Absorbing and Releasing Heat... The Culprit Fueling Extreme Heatwaves

[Anchor]

Disaster-level heatwaves feel especially harsh in urban areas. Experts point out that concrete and asphalt radiate heat like stoves, while trees that act as shade in the city are steadily decreasing.

Reporter An Huijae has the story.

[Reporter]

This is downtown Seoul this afternoon (August 7).

The asphalt roads, glowing a deep red, are boiling.

Local governments mobilize water-sprinkling trucks to cool down the roads, but it only offers brief relief before the heat quickly returns.

[Lee Chang-min / Sanitation Division, Seongdong-gu Office, Seoul: After we spray the water, it dries up and evaporates quickly, but if it can give citizens even a fleeting sense of coolness....]

"Impervious surfaces," paved with concrete and other materials that prevent rainwater from seeping in, are a major culprit making summer heatwaves even more unbearable.

Unlike soil, these surfaces absorb heat and release it later, acting like heaters.

[Yoon Young-jo / Professor, Department of Ecological Landscape Design, Kangwon National University: An impervious surface creates a structure where rainwater itself cannot circulate. The cooling function where evaporating water absorbs heat drops significantly as well.]

The trapped heat continues to be emitted even after sunset, worsening tropical nights.

Seoul's ratio of impervious surfaces hit 53.16% last year, ranking highest nationwide.

Over a six-year period, the area expanded by an amount equivalent to roughly 940 football fields.

Meanwhile, street trees that provide shade decreased by about 18,000 over the same period.

Walkways exposed to the blazing sun are thoroughly heated like this.

Just a few steps away under the lush shade of trees, you can see a temperature difference of about 10 degrees Celsius.

[Seoul Forest Visitor: Heat radiates from the road, which is terrifying. That is why I come out here to rest in the shade, and it is cool.]

A recent study showed that autonomous districts with a higher "canopy cover ratio," where trees cover more than 30% of the area, tend to have lower summer surface temperatures.

[Je Seon-mi / Researcher, Urban Forest Research Center, National Institute of Forest Science: This scientifically supports the fact that creating more urban trees and forests can be an effective way to respond to climate change and extreme heatwaves.]

The Seoul Metropolitan Government stated, "Street trees were reduced to some extent during road maintenance and various development projects," adding, "We are devising measures to expand green spaces."

(Video reporting: Choi Dae-woong, Hangyul Kim | Video editing: Yoon Tae-ho | Cooperation: Seongdong-gu Office, Seoul | Design: Kim Han-gil, Choi Jae-young, Kang Yoon-jung)
※ Please note: This article was translated by AI and may contain errors.