Definition of Business as Usual and Its Impacts on Assessment of Mitigation Efforts

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 developing countries.