So, have you been smoking lately?

The sky is everyone’s favourite muse. Scroll through a phone’s gallery and you will find pictures bright and gloomy of the expanse above. If there is a tint of crimson, especially during a sunset, then Instagram upload is a must. If not, it can be a WhatsApp forward with a brooding caption. Amid this, unseen to all, a colourless giant is silently killing the muse. Sulfur dioxide.

According to Greenpeace India and the Centre for Research on Energy and Clean Air (CREA), sulfur dioxide (SO2) emissions recorded a significant decline of approximately 6% in 2019 compared to 2018. But, India continues to occupy the top emitter's position for the fifth consecutive year. Research shows that the air pollutant increases the risk of stroke, heart disease, lung cancer, and in some cases, can even cause premature death.

In 2019, as per the report, India emitted 21% of global SO2 emissions, which is nearly double the amount generated by the world’s second largest emitter, Russia. And, the primary reason: coal. Over the past two decades, coal-based electricity generation has expanded in India. As a result, the biggest hotspots of SO2 emissions are thermal power stations at Singrauli, Neyveli, Korba, Talcher and Vishakhapatnam.

With the use of satellite data and a global catalogue, the Greenpeace-CREA report has also found that China, once the biggest offender, has managed to reduce its emissions by 87% from its 2011 peak by strengthening standards and increasing the use of scrubbers in plants. Meanwhile in India, several coal-fired power stations failed to install flue-gas desulfurization within the deadline of December 2017, as directed by the Ministry of Environment, Forest and Climate Change. Now, the deadline has been shifted to 2022.

Ironically, after making a lot of noise on renewable energy, the government invited bids from private players for 38 coal mines in India, of which 15 received no bids. It remains to be seen whether the renewable energy push brings in results or the coal sector clouded by environmental concerns gets a boost. Till then, the unseen killer will continue doing its job.