The 'bathtub ring' around Lake Mead at the Hoover Dam in 2008. Better management and conservation efforts are needed to stave off a worsening water crisis. SOURCE: flickr.com/completetosh 

By Laura MacInnis GENEVA (Reuters) – Climate change has made history an inaccurate guide for farmers as well as energy investors who must rely on probabilities and scenarios to make decisions, the head of a United Nations agency said on Wednesday. Michel Jarraud, director-general of the World Meteorological Organization, said that water and temperature projections have become more valuable than the historical weather data that long governed strategy in agriculture, hydro-electric power, solar technology and other fields. “The past is no longer a good indicator of the future,” the WMO chief told a press briefing, describing climate modeling and prediction as key to fisheries, forestry, transport and tourism, as well as efforts to fight diseases such as malaria. People looking to build energy infrastructure are especially hungry for specific environmental information that can affect the long-term profitability of their projects, he argued. “If in 100 years there is not going to be water going into the dam, it’s not a brilliant investment,” Jarraud said. …

History can no longer guide farmers, investors: U.N.