Five years of Greener NHS: improved carbon footprint assessment of the National Health Service in England

Background

Delivery of health care is a substantial contributor of greenhouse gas emissions. The National Health Service (NHS) in England has been assessing emissions associated with its activities since 2008, and in 2020 was the first health care system worldwide to set net-zero emissions targets. This Article presents updated methodology used to calculate consistent estimates of NHS emissions between 2019–20 and 2024–25.

Methods

A hybrid approach was used to estimate emissions associated with health-care activity funded by the NHS in England. NHS-specific activity and spend data were used when available. Resulting emission estimates were presented and compared with the previous estimate for 2019–20. The volume and emissions intensity data quality were also assessed and compared with the previous methodology. Insights from the emissions estimates, sources of remaining uncertainties, and the direction of future development are discussed.

Findings

Total NHS emissions increased during the COVID-19 pandemic but have since returned to pre-pandemic levels and are estimated to be 27·3 megatonnes of carbon dioxide equivalent (MtCO2e) in 2024–25. Emissions under NHS direct control have decreased by 14% (0·8 MtCO2e) since 2019–20. Data quality scores have improved by nearly 30% compared with those of the previously used methodology.

Interpretation

This Article represents the most sophisticated and granular footprinting of health care to date, adding to international evidence and supporting global efforts to decarbonise health care. Within England, improved estimates will support actionable insights at the national and local level, as well as improved monitoring of progress towards the NHS net-zero targets.