The National Institute of Forest Science under the Korea Forest Service announced in September that "urban forests (living urban woodlands) had 20-29.4% fewer heat wave days both day and night compared to urban areas." This research paper was published in the SCI-level international journal 'PLOS One'.
Forests provide shade that blocks intense sunlight and transpiration effects that cool hot air by releasing water vapor from leaves, revealing that temperatures are lower in urban forests during hot summers compared to urban areas.
In fact, urban forests significantly suppress temperature increases, with fewer heat wave days (maximum temperature above 33 degrees) the closer one is to an urban forest. When researchers measured the number of heat wave days in urban forests and urban areas during midday, they found that forests had 2 days, while urban areas had 10 days, indicating that the number of heat wave days in forests was 20% lower than in urban areas. Additionally, when analyzing the number of tropical nights (minimum temperature above 25 degrees) at night, forests had a maximum of 5 days, while urban areas had 17 days, showing that the number of tropical nights in forests was about 29.4% lower than in urban areas.
Park Chan-yeol, head of the Urban Forest Research Center at the National Institute of Forest Science, stated, "This year has seen unprecedented heat waves fluctuating around 35 degrees, with Seoul recording the longest tropical nights (34 days) in 118 years of weather observation," adding, "The scientific evidence of the forest's effectiveness in overcoming heat waves day and night suggests that urban forests play a significant role in national carbon neutrality and climate crisis response."
Urban forests are becoming one of the alternatives for responding to the climate crisis. As issues like worsening fine dust and increasing weather anomalies become commonplace, the importance of urban forests is growing day by day.
The benefits of urban forests have already been proven through various studies. According to the National Institute of Forest Science, forests in urban areas play a significant role in reducing air pollutants such as fine dust. A 1-hectare (10,000㎡) forest made up of 10-year-old trees absorbs 6.9 tons of carbon dioxide and 168 kg of fine dust annually. For example, Hongneung Forest in Dongdaemun-gu, Seoul, has fine dust (PM10) levels 25.6% lower and ultra-fine dust (PM2.5) levels 40.9% lower than surrounding urban areas.
Moreover, forests lower the average temperature during summer afternoons by 3-7 degrees. They also increase humidity by 9-23%, effectively acting as natural air conditioners during the summer. Urban forests significantly help alleviate depression as well. Just looking at trees for 15 minutes in a forest can reduce the stress hormone cortisol levels by 15.8% and lower blood pressure by 2.1%.
Kim Si-hoon, head of the Urban Forest Landscape Division at the Korea Forest Service, stated, "As the number of forests around us increases, we can directly improve living environments through fine dust reduction and climate regulation, as well as provide rest and leisure for urban residents, achieving various benefits."
Accordingly, since March 2003, the Korea Forest Service has been creating urban forests across the country using national land in collaboration with local governments. By the end of last year, 5,618 urban forests (6,541 hectares) equivalent to the size of 7,928 soccer fields had been established, and this year, an additional 211 sites covering a total of 183 hectares are being created with a budget of 124.8 billion won.
In fact, the number of climate response urban forests aimed at suppressing the inflow and spread of fine dust and other pollutants increased to 473 sites (706 hectares) last year. This year, 114 new urban forests covering a total of 158 hectares are being established. Urban wind path forests, which draw in clean, cool air from forests on the outskirts of cities, have been created in 17 cities nationwide. Plans are in place to add more in 19 cities, including Daejeon, Ulsan, and Gongju, by 2025. The Child Safety Green Forests, aimed at providing a safe and pleasant commuting environment for students, have been established in a total of 210 locations, starting with 50 in 2021.
In this way, the Korea Forest Service is promoting policies to expand urban forests so that more citizens can enjoy their various benefits. They are increasing the area by 500-600 hectares each year. As a result, the per capita area of urban forests in Korea has increased by more than 60%, from 7.0㎡ in 2007 to 11.5㎡ in 2021.
However, urban forests in Korea still account for only 0.5% of the total land area, falling short of the World Health Organization (WHO) recommended standard of 15㎡. In particular, the densely populated city of Seoul has only 4.97㎡ per person, which is about one-third of the WHO recommended standard. Compared to New York (23㎡), London (27㎡), and Paris (13㎡), this is an extremely limited size. Accordingly, the Korea Forest Service plans to increase the per capita area of urban forests from 11.48㎡ to 15㎡ by 2027. This would increase the total area of urban forests in Korea from the current 53,992 hectares to 70,860 hectares, equivalent to about 80,000 international standard soccer fields.
Recently, the Korea Forest Service selected "50 Beautiful Urban Forests" to raise awareness of the value of urban forests. These include the Hanbat Arboretum Garden in Daejeon, the Urban Wind Path Forest in Jeonju, the Pohang Railway Forest in Pohang City, and the Munsusan Barrier-Free Urban Forest in Namdong-gu, Incheon. Lim Chang-seop, head of the Korea Forest Service, stated, "The revised Urban Forest Act, which was amended in July, has made it easier to create and manage street trees by city and county," adding, "We will continuously manage urban forests, street trees, and urban green spaces in an organic manner so that green corridors can function properly." He emphasized, "We will create urban forests that reflect local characteristics in collaboration with local governments, nurturing them as tourism resources and cultural spaces for residents, thereby contributing to the revitalization of the local economy."
[Jo Han-pil, Reporter]
