By Mallica Joshi
On Wednesday, November 13, as evening sets in and levels of particulate matter (PM) 2.5 climbed steadily, an official monitoring the situation could not help but get frustrated. All construction activity in the city had been suspended a few weeks ago, the second week of the odd-even road-rationing scheme was in place, and schools had been ordered to shut for the next two days.
“This is the highest the GRAP (graded response action plan) goes. We are doing everything we can, but who can control the weather?” said the official.
Under GRAP, an action plan to combat pollution in Delhi-NCR, actions are recommended based on the concentration of pollutants. At lower levels of PM 2.5 and 10, the plan suggests making sure waste is not set on fire in the open, illegal industrial activity is curtailed and roads are vacuum-cleaned. At the highest end of the spectrum are actions such as halting construction, shutting schools and odd-even.
The Delhi government, in an affidavit, told the apex court that it relied on three external studies “to conclude that the policy works as an effective emergency measure”.
The government cited a study conducted by researchers from IIT-Delhi, IIT-Kanpur, Indian Institute of Tropical Meteorology, Pune, National Physical Laboratory and TERI, which used satellite-based estimates of PM 2.5 to examine the potential decrease due to fewer traffic emissions during odd-even.
“The estimated PM 2.5 represents the level between 10.30 am to 1.30 pm, when the satellites cross this region. The study concluded that the traffic restriction between January 1-15 in 2016 reduced PM 2.5 by 4-6% with a maximum of up to 10%, primarily at three local hotspots in Delhi,” the government told the court.
The second study the government cited was conducted by researchers at Energy Policy Institute, University of Chicago, Centre for Policy Research and Harvard Kennedy School, which studied the first two phases of the scheme.