Many times now, when searching for reconstructions and portrayals of the Ancient Near East, I have been struck by the incredible difference in fertility on display. I know that the region which is now Iraq was considered a breadbasket in ancient times, and that even today, large parts of it are still fertile flood-plains, but clearly there has been a seismic shift.

Look, for instance, at these reconstructions of ancient Ur, and then compare it to how the site looks today. The green hills, the flood-plains, the trees - all gone. The rivers can still be seen, but it is sand down to the banks.

When did this happen? Did it happen to the extent portrayed, or are these reconstructions exaggerated in how green they make the region look? I have heard it said many times that it was a combination of overharvesting and gradually salinisation due to the irrigation systems, but even so, it is a dramatic change. Are there any historical documents of people noting that the once-verdant bread-baskets were beginning to turn to desert?