Most of us see the Christmas holiday season as an opportunity to slow down, take stock, and “just be.” Accordingly, we had planned a predictable article about recommitting to old-fashioned values and taking time off. However, these are not predictable times. We are just a few short sunrises from a new decade and we have had the Xmas stuffing knocked out of us by a three-punch combination: a must-hear podcast, a should-read book, and the announcement of a don’t-miss conference. These brought home compelling arguments that climate change and pollution matter far more than us front liners may wish to know. Moreover, this decade may be our last chance to avert a major disaster. Before you roll your weary eyes, let us be clear: we don’t like it any more than you.

More and more voices are pleading that we get greener and cleaner, and STAT! As Beth Gardiner outlines in her new book, air pollution is already associated with at least 7 million excess annual deaths (roughly one-in-ten of all world deaths). Whatever the exact toll, air pollution—principally nitrogen oxides and tiny particulate matters called PM2.5—are associated with more human deaths than smoking, AIDS, diabetes, and vehicle crashes combined. Both pollution and climate change will be especially cruel to the poorest in our communities, and are therefore social justice issues, not just inconvenient truths. 

Although 40% of Americans breathe polluted air daily, worldwide it is over 80%. Hundreds of millions already struggle with pollution’s myriad of consequences to their lungs, their hearts or their brains. Pollution is even linked to poor educational and behavioural outcomes. As CO2 builds, extreme weather is expected to increasingly injure, kill, and displace populations. Disease patterns will change, and so too will microbiomes that previously protected us. Increased patient numbers mean we will struggle to squeeze yet more from our overstretched healthcare system. Anyway, Merry Christmas one and all. 

In short, and without any delight, our New Year’s resolutions likely need to be bigger and bolder. Hugh Montgomery and colleagues have set up a new conference—CODA—and are unequivocal with their recommendations: change your energy source, get out of your vehicle, forego that trip, put down that steak, and measure and mitigate your carbon footprint. Gardiner is no less Cassandra: clean air acts matter to your patients as much as any machine or pill, and as much as smoking cessation. If we healthcare professionals truly care, rather than just tweeting, we need to speak up and take the side of our current and future patients. This starts by accepting that it is later than you think.

In contrast, we blithely spent the 2010s living large and thinking of carbon dioxide as a gas that pulmonary patients need our help to get rid of. It is now our cities and environment that cannot adequately exhale, but we have yet to make a PEEP (an ICU pun for those in the know). The 2020’s will be an anthropocene: an era where human actions and our population size matters most. We hominids may be saddled with prehistoric brains, and manipulated by medieval institutions, but we have the power of gods. Much like medicine, respectful debates about cause and effect are perfectly fine; inaction and outright denial are not.

If we support the scientific method, and the collective labours of our scientific brethren, then we must accept a clear and present danger to our most important patient and greatest life support: mother earth. Like you, we would rather ignore this, or worry about just one patient at a time. Moreover, when our medical day is done we quite like driving our single-occupant car, consuming a mighty feast, planning our next conference junket, and having as many kids as we please. Beyond the workplace, we don’t really want to contemplate yet more thorny issues. For example, medicine measures success by lives extended, even as the approximate world population balloons by an eye-watering 150,000 each day. Moreover, healthcare funding comes from companies that pollute. These are critical issues to resolve, but much like a gasping patient we can’t just put this off. Unlike that hypothetical patient, we also need to accept our share of the blame. 

The first global estimate of health care related emissions was completed in August 2019. It may not be on your holiday reading list, so we will offer some lowlights. Healthcare was associated with 2 gigatons of carbon dioxide in 2014. This is over 4% of all global greenhouse gas emissions, and as much as 10% of a developed nation’s total. If healthcare were a country we, collectively, would be the planet’s 5th largest emitter, and in-hospital healthcare would be our largest polluter. Few of us have thought about the carbon consequences of the care we offer. However, this complexity is exactly why we need to get informed and involved. Healthcare workers are used to moving in when conversations are needed that others run away from. We are not experts in population growth or urban planning, but we will face their consequences.

Climate science and pollution science is complex and nuanced, obviously. However, International Commissions were unequivocal when they concluded that climate change is the “greatest threat to human health” and stated that “climate change threatens to undo the last 50 years of global health gains.” As doctors, we know that quoting scary statistics is rarely enough. It doesn’t always help being told that global temperatures have already risen by 1 degree, glaciers have lost trillions of tonnes of ice, or that sea levels are rising by a cm every three years. Healthcare professionals are extremely good at speaking up when it suits our bottom line. We also need similar eloquence on behalf of our communities. This Christmas we will take comfort in the fact the we still have a voice. After a quick holiday rest, we will look to mobilize it. 

Peter Brindley, Professor of Critical Care Medicine, Medical Ethics, Anesthesiology at University of Alberta, Canada.
Twitter @docpgb
Competing interests: None declared

Matt Morgan, honorary senior research fellow at Cardiff University, consultant in intensive care medicine and research and development lead in critical care at University Hospital of Wales, and an editor of BMJ OnExamination.
Twitter @dr_mattmorgan
Competing interests: None declared