Anthropogenic climate change is evident, and its impacts are being felt around the globe. The World Health Organization (WHO) recently revealed that approximately one in four deaths can be attributed to preventable environmental causes. Reducing greenhouse gas (GHG) emissions across all sectors is critical to contain climate change. The Healthcare Sector is a significant contributor with approximately 4.6% of the global GHG emissions in 2017. Thus, there is an urge to reduce global greenhouse gas emissions in the Healthcare Sector. Anaesthesiologists took early action to reduce global GHG emissions within their profession. National and International Societies of Anaesthesiologists such as the World Federation of Anaesthesiologists, the European Society of Anaesthesiology and Intensive Care and the German Society of Anaesthesiology and Intensive Care provided recommendations on ecological sustainability.

In addition to total intravenous anaesthesia, volatile anaesthetics (VAs) remain fundamental for delivering effective and reliable anaesthetic care. In Europe, sevoflurane, isoflurane and desflurane are currently the most commonly used VAs. Sevoflurane and desflurane are classified as fluorinated hydrocarbons, and isoflurane as fluorochlorinated hydrocarbon.

Agreements and protocols established under the United Nations Framework Convention on Climate Change (UNFCCC) cover a range of greenhouse gases, not just carbon dioxide. Countries set targets for reducing emissions across a ‘basket’ of gases, including carbon dioxide (CO₂), methane (CH₄) and various fluorinated gases. To make these different gases comparable, a common metric is used — essentially an exchange rate — that converts emissions of non-CO₂ gases into ‘CO₂-equivalent’ amounts. This allows total emissions to be reported on a consistent scale. In the 1990s, the Kyoto Protocol adopted the use of ‘global warming potential’ (GWP), using a 100-year time frame (GWP-100) to calculate the CO₂ equivalence of anthropogenic GHG emissions under the UNFCCC (http://unfccc.int/kyoto-protocol; accessed on 8 September 2025).

The 2016 UNFCCC Paris Agreement is less prescriptive in its specification of which metric should be used, but nevertheless GWP-100 remains very widely used. As a result, recommendations from anaesthesiology specialty societies regarding ecological sustainability have often relied on the differences in the GWP-100 values of VAs.