Intensifying heat and rainfall extremes, melting Himalayan glaciers, more powerful cyclones in the Arabian Sea, and extreme sea-levels — that is what India is heading towards as the century progresses, according to a new peer-reviewed study, authored by a team of climate scientists including current and past Intergovernmental Panel on Climate Change (IPCC) authors.
Published in the journal PLOS Climate, the paper provides a critical post-IPCC-AR6 update on the state of India’s climate. It does this by synthesising the latest observational data and climate model projections.
The findings underscore the urgent need for tailored, region-specific adaptation strategies to protect vulnerable communities and ecosystems from the escalating impacts.
The paper notes that India’s average temperature has risen by nearly 0.9°C in the last decade (2015-2024) compared to the early 20th century (1901-1930), with the hottest day of the year warming by 1.5-2°C in Western and Northeast India since the 1950s.
This, according to the authors, is leading to more frequent and intense heatwaves, with the number of “Warm Days” increasing by 5-10 days per decade across most of the country.
Climate models project an additional warming of 1.2-1.3°C in India’s mean temperature by midcentury relative to the recent past (1995-2014) under the moderate emissions scenario, SSP2-4.5.
The researchers point out that the southwest monsoon, the lifeblood of India’s agriculture, has become increasingly erratic.
Mean rainfall has declined over the Indo-Gangetic plains and the Northeast while extreme precipitation events have intensified, particularly in central India and coastal Gujarat.
Climate models project a 6-8 per cent increase in all-India mean southwest monsoon rainfall by mid-century, but with high spatial variability, posing significant challenges for water management and agriculture, according to the paper.
The tropical Indian Ocean, a key regulator of India’s climate, is warming at an alarming rate of 0.12°C per decade, one of the fastest in the world, according to the paper.
This, the authors say, is fueling a dramatic increase in marine heatwaves, which are projected to occur for nearly 200 days per year by 2050, from merely 20 days per year in recent decades.
As a result, there is a grave threat to marine ecosystems, including coral reefs and fisheries, which are vital for the livelihoods of millions.
The Hindu Kush Himalaya, the “water towers” of Asia, are warming at an accelerated rate of 0.28°C per decade, with higher elevations warming even faster. Consequently, glaciers are melting at an alarming rate, with mass losses accelerating in the last decade.
The study projects a 30-50 per cent reduction in glacier volume by 2100 at global warming levels of 1.5-2°C, which will have profound implications for water availability for millions of people downstream.
The Arabian Sea has become a hotspot for intense tropical cyclones, with the maximum intensity of pre-monsoon cyclones increasing by 40 per cent in recent decades. This, combined with rising sea levels, is heightening the risk of coastal flooding and storm surges.
The analysis projects that historical one-in-a-hundred-year extreme sea-level events will become an annual occurrence by mid-century under the moderate emissions scenario, SSP2-4.5.
The assessment also has a particularly alarming finding: the projected increase in “compound extremes”. This refers to the simultaneous or sequential occurrence of multiple climate hazards.
There is a growing risk of concurrent heatwaves and droughts, according to the study, which can have a far more devastating impact than either event occurring in isolation.
These compound events can overwhelm response capacities and lead to cascading impacts on agriculture, water systems, and human health.
As per the analysis, the frequency and intensity of these compound extremes in India are expected to increase as global temperatures continue to rise. This will pose a complex and escalating challenge for the country.
“India’s climate baseline has shifted. This update shows where the risks are regionally clustering — along our coastlines, in the Himalayas, and across interior regions. An emerging threat is “compound extremes,” which refers to multiple hazards that co-occur or follow in quick succession, amplifying overall risk beyond any single event,” said Chirag Dhara of Krea University, lead study author.
The authors called for the development of robust, region-specific adaptation strategies that are grounded in the latest climate science. This includes building more resilient infrastructure, multi-hazard Early Warning Systems, and climate-smart agricultural practices for extreme weather events.
There is also a critical need for greater investment in climate research and data collection to fill existing knowledge gaps and improve the accuracy of future climate projections, according to the paper.
“The science shows that heatwaves, erratic rains, rising seas, and compound extremes are no longer future risks — they are unfolding now. But this knowledge also gives us power, as we can adapt and protect our homes, farms, panchayats, and communities, safeguarding lives and livelihoods,” said Roxy Mathew Koll from the Indian Institute of Tropical Meteorology and a co-author of the study.
Besides Dhara and Koll, other authors of A post-AR6 update on observed and projected climate change in India include Aditi Deshpande from the Savitribai Phule Pune University, Padmini Dalpadado from the Institute of Marine Research, Norway and Mandira Singh Shrestha from International Center for Integrated Mountain Development, Nepal.