A new study conducted by scientists from the University of Maryland and NASA, indicates that emissions of sulfur dioxide in China have declined significantly, and in India have increased dramatically. Sulfur dioxide (SO2) is an air pollutant that leads to acid rains, fog and health problems. Today, this substance is formed mainly by burning coal for power generation.
Although China and India remain the largest consumers of coal in the world, new research has shown that SO2 emissions in China have declined by 75% since 2007, while in India they have increased by 50%. The results show that India may soon become the main source of sulfur dioxide emissions in the world. Previous studies have also shown that emissions of sulfur dioxide in the US are steadily declining.
“The rate of reduction of SO2 emissions in China far exceeds expectations and forecasts. This means that China controls emissions beyond what has been taken into account by climate models, “said atmospheric chemist Kang Li.
The maps show the emissions of sulfur dioxide by region. They were compiled on the basis of data obtained using the OMI tool on NASA’s Aura satellite. The values represent the annual mean concentrations of SO2 in India and China in 2005 and 2016.
China and India are currently the largest consumers of coal in the world, which usually contains up to 3% sulfur. Most of the emissions of sulfur dioxide are accounted for by coal-fired power plants and coal plants. In particular, Beijing suffers from serious problems with air quality due to power plants and plants located nearby and on the leeward side.
Since the early 2000s, China has begun to implement measures such as limiting pollution, setting emission reduction targets and reducing emission limits. According to a new study, these efforts were not in vain. “Sulfur dioxide levels in China have declined sharply, although coal consumption has increased by about 50%, and electricity generation has grown by more than 100%. This suggests that a significant part of the reduction is related to emission control, “Lee explained. Previous studies, based on terrestrial inventory and published policies, suggested that SO2 emissions in China could drop to the current level no earlier than 2030.
Despite a 75 percent reduction in sulfur dioxide emissions, recent work by other scientists has shown that air quality in the country remains unsatisfactory and continues to cause serious health problems. This may be due to the fact that sulfur dioxide brings about 10 to 20% of the particles that cause smog. According to scientists, if China wants to return the blue sky over Beijing, the country should also monitor other air pollutants.
In contrast to China, SO2 emissions in India have increased by 50% over the last decade. In 2012, the country opened its largest coal-fired power plant and it still needs to implement proper emission control. As Li noted, currently increased sulfur dioxide emissions in India do not cause as much health and smog problems as in China, because the largest emission sources are not located in the most densely populated region of India. However, the demand for electricity in India is growing, which means that the impact may worsen.