What you need to know about the world's water wars

Underground water is being pumped so aggressively around the globe that land is sinking, civil wars are being waged, and agriculture is being transformed, In some neighborhoods, the ground is giving way at a rate of four inches a year as water in the giant aquifer below it is pumped.

The groundwater has been so depleted that China's capital city, home to more than 20 million people, could face serious disruptions in its rail system, roadways, and building foundations, an international team of scientists concluded earlier this year.

Beijing, despite tapping into the gigantic North China Plain aquifer, is the worlds fifth most water-stressed city and its water problems are likely to get even worse.