COVID-19's paradox ... When human activities stopped, the planet became healthy.

human migration has stopped as the number of confirmed coronavirus infections (corona19) in the world reached 1 million. This is because countries such as the United States, Europe, and other countries are conducting intense movement restrictions such as “social distancing." Although daily life is shrinking as schools are closed and factories are shut down, research has shown that the sky is cleaner than ever.

According to the international academic journal Nature, China's air quality, which was recently designated as “the chimney of the world” and the source of the COVID-19 incident, has improved significantly. The air quality in Europe, where many countries have enforced strong movement restrictions, has also improved significantly. COVID-19 is a paradoxical phenomenon in which people in the world lose their lives and restrict human activities, but as a result, the air in the global village is cleared. Analysis of satellite data collected by the NASA and the European Space Agency (ESA) showed that the nitrogen dioxide in the air generated by fossil fuel consumption in China decreased dramatically during the month of February this year. According to an analysis based on satellite data by the Energy and Clean Air Research Center in Helsinki, Finland, China's industrial activity decreased by up to 40% due to the Corona 19 crisis. In February this year, coal consumption in China was at its lowest in the last four years. Oil consumption also fell by more than a third. During this period, China's carbon emissions were reduced by more than 25%.

The concentration of nitrogen dioxide in Wuhan City, Hubei Province, China, was compared. The dark-lined area on the map is where the concentration of nitrogen dioxide is high. In January, the concentration of nitrogen dioxide was high across China, but in February it decreased significantly, except in some areas. Provided by the United States Aeronautics and Space Administration

NASA Godard Space Flight Center atmospheric scientist Liu Fei said, “In China each year, the factory shuts down during the Lunar New Year's Lunar New Year holiday, and the industrial activity decreases, so the concentration of nitrogen dioxide also decreases. Since the Lunar New Year on January 25, the pollution of nitrogen dioxide in China has decreased by 10-30% compared to the same period last year."

It was analyzed that China's air quality improvement had an impact on Korea. From December of last year to March of this year, days with “very bad (more than 51 μg / microgram per m³)” fine dust counted to only two days. In the same period of the previous year, it was 18 days. Such significant reduction of coal usage is the result of China's COVID-19 factory shutdown. Data analysis of the Sentinel-5P, an Earth observation satellite operated by ESA, also confirmed the improvement of air quality in Europe. The satellite has spectroscopic equipment that analyzes wavelengths and colors when sunlight is reflected on particles in the atmosphere. It can detect nitrogen dioxide, ozone, formaldehyde, sulfur dioxide, methane, and carbon monoxide. The concentration of nitrogen dioxide arising from fossil fuel consumption is fluid when the wind direction or wind speed changes. Analyze at least 10 days of data to see the impact of changes on human activity. ESA said, "As a result of analyzing and analyzing data for 10 days, the concentration of nitrogen dioxide in northern Italy has decreased significantly, and this phenomenon is also observed in the United Kingdom, Spain and Germany." Carbon dioxide emissions are also expected to decrease, with concerns that the global economic growth rate will be the worst if the proliferation of COVID-19 is prolonged. The Organization for Economic Cooperation and Development (OECD) recently analyzed that in the worst case, the global economic growth rate will be less than 1.5% this year, and that carbon emissions will decrease by 1.2% accordingly. The OECD said, “If the telecommuting and online meetings are widely adopted due to the COVID-19 crisis, and the current global emergency continues, it will be more likely that carbon dioxide emissions will decrease.” He said that it is necessary to take a closer look at the social and economic changes that COVID-19 caused.