Delhi's air quality severe; AAP govt now mulls artificial rainfall to tackle smog

Even as the national capital continues to face alarming level of pollution, the AAP government is contemplating a spell of artificial rain on November 20-21 to provide relief to Delhi residents gasping due to a sharp dip in air quality over the past one week. The air quality index in Delhi has remained in the ‘severe’ category for seven days in a row due to stubble burning in neighbouring states coupled with local factors such as vehicular emissions.

Delhi Environment Minister Gopal Rai and Finance Minister Atishi held a meeting with a team from IIT Kanpur, which proposed that a spell of artificial rain may help amid the air emergency in the national capital. “The IIT team has said that a minimum of 40% cloud cover is necessary to create artificial rain. There is a possibility of a cloud cover on November 20-21. They have told us that if we get permission to implement this plan, we can conduct a pilot study,” Rai said.

The Delhi government has now asked the IIT team for a detailed plan. It will submit this plan in Supreme Court on Friday. The court is hearing a bunch of petitions seeking urgent steps to address Delhi's toxic air days. If the Supreme Court gives a go-ahead, the Delhi government and the Centre will take steps to implement the plan.

Gasping for clean air

Delhi gasped for clean air for the seventh consecutive day as the quality was recorded in the 'severe' category on Thursday (November 9) morning, with a marginal improvement expected just ahead of Diwali as meteorological conditions are likely to become slightly favourable.

The city's Air Quality Index (AQI) stood at 420 at 8 am on Thursday, compared to 426 at 4 pm on Wednesday (November 8). The AQI map prepared by the Central Pollution Control Board showed clusters of red dots (indicating hazardous air quality) spread across the Indo-Gangetic plains. Neighbouring Ghaziabad (369), Gurugram (396), Noida (394), Greater Noida (450), and Faridabad (413) also reported very bad air quality.

Delhi’s Environment Minister Gopal Rai has called a meeting of ministers at 12.30 pm, Thursday, at the state Secretariat to discuss the issue. The meeting will be attended by Finance and Revenue Minister Atishi, Health Minister Saurabh Bhardwaj, Transport Minister Kailash Gahlot, Social Welfare Minister Rajkumar Anand and Food and Supply Minister Imran Hussain.

“Stubble burning is much less than last year. Previously, stubble burning was happening in a scattered manner. Now that the sowing season is coming, they are in a rush to burn it all. We are talking to the people there. We need immediate action there," he told reporters on Thursday morning.

"The speed of the air has never been still for so long. In this condition, we are trying to reduce all the sources (of pollution). As a blanket layer is there, pollution is trapped inside as well. If we do not control the new pollution, then the level will increase very much... That's why we are taking so many strict measures. Whether it's the winter action plan, GRAP, or implementing the direction given by the Supreme Court," he added. 

According to officials at the India Meteorological Department (IMD), a change in wind direction from northwest to southeast due to a fresh western disturbance affecting northwest India will help reduce the contribution of smoke from stubble burning, but slow wind speed will counteract this.

However, once the western disturbance passes, the wind speed will increase from around 5-6 kmph, at present, to around 15 kmph on November 11, which will help disperse pollutants ahead of Diwali, the official said. According to data from the Decision Support System, a numerical model-based framework capable of identifying sources of particulate matter pollution in Delhi, stubble burning in neighbouring states, particularly Punjab and Haryana, accounted for 38 per cent of the air pollution in Delhi on Wednesday. It is likely to be 27 per cent on Thursday and 12 per cent on Friday. The data also shows that transport is another major factor, contributing 12 to 14 per cent to Delhi's foul air.

Winter holidays from November 9 to 18

In view of the worsening air pollution, the Delhi government on Wednesday rescheduled the December winter break of all schools, which will now be from November 9 to November 18.

Delhi Environment Minister Gopal Rai said the entry of app-based taxis into Delhi has been banned according to orders of the Supreme Court. He also said the odd-even car rationing scheme will be implemented in the national capital after the Supreme Court reviews its effectiveness and issues an order. The matter will be next heard on Friday.

On Tuesday, the apex court questioned the effectiveness of the Delhi government's car rationing scheme, aimed at curbing vehicular pollution, and referred to it as "all optics".

Anticipating further deterioration of air quality post-Diwali, Rai had on Monday announced that the flagship scheme, which permits cars to operate on alternate days based on the odd or even last digit of their registration numbers, would be enforced between November 13 and November 20.

According to the Ministry of Earth Sciences' Air Quality Early Warning System for Delhi-NCR, the region is likely to experience "very poor" to "severe" air quality for another five to six days. Doctors say breathing in the polluted air of Delhi is equivalent to the harmful effects of smoking approximately 10 cigarettes a day. Prolonged exposure to high levels of pollution can cause or exacerbate respiratory problems such as asthma, bronchitis and chronic obstructive pulmonary disease (COPD) and dramatically raise the risk of cardiovascular disease, said Rajesh Chawla, senior consultant in pulmonology and critical care at the Indraprastha Apollo Hospital.

GRAP restrictions imposed

Stringent restrictions mandated under the final stage of the central government's air pollution control plan for Delhi-NCR, Graded Response Action Plan (GRAP), have also been implemented in the national capital. The restrictions under Stage IV of GRAP, including a ban on all kinds of construction work and the entry of polluting trucks into Delhi, took effect on Sunday after the air quality in the city dropped to 'severe plus' (AQI above 450) levels.

GRAP categorises actions into four stages: Stage I - Poor (AQI 201-300); Stage II - Very Poor (AQI 301-400); Stage III - Severe (AQI 401-450); and Stage IV - Severe Plus (AQI above 450).

Unfavourable meteorological conditions, combined with vehicular emissions, paddy straw burning, firecrackers and other local pollution sources contribute to hazardous air quality levels in Delhi-NCR during the winter every year.

According to a Delhi Pollution Control Committee analysis, the capital experiences peak pollution from November 1 to November 15 when the number of stubble burning incidents in Punjab and Haryana increases.

The air quality in Delhi-NCR declined over the last two weeks due to a gradual drop in temperatures, calm winds that trap pollution and a surge in paddy straw burning across Punjab and Haryana. Delhi's air quality ranks among the worst in the world's capital cities. A report by the Energy Policy Institute at the University of Chicago (EPIC) in August said that air pollution is shortening lives by almost 12 years in Delhi.

(With inputs from agencies)