(Bloomberg) — The global health-care sector is in the front line of treating those affected by climate change, but its own contribution to the problem must be more thoroughly addressed, according to the first major study on the industry’s carbon footprint.

Greenhouse gas releases from health care account for 4.4% of the global total, equivalent to the annual emissions of 514 coal-fired power stations. The industry would be the world’s fifth-biggest polluter if it were a country, the not-for-profit group Health Care Without Harm said in a report.

Not So Healthy

“Health care’s emissions footprint has been largely ignored by those addressing climate change over the past quarter century,” the authors said, calling for the industry to target net zero emissions by 2050. “The health sector itself has paid scant attention until recently.”

About 71% of emissions are from indirect sources within its supply chain, classified as Scope 3. This includes the production, transportation, use and disposal of goods and services such as pharmaceuticals and medical devices. Direct Scope 1 emissions account for 17%.

More than half of the sector’s emissions are related to energy use. Reductions can be made by switching to renewable power wherever possible or by using cleaner modes of transport, according to the report. It urges governments to establish action plans that align with the Paris Agreement climate targets to facilitate the decarbonization of their health systems.

“Ultimately the health sector goals of health promotion, disease prevention, universal health coverage and the global climate goal of net zero emissions must become intertwined,” the authors said.