This summer has offered a compelling case study on why there’s a pressing need for the emerging field of climate medicine and what the medical system must prepare for in the years ahead as extreme heat waves, powerful storms, and out-of-control wildfires become the norm. While commonplace in the West, wildfire smoke has once again drifted in from Canada to reach the East Coast. Catastrophic flooding has devastated communities in Texas. And in Europe, a June heat wave is now estimated to have caused more than 5,700 excess deaths in France alone, the large majority in people over age 75. These are not three unrelated news stories. They are the same underlying phenomenon (a warming, crowded, highly connected planet reshaping human disease) showing up in three different clinical forms within a matter of weeks.
I call climate medicine an urgent generational health challenge, and I believe it deserves the same institutional seriousness we once gave the emergence of HIV/AIDS when I was a medical student in the 1980s. The evidence is no longer speculative; it shows up in emergency departments, in hospitalization data, and increasingly in our own patients. Physicians and health care leaders need to be thinking about planning for natural disasters and newly emerging infectious diseases caused by climate shifts. We need to act to save patient lives.
Turning wildfire smoke into actionable data
In 2023, smoke from Canadian wildfires traveled more than 2,100 kilometers to reach Baltimore, a preview of what we’re seeing again this summer as smoke drifts east. In a study published in JAMA Network Open, our University of Maryland Institute for Health Computing (UM-IHC) linked satellite smoke-plume tracking with electronic health records from 2.5 million patients across Maryland and found a roughly 20 percent increase in cardiopulmonary hospitalizations tied to that exposure. That kind of real-time linkage between environmental sensors and clinical data is exactly the capability we’re building out further: the ability to see a health effect developing in a population that resides hundreds or even thousands of miles from the source, and to prepare for it in order to prevent illness and death.
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Treating heat as a cardiovascular and public health emergency
The numbers coming out of Europe this June are sobering, and they track a pattern we already understand clinically: Extreme heat drives measurable increases in emergency department visits and mortality, concentrated overwhelmingly in older adults, along with young children, pregnant women, and people with existing cardiovascular or respiratory disease. Part of our work is making sure that pattern is recognized early: by clinicians, by hospital systems planning for surge capacity, and by public health officials deciding when and how to issue heat warnings.
Understanding what flooding does beyond the water itself
The damage from flooding events like the one in Texas isn’t limited to drowning and physical injury. Floodwater overwhelms sewage and water treatment systems, contaminates food and water supplies, and creates conditions for pathogens such as Cryptosporidium, Vibrio vulnificus, and Leptospira, the last of which recently forced us to shut down a hospital water supply on our own Baltimore campus. It also displaces people, disrupts health care delivery, and drives significant downstream mental health impact. Our researchers are working to map these secondary and tertiary health effects so that emergency response accounts for them, not just the immediate flood damage.
Staying ahead of zoonotic and vector-borne threats
My career has spanned roughly eighteen significant zoonotic disease events: HIV, SARS, H1N1, Ebola, mpox, and now recurring strains of highly pathogenic avian influenza (H5N1) moving from poultry into dairy cattle. Our faculty’s work in vaccinology and emerging pandemics, including one of the largest COVID-19 clinical trial enrollments in the country through our vaccine translational unit, is the same infrastructure we need ready for the next one. We’re also expanding surveillance and research on tick- and mosquito-borne disease as warming lengthens transmission seasons and shifts their geographic range northward.
Investing in mRNA vaccine platforms
The technology that earned Katalin Karikó and Drew Weissman the 2023 Nobel Prize in Medicine allows researchers to sequence a novel pathogen, synthesize a vaccine candidate, and begin production within roughly a month of an outbreak. Sustaining that capability, and the federal research infrastructure behind it, is one of the highest-leverage investments we can make against future pandemic threat, avian influenza included.
Studying microplastics before the evidence is decades old
Two recent studies (one in the New England Journal of Medicine linking microplastic deposits in arterial plaque to cardiovascular events, another in Nature Medicine documenting rising plastic concentrations in human brain tissue) echo, in their early stages, the pattern of the twentieth century’s leaded-gasoline crisis: widespread exposure, a vulnerable population, and causation still being established. Through our Institute of Marine and Environmental Technology, we’re beginning to study microplastic accumulation in the food chain. We don’t yet know whether plastics will prove as consequential as lead did. We should find out before, not after, the fact.
Global health as climate health
Through the decades, University of Maryland faculty have helped screen and treat more than a million people for HIV across Africa, a reminder that disease containment abroad protects health here. That same global orientation now applies to climate-linked disease: What happens with avian influenza in Southeast Asia or dengue‘s northward spread affects Maryland directly.
Academic medical centers sit at the intersection of science, clinical care, and community impact of a changing climate. We also train the majority of the country’s health professionals, so building climate medicine into that training (teaching the next generation of physicians to recognize a heat-driven cardiac event, a wildfire-smoke asthma exacerbation, or a case of leptospirosis for what it is) is as much a part of this work as the research itself. That’s the work already underway at our institution, and it’s only becoming more urgent as summers like this one make clear.
Mark T. Gladwin is a physician-scientist.
