Just in:
World over-using underground water reserves for agriculture:
http://www.reuters.com/article/2012/08/10/us-science-environment-water-idUSBRE87713B20120810
" The world is depleting underground water reserves faster than they can be replenished due to over-exploitation, according to scientists in Canada and the Netherlands.The research suggests about 1.7 billion people, mostly in Asia, are living in areas where underground water reserves and the ecosystems that rely on them are under threat, they said.
The study, published in the journal Nature, found that 80 percent of the world's aquifers are being used sustainably but this is offset by heavy over-exploitation in a few key areas.
Those areas included western Mexico, the High Plains and California's Central Valley in the United States, Saudi Arabia, Iran, northern India and parts of northern China."