The fall of the Harappan Civilization nearly 4,000 years ago has puzzled researchers for decades. A new study, however, believes it has found the culprit for the ancient civilizations rapid decline; climate change.
The LA Times reports that slow migrating monsoons across Asia helped create, then destroy, the Harappan Civilization.
The new report, published in the journal Proceedings of the National Academy of Sciences, says that the city of Harappa began to grow along the upper Indus river about 5,200 years ago. The city reached its peak, stretching across modern day Pakistan, India, and Eastern Afghanistan, about 4,000 years ago.
According to Live Science, the Harappan Civilization did not develop irrigation systems to support agriculture. Instead, the city relied on the annual monsoons. The city was able to grow rapidly thanks to the monsoons, but when they stopped coming, people started to migrate out of the city.
Researcher Liviu Giosan, said:
“Until now, speculations abounded about the links between this mysterious ancient culture and its life-giving mighty rivers… Our research provides one of the clearest examples of climate change leading to the collapse of an entire civilization.”
Giosan said that the monsoons were responsible for the life and death of the civilization. The monsoons flooded the region before it was settled, then provided plenty of water for the city to grow, then left the region and forced the people to flee.
“The Harappans were an enterprising people taking advantage of a window of opportunity — a kind of ‘Goldilocks civilization.’ As monsoon drying subdued devastating floods, the land nearby the rivers, still fed with water and rich silt, was just right for agriculture.”
The Harappan Civilization was practically forgotten about until the 1920s. Giosan said that history is full or information about ancient Egypt and Mesopotamia, but the Harappan Civilization, which was larger and more complex, remains a mystery.
“Antiquity knew about Egypt and Mesopotamia, but the Indus civilization, which was bigger than these two, was completely forgotten until the 1920s. There are still many things we don’t know about them.”
Live Science reports that remains of Harappan settlements were discovered about a century ago. The settlements showed a complex a urban city, full of art, writing, plumbing, and city grids. Giosan said:
“They had cities ordered into grids, with exquisite plumbing, which was not encountered again until the Romans. They seem to have been a more democratic society than Mesopotamia and Egypt — no large structures were built for important personalities like kings or pharaohs.”
The new study was published today in the journal Proceedings of the National Academy of Sciences.