Jay Famiglietti just published this commentary in Nature Climate Change. It's a chilling message, and he says so right below the title:

Groundwater depletion the world over poses a far greater threat to global water security than is currently acknowledged.

Anyone even remotely interested in the world's water predicament has to read this paper. It's not long. Jay lays it out, pure and simple, and it ain't very pretty. He makes the important point that estimates of the stocks (amount in storage) of groundwater are not well-known in many aquifers. So we don't know how much recoverable water is left. It's like withdrawing money from a checking account in excess of the deposits, but not knowing the total amount of money actually in the account. So you can withdraw more than you deposit, but you won't know when the money will run out until is actually does. Not good!

Read my piece, written a few months ago, about stocks and flows and estimates of the the amount of groundwater in storage.

Download JFam_Global_GW_Crisis

I'll be referring to Jay's work this afternoon (1:30 - 3 PM) in Session 25 at the AWRA Annual Conference. See you there!

Download Session_25_Campana_AWRA_2014

Enjoy - or not!