India, Nov. 12 -- Farm fires in Punjab and Haryana peaked for the season on Diwali, and the surge was far steeper than the usual numbers suggest. Analysis of data from INSAT-3DS, Isro's weather satellite, by this newspaper found that daily fire detections in the week to November 9 were 12.5 times those of the week to November 1. The count from Nasa's satellites, long considered the yardstick for stubble burning, rose 2.4 times.

The reason is timing. Nasa's satellites pass over the region in the afternoon, and the fields now burn in the evening. In 2021, another satellite - Europe's Meteosat - recorded 53% of the season's fire heat after 3pm; by 2025, the share was 98%. The count has collapsed as a result, though the burning has not. Nasa...