Early dip in stubble fires offers brief relief, but pollution threat looms

Delhi’s brief reprieve from pollution, a welcome breath of fresh air during the monsoon months, might just linger a little longer. As the first gusts of the stubble-burning season sweep in, the skies are showing a promising change — incidents of crop residue burning have plummeted by nearly 65 per cent. Between September 15 and October 8, 2024, only 546 such cases were recorded, a significant drop from 1,565 during the same period last year.

While this dip in stubble burning has helped keep Delhi’s air cleaner, the longevity of this relief hinges on the efficient enforcement of the Graded Response Action Plan (GRAP) measures by the Commission for Air Quality Management (CAQM). The crackdown on sources like vehicular emissions and construction dust will be crucial, especially as the stubble-burning season continues. Yet, if even a “slipstream” of non-compliance occurs, the air quality could take a turn for the worse.

Environment analysts say fire burning has just begun, with peak stubble burning expected in late October through early November. Combined with vehicular, industrial, and power plant emissions, as well as unfavourable weather conditions, this could significantly impact air quality in the coming weeks.

“It’s too early to determine if the drop in early fire counts will significantly reduce pollution levels,” said Sunil Dahiya, an independent pollution environment analyst.

Though it is still too early to determine whether Delhi’s air will remain breathable, the current air quality data offers a mix of both respite and concern. According to the Air Quality and Weather Bulletin for Delhi NCR on Wednesday, the overall air quality in Delhi is expected to remain in the “Moderate” category till Saturday. Over the following six days, it is likely to range between “Moderate” and “Poor”.

Data from the Central Pollution Control Board (CPCB), under the Ministry of Environment, Forest, and Climate Change, shows a subtle shift in Delhi’s air quality — from “satisfactory” in August to “moderately polluted” in September. As October advances, the Air Quality Index (AQI) inches closer to the “Poor” category, averaging a reading of 156 in the first eight days of the month.

An AQI of 50 or below is considered “good”, while “satisfactory” falls between 51 and 100. A “moderately polluted” reading ranges from 101-200, “poor” extends from 201-300, “very poor” between 301 and 400, and anything above 400 is deemed “severe” — where even the slightest breath feels like a burden. As winter looms, only time will tell whether Delhi can maintain its current atmospheric balance or if a haze will once again settle over the national capital.

The AQI data for 2024 shows a mixed performance across the months of August, September, and October, compared to previous years. In August 2024, the AQI stood at 72, a significant improvement from 116 in 2023 and 93 in 2022, reflecting better air quality.

September 2024’s AQI remained relatively stable at 105, showing a slight decrease from 108 in 2023 but higher than the 78 recorded in 2021. Meanwhile, October’s AQI dropped to 160, marking a notable improvement from 219 in 2023 and 210 in 2022.

Dahiya said over the next three to four weeks, the air quality is expected to deteriorate to “poor”, “very poor”, and even “severe” levels. This will be due to a combination of existing pollution sources, such as emissions from transportation, industry, and power plants, compounded by episodic events like stubble burning and firecracker bursting, along with lower wind speeds and colder temperatures.

The Supreme Court recently criticised the CAQM — a central body responsible for monitoring air pollution in the NCR and surrounding areas — for its inadequate action against stubble burning in Delhi-NCR. In response, the commission has launched “flying squads” to tackle stubble burning by farmers in Punjab and Haryana. It has also urged state governments to coordinate their efforts in fighting pollution and called on the NCR Pollution Control Boards and the DPCC (Delhi Pollution Control Committee) to streamline the handling of public complaints related to air quality.