10 Karnataka districts face very high heat risk: Study

Bengaluru: Dakshina Kannada, Udupi and Uttara Kannada top the chart of 10 districts in Karnataka that face "very high" heat risks, as per a new study which shows no district in the state has low risk.

Council on Energy, Environment and Water (CEEW), a not-for-profit research centre, assessed the heat risk of 734 districts by using 35 indicators to look for a granular picture of heat hazard trends from 1982 to 2022. Heat risk comprises intensity of heat and compounding factors like humidity, number of people exposed and their vulnerability.

The study looked into monsoon data, high resolution climate dataset at 12-km grid level, satellite imagery to assess 35 indicators, including land use and land cover dynamics, green cover, water bodies etc, for a more comprehensive understanding.

As many as 151 districts, including 10 from Karnataka, fell in "very high" risk category while 266 (18 from Karnataka) were in the "high" risk group and 201 faced moderate risk. Only 116 were in the low and very low risk categories and none of them were from Karnataka. Except for Chikkaballapur and Bengaluru Rural which were classified as 'moderate' risk.

The socio-economic and health vulnerabilities (NFHS 2019-21), data regarding nighttime temperature and relative humidity gave a comprehensive understanding of heat hazard beyond daytime temperatures.

Besides confirming several studies warning about the increase of "very hot" days in India, the assessment looked at the rising number of increasingly warmer nights. "Over the last 40 years (1982-2022), heat extremes in India have increased linearly. This led to landmark heatwaves in 2013, 2016, 2019, 2022 and 2024. However, in the last decade, the number of very warm nights has been rising faster than that of very hot days," the study said.

Warm days and nights are defined as periods when minimum and maximum temperatures rise above the 95th percentile threshold. Warm nights prevent the cooling down of the body, leading to significantly higher risk for heat strokes while worsening diabetes and hypertension.

Vishwas Chitale, senior programme lead at CEEW, said India needs to invest in long-term resilience. "States like Maharashtra, Odisha, Gujarat and Tamil Nadu are already taking pioneering steps by integrating climate and health data into local planning. Now is the time to scale these efforts nationally, using district-level risk assessments to prioritise funding and action," hestated.

The study also recommended further strengthening of heat action plans (HAP). "We recommend creating an open-access, centralised, national level HAP repository," it said.