Doctors are frightened by climate change. Their industry is a big part of the problem.

Health care creates a tenth of US greenhouse gas emissions.

Wildfire deaths. Smoky air. Floods. Droughts. There’s no escaping the reality that global warming is rapidly exacerbating threats to human health and communities in the United States and around the world. As the top scientists have told us over and over, we need to immediately lower our greenhouse gas emissions to avoid climate change’s most catastrophic effects. Governments and businesses are particularly on the hook, but so are citizens — we are all in this together.

That includes you, doctors.

In a New England Journal of Medicine commentary published Wednesday, a pair of Boston doctors make the case that it’s high time medical professionals engage more directly in the fight to limit climate change. Lead author Caren Solomon, a physician at Brigham and Women’s Hospital, tells Vox she was compelled to write the piece as the urgency of the climate crisis has become clearer and clearer.

“We’re getting down to a point where people need to act immediately to try to prevent the most catastrophic consequences. Physicians have a special responsibility to do something,” she said. “And it’s only going to get tremendously worse unless we take action now.”

A separate review article on the health impact of climate change, also published in NEJM this week, spells out what’s at stake for human health. Between 2030 and 2050, a quarter of a million deaths could be caused by climate change-related health problems — such as heat exposure, mosquito-borne diseases, and flooding. Air pollution, including household air pollution, already cause 6.5 million premature deaths each year.

But that’s not all: It turns out that the business of saving lives is part of the problem. In the US alone, health care accounts for nearly a tenth of greenhouse gas emissions. Lifesaving equipment like CAT scanners, respirators, and dialysis machines have huge energy demands, currently met with fossil fuel energy. If US health care were a country, according to Solomon and her co-author Regina LaRocque, it would have a $3.3 trillion GDP and rank seventh in the world in total emissions. Hospitals also produce about a pound of hazardous medical waste per bed per day.

But now it’s clear the health sector has a huge opportunity to stop contributing so much to global warming and become a much bigger player in the clean energy transition. As LaRocque and Solomon point out, there are already plenty of great examples of what doctors, hospitals, and health care companies can do. Let’s walk through them.

Hospitals can commit to 100 percent clean energy, or carbon neutrality

Hospitals should follow the lead of places like Kaiser Permanente, Partners HealthCare, and Boston Medical Center — they’re all working on reducing their emissions and getting toward carbon neutrality, write Solomon and LaRocque.

Gundersen Health Systems, a nonprofit hospital network operating in the Midwest, has already achieved that feat. They started working toward carbon neutrality in 2008 — and by 2014, became the first US health system to achieve “energy independence,” producing more energy than they consume through wind and solar power, and methane from landfills.

Advocate Aurora Health, the 10th-largest not-for-profit health system in the US, is also working toward powering its health care facilities with 100 percent renewables by 2030. They’ll likely do this by using “a combination of on-site, off-site, and purchased renewable electricity,” according to Health Care Without Harm, an organization that’s working with Advocate Aurora and other health care institutions around the world to commit to transition to 100 percent renewable electricity.

Doctors can educate policymakers and the public about the health impact of climate change

Doctors hold a privileged position in society as trusted health authorities. “We can help motivate people to act by clarifying the links between environmental degradation and tangible problems, such as air pollution, insect-borne diseases, and heatstroke,” write Solomon and LaRocque. Doctors can also help the public understand the benefits of moving to greener energy sources.

And there are already a bunch of resources for doctors to both inform and carry out advocacy work. The American College of Physicians has a climate change toolkit, which offers suggestions for steering doctors toward reducing the emissions at their practices. Also consider advocacy groups like Healthcare Without Harm, the Medical Society Consortium, and Physicians for Social Responsibility, which offer guidance on legislative actions.

Heath care can divest from fossil fuel companies

Healthcare companies with large investment portfolios sometimes hold stock in polluting sectors — like petroleum products, coal, and natural gas. But several hospital systems, including San Francisco-based Dignity Health, and doctors groups like the Canadian Medical Association, are now joining the vibrant divestment movement — selling off their stock in these companies so that they can cut their financial dependence on them.

“[H]ealth care organizations, medical schools, and individual physicians … can align their financial power with their mission of protecting health by divesting their retirement portfolios and endowments from the fossil fuel industry,” Solomon and LaRocque write.

Physicians need to get ready for increasing environmental health threats linked to climate change

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As the climate changes, so too do the health risks. Warmer temperatures are making new areas hospitable to insects like ticks and mosquitos. Lyme disease is now showing up in Canada, and a locally acquired case of mosquito-borne chikungunya appeared in Texas for the first time in 2016.

Higher temperatures are also increasing the frequency and intensity of heat waves. Heat waves last year killed people around the world, including Canada, Japan, and the US.

Rising carbon dioxide levels in the atmosphere are increasing pollen production from plants like ragweed too, and allergy seasons in the United States get worse every year.

That means doctors, nurses, and public health officials all over the world will have to anticipate and handle new illnesses and evolving hazards on their turf. These health risks will only mount as average temperatures rise.

So while the medical profession plays catch-up with current risks, it will also have to adapt to a future under a changed climate. This will require mitigating medicine’s impact on the environment, but also bracing for the changes we can’t avoid.

“Insofar as our mission is safeguarding health and alleviating human suffering, we have a situation here that’s headed to devastating consequences,” Solomon told Vox. “We all know preventing something is a more effective approach than waiting for full-blown disease. That applies to this situation.”