Is a Climate Apocalypse on the Horizon?
The Indian coastline is witnessing significant changes in tropical cyclones. The north Indian Ocean accounts for 6 per cent of global tropical cyclones, with the ratio of Bay of Bengal to Arabian Sea cyclones being 4:1 previously. However, due to the rapid warming of the north Indian Ocean, cyclones have become more frequent and stronger over the Arabian Sea, particularly during the pre-monsoon period. Sea surface temperatures leading to cyclogenesis have been higher by 1.2°C to 1.4°C in recent decades, compared to SSTs four decades ago. As a result, cyclones in the pre monsoon period (April-May) have intensified by 40 per cent in terms of wind speeds and by 20 per cent during the post monsoon season (from October to December). This is exposing coastal areas around the Arabian Sea to more frequent and intense cyclones, affecting fishing across the coastline in addition to causing coastal erosion.
Sea level rise is one of the most well documented consequences of climate change along with the threat it poses to lives, livelihoods and infrastructure along the coastlines. The sea level over the north Indian Ocean has risen by 3.3mm/year from 1993-2015 which is comparable to the global mean rise. However, the difference in the topography makes certain regions more vulnerable to the effects of sea level rise especially when combined with the subsidence rates of regions of the Ganga- Brahmaputra delta. This issue is exacerbated with the extreme sea level rise, and storm surges, driven by cyclonic storm activity. There has been a 2-3 fold increase in extreme sea level occurrences between 1995–2019, with higher risks along the Arabian Sea coastline and Indian Ocean Islands. This can lead to severe flooding and further erosion of low-lying areas and islands.
One of the most important emerging threats is that of “compound events,” which refers to multiple climate extremes occurring sequentially in the same region (“temporal compounding”), or the same extreme simultaneously affecting large regions (“spatial compounding”). The impact of such compound events can far exceed the impact of the individual events occurring in isolation. Examples of compound events are heatwave-drought, or compound flooding such as the one that precipitated the humanitarian disaster in Pakistan in 2022.
There has been a significant increase in the occurrence of compound meteorological droughts and heatwaves across India in the last four decades (1981-2020). Several parts of the country including north-central, western, and north-eastern India, along with the southeastern coastlines have emerged as hotspots for compound heatwave-drought events, which portend serious consequences for human health and agricultural sustainability.
The state of the environment over India as of 2025 stands on the brink where there is a marked increase in surface temperatures over the Indian landmass as well as over the oceans triggering extremes over land and ocean and resulting in increased stress for human and non-human life alike. This stress is compounded by changing rainfall patterns and increasing extreme precipitation events over the entire region resulting in excess rainfall over the otherwise dry regions of northwest India and drying of the Indo-Gangetic plains and northeast India. This has significant implications for agriculture and crop cycles for a country that relies heavily on agricultural output.
Coastal areas are at threat from sea level rise affecting low lying areas and increase in tropical cyclone frequency and intensity. Similarly, fragile mountainous regions and communities dwelling in them are at a higher risk of glacial lake outburst floods.
In conclusion, regional hotspots of climate change are emerging across the country. This demands regionally tailored adaptation strategies contingent not only on the nature of climate change but on the exposure and vulnerability of local communities.
(Aditi Deshpande is with Department of Atmospheric & Space Sciences, Savitribai Phule Pune University; Chirag Dhara is with Krea University; and Roxy Mathew Koll is with Centre for Climate Change Research, Indian Institute of Tropical Meteorology).
