A post-AR6 update on observed and projected climate change in India

This article provides an update on observed and projected climate change in India. India’s average temperature has risen by approximately 0.89°C during 2015–2024 relative to 1901–1930. Models project additional warming of about 1.2-1.3°C over India by mid-century under SSP2-4.5 (relative to the recent past (1995–2014)). The tropical Indian Ocean has warmed at 0.12°C per decade since 1950 and is projected to warm at 0.17°C per decade through 2100 under SSP2-4.5. Marine heatwave days are projected to rise from about 20 days per year historically (1970–2000) to nearly 200 days per year by mid-century. Mean southwest monsoon rainfall has declined by 0.5-1.5 mm day -1 every decade over the Indo-Gangetic plains and northeast India during 1951–2024. Extreme precipitation events have also intensified, with coastal Gujarat experiencing about 0.15 additional extreme events every decade during 1951–2024. CMIP6 models project about 6–8% increase in all-India mean southwest monsoon rainfall by mid-century relative to the recent past, though with high spatial variability. The Hindu Kush Himalaya have witnessed accelerated warming of about 0.28°C per decade (1950–2020); glacier mass losses accelerated from -0.17 m water equivalent (w.e.) yr -1 (2000–2009) to -0.28 m w.e. yr -1 (2010–2019), and models indicate a 30–50% reduction in glacier volume by 2100 at 1.5-2°C global warming levels. In the Arabian Sea, maximum pre-monsoon cyclone intensity has increased by 40% over 1982–2019. Sea levels in the north Indian Ocean have risen at 3.3 mm year -1 (1993–2017), with extreme sea level events increasing 2–3 fold. Historical one-in-hundred-year extreme sea level events along the Arabian Sea coastline are projected to become annual occurrences by mid-century under SSP2-4.5. We also report increasing trends in compound hot-dry extremes in parts of India. Our findings highlight spatially differentiated hotspots of climate change across India and provide policy-relevant insights.