Climate, environment and the Harappan civilization

A wide range of factors has been invoked to explain the decline anddisappearance of the urban phase of the Indus or Harappan civilization. Earliertheories based on invasions or man-made conflicts have been increasinglydiscarded; on the other hand, there has been growing evidence and acceptancethat climatic and environmental factors played a significant role. While climatic studies from the 1970s to 1990s tended to support the view that a marked trend towards aridity had set in even before the urban orMature Harappan phase (2600–1900 BCE), more recent studies have pushedthis shift to the end of the third millennium BCE. This is also the time when, inthe eastern domain of the Harappan civilization, the Sarasvati dwindled to aminor seasonal river, while floods appear to have been caused by a shiftingIndus in the west. Other possible causes include the pressure put on remainingforests by intensive industrial activities. In any case, the archaeologicalevidence records the abandonment of Harappan sites in the Sarasvati’s central basin, and a migration of Late Harappan settlements: north-eastward towardsthe foot of the Shivalik Hills, eastward across the Yamuna, possibly too westward towards the Indus plains and southward towards the Vindhyas.This paper attempts to correlate archaeological evidence withsedimentological, palynological and other palaeoclimatic studies and suggests afew possible conclusions and lines of further exploration.