ozone
Globally, the ozone layer is on a recovery path and, if current policies remain in place, ozone outside the polar regions is expected to return to around 1980 levels by about 2040, said Anumita Roychowdhury, Centre for Science Environment (CSE) executive director and lead researcher. During Nov 2025-Jan 2026, Kolkata still recorded 12 days when ozone exceeded the standard, pointing to pollution episodes outside the conventional high-ozone summer period. During March-May 2025, Rabindra Sarobar recorded ozone exceedances on 17 days, followed by Jadavpur on five, Rabindra Bharati University on three and Victoria Memorial on two.
The depletion of the protective ozone layer is a global atmospheric phenomenon rather than a local “ozone hole” over Kolkata. Kolkata: The ozone Kolkata needs is recovering. The ozone its residents breathe, however, remains a pollution concern — creating an atmospheric paradox as the world observes World Ozone Day. The two should not be confused. But that does not mean the ozone problem has disappeared. There is another Kolkata paradox: some of the city’s greener neighbourhoods have emerged as ozone hotspots. Ballygunge, Bidhannagar and Fort William recorded none, the study shows.
Kolkata’s zero summer exceedance days in 2026 are therefore encouraging, but scientists will need to determine how much resulted from emission changes and how much from meteorological factors such as cloud cover, rainfall, temperature and atmospheric chemistry. You Can Also Check: Gold Rate in Kolkata | Silver Rate in Kolkata | Bank Holidays in Kolkata | Public Holidays in Kolkata | Kolkata AQI | Weather in Kolkata | Petrol Price in Kolkata | Diesel Price in Kolkata | CNG Price in Kolkata | LPG Price in Kolkata