Farm Fire Pollution: Despite Record Low Stubble Burning, Farm Fires Still Haunt Delhi’s Air Quality
Farm Fire Pollution: This season (Oct-Nov), satellite data indicates that the number of stubble-burning incidents in Punjab and Haryana was the lowest on record. In Punjab, farm fires were down by 70% compared to the previous year, while Haryana saw a 42% reduction in incidents. Despite these encouraging figures, the impact of stubble burning on Delhi's air quality remains a concern.
How Can Low Stubble Burning Still Affect Delhi’s Air Quality?
Even though fewer farm fires were recorded this season, the contribution of stubble burning to Delhi's PM2.5 levels remained significant. Experts explain that the influence of farm fires on Delhi’s air quality depends largely on meteorological conditions, especially the wind direction and air ventilation.
Transport Winds: If strong north-westerly winds blow towards Delhi, they can carry pollutants from stubble burning in neighboring states, regardless of the number of farm fires.
Air Ventilation: Proper air ventilation is essential to disperse pollutants. Without it, even a reduced number of stubble burning incidents can lead to poor air quality in Delhi.
Impact of Stubble Burning on Delhi's Air Quality
From October 23 to November 23, 2023, stubble burning contributed over 15% to Delhi's PM2.5 levels on 26 days. On 14 of these days, the contribution exceeded 20%. The highest single-day contribution of farm fires to Delhi’s air quality occurred on November 1, 2023 (35.2%), the day after Diwali. Other significant days were October 31 (27.6%) and November 22 (26.2%).
Weather Conditions and Stubble Burning Contribution
While stubble burning impacts were significant this year, scientists point out that meteorological factors played a crucial role. According to an analysis by the Indian Institute of Tropical Meteorology (IITM), the contribution of farm fires to Delhi's air quality was higher in 2023 than in 2021 and 2022, despite lower stubble-burning counts in neighboring states.
2023 Impact: From October 22 to November 30, 2023, stubble burning contributed more than 10% to Delhi's air quality on 58% of days, over 15% on 44% of days, and above 20% on 30% of days.
2022 and 2021: In contrast, farm fires contributed more than 10% to Delhi’s air quality for 32% of days in 2022 and 2021.
The Need for Long-Term Solutions to Air Pollution
Experts like Anumita Roychowdhury from the Centre for Science and Environment stress that the contribution of farm fires to Delhi’s air quality is variable, depending on winds. While stubble burning remains a major source of pollution, local pollution sources also play a significant role in Delhi’s air quality.
Roychowdhury emphasizes that tackling air pollution in Delhi requires addressing all sources, not just stubble burning. Reducing emissions from other sources, such as industrial pollution and vehicle emissions, is crucial for improving the air quality in the entire region.
