In the US, approximately 8% of carbon emissions come from the health care system.1 The 2021 United Nations Climate Change Conference called for countries to measure health care鈥搑elated carbon emissions and attain a net-zero emission state, in which carbon dioxide emissions are not greater than carbon dioxide reductions, by 2050.2 The US Department of Health and Human Services called for health care organizations to decrease carbon emissions by 50% by 2030.3 However, these calls to action are likely to have a relatively small effect on the overall contributions of health care to climate change unless physicians, other health professionals, and health care organizations change their current practices.