How Tree Lovers Rescued a Kolkata Neighbourhood |
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Kolkata: A group of tree lovers, mostly in their 70s and 80s now, has been passionately planting trees in a Kolkata locality, which now offers its own challenge to global warming.
Kolkata has been listed as one of the 20 cities in the world that have hotted up most in the last six decades by a recent UN report. The city also sports the lowest green cover among Indian mega cities.
But the south Kolkata locality of Baishnabghata-Patuli, Patuli in short, is a pleasant surprise. Tall trees cast a fine filigree of shadows on the ground here, and a few minutes of walking into the Patuli area on one side of the E.M. Bypass, where the Patuli fire brigade building is located, you feel a sudden, sharp drop in temperature even on a cool Kolkata December morning.
Patuli. Photo: Chandrima S. Bhattacharya.
At a time climate change and global warming were distant rumours, residents of the locality began to plant trees. About three decades later, the trees number about 2,000 in an area of about 1.5 sq km, bringing with them a range of climate benefits, finds a recent report by the Kolkata-based environment group The Climate Thinker.
“The temperature of the area, in Ward 101 of Kolkata Municipal Corporation (KMC), is cooler the year round by at least 3-5°Celsius in comparison with other city localities and also with the Patuli area on the other side of the bypass in Ward 110 of KMC,” says Srijan Haldar of The Climate Thinker, a biochemistry expert who teaches at Swami Vivekananda University in Barrackpur, near Kolkata.
The air pollution levels are lower here compared to other city areas. “Patuli shows a significantly higher level of ‘good’ AQI compared to other localities in the city based on West Bengal Pollution Control data from 2012 to 2018,” adds Haldar. (See chart below)
The planted area displays a wide range of biodiversity: Haldar and his team have counted about 30 species of trees and 60 species of naturally grown herbs and shrubs. Halder says that bird watchers have spotted about 60 species of birds in the area and around it.
The Climate Thinker report was conducted with the help of satellite data and on-ground observations. “We measured the temperature for six months from September 2024 to March 2025. During the winter months, the Patuli side where trees were planted consistently measured at least 5° Celsius less than the other side. In the summer months the difference went up to about 7° Celsius,” says Haldar.
A United Nations Environment Programme (UNEP) report released in November at COP30 points out that the rise of average temperature in Kolkata, at 2.67°C, was highest during 1958-2018 among 20 global cities and regions.The Indian State Forest Report 2023 also shows Kolkata having the least green cover, by far compared to Delhi and Mumbai, among six Indian cities.
“A substantial proportion (16.6%) of trees in this region have a height above 10 metres. For a rapidly developing metro city, the high proportion of larger and taller canopies over this area is astonishing,” says The Climate Thinker report.........