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Lowering the NHS carbon footprint

Mark Greener looks at whether efforts to reduce health care’s impact on the climate are too little, too late

Samuel Johnson quipped that ‘When two Englishmen meet, their first talk is of the weather’. In 1758, the year Johnson coined his witticism, Europe was in the midst of the ‘Little Ice Age’, the continent’s coldest spell during the last millennium. The Little Ice Age lasted between the 14th and 19th centuries (climate scientists debate the exact dates).1 The Thames and the Baltic Sea froze. Famine and disease spread. And other extreme weather events, such as floods, heat waves and drought, became more common.1
Nevertheless, our national obsession with the weather became something of a joke, characterising archetypal Englishness alongside lacklustre cuisine, stiff upper lips and a penchant for tea. Today, our weather obsession seems justified. We’re facing more intense storms and floods. Heatwaves are increasingly common. And, possibly, extreme winter weather (‘Beasts from the East’, for example) could arrive more often.
Almost all scientists blame the atmospheric accumulation of greenhouse gases, such as carbon dioxide, methane and nitrous oxide, for the changing climate. As their name suggests, greenhouse gases trap heat in the Earth’s atmosphere. In response, 196 governments and other parties worldwide signed the 2015 Paris Climate Change Agreement to limit the increase in global average temperature to ‘well below 2°C above preindustrial levels’ and try to keep the rise to 1.5°C. Since the Paris Agreement, however, politicians and climate scientists have increasingly stressed the importance of keeping the rise to, at most, 1.5°C above preindustrial levels.2
Containing the increase in global average temperature means aiming for net zero carbon emissions. In other words, carbon removal technologies should balance carbon emissions from human activities. Attaining net zero depends, however, on reducing emissions (such as those from fossil fuels) to as close to zero as possible.
Reducing the NHS’s carbon footprint is essential if the UK as a whole is to reach net zero. After all, the NHS is responsible for about 4% of England’s carbon footprint and is the country’s largest employer.3 In addition, NHS staff have a personal responsibility to reduce their carbon footprint. According to the Climate Change Committee, 40% of UK carbon emissions come from households.4
But the NHS’s role in climate change goes beyond the carbon reduction and offsetting required of a large organisation. Climate change affects health and, in turn, demand on the NHS. One analysis found that climate change aggravated 58% of diseases studied caused by, for example viruses, bacteria, animals, plants or fungi.5 The NHS estimates that attaining the UK’s ambitions under the Paris Climate Change Agreement could save 5700 lives every year by improving air quality. Meeting the ambitions would also mean that a more physically active population and healthier diets would save 38,000 and more than 100,000 lives annually respectively.3
Against this background, the NHS set two targets to be carbon neutral. Firstly, to be net zero by 2040 for carbon emissions that the NHS directly controls. Secondly, to be net zero by 2045 for carbon emissions that the NHS can influence. As part of this, the NHS aims to reach an 80% reduction in directly controlled emissions by 2028 to 2032. For emissions the NHS can influence, they plan an 80% reduction by 2036 to 2039.3 The Health and Care Act 2022 places a duty on NHS England, and all trusts, foundation trusts and integrated care boards to contribute towards statutory emissions and environmental targets.3 While the NHS’s carbon footprint has undoubtedly shrunk over the last few years, emerging concerns suggest that progress may have stalled.6,7
A warming world
Meteorologists distinguish climate and weather. The weather is the state of the earth’s atmosphere at a particular place and time. Outside my study window, it’s diffuse sunlight, but hot and humid. That’s today’s weather in this part of East Anglia.
The climate is the weather pattern over a long time: often decades or centuries. According to the World Meteorological Organization, the global mean temperature in 2022 was 1.15°C above the 1850–1900 average. Indeed, 2015 to 2022 were the eight warmest years in records that stretch back 173 years.8 Concentrations of the three main greenhouse gases (carbon dioxide, methane and nitrous oxide) in 2021 were the highest since global records began in 1984. Initial data suggests that levels of these gases were even higher during 2022.8
Meanwhile, climate change directly and indirectly influences health. The World Health Organisation (WHO) estimates that climate change will cause about 250,000 extra deaths annually, from malnutrition, malaria, diarrhoea and heat stress, between 2030 and 2050.9
The 2022 heatwaves alone
were responsible for an estimated 61,672 excess deaths across Europe, including 3,469 in the UK.10
Last year’s heatwave was exceptional for the UK. Yet nurses should remember that hypothermia remains a far more serious public health problem than heat stress. Between 2000 and 2019, cold and heat caused, on average, 60,573 and 791 deaths a year in England and Wales respectively (122.34 and 1.57 deaths per 100,000 person years).11 During 2022, the heat-related excess mortality rate was 5.2 per 100,000.10
Reducing the carbon footprint may help meet another NHS priority: tackling health inequalities.12 Climate change increases energy demand.3 As we saw in the wake of Russia’s invasion of Ukraine, increases in the price of household fuel disproportionally affect poorer people. The cost of energy needed to address climate change will probably make it harder for poorer families to maintain good health, particularly for those living in poorly insulated homes.3 Furthermore, cutting emissions could prevent up to a third of asthma cases. Minority ethnic groups, children and women seem especially vulnerable to pollution’s harmful effects.3
A shrinking footprint
The NHS’s carbon footprint does appear to be shrinking. In 2019, carbon emissions by the NHS in England reached 25 megatonnes of carbon dioxide equivalent (CO2e), a fall of 26%, and a decrease of 64% for each in-patient finished admission episode, since 1990. A December 2021 survey by the British Medical Association (BMA) of 175 NHS organisations identified numerous ways in which the NHS was trying to reduce the carbon footprint including:7
A dedicated team to drive progress and deliver a sustainability plan. All Integrated Care Systems in England should have a ‘Green Plan’ that outlines ambitions and how the system will deliver sustainable practices.
Improvements to buildings that enhance energy efficiency.
Switching to renewable electricity tariffs.
Using solar panels on NHS sites and connecting to local solar farms.
Procurement changes, such as requirements to obtain carbon footprint information and reduce carbon emission.
Providing a shuttle bus between hospital sites and purchasing electric pool bikes for staff.
Some organisations set themselves a target to be net zero by 2030, earlier than the England NHS goal.

But there’s scope for further reductions. In 2019, 62% of emissions came from the supply chain (including emissions from imported foreign goods and services).6 Further procurement changes to reduce carbon emissions could help cut the supply chain’s footprint. Direct care delivery accounted for 24% of emissions, while 10% came from commuting staff, and patient and visitor travel. The authors comment that ‘health systems can have a considerable degree of influence [over the travel component] through innovations in models of care’,6 such as care closer to home and virtual consultations. Finally, 4% is from NHS-commissioned private health and care services.6
During 2019, acute care made a larger contribution to the NHS carbon footprint (12,960 kg CO2e) than primary care (5770 kg CO2e), non-clinical support services (3010 kg CO2e), mental health (1510 kg CO2e), community care (1280 kg CO2e) and ambulance services (510 kg CO2e). In primary care, pharmaceuticals and chemicals, and anaesthetic gases and metered dose inhalers (MDIs) made the two biggest contributions (2750 and 767 kg CO2e respectively).6 In primary care, pharmaceuticals and MDIs presumably had the largest footprints. So, where possible, prescribing decisions should consider the environmental impact.
Slowing progress
Nevertheless, progress towards net zero may be slowing.7 According to the BMA, median emission levels fell from 3.04 to 2.29 tonnes of CO2 per full-time staff member between 2016 and 2021. However, most of the decrease took place between 2016-2019. The reduction seems to have levelled off since 2019, possibly following implementation of ‘quick wins’, such as sustainable lighting. Moreover, issues such as the COVID-19 pandemic that placed additional pressure on the NHS probably also contributed to the slowing. The BMA comment that ‘It is important that the NHS does not lose momentum or there is a risk that future targets will not be met’.7
Even the advice you offer everyday can help reduce the UK’s carbon footprint and improve health. Agriculture (eg methane from cattle) accounts for a third of greenhouse gas emissions.13 On the one hand, climate change may mean that fresh food becomes more expensive. People struggling with the cost of living may have little choice but to turn to cheaper ultra-processed foods, which seem to increase the risk of obesity and type 2 diabetes. Ultra-processed and imported foods are also more carbon-intensive than fresh, locally sourced products.14 On the other hand, changing the average UK diet to meet the WHO’s nutritional recommendations, would reduce greenhouse gas emissions by about 17%.14
Increasing exercise, such as walking and cycling instead of taking a car, reduces greenhouse gas emissions and improves health.13 As the world warms, nurses also need to reinforce the importance of hydration. Dehydration can, for example, trigger cardiovascular events and acute kidney injury.14
Against this background, the BMA also called for further support from UK governments. ‘Given the huge pressures NHS organisations are under and the increasing energy costs, major improvements to sustainability practices may not happen if specific funding is not made available by UK governments. Funding for dedicated staff to drive sustainability practices within NHS organisations could result in major improvements being made. Any national or local funding initiatives should be widely promoted to NHS organisations with clear information on how to submit applications for funding.’7
We all know what the science says we should do to reduce our personal and occupational carbon footprints. But climatologists recognise two gaps in climate policy. The implementation gap refers to the difference between future emissions based on a temperature goal, such as limiting the increase to 1.5 °C, and what current policies can achieve. The ambition gap reflects the difference between pledged emission targets and pathways, and those needed to attain the temperature goal.15
Over the last few years, the NHS has made undoubted progress towards net zero. But whether the NHS is implementing the changes quickly enough and the targets are sufficiently ambitious remains to be seen – probably by our children and grandchildren.  

Mark Greener is a freelance medical writer
1. Oliva M. 2018. The Little Ice Age, the climatic background of present-day warming in Europe. Cuadernos de Investigación Geográfica. 44(1):7-13.
2. United Nations Framework Convention on Climate Change. The Paris Agreement. Available at Accessed August 2023.
3. NHS England. Delivering a ‘Net Zero’ National Health Service. Available at and Accessed August 2023.
4. Climate Change Committee. The Fifth Carbon Budget. How every household can help reduce the UK’s carbon footprint. Available at Accessed August 2023.
5. Mora C, McKenzie T, Gaw IMet al. 2022. Over half of known human pathogenic diseases can be aggravated by climate change. Nat Clim Chang. 12(9):869-75.
6. Tennison I, Roschnik S, Ashby Bet al. 2021. Health care’s response to climate change: a carbon footprint assessment of the NHS in England. Lancet Planet Health. 5(2):e84-e92.
7. British Medical Association. 2023. More support needed to help the NHS reach net zero. Available at Accessed August 2023.
8. World Meteorological Organization. State of the Global Climate 2022. Available at Accessed August 2023.
9. World Health Organisation. Climate change and health. Available at Accessed August 2023.
10. Ballester J, Quijal-Zamorano M, Méndez Turrubiates RFet al. 2023. Heat-related mortality in Europe during the summer of 2022. Nature Med. 29(7):1857-66.
11. Gasparrini A, Masselot P, Scortichini Met al. 2022. Small-area assessment of temperature-related mortality risks in England and Wales: a case time series analysis. Lancet Planet Health. 6(7):e557-e64.
12. NHS England. National Healthcare Inequalities Improvement Programme. Available at Accessed August 2023.
13. Stewart PM, Mirmira RG and Kaiser UB. 2021. Environmental pollution, climate change, and a critical role for the endocrinologist. J Clin Endocrinol Metab. 106(12):3381-4.
14. Al-Shihabi F, Moore A and Chowdhury TA. Diabetes and climate change. Diabet Med.
15. Fransen T, Meckling J, Stünzi Aet al. 2023. Taking stock of the implementation gap in climate policy. Nature Climate Change. 13(8):752-5.