Climate change has been termed the greatest threat to human health of the 21st century. Older people and those living with frailty are more vulnerable to the effects of climate change including heatwaves and extreme weather events, and therefore, we have a responsibility to advocate for action on the climate emergency and take steps to reduce the environmental impact of our care provision. The NHS contributes 5.7% to the carbon footprint of the UK, and by reviewing the financial costs associated with frailty, we estimate the carbon footprint of frailty to be 1.7 MtCO2e, or 7% of the total NHS carbon footprint. Resource use also increases with age with particular interventions and medical equipment such as hearing and mobility aids being predominantly associated with the care of older people. The NHS has committed to net zero carbon emissions by 2045 and in order to achieve this we all need to act-balancing the triple bottom line of environmental, social and financial impacts alongside outcomes for patients and populations when making decisions about care. The principles of sustainable healthcare are already embedded in the geriatrician's holisitic approach to the care of older people and those living with frailty, and the imperative to reduce the carbon footprint of healthcare should add weight to the argument for extending the role of the geriatrician into other specialties. It is time to begin our journey to net-zero geriatric medicine.