press trust of india
Washington, Nov 10: The need for India to implement stronger emission controls has been reaffirmed by the results of a study led by University of Maryland researchers. The study has indicated that emission of sulphur dioxide has increased by 50 per cent in India since 2007. Contrariwise, the report says, the sulphur dioxide emission of China has fallen by 75 per cent.
The study suggests that India is becoming — if it already is not — the world’s top emitter of sulphur dioxide.
The report published Thursday in the journal ‘Scientific Reports’ has been played up by China’s official media; it is embarrassing for India, particularly as the national capital Delhi and surrounding areas are choking under a blanket of smoke caused by multiple factors, including stubble burning in neighbouring states.
Sulphur dioxide is an air pollutant that causes acid rain and haze, and is hazardous to human health. It is produced predominantly when coal is burnt to generate electricity. China and India are the world’s top consumers of coal, which typically contains up to three per cent sulphur, researchers said.
Most sulphur dioxide emissions of the two countries come from coal-fired power plants and coal-burning factories.
Can Li, an associate research scientist at University of Maryland, and lead author of the study told Xinhua that the rapid decrease in sulphur dioxide emissions observed in China suggested that “China is implementing sulphur dioxide controls beyond what climate modellers have taken into account”.
Starting in the early 2000s, China had started implementing policies such as fining polluters, setting emission reduction goals and lowering emissions limits. The results of the current study, indicate that these efforts are paying off.
“Sulphur dioxide levels in China declined dramatically even though coal usage increased by approximately 50 per cent and electricity generation grew by over 100 per cent,” Li, who is also a research associate at NASA’s Goddard Space Flight Center, said.
“This suggests that much of the reduction is coming from controlling emissions,” Li said.
However, although Li’s study indicates that sulphur dioxide emissions of China have decreased by 75 per cent, recent work by other scientists has shown that the country’s air quality remains poor and continues to cause significant health problems.
This may be because sulphur dioxide contributes to only about 10 to 20 per cent of the air particles that cause haze, Li said.
By contrast, India’s sulphur dioxide emissions increased by 50 per cent over the past decade. The country opened its largest coal-fired power plant in 2012 and has yet to implement emission controls like China, the researchers said.
“Right now, India’s increased sulphur dioxide emissions are not causing as many health or haze problems as they do in China because the largest emission sources are not in the most densely populated area of India,” Li said.
“However, as demand for electricity grows in India, the impact may worsen,” said Li.
# Researchers combined emissions data generated by two methods: Collecting estimated emission amounts from inventories of the number of factories, power plants, automobiles and other contributors to sulphur dioxide emissions; using the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite, which detects a variety of atmospheric pollutants, including sulphur dioxide. Data from 2005 to 2016 was analysed and results verified by aircraft measurements.
# SO2 emissions were around 11 megatons for India while China emitted 8.4 megatons.
# Previously published studies, which relied on inventory data and published policies, had projected that China’s SO2 emissions would not fall to current levels until 2030 at the earliest
