34-million-yr-old Nagaland fossils show how Antarctic ice shaped Indian monsoon
Fossil leaves' age matches Antarctic ice formation, showing a global link that intensified monsoons in Northeast
A file image of the locality of Nagaland and the fossil leaves discovered.
Guwahati, Sept 10: A team of Indian scientists has uncovered a remarkable connection between the formation of Antarctica’s ice sheets around 34 million years ago and the early evolution of the Indian monsoon system, thanks to fossil leaves discovered in Nagaland.
Researchers from the Birbal Sahni Institute of Palaeosciences (Lucknow) and the Wadia Institute of Himalayan Geology (Dehradun), used climate reconstruction techniques to show that the Laisong Formation in Nagaland witnessed exceptionally high rainfall and temperatures during that period.
Crucially, the fossils’ age coincided with the time when massive ice sheets began to form in Antarctica. This pointed to a global link - the growth of Antarctic ice altered global wind and rainfall patterns by shifting the Intertropical Convergence Zone (ITCZ) towards the tropics, triggering intense monsoonal rains in Northeast India.
The study, published in Palaeogeography, Palaeoclimatology, Palaeoecology, employed the Climate Leaf Analysis Multivariate Programme (CLAMP) to analyse the size, shape, and structure of the fossilised leaves.
Results indicated that Nagaland’s climate at the time was far wetter and warmer than today, strongly aligning with global climatic changes brought on by Antarctic glaciation.
Scientists warn that this ancient story carries vital lessons for the present. As modern climate change accelerates Antarctic ice melt, the ITCZ may shift once again, potentially disrupting monsoon patterns across the tropics.
Such changes could have far-reaching consequences for India, where the monsoon underpins agriculture, water security, and the livelihoods of millions.
The findings highlight the global interconnectedness of Earth’s climate system.
“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,” the researchers noted, emphasising that studying past climate upheavals helps prepare for the challenges of a warming future.