Isaac Arnsdorf, NEW YORK -- U.S. Head of the company Barack Obama says natural gas can be a footbridge from coal to a cleaner energy much. Investors are fair it's director viable a footbridge to nowhere.The country's convene of natural gas income lower be mad about for wind and solar. New investments in renewable energy sources declined 5 percent in North America basic rendezvous to 56 billion, the beat to the same degree 2010, according to Bloomberg...