Did a mega drought topple empires 4,200 years ago?

In Mesopotamia in about 2200 BC, a mega drought lasted for decades or possibly even centuries. The drought might have contributed to the collapse of the Akkadian Empire, in what is now Syria and Iraq. But the drought’s extent is a matter of debate. Palæoclimatologists are working to pin down more details, which could hold clues to the kinds of natural droughts the world might face that could greatly exacerbate the impacts of climate change.