Srinagar, Sept. 5 -- High in the Nepalese Himalayas, ice and rock gave way in 2026. A wall of mud, boulders and black water came roaring down the valley. Bridges vanished, roads disappeared, and generations of work were buried in minutes.

This is the environmental disaster we know. It is sudden, violent, and caught on camera. By evening, there is a death toll.

Four thousand years ago, a civilization far bigger than any Himalayan valley town met the same enemy and never saw it coming, because it never came at all in a form anyone could point to.

It just stopped raining the way it used to.

Harappa and Mohenjo-daro were the largest cities of their age, built along the Indus with grid streets, covered drains, and granaries that fed tens o...