Hospitals, for all their life-saving capabilities, have long taken an outsized toll on the climate, with their monitors, machines, and round-the-clock lighting consuming nearly three times as much energy as the average commercial building.
Now, health care organizations here and across the country are working to decrease their environmental footprint. Hundreds, including most major hospital systems in Boston and more than half of hospitals statewide, have signed a Biden administration pledge to halve their emissions by 2030 and reach net-zero by 2050.
Health care, including hospital buildings, pharmaceutical supply chains, and other aspects of the sector, is responsible for 8.5 percent of US carbon pollution.
Health care leaders say their sector increasingly understands joining the fight against global warming to be part of their mission. Climate change has been linked to myriad public health concerns, from increased risk of respiratory infections to anxiety, with disproportionate costs borne by low-income people.
“Climate change is the biggest public health threat we’ve ever faced,” said Gaurab Basu, a physician and co-director of the Center for Health Equity Education & Advocacy at Cambridge Health Alliance.
Some Massachusetts institutions that have signed the federal Health Sector Climate Pledge — including Boston Medical Center, Mass General Brigham, Boston Children’s Hospital, Baystate Health, Tufts Medicine, Southcoast Health, and Beth Israel Deaconess Medical Center — have already made significant progress on their own.
Massachusetts General Hospital already purchases 100 percent of its electricity from local renewable sources, said Jonathan Slutzman, the hospital’s director of the Center for the Environment and Health.
For heat, it uses steam from Kendall Square’s cogeneration electric plants, which create electricity and heat at the same time. The steam heat is a waste product from electricity generation that was previously vented into the atmosphere or dumped into the Charles River.
“We need to be envisioning systems that not only use less fossil fuels, but actually are entirely fossil fuel free,” said Ben Hellerstein, state director at the advocacy group Environment Massachusetts.
For now, the hospital says using the heat byproduct of the gas-powered electric plant is more efficient than letting it go to waste.
Between 2008 and 2021, MGH also reduced its energy usage by 40 percent by taking steps such as installing automatic temperature sensors and retrofitting lightbulbs, Slutzman said.
Boston Medical Center has cut its carbon emissions from energy by 96 percent since 2011 and reduced its overall energy use by almost 20 percent since 2001, said Kate Walsh, president and CEO of the hospital.
Since 2016, the hospital has purchased electricity credits from a solar project in North Carolina. And in 2017, it began generating some electricity and heat through its own cogeneration power plant, which improves efficiency by trapping and reusing heat.
Like the Kendall Square plant, that facility also runs on gas — something the institution expects could change in five to 10 years when renewable cogeneration technology becomes more “cost-effective and scalable.”
Officials also implemented a major campus redesign and took smaller actions like switching to more efficient lighting, Walsh said.
“You have to look at everything,” she said.
A more elusive climate problem for hospitals: emissions from anesthesia. Many common anesthetic gases — like nitrous oxide, desflurane, sevoflurane, and isoflurane — are planet-warming greenhouse pollutants themselves. Unless they’re filtered or trapped, they’re emitted into the atmosphere when patients breathe them out, and they can also leak.
Boston Medical Center has reduced this impact, for example, by curbing the use of one particularly planet-heating gas, desflurane, which has more than 3,500 times the global warming potential of carbon dioxide.
MGH, meanwhile, plans to cut its use of such gases in a “clinically appropriate and safe” way by ensuring the flow to patients is not unnecessarily high, said Slutzman. It is also working with its engineers and plumbers to eliminate leaks of nitrous oxide — which is 300 times more warming than carbon dioxide — potentially by switching to a more leak-proof distribution system.
For all their progress, local hospitals could do more on the climate front. In a 2021 report for the Boston Green Ribbon Commission, the nonprofit Health Care Without Harm found that hospitals citywide slashed emissions by 18 percent between 2011 and 2019, missing their 2020 goal of a 25 percent cut.
Winston Vaughan, Massachusetts director of climate solutions at Health Care Without Harm, who authored the report, said signing the pledge is a positive step from local hospitals.
“These systems can support each other, sharing best practices, working together to solve common challenges,” he said.
Hellerstein said he finds local institutions’ leadership “encouraging,” especially because they’re such a major part of Massachusetts’ economy. But he hopes to see the facilities not just reach net-zero but switch away from fossil fuels altogether, “sooner than 2050,” he said.
Basu said that he’s “extremely impressed” with all the work local hospitals have done. An important but daunting next step, he said, will be to decarbonize their supply chains.
These networks, by which hospitals obtain, transport, and dispose of “everything from pharmaceuticals to chemicals to food and medical devices” are much harder to decarbonize because they’re not under the institutions’ direct control, said Basu. But according to one 2020 study, they’re responsible for a whopping 71 percent of the global health care sector’s climate imprint.
Walsh said tackling supply chain issues will be the most challenging aspect of her institution’s decarbonization plan moving forward.
“That’s the next frontier,” she said.
All those who signed the new federal pledge have agreed to create an inventory of supply chain emissions.
But Slutzman stressed that hospitals can’t tackle those emissions alone.
Hospitals don’t generally directly purchase their own supplies, instead typically using distributors known as group purchasing organizations. Representatives from two major distributors, Vizient and Amerisource Bergen, attended a White House event last month about the new federal pledge.
By signaling support for more sustainable supply chains, Slutzman said he hopes hospitals can push distributors in the right direction, especially with the government’s backing.
Not all of Massachusetts’ medical institutions have signed onto the pledge.
Ellen Berlin, senior director of media relations at Dana Farber Cancer Institute, which has not made the pledge, noted that institutions have until October to sign on. “We are carefully reviewing it,” she wrote in an e-mail.
More medical providers are seeing the health ramifications of climate change firsthand.
In recent years, said Slutzman, he’s seen more instances of heat illness, which was once rare in New England. He also described patients with cancer arriving at the MGH emergency room after being forced to flee faraway parts of the country due to extreme weather.
“They’re showing up at our emergency department saying, I need my chemotherapy, which, I hate to break it to you, is not something I’m at all remotely qualified to start in the emergency department,” he said. “As physicians, we take very seriously our mission that if we see disease happening, our job is to reduce it.”