Due to global warming, heat waves are becoming more and more common in India. In 2022, thermometers reached 49°C, an unprecedented temperature in New Delhi.
On hot days there is nowhere to hide, especially for those living in favela areas. In addition to little vegetation and shade, these areas have many stuffy houses with poor ventilation where large families live.
But in different parts of the country, people are looking for easy and inexpensive ways to cool off.
In Delhi, making and selling ice blocks has become a relief for many. Ice cream is made in factories using an ancient, 120yearold technique that involves mixing ammonia with salt water to create a freezing liquid. The process is more environmentally friendly than other processes used for cooling.
“Salt water is necessary to maintain the temperature for ice formation,” Anwar Tariq, owner of a local ice block factory, told the BBC.
Once the blocks are finished, they are sold by merchants in the city for around 5 or 10 rupees (less than R$1).
Vendors transport blocks of ice in Delhi (Photo: Getty Images) Ice is used by restaurants and retailers to preserve food and products, but also by residents and shopkeepers to cool down. “People take it home and to shops, the milkman takes it for his milk, the lassi seller takes it for his lassi and the butcher takes it so that his meat doesn’t rot,” explains Mohd Sameer, an ice cream dealer in Delhi .
Lassi, a mixture of yogurt, water, spices and sometimes fruit, is a traditional drink in India and is served over ice in hot weather. “Those who take a small piece are impoverished people, exhausted from daily work, who buy to feel some relief,” says Sameer.
But the richer and hotter India becomes, the more people are buying refrigerators. This contributes to climate change and harms the ice trade. “In 10 or 20 years this work will disappear,” says Sameer.
Ice cream is also used by lassi sellers (Photo: Getty Images)
Roofs painted white
Another technique that is becoming increasingly popular is painting roofs and ceilings white. In Amedabad, one of India’s most heatsensitive cities, temperatures often reach 42°C sometimes even as high as 48°C.
Shakeela Bano is a grandmother and lives with five other people in a windowless house in the city. It’s often impossible for your family to escape the heat. At the height of the 2021 heat wave, they spent the hottest days outside and alternated trying to sleep in the cooler parts of the house at night.
The heat was so hot that one of Shakeela’s granddaughters developed facial sores from the temperature and sweat. Until they were approached by a housing association that helps families cool their homes.
Floor panel painted white in Ahmedabad (Photo: BBC) The institution suggested Shakeela to paint the top floor panel of her house white to minimize heat absorption. The measure helped freshen up the environment and the Indian woman’s grandchildren can now sleep a little more comfortably in the house.
Concrete slabs absorb heat, but white paint reflects up to 90% of sunlight, reducing the temperature. “After application, the temperature can drop by 3 to 4°C,” explains Krishna Yadav of Krishna Housing Fund.
She recommends painting panels and roofs with two coats of white paint, with the second coat applied four hours after the first. In Amedabad, the fund offers lowinterest loans to families to buy paint and paint their roofs.
In Leh, further north in India, a new use for ice was found. Ecologist Sonam Wangchuk has developed a technique that uses giant cones of ice that store water to cool and irrigate vegetation in summer and drought.
The socalled ice stupas are 12 stories high and can hold around 10 million liters of water. They are built in winter and serve as relief in summer.
“Because of their geometric shape, they don’t melt until June,” says Wangchuk.
The construction of a 30meterhigh ice stupa takes almost three months. Scientists are connecting a tube connecting the river closest to where the ice cone will be.
Ice stupas in northern India (Photo: BBC) “The pressure throws water into the winter sky at 20°C and freezes into an ice cone,” explains the ecologist. In summer, the water stored from the melting ice is then used to irrigate vegetation and improve the drought situation.
“You can plant trees in the desert. The flow speed of streams can be increased so that farmers have a little more water in times of crisis,” he explains.