El Nino May Worsen Mumbai's Air Pollution, Expert Warns

Mumbai may see its air pollution getting worse in the coming months as road dust, vehicle emissions, industrial activity and construction sites continue to sink the city's air quality. Now, experts warn of another danger.

The air pollution is likely to be aggravated by the El Nino factor, an expert who spoke with NDTV has said. Mumbai's coastal location does not prevent pollution from accumulating when winds are weak. Weather conditions can reduce the dispersion of emissions, while humidity and airborne sea-salt particles can contribute to visible haze.

Dr. Gufran Beig, founder-project director SAFAR and chair professor at NIAS, IISc, told NDTV, "The air pollution scenario in this coming winter of 2026 is going to be very different under the influence of El Nino. This El Nino is a super El Nino where the Pacific Ocean is already warm by more than 3.2 degrees Celsius and it is still warming, meaning the peak has not yet come."

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"This is going to change or modulate the large-scale wind circulation. The biggest impact is likely to be in coastal areas including Mumbai, where the wind speed and directions are going to be surprisingly different. In a city like Mumbai, the large-scale circulations or winds are going to be slower, meaning that the city will lose its natural protection that it enjoys when the winds are stronger," Beig adds.

Mumbai's coastal location has long been considered an advantage in dispersing pollution. Yet, as haze engulfs the city and pollution rises across neighbourhoods, the problem cannot be explained by its construction boom alone.

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On October 24, Mumbai's Air Quality Index (AQI) reportedly touched 322, placing it in the very poor category, while Delhi recorded 176.

"When the winds are slower, it will trap the pollutants," Beig said, indicating that Mumbai's proximity to the sea may not work as effectively this time.

Explaining how the El Nino makes the situation worse, he says, "The second impact of El Nino is likely to be that winter is going to be milder. This will make pollutant-rich water near the surface warmer, which is going to go up because horizontal wind speed is a little less, so it will diffuse upwards. And then as we go up, obviously the temperature decreases so at which when it is reaches to 100 metres to 200 metres, it will find cooler air."

"When the cooler air mixes with warmer air, which is already rich in air pollutants, it will get accumulated, and the haze-like layer will be formed. That is what is being seen in the skies of Mumbai," Beig adds