The environmental impact of healthcare: how much do hospitals pollute?

Every day, hospitals produce tonnes of waste and consume enormous amounts of energy: an often invisible, yet extremely real impact on the environment. Gloves, disposable masks, dressing materials and medication wrappers constantly end up in bins, while constantly switched-on lights, heating and air-conditioning systems feed a perennial and considerable energy consumption.

According to the World Health Organisation (WHO), the health sector generates about five per cent of global greenhouse gas emissions, with higher percentages in regions such as Europe, the US and China. Without concrete action, the sector's emissions could reach six gigatonnes of CO₂ per year by 2050, equivalent to those produced by approximately 1.26 billion cars. The paradox is obvious: caring for people has a direct impact on the environment. For the WHO, the solution requires a collaboration between governments and healthcare facilities to steer the sector towards sustainability.

Data from Health Care Without Harm say that if the health care system were considered a state, it would be the fifth largest emitter of greenhouse gases globally. Hospitals, in particular, are among the most polluting facilities: their annual carbon footprint amounts to about two gigatonnes of CO₂, as much as produced by 514 coal-fired power plants. The main sources of pollution come from the production and management of materials, such as drugs, medical devices and hospital instruments, which account for about 71% of emissions. A significant share is also related to the energy consumption of facilities, while transport, chemicals and incineration of special waste further contribute to the environmental impact.

Making healthcare sustainable is now a global challenge. At COP26 in 2021, fifty countries pledged to develop low-emission healthcare systems and fourteen promised to zero net emissions by 2050. The European Union has integrated sustainability into its climate agenda, mainly through the European Green Deal, although the focus in healthcare is often more on adaptation to climate change than on reducing emissions. Some key programmes include the European pharmaceutical strategy, which promotes sustainable and climate-friendly medicines, the digitisation of healthcare, which can support decarbonisation, and the 'farm-to-fork' strategy, which aims to promote sustainable food and reduce waste.

Several European hospitals are already experimenting with sustainable innovations. In Catalonia, the University Hospital of Mollet del Vallès, designed in 2010 with sustainability in mind, uses geothermal energy, rainwater harvesting and radiant air conditioning systems, while the subsequent installation of solar panels and efficient windows has reduced emissions by 91% between 2012 and 2024, despite a 50% increase in patient numbers. In Barcelona, the Hospital de la Santa Creu i Sant Pau introduced the Green Breath project to limit the impact of inhalant drugs, which contain hydrofluorocarbons, a very potent greenhouse gas. Thanks to a database that classifies inhalers by environmental impact and a prescription support algorithm, doctors can consider both the needs of the patient and the sustainability of the drug. In 2025, Spain's first national guide on the sustainable prescription of inhalers was published.