Climate crisis is a public health emergency

The warming of the Earth—driven by human activity—poses a direct threat to future generations. Yet Korea’s response remains inadequate in both awareness and action. This must change.

Yim Jae-joon

The author is a professor of Internal Medicine at Seoul National University College of Medicine and Seoul National University Hospital

The world is indisputably warming. According to a United Nations report, the global surface temperature between 2011 and 2020 was 1.09 degrees Celsius (1.63 degrees Fahrenheit) higher than during the preindustrial period of 1850 to 1900. As a result, the average area of Arctic sea ice in September between 2010 and 2019 shrank by 40 percent compared to 30 years ago, and the global sea level has risen by 20 centimeters since 1901.

If greenhouse gas emissions continue at current levels, many experts project that by the end of the 21st century, the average global temperature will rise by 3 to 5 degrees Celsius compared to preindustrial levels.

Residents seek shade in a low-income neighborhood near Seoul Station, known as a “jjokbangchon,” on July 24, as midday temperatures in the capital soared. [YONHAP]

The consequences of this warming extend far beyond environmental degradation; climate change directly threatens human health. Rising temperatures and increased rainfall create favorable breeding conditions for mosquitoes, leading to a higher risk of mosquito-borne diseases such as malaria, dengue fever and Japanese encephalitis.

Extreme heat waves — like those recently pushing temperatures near 40 degrees Celsius — take a toll on the cardiovascular system. Elevated body temperatures can increase heart rate and cardiac output, placing greater stress on the heart. Blood becomes more viscous, raising the risk of ischemic heart diseases such as angina and strokes. Some studies have shown that for every 1-degree increase in average daily temperature, the suicide rate rises by 1.7 percent, highlighting the impact of climate change on mental health as well.

Climate change is not simply about higher temperatures and more hot days. Rising temperatures disrupt the Earth’s water cycle, increasing the frequency and intensity of extreme weather events like floods, droughts and wildfires. These phenomena also pose serious health risks. Floods can spread waterborne diseases like cholera. Thunderstorms can trigger asthma attacks, and wildfire smoke worsens respiratory and cardiovascular conditions.

After a large wildfire struck Korea’s eastern coastline in 2017, local residents saw a marked increase in hospital visits for chronic obstructive pulmonary disease, pneumonia and heart failure, according to the 2024 issue of the Weekly Health and Disease report.

To mitigate these health impacts, reducing carbon emissions is critical. However, the health care sector itself is a significant contributor to emissions, particularly through the production of vaccines, medicines and medical equipment, as well as testing and treatment procedures. In 2019, the health care sector accounted for more than 5 percent of global greenhouse gas emissions.

These emissions vary significantly by country. According to a 2022 study published in The Lancet, the United States had the highest per capita healthcare-related emissions at 1.7 tons, yet its average healthy life expectancy was only 66.2 years. Korea, by contrast, had a higher average healthy life expectancy of 73.1 years, while its healthcare-related emissions per person stood at 1.1 tons. France, with a life expectancy of 72.1 years — comparable to Korea's — emitted just 0.3 tons per person, suggesting that emission levels can be reduced without compromising health outcomes.

Hospitals in Korea are major energy consumers. As of 2023, three of the 10 most energy-consuming institutions in Seoul were large hospitals. Given the high energy demands of testing, surgeries and patient care some level of consumption is unavoidable. Still, efforts to reduce emissions remain insufficient.

Many hospitals have recently announced commitments to environmentally friendly operations, but without clear regulations and standards, such declarations may have limited impact. Including carbon reduction criteria in hospital accreditation systems and the designation of tertiary general hospitals could create stronger incentives for meaningful change.

Smoke billows out from a forested hill in Okjong-myeon, Hadong County, South Gyeongsang, on April 7. [KOREA FOREST SERVICE]

Medical schools also have a role to play. In Korea, very few medical schools include climate change as part of their curricula. In the United States, more than half of medical schools have made climate-related courses mandatory. Harvard Medical School, for example, identifies "climate, environment and health" as a core competency and teaches students about climate-related diseases and the impact of climate change on health equity.

Climate change is not merely an environmental issue. As the World Health Organization has repeatedly emphasized, it is a grave public health crisis. The warming of the Earth — driven by human activity — poses a direct threat to future generations. Yet Korea’s response remains inadequate in both awareness and action.

This must change. Policies need to shift, and there must be greater investment in climate-related education and research. Lifestyle choices that ignore carbon impact and prioritize convenience must also evolve. The decisions we make today will shape the health and well-being of generations to come.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.