‘Heat trap’ cities making summers worse: official

Indian cities have become “heat traps” due to their unbalanced growth devouring water bodies and increasing greenhouse emissions, a senior government official said yesterday, as a scorching summer killed dozens in some parts of the country.
The India Meteorological Department (IMD) has forecast above-normal temperatures for June in the northwest and central parts of the country including Delhi, making it one of the longest heatwave spells.
The highest daily temperatures in the capital have stayed above 40 degrees Celsius since May 12 and are forecast to fall below that mark only on June 26.
The IMD’s heatwave criteria start with 40C in the plains and 30C for hills where it is generally cooler because of elevation.
Delhi, which is also facing a water shortage, recorded about 44C late yesterday afternoon but the IMD said it felt like 49.2C.
“Climate change plays an important role,” Krishna S Vatsa, a member of the National Disaster Management Authority, said.
Unbalanced urban growth, which has reduced wetlands and water bodies, was another factor, Vatsa said. “The emission of greenhouse gases has gone up. The permeable spaces have gone down considerably. The cities actually have become heat traps.” As a result, he said, nights are nearly as uncomfortable as days. According to a study by the Centre for Science and Environment (CSE) published last month, land surface temperatures in the summers of 2001-2010 in cities such as Delhi, Hyderabad, Kolkata and Mumbai used to drop by up to 13.2C during the night from their day-time peak. Between 2014 and 2023 they were only cooling off by up to 11.5C.
“Hot nights are as dangerous as mid-day peak temperatures,” the Centre’s report said. “People get little chance to recover from day-time heat if temperatures remain high overnight.”
Vatsa said most Indian states were implementing heat action plans that include provisioning drinking water and better medical facilities, as well as rescheduling outdoor work and school vacations.
But Anumita Roychowdhury, CSE’s executive director, said there was no clear mandate to implement long-term strategies. Delhi’s long-term plan includes increasing heat insulation of buildings, developing shelters for urban poor and slum dwellers, and investing in cooling water bodies.