Bakhira Lake sediments reveal 25,000 years of Indian Summer Monsoon variability, offering valuable evidence for climate modelling, water management and future rainfall planning.

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• Researchers reconstructed 25,000 years of Indian Summer Monsoon variability using environmental magnetic properties preserved within sediments from Bakhira Lake, Uttar Pradesh.
• The study was conducted by researchers from the Birbal Sahni Institute of Palaeosciences under the Department of Science and Technology.
• Bakhira Lake is a major perennial wetland within the Ghaghara-Rapti alluvial system and became a Ramsar Site in 2022.
• Seven accelerator mass spectrometry radiocarbon dates helped establish a well-dated sediment record covering major Late Quaternary climate phases.
• The reconstruction identified weakened monsoon conditions during the Last Glacial Maximum, followed by stronger rainfall during warmer Bølling–Allerød conditions.
• The Younger Dryas brought renewed cooling, drying and weakened monsoon activity, while the Holocene Climatic Optimum recorded warmer and wetter conditions.
• Researchers combined magnetic measurements with grain-size, geochemical and clay-mineralogical evidence to track changes in hydrology, erosion and weathering.
• The findings provide a long-term climate baseline that could improve climate models, water-resource planning, agriculture, flood mitigation and wetland conservation.
• The research also helps distinguish natural long-term monsoon variability from more recent climate changes associated with human activities.
• Published in Palaeogeography, Palaeoclimatology, Palaeoecology, the study strengthens understanding of monsoon responses across the Central Ganga Plain.
• Long-term monsoon evidence could help assess how rivers, lakes and wetlands may respond to changing rainfall patterns across northern India.
• The research offers important scientific support for managing water resources and reducing risks from droughts, floods and changing monsoon behaviour.