The planet is entering an era of global "water bankruptcy," a United Nations research agency said in a new report, which warns that humans' water use over the long term has exceeded the renewable water sources worldwide and, potentially, passed a point of no return. "Bankruptcy" means the Earth's water repositories, such as rivers, lakes and aquifers, are being depleted at faster rates than they can be restored, according to the  report from researchers at the United Nations University's