At the 79th World Health Assembly in Geneva, a new platform launched with a stark fact: if health care were a country, it would rank as the world's fifth-largest carbon emitter, producing more CO2 emissions than all of aviation and shipping combined. Yet until now, doctors, hospital administrators, and health policymakers have had access to carbon data for less than 1% of the products they use every single day.
The Lancet MedZero changes that. Convened by The Lancet and developed by an international academic consortium of clinicians, the platform offers the first comprehensive carbon analytics across the full spectrum of health care—from pharmaceuticals and surgical instruments to diagnostic imaging and laboratory tests. At launch, it contains over 14,000 entries, each one designed to help clinicians and health system leaders make decisions that simultaneously save money, reduce waste, and fight climate change.
The platform's power lies in its specificity. A health policymaker in the UK could use MedZero to discover that switching from polluting incineration to recycling would eliminate over 311,000 metric tons of CO2 equivalent annually—the same as removing 212,000 British cars from the road—while saving 76 million pounds each year. A hospital CEO in Singapore can see that transitioning to reusable surgical gowns would cut emissions by 4,407 metric tons and save around 700,000 Singapore dollars annually. National procurement experts worldwide can compare logistics options and identify savings of over 3.85 million metric tons of CO2 equivalent by shifting to lower-carbon freight methods for pharmaceuticals, equivalent to nearly twice Malta's entire national emissions.
The launch brought together leaders from across global health: Dr. Richard Horton, Editor-in-Chief of The Lancet; the Minister of Health of the Philippines; the International Medical Secretary for Doctors Without Borders; the UK NHS's Chief Sustainability Officer; and the Permanent Secretary of the Thailand Ministry of Public Health. Their unified presence reflected the urgency of the moment. More than 100 countries, covering over half the world's population, have already committed to tackling climate change through a WHO-led Alliance for Transformative Action on Climate and Health. But commitments require action, and action requires data.
"Measurement is the foundation of accountability, and accountability is the motivation for action," Dr. Horton said. Until MedZero's launch, that data was fragmented and nearly impossible to access. A surgeon redesigning a care pathway, a pharmacist restocking supplies, a procurement specialist renegotiating contracts, or a health minister setting national strategy—all faced the same barrier: they couldn't reliably compare the carbon footprint of the products they needed to use.
MedZero was designed by clinicians, for clinicians, to dissolve that barrier. By providing trustworthy, product-level carbon information accessible in real time, it transforms climate action from an abstract commitment into concrete, evidence-based decisions. It measures what matters most: the ways health systems can heal the planet while healing people.