Kolkata: The soaring summer heat is linked to shrinking green cover and rising built-up areas, according to a report by the Centre for Science and Environment (CSE).
Summers in Kolkata are becoming increasingly unbearable, not just because of rising mercury but due to the city’s rapidly transforming landscape. The report highlights that unchecked urban expansion, shrinking green space and diminishing water bodies are altering the city’s natural ability to stay cool, turning it into a heat trap.
CSE, a Delhi-based environmental think tank, conducted a study from 2001 to 2023, analysing land surface temperatures and humidity trends across six megacities — Delhi, Mumbai, Kolkata, Hyderabad, Bengaluru, Chennai — and four smaller cities — Chandigarh, Jaipur, Lucknow and Pune. The findings reveal a disturbing trend: urban areas are becoming heat zones, with heatwaves growing more intense.
In Kolkata, the study found that the built-up area, which includes concrete infrastructure and roads, rose sharply from 70% in 2001 to 80.1% in 2023. In contrast, green cover, crucial for temperature regulation, slightly declined from 15.2% to 14.5%. Alarmingly, scrubland and barren land, which earlier acted as buffer zones, plummeted from 9.8% to 3.4%, and water bodies reduced by more than half — from 5.1% to 1.9%.
These changes are key contributors to the Urban Heat Island (UHI) effect, where densely built-up urban areas retain more heat than their surroundings. With less vegetation and water to moderate temperatures, heat lingers well into the night, increasing public health risks, particularly during summer and monsoon months.
What makes Kolkata’s heat even more punishing is its high humidity. The CSE report underscores that humidity has become a major driver of urban heat stress, particularly in coastal cities like Kolkata and Mumbai. The Heat Index — a measure of how hot it feels when relative humidity is factored in — has skyrocketed. In cities like Chennai, humidity added nearly 7°C to the perceived temperature. Kolkata, with its already high humidity levels, now frequently crosses thresholds that cause extreme heat stress.
CSE’s analysis utilised satellite data from Landsat 7 and 8, focusing on the Normalised Difference Vegetation Index (NDVI) to assess green cover during India’s hottest months — April to June. NDVI readings showed a consistent decline in vegetation, particularly during heatwave periods, correlating directly with the city’s rising thermal stress. The reduced green cover means the city has lost its natural heat-mitigation shield, accelerating the impact of climate change at a hyperlocal level.
The CSE report makes it clear: India’s cities are becoming hotter, wetter, and more dangerous, particularly for vulnerable populations. Without a clear and immediate shift in urban planning — focused on restoring green cover, conserving water bodies, and limiting unplanned construction — the situation is set to worsen.

Koraput: Tension gripped the block headquarters of Padmapur in Rayagada district after a 55-year-old man was allegedly lynched by a mob on Monday night over the suspicion of practising sorcery. The deceased, identified as Bhairav Sahu, a resident of Hatapada Sahi, succumbed to his injuries while undergoing treatment at Padmapur hospital, police said.
According to Sahu’s daughter, Rasmita, a group of villagers confronted her father around 9 pm, accusing him of being responsible for the recent death of a local. The deceased reportedly suffered from blood cancer, but villagers alleged that he died due to “black magic” performed by Sahu.
What began as questioning by the group soon turned violent, Rasmita said. “A crowd of nearly 200 people attacked my father. They paraded him naked through the village, beating him mercilessly with sticks, iron rods and sharp-edged weapons from one street to another,” she said.
She added that their house was also vandalised. “We pleaded with the mob to let him go. My father had no connection with sorcery. But the brutality went on for nearly four hours,” she said.
Police were alerted and a team led by IIC of Padmapur police station, Dharanidhar Pradhan, arrived at the scene. However, the situation spiralled out of control, and the IIC sustained a serious head injury after being struck by a stone hurled by the mob.
As Pradhan was being rushed for medical attention, the mob’s fury turned entirely towards Sahu. Police managed to eventually rescue him and rushed him to Padmapur hospital, where he died during treatment.
In response to the violence, four platoons of security personnel have been deployed in the area to maintain law and order.
Rayagada SP Swathy S Kumar said that 28 people have been arrested in connection with the crime.
Two FIRs have been registered — one by the police for the attack on the IIC and another by the family of the deceased. “Investigation is ongoing, and efforts are underway to identify and apprehend others involved,” the SP said. “The situation in the village is now under control and additional forces have been stationed to prevent any further unrest,” she added.

JACTO-GEO members taking out a rally in Madurai on Tuesday.
| Photo Credit: R. ASHOK

Raising several demands, including implementation of old pension scheme, members of Joint Action Council of Tamil Nadu Teachers Organisations and Government Employees Organisation (JACTO-GEO) took out a rally from World Tamil Sangam to Collectorate here on Tuesday. 

They demanded the abolition of the Contributory Pension Scheme (CPS) and sought the revival of the old pension scheme, ending the practice of outsourcing employees for government departments through private agencies, disbursement of dearness allowance without delay and resumption of the leave encashment.   

Murugaiyan, State coordinator, said that their demands were not new, but which were promised by DMK during the election.  

Now, it is more than four years, but still the government was not heeding to the voices of the protesting teachers, he added.  

Even some of the basic demands like pay for teachers of all grades – middle, primary, high and higher secondary, including physical education teachers, on a par with the pay scale of the Central government, filling of existing vacancies to reduce the burden off the existing staff, were not fulfilled by the State government, Mr. Murugaiyan stated.  

“We demand the immediate announcement of the promises in the Assembly session itself,” he added.  

The protesters warned that if the demands were not met, they would organise a mass State-wide strike in Chennai.