Reuters: The city of Changsha, the capital of Hunan province in south-central China, is preparing to launch an emissions trading scheme, its mayor said on Tuesday. Changsha’s plan is a local version of a tentative outline drawn up by the central bank, for a domestic emissions trading scheme that could cover everything from greenhouse gases to water pollutants, and speed China’s push for greener growth. Changsha would assign its local districts quotas for dust, carbon dioxide and …