Paleoclimatologists have often attributed the downfall of civilizations in Greece, Mesopotamia, and Egypt to a drought that started in 2000 BC, and they are of the belief that the Indus Valley Civilization may have suffered the same fate.

A new study on the Indus Valley Civilization sheds light on climate change, which is assumed to have also occurred almost thousands of years back, and the manner in which humans during that period were affected by the alterations in the environment.

Climate change and its effects are concerning in the current era and make one marvel how our ancestors grappled with such shifts. Thanks to new research methodologies, scientists are able to demystify the climatic patterns that have reportedly occurred several thousand years ago, which gives humans an inkling into how our ancestors coped with the oscillating conditions.

In the journal Current Anthropology, researchers discuss the various nuances of how the human civilization adapted to the changing environment. The study was based on the Indus Valley Civilization of South Asia during the period between c.3000 and 1300 BC. 

Based on isotope data from the sediments of an ancient lake, the scientists suggest that the monsoon cycle,  which is pivotal to the South Asian countries' livelihood, suddenly halted for nearly two centuries.

"For most ancient complex societies, water was a critical factor, and the availability of water and the way that it was managed and used provide critical insight into human adaptation and the resilience of subsistence practices," shared Dr. Cameron Petrie of the Division of Archaeology, University of Cambridge, the lead author of the study.

The research delved into the land, water, and settlement dynamics of the ancient civilization. It also studied how the population present in North-West India adapted itself to the climate change.

Remnants Of The Past

The researchers believe that the Indus Valley Civilization evolved in a particular environment where there was an overlap in the summer and winter rainfall systems.

Data reveal that during the period between c.2500 and 1900 BC, the area was exposed to climatic changes, which coincides with the timeline of the Indus Valley Civilization being at its peak.

The various facts based on the civilization offered the researchers with the opportunity to gather insight on how the society grappled with such varied and dissimilar ecosystems, as well as the climatic constraints.

During early Holocene, the Indus Valley Civilization was located closer to the lake Kotla Dahar in the plains of the northwestern part of India. This proximity suggests that the ancients had a consistent supply of rainfall which would counter evaporation. The rainfall, however, would have been heavier during the monsoons.

The lake, however, provided proof of sudden changes in the monsoon rainfall pattern. It also indicated a decrease in the water level of Kotla Dahar.

During the course of the study, the state of the lake in the period between ca.2200 and 2000 BC was observed, likely due to the sporadic rainfall and disruptions in the monsoon cycle. This hints that the monsoon during this period was affected by the spontaneous change in the climate. 

The significance of Kotla Dahar is emphasized by researchers as they have discovered that it was inhabited by a large population. It is also thought to be the primary reason which contributed towards the deurbanization of the Indus Civilization.

Photo: Nagarjun Kandukuru | Flickr

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