Govt's current tools underestimate India's heatwave vulnerability

The vulnerability score improvised with the addition of heat index put 90% of the country in the 'extremely cautious' or 'danger' range

More than 90 per cent of India's territory is in the 'extremely cautious' or 'danger' range of heatwave impacts but the Union government's official Climate Vulnerability Index underestimates the risk by limiting the danger zone to 45 per cent of the country, a new study has said.

The study titled Lethal heatwaves are challenging India's sustainable development was published on Wednesday. Researchers from University of Cambridge, California Institute of Technology and Yale University have sought to provide an empirical basis for evaluating and rethinking India's approach to vulnerability measurement.

The publicly available data set on state level climate vulnerability indicators as well as the National Climate Vulnerability Assessment Framework was used to build India's present Climate Vulnerability Index (CVI) map.

Researchers then estimated the vulnerability of Indian states and territories based on 17 risks, from migrant population to vehicle population, urbanisation to area under forest cover, water bodies to water stressed regions and other indicators.

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While India's official estimates that 45 per cent of the area is highly vulnerable, the vulnerability score improvised with the addition of heat index put 90 per cent of the country in the "extremely cautious" or "danger" range, "demonstrating that heatwaves put more people at extreme risk across India than estimated by CVI".

Researchers also conducted a trend analysis to map India's progress for the last 20 years in achieving the sustainable development goals (SDG). "The results indicate that the use of CVI may underestimate the actual burden of climate change concerning heat suggesting India's need to reconsider its assessment of climate vulnerabilities to meet the SDGs," the study said, noting that CVI doesn't include measures of the primary climate change risks, including heatwaves.

The researchers said it was imperative to reflect on the social, cultural, economic and structural development factors, their inter-relationships and environmental vulnerabilities.
A case study of Delhi's heatwave incident of last year also helped to understand the threat posed by heatwave to urban sustainability.

"India's preparedness and performance of SDG 11 (sustainable cities and communities) and SDG 13 (climate action) had declined significantly. Furthermore, regional analysis in the SDG 11 context showed that Delhi's urban sustainability is severely challenged as its current district-level climate change vulnerability measurements do not factor in heat wave impacts," it said.