The Indus Valley Civilization flourishing circa 2600-1900 BCE, exemplifies how climate variability shaped agrarian societies and precipitated socio-economic decline. this study examines the interplay between holocene climate shifts particularly the 4.2 kiloyear aridification event and evolving crop patterns in the Civilization heartlands of northwest India and Pakistan. drawing on paleoclimatic proxies archaeobotanical evidence from sites like Harappa, Mohenjodaro, Rakhigarhiand GIS based modeling of hydroclimatic trends, we reconstruct a transition from diversified winter (wheat, barley) and summer (rice, millets) cropping systems to stressed, drought resistant assemblages. findings reveal that intensified monsoon failures and winter rainfall deficits around 2200-1900 BCE reduced crop yields by up to 40% triggering shifts toward resilient millets and pulses while undermining surplus based urbanism. this environmental stressor compounded by tectonic disruptions to the Sarasvati river, likely fuelled deurbanization, migration and cultural fragmentation by integrating climate crop dynamics with I Civilizations adaptive strategies, this research underscores the vulnerability of early complex societies to abrupt environmental change offering insights for contemporary South Asian agrarian resilience amid accelerating global warming.
Kumbhar et al. (Tue,) studied this question.