New York Times: On a showery afternoon last week in West London, a ripple of enthusiasm went through the trading floor of CF Partners, a privately owned financial company. The price of carbon allowances, shown in green lights on a board hanging from the ceiling, was creeping up toward three euros. That is pretty small change $3.90, or only about 10 percent of what the price was in 2008. But to the traders it came as a relief after the market had gone into free fall to record lows two days earlier, after the European...