On: Humans are more dependent on water than many other...

[abdullahkhalids]

No. Rather productivity is down 50% or more for the entire month.

Imagine two civilizations otherwise equal. One works 12/12=100% of the year, and the other 11.5/12=96% of the years. Then compound the gains over 14 centuries!

[jopsen → abdullahkhalids]

You're assuming no wars or other inefficiencies...

In practice there is probably plenty of inefficiencies to go around. Maybe less today, but 14 centuries ago.