Emergency medicine (EM) is on the frontlines of climate change, which the Lancet Commission declared “the biggest global health threat of the 21st century” with “potentially catastrophic risk to human health.”1,2 Climate change is having broad and profound negative impacts on the health of our patients, especially for the vulnerable populations. It is also affecting our healthcare systems and mandating the creation of climate-resilient emergency departments (ED) with robust disaster preparedness. EM needs to engage climate change advocacy efforts for 2 key reasons. It has a profound impact on our specialty, and it is built into the moral fiber of our practice. As this threat continues to grow, EM is perfectly situated to lead the charge.

climate change on human health CDC graphic

Impacts of Climate Change on the Practice of Emergency Medicine

There is consensus among scientists that climate change is happening.3 We know that the driving factor is increased greenhouse gases, such as carbon dioxide (CO2), which has led to increasing global temperatures, rising sea levels, and more frequent and severe extreme weather.4 The downstream health effects, as demonstrated in the Center for Disease Control diagram below, bring patients to already crowded EDs.5–10


  • An elderly heat stroke patient during one of the increasingly frequent heat waves.
  • A pediatric patient with an asthma exacerbation secondary to the increased allergen production from higher CO2 levels.
  • A middle-aged woman with Lyme disease, a climate-sensitive vector borne illness, in a location where it previously hasn’t been endemic as climate change alters vector ecology.

While the specialty of EM prides itself on resilience, the current practice structures and infrastructure can only bend so far, for so long, until it breaks.

Disasters: A Matter of WHEN and not IF

EM is the expert in disaster management. In 2017, the United States had a record-tying year of 16 billion-dollar weather and climate disasters.11 Wildfires in Northern California caused Kaiser Permanente’s Santa Rosa hospital to evacuate nearly 130 patients in under 3 hours.12 The incidence and frequency of wildfires is increasing secondary to higher temperatures, extremes in precipitations (e.g. droughts), and changes in insect outbreaks.6

Emergency medical staff at St. Joseph Medical Center in Houston literally worked a full-week, some without going home, after Hurricane Harvey devastated their community and brought droves of patients to the ED. Extreme precipitation and flooding events are increasing with climate change.6

Each geographic region has respective extreme weather vulnerabilities. In fact, every state has had a billion-dollar weather and climate disaster.11 Thus it is not a question of if – but when. This mandates that EM create climate-resilient infrastructures and supply chains for emergency preparedness.12

Action on Climate Change is Embedded in EM’s Moral Fiber

While more work needs to be done to quantify the health outcomes and impacts on healthcare utilization and costs, the evidence to act is clear. The precautionary principle mandates this. We pride ourselves on our ability to make decisions with inherent uncertainty, and the uncertainty surrounding the impacts of climate change is far less than many of our daily practice decisions.

Caring for our Vulnerable Populations

The ED proudly sits at the hospital front door as the healthcare system safety net. It is the vulnerable populations that are most affected by climate change and these patients are already a clear focus of our practice.6 These vulnerable populations are the “canaries in the coal mine,” as the impacts are increasingly touching us all. The Hippocratic oath mandates that we must inform our patients about everything that threatens their health.

Being Proactive Rather Than Reactive: Anticipating Threats

All of those working within an ED pride themselves on being able to anticipate a patient’s “crash” by detecting the slightest alterations in physical exam or physiology. These signs are clearly present for climate change and mandate that we anticipate the coming threats through clinical adaptation and climate-resilient infrastructure.

Taking Charge and Leading

As natural communicators and collaborators, EM providers must take a leading role in mobilizing the healthcare community as climate change is reframed as the public health threat that it is. The existing gaps will only be filled through teamwork, something we exhibit daily in our trauma bays. We are the specialty that creates calm within the chaos.


Our specialty was bred out of necessity, and this necessity to address climate change falls on us. We have never shied away from a challenge, and we must rise to meet this one – perhaps our greatest yet.

To learn more about engaging with the mobilization of emergency medicine around climate change, join the Society of Academic Emergency Medicine Climate Change and Health Interest Group and attend SAEM18 events including the advanced pre-meeting workshop and didactic.


Costello A, Abbas M, Allen A, et al. Managing the health effects of climate change: Lancet and University College London Institute for Global Health Commission. Lancet. 2009;373(9676):1693-1733. [PubMed]
Cook J, Nuccitelli D, Green SA, et al. Quantifying the consensus on anthropogenic global warming in the scientific literature. E. 2013;8(2):024024. doi:10.1088/1748-9326/8/2/024024
Watts N, Adger W, Ayeb-Karlsson S, et al. The Lancet Countdown: tracking progress on health and climate change. Lancet. 2017;389(10074):1151-1164. [PubMed]
Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press; 2014:151pp. http://www.ipcc.ch/report/ar5/syr/. Accessed May 12, 2018.
Climate Change and Public Health – Climate Effects on Health. Center for Disease Control and Prevention. http://www.cdc.gov/climateandhealth/effects/default.htm. Published 2016. Accessed May 12, 2018.
Crimmins A, Balbus J, Gamble C. The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment. Washington DC; 2016:332pp. https://health2016.globalchange.gov/downloads. Accessed May 12, 2018.
Chen T, Sarnat S, Grundstein A, Winquist A, Chang H. Time-series Analysis of Heat Waves and Emergency Department Visits in Atlanta, 1993 to 2012. Environ Health Perspect. 2017;125(5):057009. [PubMed]
Rosenheim N, Grabich S, Horney J. Disaster impacts on cost and utilization of Medicare. BMC Health Serv Res. 2018;18(1):89. [PubMed]
Dohrenwend P, Le M, Bush J, Thomas C. The impact on emergency department visits for respiratory illness during the southern california wildfires. West J Emerg Med. 2013;14(2):79-84. [PubMed]
Gotanda H, Fogel J, Husk G, et al. Hurricane Sandy: Impact on Emergency Department and Hospital Utilization by Older Adults in Lower Manhattan, New York (USA). Prehosp Disaster Med. 2015;30(5):496-502. [PubMed]
Smith A. Billion-Dollar Weather and Climate Disasters: Overview. National Centers for Environmental Information. https://www.ncdc.noaa.gov/billions/. Published 2018. Accessed May 12, 2018.
Safe Haven in the Storm. Health Care Without Harm. https://noharm-uscanada.org/sites/default/files/documents-files/5146/Safe%20Haven.pdf. Published 2017. Accessed May 12, 2018.
Renee Salas, MD MPH MS

Renee Salas, MD MPH MS

Clinical Instructor
Department of EM, Division of Wilderness Medicine
Harvard Medical School / Massachusetts General Hospital
Affiliated Faculty, Harvard Global Health Institute
Chair, SAEM Climate Change and Health Interest Group
Renee Salas, MD MPH MS


Climate Crisis, Health, Care Delivery, & Equity @HarvardGH @HarvardCCHANGE | Emergency Doctor @MassGeneralNews @HarvardMed | U.S. Brief Lead @LancetCountdown
Renee Salas, MD MPH MS

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