Researchers conclude that climate change led to collapse of ancient Indus civilization

A new study combining the latest archaeological evidence with state-of-the-art geoscience technologies provides evidence that climate change was a key ingredient in the collapse of the great Indus or Harappan Civilization almost 4000 years ago. The study also resolves a long-standing debate over the source and fate of the Sarasvati, the sacred river of Hindu mythology.

http://phys.org/news/2012-05-climate-collapse-ancient-indus-civilization.html