Doctors Step Up Against the Climate Health Emergency

Canadian emergency medicine resident Julia Sawatzky had an eye-opening experience early in her medical training that reshaped her understanding of the climate crisis’s health impact. During a shift in the emergency room amid Canada’s wildfire season, she found herself surrounded by patients with symptoms linked to extreme heat and smoke exposure. Some patients collapsed from heat exhaustion, while others struggled to breathe due to respiratory distress. “Everyone was suffering from the heat or the smoke,” Sawatzky recalled.

Outside the hospital, the heat was intense, and whenever the automatic door opened, smoke billowed in. “That pollution was literally entering the hospital,” she said. The scene underscored the reality that the environmental crisis wasn’t just a topic for news reports or weather updates — it was infiltrating healthcare systems. “We’re immersed in it. There’s no separation between the hospital and what’s happening outside,” she explained.

This situation also highlighted the vulnerability of healthcare systems in the face of extreme weather events. As a member of the Canadian Association of Physicians for the Environment, Sawatzky connects environmental awareness directly to her ability to care for patients. “We did all this training to help people, and the thought that this could be at risk is terrifying.”

The climate crisis, experts warn, is not only a climate challenge but also a health crisis. Rising temperatures, deteriorating air quality, and increasing extreme weather events are shifting disease patterns, pressuring hospitals, and exacerbating health inequities. The effects go beyond emergency medicine, affecting the entire healthcare system, from primary care to mental health.

Global Health Threat

According to the World Health Organization (WHO), climate change ranks among the greatest global health threats of the 21st century. The WHO links the crisis to rising deaths from extreme heat and respiratory or cardiovascular diseases caused by air pollution. Around 99% of the world’s population is exposed to air with pollutant levels exceeding recommended standards, with fossil fuel combustion being the primary cause. Climate change also fosters the spread of infectious diseases, heightens food insecurity, worsens mental health, and increases the vulnerability of populations to floods, droughts, and landslides.

Reports from organizations such as the Planetary Health Alliance emphasize the impact of climate change on health, including increased exposure to extreme heat, rising natural disasters, and ecosystem degradation. These factors affect everything from food production to mental well-being, highlighting the importance of health as a universal language for communicating risks and driving action.

A United Nations (UN) report released in June 2024 estimated that more than 100,000 people died from heat-related causes in Europe between 2022 and 2023. It underscores that climate change, poor air quality, and ecosystem degradation are increasing pressures on healthcare systems, especially in regions with social inequality and inadequate infrastructure.

These effects are becoming evident in clinical practice. For many healthcare professionals, environmental factors are no longer distant concerns but an integral part of daily medical care.

Challenges in Latin America

In Latin America, the environmental crisis directly affects healthcare, with cities like Cuiabá in Brazil, facing extreme heat. Natasha Slhessarenko, a pediatrician in Brazil, reports seeing children with dehydration, asthma, and bronchiolitis due to the intense heat. Climate-related diseases, such as dengue and other arboviral infections, also surge during the rainy season. The Lancet Countdown’s recent report highlighted that heatwave exposure among children younger than 1 year increased by 250% between 2014 and 2023 in Brazil.

Recognizing the urgent need for action, Evangelina Vormittag, a clinical pathologist and founder of the Instituto Ar in Brazil, has spearheaded efforts to connect healthcare with climate action. Her initiatives led to the creation of Brazil’s first National Air Quality Law and campaigns like the “Clean Bus Law” in São Paulo. She advocates for climate-friendly policies in healthcare and is focused on the impact of climate change on workers’ health. Inspired by the British campaign Doctors Against Diesel, initiated by pediatrician Jonathan Grigg, she created the Doctors for the Climate project, which mobilizes healthcare professionals in different regions of the country and has a network of physician ambassadors.

Renato Kfouri, a pediatrician in Brazil, emphasizes that climate change also disproportionately affects older individuals. He pointed to increased cases of respiratory illnesses during extreme weather events in Brazil, warning that doctors across all specialties need to be aware of the climate-health nexus.

A Global Web for Health

Doctors worldwide are working independently yet complementarily to raise awareness and address the effects of the climate crisis on human health. Though there is no formal coordination between these professionals, their collective efforts are forming an organic global movement united by the urgency of mitigating the impacts of global warming.

In Europe, the Doctors Against Diesel campaign has led to the creation of the Ultra Low Emission Zone in London, reducing diesel vehicle emissions to improve public health.

In the US, particularly in Reno — the fastest-warming city in the country — pediatrician Debra Hendrickson is at the forefront of addressing the climate crisis’ impact on child health. “We see children coming into the clinic with wheezing, coughing, and some requiring hospitalization for oxygen,” she said. Hendrickson, trained in environmental science, realized the importance of translating global environmental crises into actions that could reduce their impact on children’s health. The case of a 10-month-old baby with a respiratory crisis during an episode of intense wildfires motivated her to write the book The Air They Breathe, exploring the connection between air pollution and child health.

For Hendrickson, health is a powerful tool for raising awareness. “The love a parent feels for their child is the most powerful force that exists. We can use that to drive change,” she said, emphasizing the significance of local engagement: “If millions of people make small changes, the collective impact will be enormous.”

Across the Atlantic, Croatian pathologist Ana Rakovac, who works at Tallaght University Hospital in Dublin, Ireland, is part of the Irish Doctors for the Environment group. Her focus on the dangers of endocrine disruptors in plastics and their effects on reproductive health and cancer rates stemmed from her interest in sustainability.

In Ireland, Rakovac highlighted the health risks posed by the historic use of peat as a fuel, poor air quality, and a healthcare system unprepared for rising temperatures. “The perception that climate change is a distant issue, especially in Ireland, is false,” she said. According to the World Meteorological Organization, Europe is warming faster than any other continent, and 2024 was the hottest year on record. Rakovac added that this denial of the climate crisis results in inaction, preventing recognition of immediate health impacts, such as asthma attacks from pollution or floods exacerbated by fossil fuel use.

Kate Wylie, a family physician and executive director of Doctors for the Environment Australia (DEA), believes framing the climate crisis from a health perspective makes the issue more relatable to the public. “By saying that climate change affects your health through increased extreme heat and cost of living, I’m making it personal, which brings the issue closer,” she explained. The DEA helped develop Australia’s National Health and Climate Strategy, launched in 2023, and is working to integrate climate and health education into medical training. “Today, every medical student in Australia must learn about climate and health. This is significant,” she added.

For Wylie, medicine is an ethical responsibility in the context of the climate emergency. “When we take the Hippocratic Oath, we promise to dedicate our lives to serving humanity. If we’re not addressing the planetary crisis, we’re failing in that commitment,” she said. Wylie noted that even in developed countries, the connection between health and climate is still not well understood. “Not everyone realizes that fossil fuels harm our health, just as we now understand the dangers of smoking,” she argued.

In Africa, countries are responding to the climate-health crisis by formulating policies and executing on-the-ground actions. In 2024, the WHO African Region approved a landmark resolution to strengthen resilient, low-carbon health systems through the Alliance for Transformative Action on Climate and Health. The region also developed a strategic plan focusing on disease surveillance, infrastructure adaptation, and risk mitigation.

In addition to institutional advancements, local initiatives are gaining momentum. The Africa Climate and Health Responders Course has trained doctors to respond to climate disasters and disease outbreaks. In Uganda, John Bosco Isunju leads efforts to adapt the healthcare system to climate-related challenges, with the country becoming the first in Africa to implement a National Climate Change Adaptation Plan. In Kenya, Umra Omar founded Safari Doctors, a healthcare organization that serves remote coastal communities. Recognized by the UN for her efforts, Omar combines healthcare provision with environmental education and climate justice advocacy, aiming to bridge health, equity, and the environment.

With the increasing frequency of extreme weather events, the medical community must confront the climate crisis on multiple fronts: through education, policy advocacy, and direct action. As Enedina Scuarcialupi, a pulmonologist and ambassador for Doctors for the Climate, said, “We are like a hummingbird trying to put out a fire. But if everyone does their part, the impact can be significant.”

Climate and Health: A Common Agenda

The medical community’s prominence in the environmental debate has gained further strength due to the high trust society places in these professionals. According to the Ipsos Global Trustworthiness Index 2022, doctors and scientists top the list of the most trusted professions globally, with 59% and 57% trust, respectively.

This prestige also appears in the 2024 Edelman Trust Barometer, which shows that 83% of the population trusts doctors to tell the truth about how to protect health. The study emphasizes that, in times of misinformation, consulting a doctor is the primary way to verify health information.

This credibility becomes even more relevant given the reports from healthcare professionals experiencing the effects of the climate crisis firsthand. In addition to what’s evident in hospitals and clinics, the WHO estimates that by 2050, climate change could cause about 250,000 additional deaths per year from causes like malnutrition, malaria, and heat stress.

In Brazil, the number of reports from professionals identifying worsening respiratory diseases, outbreaks of arboviral diseases, and challenges in care during extreme events like floods and droughts is increasing.

Given this scenario, the active role taken by healthcare professionals in responding to the climate emergency through clinical practice, knowledge production, and institutional coordination is greatly welcomed.

Even without formal coordination between countries, this movement shares a common understanding: health systems are on the front lines of the climate crisis. Integrating health and climate into public policies, medical training, and communication with society is a necessary step to protect lives — and the planet — amid deep and accelerating transformations.

This story was translated and adapted from Medscape’s Portuguese edition.