Overview

• The study links the onset of Antarctic ice sheets at the Eocene–Oligocene boundary to a tropics-ward shift of the ITCZ that strengthened early monsoon rains over present-day Northeast India.
• Researchers applied the CLAMP method to well-preserved leaves from the Laisong Formation in Nagaland, revealing conditions far wetter and warmer than today.
• The work was led by teams at the Birbal Sahni Institute of Palaeosciences and the Wadia Institute of Himalayan Geology and appears in Palaeogeography, Palaeoclimatology, Palaeoecology.
• India’s Department of Science and Technology publicised the findings, underscoring how polar changes can reorganise tropical rainfall patterns.
• The authors caution that ongoing Antarctic ice loss could shift the ITCZ again and disrupt South Asian monsoon behaviour with consequences for agriculture and water security.