On Friday, thousands of adults across the world will take part in the global climate strike to show solidarity with Greta Thunberg and the young students who have been walking out of school for months to raise awareness of the climate emergency. Among them will be many public sector workers, including some NHS staff.

With the UN Intergovernmental Panel on Climate Change report last year warning that the human race has just 12 years to limit the most devastating impacts of global heating, stark images of the toxic effect of plastic on marine life in David Attenborough’s Blue Planet II and the devastating fires in the Amazon rainforest, the scale of the crisis is all too clear. New research published last week by the Health Care Without Harm (HCWH) campaign (an NGO that works to reduce the environmental footprint of health worldwide) and consultancy firm Arup, calculates that globally, healthcare’s climate footprint accounts for an astonishing 4.4% of the world’s net C02 emissions. If healthcare were a country it would be the fifth largest emitter on the planet.

The report also finds that the NHS produces higher emissions than the global average for healthcare and is responsible for 5.4% of the UK’s total carbon emissions, equivalent to the greenhouse gas emissions of 11 coal-fired power stations. Its emissions are not much lower than those for both aviation, and agriculture, forestry and land use in the UK (each 6.5% according to Committee on Climate Change figures).

The NHS was one of the first national health systems to produce a carbon reduction strategy 10 years ago and started measuring emissions in 2007. Since then the health and social care sector has cut emissions by 18.5%, according to the NHS Sustainable Development Unit, despite a 27% increase in clinical activity over the same period.

Our actions must cover the types of drugs we purchase, the energy we use in our buildings and the waste we generate

But Kristian Steele, an associate at Arup and one of the HCWH report’s authors, says the findings show that the NHS needs to up its game. “As we continue to work to deliver high standards of quality healthcare, we must also address the environmental burden associated with this. The sector must strive to do no harm by working to cut its carbon emissions.”

This summer, more than 1,000 doctors signed an open letter calling for widespread nonviolent civil disobedience in the face of the environmental crisis and the UK Health Alliance on Climate Change, which represents all major health bodies and 650,000 healthcare professionals in the UK, has recognised the climate crisis.

“While the UK Health Alliance is not calling for health professionals to join strikes during scheduled working hours, we share the fervour of strikers for urgent action to mitigate against the damaging effects of climate change through changes to our behaviours as individuals, members of institutions such as the NHS, and as a country,” says Nicky Philpott, director of the alliance. “Failure to act quickly will heighten existing national health challenges, place undue financial strain on the NHS, and worsen health inequalities both within the UK and internationally.”

Yet, so far, only two NHS bodies have declared a climate emergency: Newcastle upon Tyne hospitals NHS foundation trust and the Greater Manchester health and social care partnership. In contrast, more than 100 local authorities have declared a climate emergency, and the government has committed the UK to achieving net zero carbon emissions by 2050. “In a sector that has health promotion and healing in its mission, it’s a no-brainer for it to want to protect health by cutting its own carbon footprint,” says Josh Karliner, HCWH international director. “Health systems need to weigh in for clean, renewable energy to protect the health of their patients. Decarbonising will reduce morbidity and mortality caused by the combustion of fossil fuels.”

‘The NHS long-term plan has committed to cutting mileage and air pollution from ambulances, patient transport and staff journeys by a fifth by 2024.’ Photograph: Alamy Stock Photo

Coming from a partnership that represents all health and social care bodies in the region and around 100,000 workers, Greater Manchester’s climate emergency declaration last month is potentially a game-changer. Some £6bn a year is spent on health and social care in the city region. Getting all 13 trusts, 10 clinical commissioning groups and the 10 councils responsible for social care to become carbon neutral by 2050 will be no mean feat. Anthony Hassall, joint chair of the partnership’s sustainable development leadership group, says: “Our actions must cover everything from the types of drugs and treatments we purchase, the energy used in our buildings, the waste we generate in clinical procedures to the transport our staff and patients use.”

A detailed plan is due to be published by the end of the year. As air pollution causes 1,200 deaths a year in the region, one of the priorities will be to improve public transport to and between NHS sites and reduce emissions from delivery vehicles, as well as installing electric vehicle charging points. It also aims to improve energy efficiency of NHS buildings, reducing single-use plastics, and planting trees.

Newcastle upon Tyne’s declaration – which came in June, before Greater Manchester’s – made it the first healthcare organisation in the world to declare a climate emergency and pledge to become carbon neutral by 2040. Newcastle has been in the vanguard of sustainability for decades. The trust installed combined heat and power plants in its hospitals in the late 1990s and all electricity bought comes from 100% renewable sources. It has sent zero waste to landfill since 2011 and recycles more than 40% of non-clinical waste (the average in the NHS is 23%). All procurement contracts include sustainability criteria, while hospital cafes and restaurants provide compostable cutlery and plates. The trust has commissioned new staff, patient and visitor electric bus services for 2020 and already has electric catering and estates vehicles.

But it is in the clinical areas – dialysis for kidney patients and anaesthetics in its operating theatres – that Newcastle really stands out. Its “renal green group” has been working to reduce the environmental impact of dialysis since 2010. It recycles packaging and used dialysis fluid canisters, while energy-saving measures include the retrofitting of heat recovery technology within dialysis machines. The trust has also pioneered ways to cut greenhouse gas emissions from anaesthetics, which make up 5% of acute hospitals’ total emissions and 1.7% of CO2 for the UK’s health and social care sector. Much of this is about the choice of anaesthetic: some gases are more polluting than others. The two most common anaesthetic gases are Sevoflurane and Desflurane, which largely do the same job. But Desflurane has a global warming potential 20 times greater than that of Sevoflurane.

Dr Cathy Lawson, a fellow in environmentally sustainable anaesthesia for the Association of Anaesthetists and the Centre for Sustainable Healthcare, based at Newcastle upon Tyne hospitals, saysreducing the use of Desflurane can make a real difference. “Since 2016, we have cut emissions from anaesthetic gases by 45%, through education about the environmental impact that our different gases have, supporting our colleagues to make informed choices about their clinical practice and using behavioural nudges to reduce unintentional use of our more harmful agents.”

From November she hopes to start introducing technology to capture these gases, and support staff in using alternative techniques with less emissions. She is also working with colleagues to improve the sustainability of operating theatres by cutting energy use and waste, reducing single-use plastics through recycling, and procuring more sustainable and reusable clinical items.

‘Greenhouse gas emissions from anaesthetic gases make up 5% of acute hospitals’ total emissions and 1.7% of CO2 for the UK’s health and social care sector.’ Photograph: Burger/Phanie/Getty Images/Canopy

Jonny Groome, co-founder of the Greener Anaesthesia and Sustainability Project and anaesthetic registrar at Barts Health NHS trust, points out that 40% of waste in operating theatres is a high-quality product that could be recycled. Unfortunately, most waste ends up being labelled as “infectious clinical waste”, he says, and gets incinerated at a high financial and environmental cost.

Transport is a big contributor to NHS emissions. The NHS accounts for almost 10bn road journeys each year – around 3.5% of all road travel. The long-term plan has committed to cutting mileage and air pollution from ambulances, patient transport and staff journeys by a fifth by 2024 – and ensuring that nine out of 10 vehicles are low emission within a decade. In February, NHS chief executive, Simon Stevens, called on vehicle manufacturers to develop greener ambulances.

Some trusts are introducing energy-saving measures to reduce car journeys such as lift-share schemes for staff, free shuttle buses between sites, and cycle-to-work schemes, as well as building staff accommodation within walking distance of work. Sussex Community NHS foundation trust has introduced a “care without carbon” mantra throughout the organisation. It developed an internal network to encourage departments to re-use furniture and unwanted office products, opened a travel bureau in 2013 to encourage public transport and cycling and has introduced a car lease scheme for staff with a cap on car emissions. As a result, emissions are down by 37%, says Susie Vernon, associate director of sustainability at Sussex Community NHS foundation trust.

Oxford University hospitals NHS foundation trust provides a cycle-to-work scheme, as well as a free staff shuttle bus between the trust’s four sites in Oxford. It offers a lift-share scheme, as well as discounted bus and rail passes. The trust is also building two nearby staff accommodation developments. University hospitals Coventry & Warwickshire NHS trust projects carbon savings of 2,000 tonnes over 20 years due to reusable sharps containers. But with two hospitals still using coal boilers and some oil-fired, getting to net zero emissions is a huge challenge for the NHS.

Stephen Powis, medical director for NHS England, says: “As part of our long-term plan, the NHS is doing its bit to protect our environment with practical measures like reducing the need for road traffic for appointments, phasing out coal in our buildings, supporting staff to use bike and car hire schemes and making use of safe, greener treatments including low-emission inhalers where it’s appropriate and good for patients.”

“For more than 70 years the health service in England has protected our country’s health with world-leading treatments, research and staff, but we also are doing more to protect our patients’ environment and help prevent ill health, which will not only safeguard the NHS and public health for future years, but save taxpayers money into the bargain.”

In the end, though, the best way to cut emissions is to keep patients healthier. “Nothing could be less environmentally sustainable than delivering interventions that do not work,” says Chris Naylor at The King’s Fund. “Arguably the best way to cut emissions would be to change the way we do healthcare, to prevent illness in the first place.”