BBC: The Garden of Eden is in danger of turning into a dustbowl. The legendary Eden was in Mesopotamia, the land between two rivers – the Tigris and the Euphrates. For hundreds of miles between their lower reaches there is fabulously fertile farmland. But it’s hardly rained in Iraq for more than two years, the river levels have dropped by half in some places, and farmland is drying out. The drought is having a devastating effect on Iraq’s most renowned export after oil – its …