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CO2 emissions in the healthcare system

Where are most climate-damaging emissions generated?

The healthcare system promotes the health and well-being of the population. However, greenhouse gas emissions from the healthcare system are high and contribute significantly to man-made climate change and thus to health damage. The healthcare sector is responsible for 4.4% of all CO2 emissions worldwide and thus - if it were a country - would rank fifth among the countries with the highest CO2 emissions [1]. While direct (Scope 1) and indirect emissions from purchased electricity, heating, etc. (Scope 2) together account for just under a third, the lion's share is accounted for by the so-called Scope 3 emissions [1], which include goods, services, production, and transport. To identify potential savings, it helps to take a closer look at the biggest "climate sinners" in hospitals.
Note: The figures come from different studies from different hospitals in different countries and are therefore only comparable to a limited extent. In this article, CO2 equivalents also fall under the term CO2 for simplification. CT = computed tomography; MRI = magnetic resonance imaging.

Anaesthetic gases account for the majority of emissions in the operating room

Anyone who is not an expert would hardly think that anaesthetic gases have an extreme greenhouse effect. In fact, gases such as desflurane and sevoflurane are hundreds to thousands of times more harmful to the climate than CO2and can account for two-thirds of the emissions in the operating room or one-third of hospital-wide emissions [2-4]. For example, the climate-damaging effect of a 7-hour operation with desflurane is roughly equivalent to a car journey from Germany to China (approx. 8,000 km) [4]. In addition, the heating, ventilation, and air conditioning of operating rooms can account for up to 84% of the emissions of the operating room in individual cases, depending on the type of electricity generation [3], while the heating of the entire hospital accounts for about a quarter of all hospital emissions on average [5].

Inpatient care, catering, and transport with a large carbon footprint

Inpatient care has not been resource-saving either. While an acute ward produces 5.5 kg of waste and 45 kg of CO2per patient per day, an intensive care unit produces 7.1 kg of waste and 138 kg of CO2[6]. In a fully occupied 500-bed hospital with 20 intensive care beds, this would add up to almost 9,000 t of CO2per year. There is also great potential for savings in catering, which is responsible for about 17% of all hospital emissions: here, for example, a wider range of regional vegetarian dishes could have a positive effect on the carbon footprint [5]. There is also considerable potential for savings in commuting or travel by employees and in patient and visitor transport, which together account for about 18% of CO2emissions, e.g. through more sustainable types of driving and switching to public transport or the bicycle [7]. As the production of medicines is energy-intensive and medicines cause about 12% of hospital emissions, it would also help to deal with them in a more sustainable and forward-looking manner [3].

Diagnostic imaging also contributes to emissions

Diagnosis always precedes treatment. Since about every fourth to fifth hospital stay requires diagnostic imaging [8], these - often energy-intensive - procedures are also included in the overall calculation. For example, the average CO2emissions of a magnetic resonance imaging and a computed tomography are 17.5 and 9.2 kg per scan, respectively. To save resources, unnecessary examinations could be avoided, and equipment could be utilised more intelligently and switched off completely during idle periods [9].

A ward with 20 beds consumes up to 10,000 litres of water per day

The valuable resource of water is also consumed on a large scale in hospitals, e.g. for laundry, sterilisation, heating and cooling. In Germany, for example, about 500 litres of water are needed per bed every day [10], which amounts to 10,000 litres in a 20-bed ward or 250,000 litres in a 500-bed hospital. For the prevention of legionella in drinking water alone, the 5-minute flushing of 40 taps at 15 l/min each, which should be done every 72 hours, results in 7,000 L per week.

The road to a climate-neutral hospital is long, but things are happening

In order to counteract climate change, the healthcare system must also be drastically rethought. Since more and more people will fall ill as a result of climate change - e.g. due to extreme heat or poor air and water quality - not only must the hospital's own emissions be reduced, but efforts must also be made towards primary prevention. The topic of "sustainable hospitals" is fortunately gaining more and more attention, but there is still a long way to go and it requires the commitment of everyone involved.


  1. Karliner Jet al. (2019) Health care’s climate footprint. How The Health Sector Contributes To The Global Climate Crisis And Opportunities For Action 26.06.2023)
  2. Richter Het al. (2020) Der CO2-Fußabdruck der Anästhesie. Wie die Wahl volatiler Anästhetika die CO2-Emissionen einer anästhesiologischen Klinik beeinflusst.Anästh Intensivmed 61: 154-161
  3. MacNeill AJet al. (2017) The impact of surgery on global climate: a carbon footprinting study of operating theatres in three health systems. Lancet Planet Health 1: e381-e388
  4. 26.06.2023)
  5. Keller RLet al. (2021) From bandages to buildings: Identifying the environmental hotspots of hospitals. J Cleaner Prod 319: 128479
  6. Prasad PAet al. (2022) Environmental footprint of regular and intensive inpatient care in a large US hospital. Int J Life Cycle Assess 27: 38-49.
  7. Tomson C (2015) Reducing the carbon footprint of hospital-based care. Future Hosp J 2: 57-62.
  8. 26.06.2023)
  9. McAlister Set al. (2022) The carbon footprint of hospital diagnostic imaging in Australia. Lancet Reg Health West Pac 24: 100459.
  10. 26.06.2023)

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