Heatwaves may burden health, agriculture in India: Cambridge study

Heatwaves in India are increasing in frequency, intensity and lethality, burdening public health, agriculture, and other socio-economic and cultural systems, says a study. The study, "Lethal heat waves are challenging India's sustainable development" published in PLOS Climate by Ramit Debnath of University of Cambridge, Britain, and colleagues, suggests heatwaves made more likely by climate change may impede India's progress toward its sustainable development goals.

India has committed to achieving 17 UN Sustainable Development Goals (SDG), including no poverty, good health and well being, and decent work and economic growth. However, current climate vulnerability assessments may not fully capture how heatwaves linked to climate change may impact SDG progress.

In order to analyse India's climate vulnerability, and how climate change may impact SDG progress, researchers conducted an analytical evaluation of India's heat index with its climate vulnerability index, a composite index using various indicators to account for socioeconomic, livelihood, and biophysical factors. They accessed a publicly available dataset on state-level climate vulnerability indicators from the Indian government's national data and analytics platform to classify severity categories.

The researchers then compared India's progress in SDG over 20 years (2001-2021) with extreme weather-related mortality from 2001-2021.

The researchers found that heatwaves have weakened SDG progress more than previously estimated and that current assessment metrics may not sufficiently capture the nuances of India's vulnerabilities to climate change impacts. For instance, in estimating heat index, the study shows that nearly 90 per cent of the country is in danger zone from heatwave impact.

According to climate vulnerability index, around 20 per cent of the country is highly vulnerable to climate change. Similar effects were observed for the national capital, where heatwave impact estimates shows almost all of Delhi is threatened by severe heatwave impacts, which is not reflected in its recent state action plan for climate change.

However, this study had several limitations, for example the incongruent timeframe for climate vulnerability index data (2019-2020) and heat index data (2022). Future studies should incorporate more recent data.

According to the authors, "This study shows that heatwaves make more Indian states vulnerable to climate change than previously estimated with the climate vulnerability index.