Once enough to stain shirt collars, smog is lifting over greater Seoul

Photo: AFP/Ed Jones

Cho Jang-hun remembers a time in the 1990s when it was almost impossible to escape the dirty air from exhaust fumes, coal-fired power plants and massive industrial projects that hung over his home in Gyeonggi, Republic of Korea.  

The smog used to be so bad that the collars of the white shirt that Cho wore in the morning were black with soot by the evening. 

But in recent years, the 47-year-old schoolteacher has noticed a marked reduction in the air pollution that once plagued Gyeonggi, which, together with Seoul and Incheon, forms the Seoul metropolitan region.  

“The air is much healthier, and the skies are clear,” he said. 

Data published in a recent UN Environment Programme (UNEP) report on air quality in the metropolis bears this out. It found that concentrations of the most damaging air pollutants, such as particulate matter (PM), far exceeded national standards and World Health Organization (WHO) air quality guidelines in 2005 but fell significantly by 2020.  

Two women on their phones sitting on a bench
In greater Seoul, concentrations of one particularly toxic airborne contaminant, PM10, fell by up to 40 per cent between 2005 and 2021. Photo: AFP/Ed Jones

When inhaled, particulate matter—tiny, invisible airborne particles—can penetrate deep into the lungs and enter the bloodstream, causing heart disease, stroke and respiratory issues.  

The report found that annual average concentrations of particulate matter smaller than 10 micrometers (PM10) were 30–40 per cent lower in 2021 compared to 2005. Across the Republic of Korea, emissions of PM2.5 fell by 19 per cent between 2005 and 2020, with even greater reductions in Seoul and Gyeonggi.  

The improvement in Seoul’s air quality is the culmination of decades of work by the government of the Republic of Korea to tackle air pollution, which claims almost 7 million lives globally every year. Its approach is seen as a success story in the Asia-Pacific region where 92 per cent of the population – some 4 billion people – are breathing unhealthy air with the risk of damage to the heart, lungs and brain.  

A recipe for cleaner air 

The Seoul metropolitan region is home to 26 million people, around half the population of the Republic of Korea. 

The region, a key driver of the country’s economy, was responsible for 48 per cent of national gross domestic product in 2016, according to the World Bank. However, much of the economic activity that makes it such a powerhouse has led to increased transport, industry, waste and electricity production, which often contribute to higher air pollution. 

Over the past couple of decades, the government has responded by creating a robust legal framework to manage air quality in the Seoul metropolitan region. It has also made long-term air quality data publicly available and invested heavily in air quality management systems, among other key measures. 

The air quality regulatory framework in the Republic of Korea consists of multiple levels of planning and policy making. A governing act serves as an overarching framework at the national level. Meanwhile, distinct plans outline how the act will be implemented at the national and local levels.   

“The air quality legislation provides a strong foundation for action to combat air pollution in the Seoul metropolitan region,” said Mushtaq Memon, UNEP Coordinator of Chemicals and Pollution Action for Asia and the Pacific. “It has been particularly effective because it identifies the roles and responsibilities of different organizations at national and sub-national levels. This has created clarity as to who is responsible for implementing different components of air quality management.”  

A man clean up rubbish in a high-rise
The smog in the Seoul region was once so bad it would turn white shirt collars black, say residents. Photo: AFP/Ed Jones

To assess compliance with the legal framework, hundreds of monitoring sites providing data on air pollution were set up across the Seoul metropolitan region and elsewhere in the Republic of Korea. The data is publicly available via a real-time air quality information website, which allows researchers to identify trends and provides information on which government agencies can act. 

Substantial investment has been critical to improved air quality. Between 2007 and 2020, the Seoul, Incheon and Gyeonggi governments invested US$9 billion on air quality management, with 56 per cent of the funding focused on measures to reduce emissions from the transport sector. Some US$3.2 billion was also devoted to evidence generation and public engagement on air quality.  

“Sustained investment to address climate change and improve air quality simultaneously will be pivotal going forward.”

Cho Kyeong-doo, Director General of the Incheon Carbon Neutrality Center.

In addition, governments in the Seoul metropolitan region have introduced a number of policies to address air pollution in recent years. These include the mandatory installation of eco-friendly boilers in households, restrictions on driving pollutant-emitting vehicles, and the greening of public transport fleets. 

The resulting cleaner air has brought positive results for human health. Between 2006 and 2015, the number of premature deaths associated with air pollution exposure was estimated to have fallen substantially in Seoul, Incheon and Gyeonggi, found one study. 

A need to jointly address air pollution and climate change 

Improving air quality is key to tackling the triple planetary crisis of climate change, nature and biodiversity loss, and pollution and waste. Not only does air pollution reduce the world’s biodiversity, it is also a key factor in the destabilization of the global climate.  

Despite the Seoul metropolitan region’s progress on air quality, the release of planet-warming carbon dioxide remains a persistent problem.  

The sun rises over high-rises in downtown Seoul
With air pollution ebbing, government officials are now aiming to reduce greenhouse gas emissions and make the Seoul area carbon-neutral. Photo: AFP/ Jung Yeon-Je

UNEP and the Climate and Clean Air Coalition have identified 25 science-based solutions to deliver wins for climate and pollution in the Asia-Pacific region. These include switching from fossil fuel to renewable energy sources and improving energy efficiency in transport and industry. The Republic of Korea has recognized that these measures will be key to the country achieving its goal of carbon neutrality by 2050

Governments in the Seoul metropolitan region are already embracing this new direction.  

“While past research focused primarily on air quality improvement, current studies aim to achieve both health benefits and energy transitions through carbon neutrality,” said Cho Kyeong-doo, Director General of the Incheon Carbon Neutrality Center. “Sustained investment to address climate change and improve air quality simultaneously will be pivotal going forward.” 

Integrating the pollution and climate agendas is a crucial opportunity to benefit human and planetary health in cities and regions worldwide.

An aerial view of Seoul

Suh Jeom-sook, Team Leader of the Air Quality Policy Division of the Seoul Metropolitan Government, believes the region’s success can inspire others.  

“We have seen what is possible with the right policies and dedicated efforts from actors across the Seoul metropolitan region and are excited about the work ahead to further improve the air we share,” she said. “We hope that our experiences can serve as a positive example for governments in Asia-Pacific and around the globe in the push for clean air for blue skies.” 

To fight the pervasive impact of pollution on society, UNEP launched #BeatPollution, a strategy for rapid, large-scale and coordinated action against air, land and water pollution. The strategy highlights the impact of pollution on climate change, nature and biodiversity loss, and human health. Through science-based messaging, the campaign showcases how transitioning to a pollution-free planet is vital for future generations. 

Top Stories