Overview
A recent study by IIT Gandhinagar together with Stanford and Purdue universities finds that hot‑humid conditions during India’s monsoon could soon produce UHS on a scale comparable to the summer season if global warming reaches 2 °C above pre‑industrial levels.
Key Developments
- From the 1980s to 2020, areas experiencing UHS grew from 0.01 million km² to 0.04 million km².
- During summer (March‑June), UHS currently affects about 8 % of India and is linked to most heat‑related deaths.
- Projected under 2 °C warming, UHS could cover 60 % of the country in summer and 53 % in the monsoon.
- Population exposed may rise to between 0.8 billion and 1.2 billion people, depending on the warming scenario.
Important Facts
The study used the Gridded Population of the World for population data, and heat‑mortality records from the NDMA and IMD. Summer UHS is concentrated in the Indo‑Gangetic plain and coastal belts, driven by high temperatures and moisture transport from the Bay of Bengal. In the monsoon, UHS appears in a narrower temperature band (35‑38 °C) but is amplified by high humidity, especially during monsoon breaks. Northwestern states like Punjab and the Gangetic plain are identified as emerging hotspots.
UPSC Relevance
- Links climate change, public health, and labour productivity – core topics for GS III (Environment & Climate, Economy).
- Illustrates the impact of extreme weather on vulnerable populations, a key theme in GS II (Society).
- Shows the role of agencies such as NDMA and IMD in climate‑risk assessment.
- Provides data‑driven evidence useful for answering questions on climate‑induced health emergencies and policy responses.
Way Forward
Policymakers need to integrate heat‑stress projections into urban planning, occupational safety norms, and agricultural calendars. Strengthening early‑warning systems of IMD, expanding cooling infrastructure, and promoting climate‑resilient crops can mitigate health and productivity losses. Coordination between health, labour, and environment ministries will be essential to address the dual challenge of summer and monsoon heat stress under a warming climate.