Make it a couple of 1000 years: https://en.wikipedia.org/wiki/Mesopotamia#Agriculture https://en.wikipedia.org/wiki/Mesopotamia#Agriculture >Over time the sout

Make it a couple of 1000 years: https://en.wikipedia.org/wiki/Mesopotamia#Agriculture https://en.wikipedia.org/wiki/Mesopotamia#Agriculture >Over time the southernmost parts of Sumerian Mesopotamia suffered from increased salinity of the soils, leading to a slow urban decline and a centring of power in Akkad, further north.