https://orcid.org/0009-0006-9144-9891
Citation: Bakhshi M, Chaudhari R, Alaga L, Balasubramaniam N, Belaiche A, Bouchet T, et al. (2025) Medicine in a warming world: The critical role of physicians. PLOS Clim 4(5): e0000630. https://doi.org/10.1371/journal.pclm.0000630
Editor: Jamie Males, PLOS Climate, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
Published: May 14, 2025
Copyright: © 2025 Bakhshi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
The escalating climate crisis presents an unprecedented threat to global health, necessitating immediate and decisive action from all sectors, particularly the medical community. Physicians, entrusted with safeguarding public health, are uniquely positioned to lead efforts in mitigating climate change and its detrimental health effects. Their roles encompass patient education, advocacy for sustainable practices, research, and systemic transformation within healthcare through policymaking.
Climate change and the gap in health disparities
Climate change exacerbates a myriad of health issues, including heat-related illnesses, respiratory disorders from deteriorating air quality, and the proliferation of vector-borne diseases [1]. A record-breaking wildfire season in Canada in 2023 led to a surge in asthma-associated emergency department visits, illustrating how environmental hazards directly translate into patient harm [2]. Marginalized and low-income communities are disproportionately affected, facing a greater burden of these threats due to limited resources and inequitable access to healthcare [3]. This includes the impacts of extreme heat, disasters that disrupt healthcare infrastructure, and climate-driven forced migrations.
Other than healthcare inequities being magnified by climate change, there is also a disparity about the responsibility for greenhouse gas (GHG) emissions at the national level. The richest 1% worldwide has more than double the emissions of the poorest 50%, yet the latter bears the greatest burden, a stark illustration of the power imbalances driving the climate crisis [4]. Physicians who witness these inequities have an ethical obligation to advocate for both upstream and community-based solutions that protect the vulnerable, be they in the Global South or underserved communities of Global North nations.
The carbon footprint of healthcare
Ironically, the healthcare sector itself plays a significant role in driving climate change. Estimates suggest that if global healthcare were a country, it would be among the top emitters of greenhouse gases, accounting for roughly 4–5% of emissions in many high-income nations [5]. In Canada, healthcare alone produces 4.6% of the country’s total GHG emissions, as well as more than 200 000 tons of other pollutants, resulting in 23 000 years of life lost every year from disability or early death, a figure that highlights the need for systemic reform [6]. This outsized environmental footprint arises from energy-intensive facilities, extensive single-use materials, and carbon-intensive supply chains. Physicians stand at the center of these systems and have a crucial role in influencing procurement and disposal policies, practice patterns, and staff awareness.
One example is the reliance on high-global-warming-potential anesthetic agents. Desflurane and nitrous oxide are potent greenhouse gases. Switching to lower-emission inhaled anesthetics or total intravenous anesthesia (TIVA) significantly decreases operating room emissions [7]. Similarly, in the case of inhalers for airway disease, pressurized metered-dose inhalers (pMDIs) rely on propellants that are substantially more harmful to the climate than those in dry powder inhalers (DPIs). Studies have shown that a single pMDI can have a carbon footprint equivalent to a long car journey, whereas substituting pMDIs with DPIs can reduce inhaler-related GHG emissions by up to 80% [8,9]. Given that a notable proportion of inhalers may be prescribed for patients without objectively confirmed asthma, improved diagnostics and prescribing can avoid unnecessary environmental impacts while maintaining quality care.
Physicians as educators and advocates
Physicians are uniquely trusted voices on health issues, making patient education a powerful tool for climate action. Simple measures such as advising at-risk individuals on preventing heat exhaustion, counseling those with asthma to monitor air quality indexes during wildfire seasons or guiding patients toward low-carbon lifestyle modifications can strengthen community resilience. Encouraging active transportation, plant-rich diets, and nature immersion not only reduces carbon footprints but also confers direct health benefits, from improved cardiovascular fitness to better mental well-being [10].
Beyond individual encounters, medical professionals can shape public perception by framing climate change as an urgent health issue through media appearances, op-eds, and forums with policymakers. Professional bodies like the Canadian Association of Physicians for the Environment, the UK Health Alliance on Climate Change, and similar organizations worldwide demonstrate how physicians can amplify climate advocacy. Notably, leveraging clinical data such as spikes in respiratory admissions during extreme weather can powerfully illustrate the immediate human toll of climate change and highlight why policy responses should not be delayed.
Implementing sustainable practices in clinical settings
Improving sustainability in everyday clinical practice is another vital step. Resource stewardship campaigns, such as Choosing Wisely, encourage physicians to question the necessity of certain tests, procedures, or prescriptions, thereby reducing waste. Deprescribing unnecessary medications curtails both costs and emissions associated with manufacturing and disposal. Studies suggest that switching from intravenous to oral antibiotics when clinically appropriate can shorten hospital stays and reduce the carbon footprint associated with intravenous lines, fluid bags, and extended facility usage [11]. Similarly, technology can be a powerful tool in reducing carbon footprint. For example, telemedicine (digital appointments and digital reports) lowers transportation-related emissions while increasing patient convenience, particularly for follow-up visits where physical examination is not essential [12]. Furthermore, artificial intelligence (AI) and its increasing uses present a potential for reduction of carbon footprints. A real-world study of clinical encounters using autonomous AI compared to medical specialists showed a reduction in healthcare greenhouse gas emissions of up to 80% [13].
Hospitals themselves can become hubs for greener innovation. Replacing single-use plastics with safer reusables, improving waste segregation, establishing robust recycling programs, and harnessing renewable energy can drastically decrease facility-wide emissions [14]. Some systems have even explored “Green Hospital Certification”, akin to the Leadership in Energy and Environmental Design (LEED) designation for buildings, as a transparent metric for measuring institutional progress on sustainability. Such initiatives require buy-in from stakeholders across all levels but often yield cost savings over time.
Leadership in policy and systemic change
Individual and institutional efforts, while important, cannot substitute for more comprehensive policy change. Physicians hold key credibility in influencing legislation that addresses the root causes of climate change. Whether calling for stricter emissions regulations, pushing for fossil fuel divestment, or endorsing large-scale renewable energy transitions, the medical community’s voice carries weight due to its perceived impartiality and scientific grounding. Demonstrable patient-level impacts such as rising emergency visits during wildfires turn abstract climate metrics into real human narratives that motivate legislative bodies.
Moreover, advocating for social policies that reduce emissions can yield substantial associated health benefits. For instance, expanding accessible public transportation can both reduce pollution and decrease traffic-related accidents. Boosting green spaces in urban areas not only lowers local temperatures but fosters social cohesion, mental health, and physical activity. Collective physician engagement through testimony at legislative hearings, local council meetings, and national climate summits can spotlight the interplay between climate and health, compelling decision-makers to adopt more equitable environmental policies.
Rethinking medical education for a changing world
Equipping future physicians with the knowledge and skills to address climate-related health challenges is equally important. Although curricula increasingly integrate subjects like social determinants of health, there is inconsistency regarding comprehensive training on planetary health. Initiatives such as the University of Toronto’s Climate, Health & Sustainable Care Student Training Program and the European Network on Climate & Health Education (ENCHE) provide templates for integrating climate realities into medical education [15]. These programs illuminate the ways climate change reshapes disease distributions and highlight strategies to safeguard health in a warming world.
By reinforcing climate literacy in every specialty, from anesthesiology’s role in reducing greenhouse gases to infectious disease’s need to track emerging pathogens, students become adept at recognizing and responding to the health dimensions of climate change. Training in advocacy and interprofessional collaboration further empowers young physicians to spearhead environment-focused research and policy discussions.
Conclusion
The climate crisis stands as a defining challenge for this century, and the medical profession has both an ethical imperative and a practical capacity to lead. As the impacts of climate change increase, from unprecedented wildfires to rising infectious diseases, physicians’ voices and actions have never been more critical. The time to mobilize for a healthier planet is now, and the medical community cannot sit on the sidelines.
Acknowledgments
All the authors are medical students at McGill University in Tiohtià:ke (Montreal), Canada. They wish to thank Professor Madhukar Pai, MD, PHD, FCAHS and Dr. Owen Luo, MDCM for their generous support and teachings.
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