Reuters: The world needs to act urgently to avoid a global water crisis due to increased population, rising living standards, dietary changes and more biofuels production, the United Nations warned on Thursday. By 2030, nearly half of the world’s people will be living in areas of acute water shortage, said a report jointly produced by more than two dozen U.N. bodies and issued ahead of a major conference on water to be held in Istanbul next week. The report, “Water in a Changing World,” …