| Black Eagles ― the Republic of?Korea Air Force?Aerobatic Team ― zip across a clear sky over Yeouido, Seoul, Sept. 21, 2022, as they practice for the country's Armed Forces Day the following month. Yonhap |
Pollutant reduction policies, China's improved air quality major contributors
By Ko Dong-hwan
In hindsight, the sky over Seoul in 2022 was at its cleanest in more than a decade, according to the city government. And the record, the authority said, will improve further and reach the level of advanced cities around the world.
The Air Quality Policy Division under the city government's Climate and Environment Headquarters, together with the city government's Research Institute of Public Health and Environment, have rolled out the results of an analysis of air quality statistics throughout the previous year and what contributed to the figures. The research concluded that the year saw the most outstanding air quality in more than a decade and noted that various pollutant-reduction regulations by the city government plus climatic conditions over Korea and neighboring areas were the reason.
The average concentration rate of PM2.5 (particulate matter with a diameter 2.5 micrometers or less) last year was 18 micrograms per cubic meter. It's the lowest since the country started measuring the figure in 2008. Since 2019, the city's PM2.5 rate has gone down steadily. It was 25 micrograms per cubic meter in 2019, followed by 21 and 20 in 2020 and 2021, respectively. The most visibly reduced levels were seen from between December and March when air pollutants tend to be mostly generated each year due to energy consumption for winter heating.
| Seoul Metropolitan Government's trucks spray roads in the city's eastern district of Songpa with water to clear particulate matters and other air pollutants, March 2022. Korea Times file |
Another point of reference as to the level of air quality is the number of days when conditions were "good" (when the daily average rate of PM2.5 is 15 micrograms per cubic meter or less) or "bad" (when it is higher than 35). There were a total of 182 "good" days in 2022, the most since 2008, and 31 "bad" days the same year, the least since 2008, the city government said.
"The lowest record in three years in a row was possible because of various countermeasures by the city government and support from our citizens, as well as climate conditions that worked in favor of our city's sky," Lee In-geun, the chief of Climate and Environment Headquarters, said. "And the city government will manage to present the same result over our city sky this year as well."
The Seoul Metropolitan Government has been enforcing anti-air pollution measures across various sectors including public transport, traffic, manufacturing and sanitation since 2007. It was the year when the authority announced "Clear Seoul 2010" to realize cleaner air quality over the city. Now the campaign has been replaced with "Clearer Seoul 2030."
| A hydrogen bus runs past Cheonho Station in Seoul's eastern district of Gangdong, December 2020. Yonhap |
Other regulations followed. The city in 2015 started promoting and subsidizing eco-friendly boilers and other heating systems which run on less energy. A set of new emergency manuals were introduced two years later to reduce air pollutants during random periods with high pollution risks, controlling emissions from public facilities, factories and public transport. In 2019, the city introduced green traffic zones to reduce vehicle volume and emissions. Seasonal anti-pollution regulations were also enforced every winter starting the same year, banning operations of government-run vehicles with certain license plate numbers to reduce traffic volume on roads and dispatching road clean-up trucks more often than during other seasons to sweep or spray down the roads to clear accumulated dust and pollutants.
Progress was visible in the public transport sector. As of this month, over 8,900 buses operating in and around the city have been replaced by those running on compressed natural gas ― instead of diesel fuel ― to reduce emissions. With the rising domestic sale of electric vehicles, the city has rolled out a goal to make at least 10 percent of the city's registered vehicles electric.
The average PM2.5 rate from 2022 came out even lower than what experts had anticipated. The city's public health and environment research institute had made a model to forecast levels based on the previous year's data and announced the figure would be 19.8 micrograms per cubic meter. The actual figure came out 1.6 micrograms per cubic meter lower.
| In these graphics by the Seoul Metropolitan Government's Research Institute of Public Health and Environment, the average level of PM2.5 in China's northeastern region (inside the box) in 2022, right, is lower than that of 2019-2021, left. Courtesy of Seoul Metropolitan Government |
More than 1,775 millimeters of rain that fell in 2022 and 113 days with no winds the same year helped keep the air over Seoul clear of aerosols. The precipitation was higher than 2019 (891 millimeters), 2020 (1,651 millimeters) and 2021 (1,186 millimeters), while the number of days with no winds was lower than 2019 (208), 2020 (117) and 2021 (121).
Improved air quality over northeastern China was another contributor to clear skies over Seoul in 2022, the city government said. The average level of PM2.5 over Beijing, Liaodong and Shandong came down steadily from 46 micrograms per cubic meter in 2019 to 41, 38 and 36 in 2020, 2021 and 2022, respectively. The latest figure was down 14 percent from that of 2019.
"By 2026, the city's PM2.5 level will be reduced to 15 micrograms per cubic meter, which is the international air quality standard, and by 2030 it will be 13, the average level in London and Paris," Lee said. "The city government last September announced 'Clearer Seoul 2030' to meet those goals. Tackling them will involve reining in diesel-running vehicles with comparatively lower grades of emission, expanding the Green Traffic Zone further throughout the city, as well as controlling air pollutants from large factories more effectively using IoT monitoring systems."