Seoul Battles Urban Heat: Can Smart Design Cool the City?

It’s mid-October in Seoul, and the temperature still lingers near 29°C—abnormally high for the season. For many residents, it’s more than an uncomfortable autumn. It’s the latest sign that Korea’s capital is grappling with a growing environmental challenge: the urban heat island (UHI) effect.

The phenomenon, where cities retain more heat than surrounding rural areas due to dense infrastructure and limited vegetation, has intensified in Seoul over the past decade. According to the Korea Meteorological Administration, Seoul’s average nighttime temperatures are now 2.5°C higher than adjacent rural towns, largely due to heat-trapping surfaces like concrete, asphalt, and glass.

“Seoul is heating up faster than most people realize,” says Dr. Kang Seung-woo, a climate architecture specialist. “We’ve reached the point where design is no longer just aesthetic—it’s survival.”

In response, the city government has launched the Cool Seoul 2030 Plan, a comprehensive strategy to combat urban heat. It includes the installation of reflective rooftops, the expansion of vertical gardens on high-rise buildings, and an ambitious goal to plant 30 million urban trees by 2030.

One innovative project is the Seoul Sky Garden, a repurposed highway overpass now transformed into a mile-long botanical walkway. Not only does it offer shade and reduce surrounding temperatures by 3–5°C, but it also serves as a community space for education and leisure. Another initiative, “Green Roof Seoul,” offers subsidies for residents who install vegetation on their rooftops.

Private developers are also adapting. New office buildings in Gangnam are being constructed with permeable pavements and rooftop rainwater collectors to reduce both heat and flooding risk. Some districts are experimenting with “cool pavements” that reflect sunlight instead of absorbing it.

Yet challenges remain. Real estate pressure limits green expansion, and older neighborhoods lack the infrastructure for large-scale retrofits. Public awareness is also low. A recent survey found that only 38% of Seoul residents are familiar with the term “urban heat island.”

Still, momentum is growing. As summer heat creeps deeper into fall, citizens and planners alike are realizing that the city’s survival may depend on its shade.

Date: 2024-10-21

Reporter: 박근홍