China formally launched the carbon trading pilots in seven provinces and cities in 2013.Based on the operating situations of international carbon emission trading markets and that in China,this study compares and analyzes the potential risks in the European Union Emission Trading Scheme,California’s cap-and-trade system,and the seven regional carbon trading pilots in China.It mainly recognizes market operation risks,risks of uncertain policy expectation,and risks of uncertain mechanism designs existing in China's carbon trading pilots.The carbon market risks are not good for the formation of rational price signals,making it difficult to guide enterprises on how to make low-carbon technology in-vestments.Such risks also affect the effectiveness and functions of carbon markets,which can lead to the non-achievement of national emission reduction goals.China has launched the national carbon emission trading scheme on December 19,2017.While building the national carbon trading scheme,it is important to fully refer to the experiences of international carbon markets and China's carbon trading pilots apart from strengthening the recognition,control,and supervision of carbon market risks.Doing so can promote the healthy development of China's na-tional carbon trading scheme.
Business as Usual （BaU） scenario in developing countries has been a debated issue in climate change negotiations. This paper analyzes different definitions of BaU and points out that the major difference among these definitions is how to set the starting point of BaU projections, that is the so called base year. Some international institutions use current policy scenarios to project a BaU trajectory of developing countries. Such definition will lead to an underestimation of BaU emissions of developing countries and thus an underestimation of mitigation efforts. This paper concludes with a suggestion to use a without policy scenario with a clear base year as definition of BaU. Such a definition will set an objective benchmark to assess mitigation efforts of develonin countries.
