NGT amicus flags data gaps and cloud seeding failures in NCR pollution

The submission cites cases of sprinkling near monitors and seeks answers from CAQM and states on how monitoring integrity is being safeguarded.

The National Green Tribunal-appointed amicus curiae Sanjay Upadhyay,on November 19, has raised urgent concerns over worsening air pollution in the National Capital Region (NCR), stating in an affidavit to the tribunal that despite the Graded Response Action Plan (Grap) being in force, air quality has not improved and emergency interventions such as cloud seeding have delivered no measurable results. He has also flagged discrepancies in pollution data, including instances of water being sprinkled near air monitoring stations, and suggested that the tribunal may question the Delhi government for its expenditure on cloud seeding and state pollution control boards for anomalies across multiple states.

Thick haze engulfs Motilal Nehru Marg on Wendesday morning. (Arvind Yadav/HT)

The affidavit, dated November 6 and shared recently, said source apportionment studies had not been completed in several non-attainment cities, and even where they had been carried out, city action plans had not been updated accordingly. This included Delhi, with Upadhyay noting that although the latest source apportionment study was completed in 2023, the city action plan was last updated in 2018.

“Stage 1 Grap was initiated on October 14, and stage 2 on October 19, 2025. Despite stage 2 Grap orders, the AQI has consistently remained in ‘poor’ to ‘very poor’ quality,” the submission said, listing data quality as a central concern.

Citing newspaper reports, the amicus said there had been “tampering with AQI monitor readings by undertaking sprinkling close to AQI monitors and thus reducing the PM level reading by the monitors to mislead and misinform about the severity of the air quality situation,” giving examples of such sprinkling outside the Anand Vihar and RK Puram monitoring stations.

The tribunal has been hearing multiple pollution-related cases from NCR and other parts of the country and had clubbed them into one application. In October 2024, it appointed senior advocate Sanjay Upadhyay as amicus.

Upadhyay said pollution control boards must explain the causes behind data anomalies. “This appears to be a very serious allegation where human health and the right to life itself are at stake. The CAQM (Commission for Air Quality Management) also needs to explain the action taken in this regard,” he said, adding that emergency measures such as cloud seeding had failed.

He pointed to the Delhi government’s memorandum of understanding with IIT Kanpur worth ₹3.21 crore for five cloud seeding trials. “Two experiments were undertaken in October 2025; however, the experiment failed both times. One of the main causes for the failure as reported by both IIT Kanpur and IIT Delhi is that winter months are climatologically unsuitable for consistent cloud seeding due to lack of moisture and saturation and western disturbances,” he said, adding that multiple reports indicate it is only a short-term measure.

“The Delhi Government may be asked to explain the raison d’être of going for cloud seeding and paying taxpayers’ money. What were the other emergency measures taken for curbing air pollution other than cloud seeding measures, which have turned out to be a failure admittedly?” the submission said.

Upadhyay added that stubble burning still continued in parts of Punjab, Haryana and NCR Delhi, though somewhat reduced. He said the tribunal may seek updated information on stubble burning incidents and action taken by CAQM and state boards. “Secondly, what are the ground measures that have been taken to discourage or incentivise the stubble burning?” the submission stated.

Sharing data on source apportionment studies, he recalled the tribunal’s order dated July 29 directing the CPCB to reveal the status of such studies across 53 cities. Source apportionment has been completed in 12 cities and is underway in seven, including Noida, Khurja, Jhansi, Lucknow, Amritsar, Thane and Faridabad.

“In the 12 cities where the source apportionment studies have been completed, i.e., the City Action Plans are yet to be refined or aligned as per the source apportionment studies. The existing city action plan in these cities is merely based on the available data and understanding of pollution sources in each city,” he said, adding Delhi has the same problem.

In the medium term, he proposed the creation of a committee for establishing and monitoring urban airshed models in different states, with inputs from non-attainment cities. “Can a technical committee be constituted by NGT to identify airsheds across states?” he added, also raising the question of whether city-specific Grap should replace the current emergency-only format. “Grap can no longer be limited to the NCR region and areas adjoining it and should be extended to other states and regions,” the note said.