China Daily: There’s $30 billion floating in the air over China, but it won’t be easy to grab it. It’s China’s carbon trading market. The world market for trading greenhouse gas emissions doubled last year to about $70 billion, according to World Bank figures. China accounts for 73 percent of the clean development mechanism (CDM) projects – a major carbon trading business. Until just a few years ago, the idea of making money from emissions trading would have sounded like madness to most …