Delhi air pollution set to spike again as stubble burning begins and economy reopens

Experts say Covid-19 lockdown has reduced pollutants before stubble burning, so AQI is likely to be lower than last year. But a sharp spike is still expected.

A Delhi Metro train running through the smog in November 2019 | File photo: Suraj Singh Bisht | ThePrint

New Delhi: The approaching winter signals the annual return of the dreaded pollution and smog in Delhi — largely attributed to Punjab and Haryana farmers burning paddy stubble in their fields. But this time around, the resumption of economic activity after the Covid-induced lockdown could end up being as big a culprit.

The lockdown gave Delhiites a breath of fresh air for several months. At the beginning of September, the air quality index (AQI) in Delhi was recorded at 41 — the lowest since the National Air Quality Index was launched in 2014.

However, just as satellite images began spotting farm fires in Punjab last week, Delhi’s air quality too began to deteriorate — the capital’s AQI Monday morning was at 140, which falls in the moderate category.

According to the System of Air Quality and Weather Forecasting And Research (SAFAR), the pollution predictor run by researchers at the Indian Institute of Tropical Meteorology, favourable weather and wind conditions have so far kept the AQI in Delhi from getting any worse than ‘moderate’. The air quality is predicted to remain in the moderate category for the next three days.

Experts expect a spike

Experts say the gains from the lockdown are expected to be reversed now.

A.P. Dimri, professor at the Jawaharlal Nehru University’s School of Environmental Sciences, told ThePrint that the baseline pollution load — the level of pollutants already present in the air before the crop burning started — is less than last year, which might result in overall reduction in pollution. However, if the scale of stubble burning is similar to last year, Delhi is still likely to see a sharp rise in air pollutants.

“The gaseous constituents of the pollution may change. For example, due to the lockdown, pollutants like sulphur and nitrogen oxides, as well as surface ozone are likely to be down. But as far as PM2.5 and PM10 are concerned, they are likely to be at the same levels as before,” Dimri said.

Chandra Bhushan, environmentalist and CEO of the International Forum for Environment, Sustainability and Technology (iFOREST), also predicted that the low pollution levels will quickly be reversed due to the reopening of the economy.

“Energy consumption, transport sector and construction is going to get a lot of impetus. On the other hand, crop residue burning has already started,” Bhushan said. “I am expecting the pollution levels to spike in the coming weeks. The only saving grace can be if the meteorological conditions are in our favour.”

He also pointed out that people will need to be more careful because air pollution causes respiratory issues, as does Covid-19, and thus, “masks will become even more important than they have been so far”.

What happens every year

A Central Pollution Control Board report published last week estimated the impact of the Covid-19 lockdown on the air quality in different cities, and showed significant reduction in PM2.5, PM10 and NO2 levels this year, due to a combination of a reduced number of vehicles on the roads, the functioning of only essential commercial units, and prevailing weather conditions.

According to a 2018 study conducted by The Energy and Resources Institute (TERI) and the Automotive Research Association of India (ARAI), the major sources of pollution in Delhi in the summer include dust and construction activities (38-42 per cent), transport (15-17 per cent) and industry (22 per cent).

However, as the winter approaches, farmers in Punjab and Haryana begin to clear out the paddy residue on their farmlands by setting it on fire. The particulate matter from these fires travels down the entire Gangetic plain, enveloping vast swaths of northern India in smoke.

Cities like Delhi, Noida and Gurgaon, which are already choked with pollution from vehicles and industries that operate year-round, bear the brunt, as their meteorological conditions prevent the smoke from dissipating.

As winter sets in, the cold makes it harder for the particulate matter to rise up — leaving people exposed to the toxic smog. The festival of Diwali — which will be celebrated on 14 November this year — introduces more pollutants as people light firecrackers.

Between 2016 and 2018, Delhi pollution levels did dip by about 25 per cent, but the AQI numbers remained far higher than what is considered to be safe. According to a study by the Centre for Science and Environment, Delhi needs to cut its pollution levels further by 65 per cent to meet air quality standards.

And yet, on 22 September, satellite data began to spot the first instances of stubble burning in Amritsar, despite the fact that crop burning is now a punishable offence.

City-centric policies 

Bhushan said the work to reduce air pollution has so far been city-focussed, with measures revolving primarily around the automobile sector. For example, the Aam Aadmi Party government in Delhi imposes an ‘odd-even’ scheme for limited periods in Delhi every year — odd-numbered vehicles on odd-numbered dates and even on even dates. However, the scheme has been contentious, with studies showing it does little to reduce the pollution levels in Delhi.

The BJP-led central government, meanwhile, opened up the Eastern and Western peripheral expressways, which help 30,000-40,000 vehicles that are not bound for Delhi bypass the city every day.

Environment Minister Prakash Javadekar had also claimed that the new Motor Vehicles Act of 2019, measures to reduce stubble burning, introduction of Bharat Stage VI compliant fuel and vehicle norms, incentivisation of e-vehicles and augmentation of the Delhi Metro network had helped in reducing air pollution in the city.

However, Bhushan said the government has “lost the plot” when it comes to handling biomass burning — which contributes to the spike in pollution every year.

Dimri concurred, adding that policies against stubble burning have not been successfully implemented at the ground level.