As per a study published in journal Nature on 9 November 2017, India is overtaking China as the World’s largest emitter of Anthropogenic Sulphur Dioxide (SO2).
The study, led by researchers at University of Maryland in the US, reveals that India's emissions of the air pollutant sulphur dioxide has increased by 50 per cent since 2007, while China's fell by 75 per cent.
The rapid decrease of sulphur dioxide emissions in China far exceeds expectations and projections. This can be attributed to the emission control measures undertaken by China. While, India is yet to implement emission control measures.
• Sulphur dioxide is an air pollutant that causes acid rain, haze and many health-related problems. It is mainly produced when coal is burned to generate electricity.
• China and India are the world's top consumers of coal, which typically contains up to three per cent sulphur.
• The sulphur dioxide emissions are generally the product of the coal-fired power plants and coal-burning factories.
• Beijing suffers severe haze problems due to coal-burning factories and power plants. However, in the early 2000s, China began implementing policies such as fining polluters, setting emission reduction goals and lowering emissions limits. These efforts are paying off well.
• Sulphur dioxide levels in China declined significantly, though the coal usage increased by approximately 50 per cent and electricity generation grew by over 100 per cent.
• Despite 75 per cent drop in SO2 emissions, China's air quality continues to cause significant health problems as SO2 contributes to only about 10-20 per cent of air particles that cause haze.
• By contrast, India's sulphur dioxide emissions increased by 50 per cent over the past decade as India opened its largest coal-fired power plant in 2012 and has yet to implement emission controls.
• India's increased sulphur dioxide emissions are not causing as health or haze problems as in China because the largest emission sources are not in the most densely populated area of India.
• However, with the growing demand for electricity in India, the impact may worsen.
• In order to generate an accurate profile of emissions over India and China, the researchers combined emissions data generated by using two different methods.
• The first method was the collection of estimated emission amounts from inventories of the number of factories, power plants, automobiles and other contributors to sulphur dioxide emissions.
• The second data source was the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite, which detects a variety of atmospheric pollutants including sulphur dioxide.
What: Revealed by a study
When: 9 November 2017