The Extinction of Indus Valley Civilisation was Due to Climate Change: Research

The mysterious extinction of Indus valley civilisation, one of the world’s oldest and the largest urban civilisations could have been destroyed by climate change, but not due to any regional strife or foreign invasions, say the researchers.

A brief history

Indus civilisation, which is popularly known as Harappan civilisation (Harappa is the name of the place, which is now distributed over Pakistan, north western India and eastern Afghanistan), once extended over sprawling 6,25,000 square miles rivaling ancient Egypt and Mesopotamia in its accomplishments. This colossal civilisation, which existed nearly 4,500 years ago, flourished for 600 years and then slowly disintegrated as the vast majority of people migrated and fractured into small villages and towns.

Dispelling the myth

Previously, scholars believed that the foreign invasions led to the extinction, while few others believed that it could be due to the environmental factors. But the recent research published in the Proceedings of the National Academy of Sciences, confirmed that the climate change is the key culprit for the fall of civilisation. This conclusion is drawn by a group of geologists, geomorphologists, archaeologists, and mathematicians who joined forces to answer the most daunting question of centuries.

Studies revealed 10,000 years of human history and landscape changes

The researchers conducted a study using satellite photos and topographical data to prepare digital maps of the Indus river landscape. They collected field samples to determine the age of the sediments. Then they overlaid that information with the prior archaeological findings which yielded a new and compelling chronology of 10,000 years of human history and landscape changes.

Conclusions from the research

Finally their efforts revealed that – there were wild, untamed rivers passing through the heart of Indus plain, which were so unpredictable and dangerous that no city could take root on their banks. Many scholars previously thought that Harappan civilisation received its waters from a large glacier-fed Himalayan river, while some thought it to be from Saraswathi (a sacred river of Hindu mythology), but now the researchers found that only monsoon-fed rivers flowed through the region.

Unlike the Egyptians and Mesopotamians, who used irrigation system to support crops, the people of Harrappan civilization used to rely on a gentle dependable cycle of monsoons, that keyed seasonal floods.

The researchers identified the monsoon-drenched rivers were prone to devastating floods, which enabled agriculture and civilization to flourish only for a significant period. As the time passed, monsoons were affected by the lower insolation and continued to weaken until the rivers no longer flooded and thus, the crops failed. Eventually, the rivers completely dried up making it unfavourable for the civilisation to live. Slowly, people began abandoning the cities and moved eastward towards the Ganges basin where the rains were more dependable. Finally, the civilisation dispersed, fracturing into small villages and towns.

The remnants of river Saraswathi

The researchers also found the geologic remnants of the Saraswathi river in the sprawling desert surrounding the modern day Ghaggar-Hakra valley. But as per the previous assumptions, it was not fed by Himalayan glacier, but was fed by the monsoons. Hence the weak rains at that time dried that river too.

Lessons to today’s generation

The researchers tried to derive lessons to the present generation from the Harrappans’ fate. According to them, just as the Indus civilisation did, we too are depending heavily on natural resources (ex: Fossil fuels). Thinking about tomorrow and the coming generations we are accumulating more than what is required, which will ultimately lead to deterioration of climatic conditions and resources gradually. They concluded saying that the modern day policy makers should take these things into account and plan properly in order to save the natural resources.

Source: The Financial Express

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