Anesthesia and Climate Change
Climate change has profound effects on humans, animals, plants and other living species on Earth. According to the United States National Aeronautics and Space Administration (NASA), levels of carbon dioxide in the air, which contributes to global warming, are now at their highest in 650,000 years.1,2 Meanwhile, the amount of arctic ice is decreasing and sea levels and temperatures are rising.1 The National Climate Assessment shows that extreme weather events in the United States, such as heat waves, droughts, heavy downpours, floods, hurricanes and winter storms, have been increasing in frequency and intensity over the last 50 years.3 Climate change is not only harmful to the planet, but also results in human and financial costs.3 Humans’ production and consumption of resources has contributed to climate change and air pollution.4 The field of anesthesiology in particular contributes to climate change, specifically through anesthetic gases that, after exhalation, are released into the environment.5 In order to help preserve our planet, anesthesia providers should be familiar with the basics of climate change, the harms of anesthetic gases and recent research on anesthesiology and the global environment.
Climate change is defined as a significant variation in average weather conditions over several decades or more, which distinguishes it from short-term natural weather variability.6 Global warming, one of the most well-known effects of climate change, is caused by emission of greenhouse gases including water vapor, carbon dioxide, methane, nitrous oxide, ozone and some artificial chemicals.6,7 Greenhouse gases normally keep the planet warm by absorbing and radiating some of the sun’s energy when it reaches Earth’s atmosphere.7 Modern human activities, such as burning fossil fuels (coal, oil and natural gas), agriculture and land clearing, have increased the amount of greenhouse gases in the atmosphere and therefore contribute to a gradual warming of the planet.7 Global warming, along with some other aspects of climate change such as extreme weather and ocean acidification,8 may cause extinctions in the majority of the world’s ecosystems.9 A recent policy paper by Spratt and Dunlop shows that global warming may even make the planet uninhabitable for humans by the year 2050.10 Clearly, global warming and climate change in general could lead to devastating effects for the environment, animals and human beings.
Anesthetic gases play a significant role in the greenhouse effect, and thus to global warming and climate change. Anesthetics are inhaled by the patient, undergo minimal metabolic change in the body, are exhaled into the operating room and are subsequently vented out of the building into the atmosphere.11 Anesthetic greenhouse gases include nitrous oxide (i.e., laughing gas) and volatile halogenated ethers such as desflurane, sevoflurane and isoflurane.12 Additionally, anesthesiology may contribute to global warming through the disposal of equipment and products used in the operating room.12 By not reusing or recycling materials, operating room clinicians increase the energy consumption needed to make new products.13 Through gas emission and high product consumption, the field of anesthesiology contributes to global warming and climate change.
Climate change research shows that anesthesia providers can make choices to lower their environmental impact. Anesthesia providers may choose not to use desflurane or nitrous oxide, which have been shown to have higher global warming potentials than isoflurane and sevoflurane.12 In fact, sevoflurane is considerably less expensive than the alternatives, which can be beneficial to the hospital.14 Propofol also serves as a better option, as its environmental footprint is four orders of magnitude lower than nitrous oxide.12 Other strategies to reduce anesthetic gas emissions include using scavenging systems and capturing exhaled anesthetics in canisters.11 Aside from managing anesthetic gases, anesthesiology professionals can practice healthy climate behaviors through reducing administration of intravenous drugs, as the necessary sterilization increases their carbon footprint above oral versions; reducing, reusing, recycling and disposing of waste correctly; and ordering stock in bulk to reduce transport emissions.15 For example, a study by Eckelman et al. found that reusable laryngeal mask airways (LMAs) had far fewer environmental impacts than disposable LMAs.16 Future research is needed to assess the ratio of infection risk to environmental benefits in reusable operating room products.16 Furthermore, operating rooms and hospitals can have designated “green teams” to standardize practices that have lower environmental impacts.11
Climate change poses a serious hazard to humans and our environment. Anesthesiology professionals can reduce their contribution to global warming through choosing different anesthetic drugs, opting for reusable or recyclable materials and assigning a team to monitor environmental protocols. In the future, anesthesia providers should be open to recycling efforts12 and investigate the use of alternative anesthetics, such as xenon.5 Contemporary anesthesiology professionals have a duty not only to their patients, but to their patients’ environment.17
1. Shaftel H, Jackson R, Callery S, Bailey D. Global Climate Change: Vital Signs of the Planet. January 15, 2020; https://climate.nasa.gov/.
2. Przyborski P, Levy R. Effects of Changing the Carbon Cycle. Earth Observatory June 16, 2011; https://earthobservatory.nasa.gov/features/CarbonCycle/page5.php.
3. GlobalChange.gov. National Climate Assessment: Extreme Weather. Washington, D.C.: U.S. Global Change Research Program; 2014.
4. Hagelberg N. Air pollution and climate change: two sides of the same coin. UN Environment Programme April 23, 2019; https://www.unenvironment.org/news-and-stories/story/air-pollution-and-climate-change-two-sides-same-coin.
5. Ishizawa Y. General anesthetic gases and the global environment. Anesthesia & Analgesia. 2011;112(1):213–217.
6. Denchak M. Global Climate Change: What You Need to Know. Natural Resources Defense Council February 23, 2017; https://www.nrdc.org/stories/global-climate-change-what-you-need-know.
7. Australian Government Department of the Environment and Energy. Greenhouse effect. Understanding climate change 2020; https://www.environment.gov.au/climate-change/climate-science-data/climate-science/greenhouse-effect.
8. Shaftel H, Jackson R, Callery S, Bailey D. Climate Change: How Do We Know? Facts January 15, 2020; https://climate.nasa.gov/evidence/.
9. World Wide Fund For Nature. A growing need for species to adapt to a changing world. Climate Change 2019; https://wwf.panda.org/our_work/wildlife/problems/climate_change/.
10. Spratt D, Dunlop I. Existential climate-related security risk: A scenario approach. Melbourne, Australia: National Centre for Climate Restoration; May 2019.
11. Gadani H, Vyas A. Anesthetic gases and global warming: Potentials, prevention and future of anesthesia. Anesthesia, Essays and Researches. 2011;5(1):5–10.
12. Ryan S, Sherman J. Sustainable anesthesia. Anesthesia & Analgesia. 2012;114(5):921–923.
13. King County Solid Waste Division. Climate change, recycling and waste prevention. Climate change and solid waste May 7, 2018; https://kingcounty.gov/depts/dnrp/solid-waste/programs/climate/climate-change-recycling.aspx.
14. Foden-Vencil K. Common anesthetic is a greenhouse gas, but doctors are turning to safer—and cheaper—alternative. CNN Health. Web: Cable News Network; May 31, 2019.
15. Charlesworth M, Swinton F. Anaesthetic gases, climate change, and sustainable practice. The Lancet Planetary Health. 2017;1(6):e216–e217.
16. Eckelman M, Mosher M, Gonzalez A, Sherman J. Comparative life cycle assessment of disposable and reusable laryngeal mask airways. Anesthesia & Analgesia. 2012;114(5):1067–1072.
17. Sherman JD, Ryan S. Ecological Responsibility in Anesthesia Practice. International Anesthesiology Clinics. 2010;48(3):139–151.