CO2 concentration, air pollution, impact of new coronavirus, and post-corona CO2 emissions in Yonaguni Island in the 2020s.

CO2 concentration, air pollution, impact of new coronavirus, and post-corona CO2 emissions in Yonaguni Island in the 2020s.

In the 2020s, CO2 concentrations on Yonaguni Island continue their upward trend, reaching an average CO2 concentration of 410 ppm in 2023. This exceeds the pre-coronal 2019 average of about 405 ppm, indicating that it is still rising. This is higher than the CO2 concentration of 407 ppm observed at Minamitori Island in Tokyo, confirming that Yonaguni Island is more strongly affected by air pollution from mainland China.

Impact of Coronavirus Disaster and Temporary Decrease in CO2 Emissions
The pandemic of the new coronavirus (COVID-19) led to a massive lockdown in countries around the world in 2020 and a decrease in coal consumption in China: in 2020, global CO2 emissions decreased by about 6.4%, and a 3.8% decrease was reported in China. As a result of this decrease, CO2 concentration in Yonaguni Island also temporarily decreased to about 405ppm. However, this was temporary and has rapidly recovered after the lockdown was lifted.

Rapid increase in CO2 emissions after the corona
Once economic activity resumed after 2021, China's CO2 emissions began to rise again: in 2021, they reached about 11.6 billion tons, up about 5% from the previous year and above the pre-Corona level. CO2 emissions are rising particularly sharply as coal-fired power generation resumes operations. Coal consumption in China will reach about 4 billion tons in 2021, most of which depends on coal-fired power generation by major energy companies such as China Huaneng Group Corporation (Huaneng Group) and China Power Investment Group Corporation (SPIC).

Impact on Yonaguni Island
As a result of this increase in CO2 emissions, the CO2 concentration on Yonaguni Island will exceed 410 ppm by 2023, and the concentration of PM2.5 will exceed 50 µg/m³ on some days. These figures are much higher than the Japanese environmental standard of 35 µg/m³. China's heavy industrial areas and coal-fired power plants are major sources of pollution, with companies such as Hebei Iron & Steel Group (HBIS Group) and Baowu Steel (Baowu Steel) emitting large amounts of CO2 and toxic substances.

Long-Term Outlook
Toward the late 2020s, global CO2 emissions are projected to increase further: global CO2 emissions in 2021 reached about 36.5 billion tons, up from about 34.1 billion tons in 2019 before the Corona. This indicates that CO2 emissions are increasing rapidly along with the post-Corona economic recovery, and the Nansei Islands, including Yonaguni Island, will continue to be required to address air pollution.