RISING HEAT RISKS THREATEN OVER 76% OF INDIA'S POPULATION

A recent study by the Council on Energy, Environment and Water (CEEW) has found that 57% of India's districts—home to over three-fourths of its population—are now at high to very high risk from extreme heat.

- S V KRISHNA CHAITANYA @Chennai

A recent study by the Council on Energy, Environment and Water (CEEW) has found that 57% of India's districts—home to over three-fourths of its population—are now at high to very high risk from extreme heat. The report, "How Extreme Heat is Impacting India: Assessing District-level Heat Risk", issues a stark warning: heat stress is no longer a seasonal discomfort but an accelerating disaster.

Using a composite Heat Risk Index (HRI) developed for 734 districts, the CEEW study identifies Delhi, Andhra Pradesh, Goa, Kerala, Maharashtra, Gujarat, Rajasthan, Tamil Nadu, Karnataka, and Uttar Pradesh as the 10 most heat-risk-prone states and Union Territories. The report is based on 35 indicators including frequency of very hot days, warm nights, rising humidity, population exposure, urbanisation trends, and health vulnerabilities.

One of the study's most alarming findings is the rapid increase in very warm nights—defined as nights where minimum temperatures exceed the 95th percentile of historical norms. Over the past decade (2012-2022), nearly 70% of districts saw at least five more such nights per summer compared to the 1982-2011 average. In contrast, only 28% of districts experienced similar increases in very hot days.

Cities are bearing the brunt. Mumbai saw 15 additional very warm nights, Bengaluru 11, Bhopal and Jaipur 7 each, Delhi 6, and Chennai 4.

This trend is largely attributed to the urban heat island effect, where concrete-heavy infrastructure traps heat during the day and releases it at night.