碳排放交易(简称碳交易)是运用市场机制削减污染物的重要手段。通过排放权交易,减排成本低的企业可出售富余的指标获得收益,减排成本高的企业可购买指标降低减排成本,达到合规要求,从而实现社会污染总成本最小化的目的。国际上,美国最早开始二氧化硫排放交易。自20世纪90年代以来,我国环境行政主管部门与美国环保部门合作开展排放权交易的研究和试验,探索通过市场机制实现环保减排。清洁发展机制(CDM)是《京都议定书》第12条确立的机制,其核心 Carbon emissions trading (referred to as carbon trading) is an important means of using market mechanisms to reduce pollutants. Through emission trading, enterprises with low emission reduction costs can sell surplus indicators to obtain benefits. Enterprises with high emission reduction costs can purchase indicators to reduce emission reduction costs and meet compliance requirements so as to minimize the total cost of social pollution. Internationally, the United States started as the earliest sulfur dioxide emissions trading. Since the 1990s, China’s environmental administrative department has conducted research and experiments on emission trading with the U.S. Environmental Protection Department and explored ways to reduce emissions through environmental protection. The Clean Development Mechanism (CDM) is the mechanism established by Article 12 of the Kyoto Protocol and its core