Delhi's air pollution is down by 25%, need is to reduce another 65%

Enforcement of graded response action plan on pollution hotspots in the national capital can help achieve clean air

Delhi has, in the last 10 years, made visible strides in ameliorating its air quality.

Director General of Centre for Science and Environment (CSE) Sunita Narain and Anumita Roychowdhury, executive director and head of the air pollution and clean transportation programme at CSE discuss how this was achieved and how to bring it down even further.

CSE conducted a granular analysis of the air quality data provided by the Central Pollution Control Board for the last 10 years.

Delhi has managed to bend the pollution curb “with over all particulate pollution down by 25 per cent”, Roychowdhury said. This has happened because of transition to clean fuel in the capital.

“First of all three (thermal) power plants were shut equalling 1,245 megawatts of generating capacity. Dirty fuels like pet coke, furnace oil and coal were also banned. As a result, a massive transition to natural gas happened not only in the transportation sector but also in the industrial sector,” Roychowdhury said. 

BSVI fuel has already arrived and has been scaled up in the city, she added.

Other measures for cleaner air include regulation of trucks entering the city, a ban on 10-year-old trucks and environmental cess on them. A cashless system tax collection using RFID (radio frequency identification) improved cess collection.

There is also a reduction in the use of diesel generators, all these have helped immensely.

But Roychowdhury cautioned that in order to meet clean air standards, pollution load will have to be reduced by another 65 per cent and that could bring in more disruptive measures.

Narain said that while pollution usually increases after mid-October, the sources of pollution remain the same. There is little dispersion of pollutants as there is no wind, she said.

“Cold wind is coming into Delhi. No wind, no dispersion, that makes the same sources of pollution choke us,” Narain said.

“Local sources of pollution are key reason why Delhi and its surrounding areas are seeing poor or very poor pollution levels,” she expalined.

Pollution from stubble burning in Punjab and Haryana contribute about 5-7 per cent to Delhi's pollution load, but could go up if there is a wind blowing down from the north. But the main sources of pollution are still local, she said.

The graded response action plan (GRAP), which came into effect from October 15, requires every city in the National Capital Region (NCR) to act. Roychowdhury said enforcement of the GRAP will be crucial for curbing pollution this winter. 

Pollution hotspots in NCR will be a key focus this year. There are 14 such areas where pollution levels exceed the city average. These areas have high pollution because of the burning of municipal solid waste and industrial waste. 

Narain said that the only way to reduce the remaining 65 per cent of pollution is by ensuring that local sources of pollution are kept in check. For this local action plans will have to be implemented in these pollution hotspots which are enforceable.