Kohima, September 10: A groundbreaking study by Indian scientists has uncovered how the formation of massive Antarctic ice sheets around 34 million years ago profoundly influenced the evolution of the Indian monsoon system, with crucial evidence emerging from fossil leaves discovered in Nagaland.

The research, conducted by experts from the Birbal Sahni Institute of Palaeosciences (Lucknow) and the Wadia Institute of Himalayan Geology (Dehradun), used advanced climate reconstruction techniques on the fossil-rich Laisong Formation of Nagaland. Findings revealed that the region once experienced exceptionally high rainfall and warmer temperatures, pointing to intense monsoonal activity during that era.

Crucially, the fossils’ age aligns with the period when Antarctica’s ice sheets first began forming, triggering a global climate shift. The growth of ice in the southern continent is believed to have altered wind and rainfall patterns by displacing the Intertropical Convergence Zone (ITCZ) towards the tropics, intensifying monsoon rains in Northeast India.

The study, published in Palaeogeography, Palaeoclimatology, Palaeoecology, employed the Climate Leaf Analysis Multivariate Programme (CLAMP) to examine the size, shape, and structure of fossilised leaves. The results confirmed a wetter and warmer climate in Nagaland compared to present conditions, reinforcing the global link between polar glaciation and tropical rainfall systems.

Scientists caution that the discovery carries critical lessons for the present. With modern climate change accelerating Antarctic ice melt, the ITCZ could shift again, posing serious risks to the Indian monsoon, which sustains agriculture, water resources, and millions of livelihoods.

Highlighting the interconnectedness of Earth’s climate system, researchers observed: “What happens in one corner of the world — whether in the icy expanses of Antarctica or the humid forests of Nagaland — can reverberate across continents.”