Similar effects were observed for the national capital, where HI estimates show almost all of Delhi is threatened by severe heat wave impacts, which is not reflected in its recent state action plan for climate change, the researchers said.
Heat waves made more likely by climate change may impede India's progress towards its sustainable development goals, according to a study. 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, researchers at the University of Cambridge, UK, and colleagues suggests that current climate vulnerability assessments may not fully capture how heat waves linked to climate change may impact SDG progress. "This study shows that heat waves make more Indian states vulnerable to climate change than previously estimated with the CVI," the authors of the study said.
"The heat waves in India and the Indian subcontinent become recurrent and long-lasting, it is high time that climate experts and policymakers reevaluate the metrics for assessing the country's climate vulnerability," they said.
The study, published in the journal PLOS Climate, evaluated India's heat index (HI) with its climate vulnerability index (CVI), a composite index using various indicators to account for socioeconomic, livelihood, and biophysical factors.
The team accessed a publicly available dataset on state-level climate vulnerability indicators from the Indian Government's National Data & Analytics Platform to classify severity categories. They then compared India's progress in SDG over 20 years (2001–2021) with extreme weather-related mortality from 2001–2021.
The researchers found that heat waves 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 HI, the study shows that nearly 90 per cent of the country is in danger zone from heat wave impacts.
According to the CVI, about 20 per cent of the country is highly vulnerable to climate change. Similar effects were observed for the national capital, where HI estimates show almost all of Delhi is threatened by severe heat wave impacts, which is not reflected in its recent state action plan for climate change, the researchers said.
However, this study had several limitations, for example the incongruent timeframe for CVI data (2019–2020) and heat index data (2022). Future studies should incorporate more recent data, the researchers said. The study offers a scope for developing a holistic vulnerability measure through international cooperation and partnership.
"Heat waves are getting more intense in India, putting 80 per cent of the country's people in danger, which remains unaccounted for in its current climate vulnerability assessment," the researchers said. "If this impact is not addressed immediately, India can slow its progress towards sustainable development goals," they added.