Reuters: Government ministers from 120 countries, scientists and campaigners meet in Istanbul this week to discuss how to avert a global water crisis and ease tensions between states fighting over rivers, lakes and glaciers. Nearly half of the world’s people will be living in areas of acute water shortage by 2030, the United Nations warned last week, and an estimated 1 billion people remain without access to safe drinking water and sanitation. The world’s population of 6.6 billion is …