• Cross-border pollution, particularly from China, has also been a major factor, Mark Jacobson of Stanford University tells Anadolu, explaining that 'from China, emissions are going to blow over the Pacific. So, they’ll affect Japan. They’ll affect South Korea'
• Weather patterns tied to climate change could complicate future progress, says environmental chemist Charles Driscoll, adding: 'If we control pollutants ... not only do we improve the climate, but also air quality and health outcomes'

ISTANBUL

Air pollution stands as one of the most serious environmental health threats globally. While all but a few nations struggle to meet air quality standards, one country stands out as a recent success story — South Korea.

One of the world’s most industrialized countries, South Korea’s Environment Ministry recently revealed that the national average concentration of small, hazardous airborne particles, known as PM2.5, hit an all-time low in 2024 — the lowest since monitoring began in 2015.

The ministry’s report also showed a sharp increase in the number of “good” air quality days, reaching a record 212, while the number of “bad” days fell to just 10 — also a record low — with no days classified in the worst category, “very bad.”

In the capital Seoul, one of the most affected parts of the country, the average annual PM2.5 level was 17.6 micrograms per cubic meter last year, according to local authorities. While this is still far above the World Health Organization recommendation of 5 micrograms per cubic meter, it is still a record decline from 2008’s reading of 26.

Experts credit the improvement to a combination of domestic policies, cross-border cooperation, and favorable weather patterns.

“Certainly, they made a big step towards improving air quality, the numbers clearly show that this scientifically guided policy made an impact,” said Saewung Kim, an associate professor of atmospheric chemistry at the University of California, Irvine.

Domestic policies driving change

One of the key drivers has been tighter regulations on industrial emissions. The industrial sector now operates under total emissions caps in designated areas for air quality management. The number of businesses affected by the measures has grown from 400 in 2020 to 1,013 by 2024.

Kim noted that another major factor has been efforts to phase out coal power, which he called the “the most dirty way” to generate electricity. “They have shut down coal power plants substantially, which actually contributed to decreasing the amount of particles in the atmosphere,” he said.

The government has also promoted eco-friendly boilers, distributing 17,696 units to vulnerable groups, such as low-income households, in 2024 alone. Since 2017, more than 1.48 million units have been installed nationwide.

In the transportation sector, South Korea offered incentives to scrap old diesel vehicles, cutting the number of Grade 5 diesel cars — the highest in emissions — by 25.6% from last year. Compared to 2020, the reduction stands at 79.1%. Meanwhile, the number of climate-friendly electric and hydrogen-powered vehicles rose to 750,200 in 2024, a 25.1% increase, supported by an expanding charging infrastructure.

Kim noted that small passenger cars now emit significantly fewer air pollutants compared to 50 years ago, adding: “If we just keep converting our fleet to electric cars, definitely air pollution is going to be improved.”

Cross-border pollution

However, experts also emphasize that South Korea’s progress is not solely the result of domestic action. Cross-border pollution, particularly from China, has long been a major factor.

China is “basically up(stream) in the region, which means that … because of the location of the earth, the air is moving from China to Korea,” Kim explained, stressing that China's substantial reduction in air pollution has contributed significantly to Korea’s cleaner skies.

According to the Environment Ministry, fine dust concentrations in northeastern China and surrounding regions fell by 45.2% in 2024 compared to 2015, reaching their lowest levels in nearly a decade.

Annual dialogues such as the Tripartite Environment Ministers Meeting, which brings together South Korea, China, and Japan, have also helped foster regional cooperation. In 2025, the three countries are set to draft their fourth Tripartite Joint Action Plan (2026-2030), prioritizing air quality improvements.

Weather patterns and climate concerns

Weather conditions have also worked in South Korea’s favor. The Environment Ministry report noted that last year, increased rainfall and fewer stagnant air days helped reduce fine dust levels.

Mark Jacobson, a professor at Stanford University, explained the link between weather and air quality: “Fast winds clear it (pollution), while slow winds cause stagnation, and rainfall removes 90% of particles.”

Jacobson also highlighted that winds in the region are usually “mostly westerly,” meaning they blow from west to east. “So, from China, emissions are going to blow over the Pacific. So, they’ll affect Japan. They’ll affect South Korea,” he added.

The ministry report emphasized that in February, fine dust levels dropped substantially compared to the previous year, due to the cleansing effect of rainfall and changes in wind patterns, with more easterly winds and fewer westerly ones.

Experts warn, though, that shifting weather patterns tied to climate change could complicate future progress. Charles Driscoll, an environmental chemistry professor at Syracuse University, pointed to the “climate penalty” effect, where rising temperatures accelerate pollution reactions.

“We have to even reduce the emissions further to account for the effects of warmer temperatures,” he said. Highlighting the connection between air pollution and climate change, he added that if the climate continues changing, the impact of emissions on air pollution will become “more severe because of the temperature effects.”

Driscoll added: “If we control pollutants from climate change, we get two benefits — not only do we improve the climate, but also air quality and health outcomes.”

While South Korea’s progress is notable, experts caution that it must continue the fight against air pollution.

The country has made good progress, but “they are far from over,” says Kim, adding: “Long-term policy planning is required to address the issue.”