The heavy blanket of smog that enveloped Delhi for days after Diwali could return soon as the constant sources of pollution have remained largely the same, experts said.
If windspeed drops, cooler temperatures in the weeks ahead could provide a favourable setting for smog to develop and stick around. According to air pollution experts, the long spell of toxic smog seen in early November did lead to some emergency measures being put in place, but action against sources of pollution has been minimal.
“We have not done much to curtail any source [of pollution]. If the meteorological factors become worse, similar smog can return,” said Sumit Sharma, a fellow at TERI.
Burning of agricultural residue
A factor that contributed to heavy particulate matter concentration during the recent smog episode was burning of agricultural residue in neighbouring States. The government is yet to look at a long-term plan to prevent the practice, he said, adding that farmers should be given incentive to not burn their crop waste.
Other sources of pollution, including industries, power plants and vehicles, have also remained largely untouched. “Background pollution sources in north India are the same today. Apart from closure of the Badarpur power plant here, no strong action has been taken against power plants and industries in the upwind direction,” said Sunil Dahiya of Greenpeace India.
He added that the government had remained slow to act, and it was the judiciary that took up the monitoring of air pollution. The Supreme Court has asked the Centre and the NCR governments to come up with action plans.
Though winter pollution, which is aided by cooler temperatures that prevent dispersion of particulate matter and gases, has the attention of the Delhi government right now, experts say that will not be enough. “We can’t forget about pollution when winter is over. That is what happened last year. There will have to be sustained efforts and systemic changes, including in public transport and walking tracks,” said Anumita Roychowdhury of the CSE. She said though air quality had improved after implementation of emergency measures, including ban on construction activity, smog “could happen any day”.
While there are certain time restrictions and monetary charges on commercial vehicles entering Delhi, vehicular emissions within the city have not been curbed. “Why aren’t we looking at congestion pricing? Revenue from that can be used to boost public transport. But, we are stuck on odd-even, which is not efficient long-term,” said Mr. Sharma.