%0 Journal Article %A Fei teng %T Definition of Business as Usual and Its Impact on Assessment of Mitigation Efforts %D 2012 %R %J Advances in Climate Change Research %P 272-277 %V 8 %N 4 %X Business as usual (BAU) scenario has been a debated issue during climate change negotiation. This paper introduces different definitions of BAU and points out that the major difference among different definitions is how to set the starting point of BAU projection, so called the “base year” of BAU. Some international institutions used “existing policy scenarios” to project the BAU trajectory of developing countries. Such a definition will lead to an underestimate of the BAU emissions of developing countries and thus an underestimate of mitigation efforts. This paper suggests to use the “without policy scenario” with a fixed base year as the definition of BAU, this definition will set an objective benchmark for assessing the mitigation efforts of developing countries. %U http://www.climatechange.cn/EN/abstract/article_708.shtml