Study links Antarctic ice formation to origins of Indian monsoon

New Delhi, Sep 9: A new study has traced the roots of the Indian monsoon system back 34 million years, linking its early evolution to the formation of massive ice sheets in Antarctica. Scientists from the Birbal Sahni Institute of Palaeosciences, Lucknow, and the Wadia Institute of Himalayan Geology, Dehradun, analysed fossilised leaves from the Laisong Formation in Nagaland.

The fossils, preserved from around 34 million years ago, revealed evidence of a warm and wet climate with very high rainfall.

Using the Climate Leaf Analysis Multivariate Program (CLAMP), the researchers reconstructed the region’s ancient climate and found that the timing coincided with the onset of Antarctic glaciation. The growth of ice sheets at the South Pole, they argue, shifted global wind and rainfall patterns by displacing the Intertropical Convergence Zone (ITCZ) toward the tropics, intensifying rainfall across the Indian subcontinent.

Their findings, published in Palaeogeography, Palaeoclimatology, Palaeoecology, suggest that the birth of Antarctica’s ice cover helped trigger the climatic conditions that nurtured lush forests and shaped the Indian monsoon system.

Beyond offering insights into Earth’s distant past, the study carries present-day warnings. Researchers caution that today’s rapid Antarctic ice melt could again shift the ITCZ, with potentially disruptive consequences for monsoon patterns across South Asia—a region where rainfall remains critical for agriculture, water security and livelihoods. “The study underscores how Earth’s climate is interconnected—what happens in Antarctica can profoundly affect rainfall in India,” the authors said.