-effectiveness recommendation. One study illustrates this by looking at dialysis treatments performed in a hospital setting or at home. When accounting for the social cost of carbon emissions associated with treatment, home dialysis came out as the more cost-effective option (de Preux and Rizmie, 2018).
The WHO released an update of its Air Quality Guidelines in September 2021, lowering recommended air pollution thresholds as more evidence reveals the benefits of cleaner air quality. This offers an opportunity for policy-makers to implement tougher targets and regulations. Further, putting a price on emissions – what economists refer to as ‘internalising externalities’ – is an essential step to force decision-makers to adopt a broader perspective and anticipate the future benefits of a greener transition.
Healthcare providers that are large carbon emitters in Europe are part of the Emissions Trading System (EU ETS), which forces them to put a price on their emissions. Yet there are numerous exemptions, as well as other pollutants with social impacts that are still absent from the decision process when choosing the best intervention or approach. As long as these are not quantified and thus omitted from the decision process, health leaders will not make environmentally sustainable choices.
Climate change is a threat and an opportunity for already overstretched healthcare systems. By adopting a holistic and responsible approach to health management, by reducing their emissions and protecting individuals’ health even before they need care, the whole of society will benefit. It is an essential cornerstone for financially, environmentally and socially sustainable healthcare sectors.
Where can I find out more?
- The NHS long term plan
- The Lancet countdown on health and climate change
- World Health Organization fact sheet on climate change and health
- US Centers for Disease Control and Prevention: Climate effects on health