Under special contract with The Economist: A fictional picture from June 2041 How Indian cities will cope with the scorching heat

The Economist creates an imaginary picture of some possible situations every year. These reports are based on historical facts, current estimates and science. This report takes stock of the extreme heat conditions in two cities of India-Hyderabad and Chennai in the year 2041.

Three weeks have passed since the deadliest heat wave in the history of India. The temperature in the capital Delhi is 49.3 degree Celsius. South India is even hotter. Chennai city has the biggest crisis. There are crowds of people sick with the heat in the hospitals. The real problem of Chennai is moisture. The heat and moisture in the air are called wet bulb temperature. It is the minimum temperature at which anything cools through evaporation from the surface.

Even in dry air at 37 degrees human body temperature, people can sweat and cool down. But, physical exertion at the weight bulb temperature of 32 degrees is not free from danger, says physicist Motsim Ashfaq of Oak Ridge National Laboratory, Tennessee. Very few people survive in the 35 degree wet bulb temperature. In Chennai, the wet bulb temperature for the last ten years is more than 32 degrees.

According to official figures, 17 thousand 642 people have died due to heat in Chennai. But, when compared with the nearby Hyderabad, this figure looks quite shocking. The population of both the cities is about one crore. The temperature of their surroundings is the same. But only 26 deaths have occurred in Hyderabad, the least of any other major city in South India.

After the heat wave in Hyderabad 26 years ago, efforts to reduce the heat in the city began rapidly. In 2015, 585 people died in the scorching heat in the city and nearby areas. This was the turning point of change. The heat can be reduced by reflecting the sun’s rays from the buildings to the other side.

The Hyderabad Municipal Corporation started the Cool Roof Program in 2017 in low-income areas of the city. The worst hit of heat wave falls in these areas. Cheap white polyethylene coating sheets were installed on the roof of the houses. The temperature of the houses dropped by two degrees.

hypothetical situation of 2041

Cool Roof Program was implemented in Telangana in 2019. By 2027, cool roofs were installed in over 8,000 buildings in Hyderabad. Under NREGA, the rural employment scheme implemented in cities in 2030, white lime was painted on slums and temporary constructions. 25 lakh saplings were planted in the city.