Hill: The goal of the new Tom Steyer-Hank Paulson-Michael Bloomberg climate initiative has been revealed: make the case that failing to act on global warming is far more expensive than cutting emissions. The New Yorker reported last month that the billionaire ex-hedge fund chief Steyer, George W. Bush-era Treasury Secretary Paulson and outgoing New York City Mayor Bloomberg were launching some sort of bipartisan effort. On Tuesday Bloomberg Markets Magazine filled in some of the details: The three men...