Abstract:Global climate change is one of the most important and challenging problems facing the world today. The tourism sector is the world's biggest industry, and the measurement and control of tourism-related carbon emissions or its carbon footprint is of great significance if the global emission reduction targets are to be met. This paper discusses the deficiencies and weaknesses in existing research; and proposes the emphasis and direction that future research should take. The literature review shows that there has been considerable research on carbon emissions by the tourism sector, and its carbon footprint. However, few of these studies included uncertainty analyses, and their reliability and validity is hard to identify. Studies are difficult to compare, and the carbon intensity and ecological efficiency of the tourism sector or tourism consumption cannot be confirmed because there is no consensus about the intension and extension, system boundary, accounting caliber, and measurement methods. Finally, the emphasis and direction of the future research, which includes defining the intension and extension of carbon emissions or the carbon footprint that unifies the system boundary, and combines the strength of two methods, i.e., bottom-up based Process Analysis(PA) and top-down based Input-Output Analysis(IOA), to construct a detailed and comprehensive hybrid approach, are presented.