Delhi's Air Quality Slips to 'Very Poor' on Diwali Eve, CAQM Imposes Stage 2 of Grap

Strategic Insights -

As the capital prepares to celebrate Diwali, the air quality in Delhi slipped to the 'very poor' range on Sunday evening, prompting the Commission for Air Quality Management (CAQM) to impose stage 2 of the Graded Response Action Plan (Grap). This move restricts the use of diesel generators (DG sets) across the National Capital Region (NCR) and bars interstate buses, other than those running on electricity, CNG or BS-VI diesel, from entering Delhi. Forecasts indicate that unfavourable weather conditions and emissions from firecrackers will worsen the air quality to 'severe' levels by Tuesday.

Key Takeaways:

  • The air quality in Delhi slipped to the 'very poor' range on Sunday evening, prompting CAQM to impose stage 2 of Grap.
  • Stage 2 of Grap restricts the use of DG sets across NCR and bars interstate buses, other than those running on electricity, CNG or BS-VI diesel, from entering Delhi.
  • Forecasts indicate that unfavourable weather conditions and emissions from firecrackers will worsen the air quality to 'severe' levels by Tuesday.
  • The impact of additional emissions due to firecrackers on Diwali is likely to stay in the air through most of the week, with no respite from extremely toxic air until at least Friday.
  • According to the Air Quality Early Warning System (AQEWS), further deterioration of air quality to the higher end of the 'very poor' category is expected by Diwali day, and to 'severe' levels by Tuesday.
  • Mahesh Palawat, vice president at Skymet Meteorology, attributed the accumulation of local emissions to stagnation, saying that for the last three to four days, winds have been calm, preventing pollutants from dispersing.
  • In the next four to five days, Palawat warned that there will be no significant relief from pollution, as winds will not pick up and the impact of firecrackers may linger for a few days.
  • Delhi has had some form of ban on firecrackers since 2017, with limited use of green firecrackers allowed in 2018 and 2019.

Statistics:

  • The city's average air quality index (AQI) during the preceding 24 hours stood at 296, in the upper end of the 'poor' zone, at 4pm Sunday.
  • By 7pm, the AQI had slipped into the 'very poor' range at 302.
  • According to the AQEWS forecast, the air quality is likely to worsen to the higher end of 'very poor' on Monday.
  • The impact of additional emissions due to firecrackers on Diwali is likely to stay in the air through most of the week, with no respite from extremely toxic air until at least Friday.

Sources:

  • Times of India, New Delhi: The capital's air quality slipped to the 'very poor' range on Sunday evening, a day before Diwali, prompting CAQM to impose stage 2 of the Graded Response Action Plan (Grap). Stage 2 of the plan restricts use of DG sets across NCR and bars interstate buses, other than those running on electricity, CNG or BS-VI diesel, from entering Delhi.
  • Skymet Meteorology: Mahesh Palawat, vice president at Skymet Meteorology, said despite stubble burning not playing a key role yet, local emissions were accumulating due to stagnation.
  • Air Quality Early Warning System (AQEWS): The AQEWS bulletin stated that the air quality is very likely to be in the 'severe' category from Tuesday till Wednesday - in case of enhanced emissions from firecrackers.