Despite the cloudy sky of the winter noon, all the lights are off. Huge windows brighten the tall hall of Mollet University Hospital, surrounded by the hills of the nearby Gallecs natural protected area, and built around a centenary oak that is also the logo of the institution. By allowing the daylight to filter through the natural courtyards, the hospital has reduced its lighting consumption by 40 per cent.

Built from scratch and inaugurated in July 2010, the university hospital and its Green Hospital project, in the town of Mollet del Vallès, about 30 kilometres north of Barcelona, Catalonia, has since achieved its original goal of reaching net zero in both direct and indirect emissions.

How? For a start, through its architecture, featuring radiant ceilings that provide cooling, sustainable roofs that reduce the need for heating, and a rainwater collection system that supplies water for irrigation of the interior courtyards. The geothermal energy from 148 wells of 146m depth helps reduce consumption for heating and cooling; 1368 solar panels cover 12.5 per cent ​​of the hospital’s overall energy needs, while the rest of the electricity is purchased from certified renewable sources. Recycling and waste management also play a role, along with reducing hospitalisation, unnecessary diagnostic tests and medication waste, minimising travel and mobility, and cultivating a shared culture of sustainability among the workers.

This has made Mollet Hospital an international example of sustainability in a sector that presents a paradox in the era of the climate crisis. The health impacts of pollution, heatwaves, and other so-called “natural” disasters increase the pressure on the health care system. At the same time, the sector is actively contributing to climate change and its impacts on people’s health.

Emissions and waste

If the health sector were a country, it would be the fifth-largest emitter in the world. According to the World Health Organization (WHO), in 2020 it was responsible for approximately 5 per cent of global greenhouse gas emissions. In Europe, hospitals are responsible for 4.4 per cent of total CO2 emissions, while the aviation sector accounts for 2.5 per cent.

Top ten emitters as percentage of global health care footprint. Source: Health Care Without Harm

If we don’t act quickly, by 2050, our healthcare systems will produce six gigatons of CO2 per year.

Electricity consumption from the lights (normally always on), ventilation, heating and air conditioning systems also add to the environmental impact of health centres. Still, the main culprit is the production, packaging, transportation, and disposal of goods and services: think of the number of gloves, paper towels, masks, needles, syringes, bandages, sponges, gowns, medicine wrappers, and underpads, many of which are single-use, daily used in one single hospital, and in one single procedure.

In 2021, artist Maria Koijck and her daughter Eva Glasbeek turned the waste from Koijck’s breast reconstruction surgery after cancer into a work of art. The procedure generated over six bags full of plastic waste, 60 per cent of which was disposable. “Humans always seek to ‘get better’, but what is the cost to our environment? Is there another way?”, Koijck asked.

For the WHO, what is needed is joint action between governments and healthcare companies to move towards sustainable healthcare systems.

One of the first international organisations to draw attention to the issue was Health Care Without Harm. Since 1996, the NGO has been publishing reports and data that provide a snapshot of the problem. These documents highlight that hospitals are among the most polluting facilities in the world. The majority of their emissions (about 71 per cent) come from the supply chain, namely the production, packaging, transport, use, and disposal of pharmaceuticals and medical devices, hospital equipment, and instruments. Energy comes next: 13 per cent of the sector’s carbon footprint comes from electricity and heat consumption in the health facilities. Then there’s pollution from transportation, toxic substances found in medicines, detergents, and disinfectants, and dioxins leaking from medical waste incinerators.

Green pioneers

The Mollet Green hospital project started five years before the 2015 Paris Agreement on climate change was adopted. “By 2012, we were already calculating our carbon footprint and establishing a plan to reduce CO2 emissions”, proudly recalls Miguel Ángel Martínez Sánchez,  director of Sustainability, Health and Safety at the Fundació Sanitària Mollet (FSM). The FSM is a private, non-profit institution providing public health care services to 11 municipalities (about 170,000 people) through six centres: besides the university hospital, it runs facilities offering socio-sanitary, residential, and non-residential services (rehabilitation, elderly and disability care, treatment of mental health conditions and addictions).

Martínez was born in Mollet in a family that he describes as “very connected to nature”. His mother comes from a small town in the mountains of the southern Spanish region of Andalusia. As a child, he used to see deer, squirrels and foxes on his vacation strolls, and dreamt of studying something related to the environment. As an adult, after earning a degree in industrial technical engineering (chemistry) and a master’s in occupational risk prevention, he went on to study Environmental Sciences at the Universitat Autònoma de Barcelona (UAB). When he heard that the hospital in his hometown had just opened a new building and aimed to put sustainability at its core, he was 30 years old and working as an auditor and consultant in the climate change department of a multinational firm. “I was travelling all day up and down, commuting by train from and to Barcelona, and I thought ‘what a great chance to be part of a very cool project and to improve my life quality’, and indeed it was,” he recalls. His office, in the recently opened campus area, is only a few meters away from the hospital. The building also houses classrooms, a lab, a community library and an auditorium.

Martínez has a long, light brown ponytail, moustache and beard, and the air of an eternal child. He is wearing a cable-knit sweater that is as white as the surroundings. Just like the rest of the hospital area, his office looks minimal, new, and bright. He believes that a decisive step in the hospital’s path toward sustainability came in 2012, when it obtained ISO certifications for environmental and energy management systems and made sustainability training mandatory for all professionals.

Mollet Hospital has been a pioneer in this regard. It took the UN another decade to recognise sustainable healthcare as a priority at COP26 in Glasgow (2021). However, only six EU countries (Belgium, Germany, Ireland, the Netherlands, Norway, and Spain) submitted formal commitments to the COP26 presidency to strengthen and develop sustainable healthcare systems.

In the EU, when it comes to healthcare systems, the emphasis is largely on climate adaptation rather than emissions mitigation – with few exceptions. The European Commission’s Pharmaceutical strategy for Europe (2020), for example, stresses the importance of using environmentally sustainable and climate-neutral pharmaceutical products, while the digital healthcare strategy eHealth could play a key role in decarbonisation by slashing transportation needs, digitising paper-heavy workflows, and enhancing resource efficiency.

For Martínez, the key to Mollet Hospital’s success is “the widespread green culture among the staff, the word-of-mouth”. All employees attend a two-hour environmental sustainability training every four years, while the 20 staff members who volunteer as environmental ambassadors also have bimonthly meetings with Miguel and receive additional training to chaperone their colleagues in minimising the impact of the hospital’s processes. The ambassadors perform their function as part of their job, during regular working hours.

Best practices range from increasing the percentage of online consultations (up by 24 per cent, according to the hospital’s figures) to introducing new systems such as a semi-automated medication dispensing system, which reduces waste (by 29 per cent) and increases safety by minimising mistakes. 

Mollet University Hospital’s Director of Sustainability, Miguel Ángel Martínez Sánchez, shows the semi-automated medication dispensing systems. Photo: Elena Ledda

Results are not just visible through the satisfaction on Miguel’s face – they are also measured by the hospital. According to the institution’s calculations, from 2012 (their baseline) to 2024, direct and indirect emissions (the latter from purchased electricity) dropped by 91 per cent, despite the number of patients doubling in the same period.

The FSM has received several recognitions for its commitment to the fight against climate change in the health sector, including the 2025 Health Care Climate Champions award for Europe, promoted by Health Care Without Harm.

Joining forces

Mollet is no longer an exception in Catalonia. In 2025, another privately owned but publicly funded hospital, the Barcelona Hospital de la Santa Creu i Sant Pau, won the European Sustainable Healthcare Awards for its Green Breath initiative.

Since 2023, the initiative has been aiming to reduce the environmental impact of inhaled medications used to treat asthma and other respiratory conditions. These drugs come in various types of inhalers: pressurised metered-dose (pMDIs), dry powder, and soft mist. pMDIs are the most commonly used and most polluting: they contain hydrofluorocarbons (HFCs), greenhouse gases with a global warming potential thousands of times greater than CO2: one inhaler emits the HFC equivalent of 20 kg of CO2, which is comparable to driving 200 to 300 kilometers by car; in medical tests like spirometry, which evaluates a person’s breathing efficiency, inhalers are discharged after a single puff. Dry powder and soft mist inhalers emit 1kg of CO2: they use no chemical propellants for the drug, so their carbon footprint is mostly linked to their manufacturing. This is why Green Breath aims to reduce the use of pMDIs whenever patients’ conditions allow. It estimates that a 10 per cent shift from pMDI inhalers to dry powder or soft mist could reduce annual CO2 emissions by 40,000 tons in Spain alone. The project also aims to promote better disposal and waste management practices to reduce environmental impacts linked to the manufacturing, distribution, and packaging of all types of inhalers.

Different types of inhalers. From left to right: pressurised metered-dose, dry powder, and soft mist inhalers. Photo: Noé Garin Escrivà

According to the WHO, 24 per cent of deaths worldwide are related to environmental factors. “As a health professional, I saw that there was something I had to do”, says Noé Garin Escrivà, Green Breath coordinator and deputy at the hospital’s pharmacy service. Pneumology is one of the areas he focuses on and researches. Since his high school times in Sant Boi, a small industrial city in the Barcelona metropolitan area, Noé knew he would dedicate his professional life to caring for people.

Without external funding and with the help of Green Breath’s three-person team, Escrivà has developed and continues to update the first database that classifies inhalers based on their environmental impact, taking into account carbon emissions, toxicity, and water pollution.

This tool has been complemented by an algorithm that supports doctors when prescribing inhalers, bearing in mind both patient needs and the medications’ environmental impact. Escrivà contributed to the first national guide on sustainable prescribing of inhalers, published by the Spanish Ministry of Health in early 2025. Green Breath also includes a national project involving 40 hospitals to improve the proper disposal of inhalers by patients, and a pilot project to optimise the disposal of unused inhalers at the Hospital de Sant Pau.

Both Mollet and Sant Pau are members of the Global Green and Healthy Hospitals (GGHH) network, a project of Health Care without Harm. With over 70,000 hospitals and health centres in more than 80 countries, it represents the largest sustainable healthcare network in the world.

And it is not just health centres that are driving innovation. For example, the Dutch Green Health Alliance (Groene Zorg Alliantie), a grassroots non- profit network, was created in 2021 to build advocacy and foster a culture of greener healthcare. Today, it unites about 40,000 healthcare professionals: through a podcast, a book, and an annual festival, the alliance is placing sustainability at the core of the debate. Its co-founder and chair, medical doctor and researcher in sustainable healthcare Evelyn Brakema, was the Sustainability Champion of the Year winner at the same 2025 European Sustainable Healthcare Awards where Miguel’s and Noe’s work were also recognised.

There is still a long way to go, but some people and institutions in the sector are already acting with the understanding that safeguarding people’s health necessarily also involves protecting the planet. 

This article was produced as part of the PULSE collaborative cross-border journalism initiative (coordinated by n-ost and OBCT) and in collaboration with journalist Alice Facchini.