Tourism is one of the most dynamic and far-reaching economic sectors in the world. Numerous different and complex activities are involved in the efficient development of tourism. These activities interrelate economic, environmental, social, cultural and political dimensions in the overall supply chain. However, apart from its key role as a driver of socio-economic progress, tourism is responsible for environmental deterioration, not only in areas popular with tourists, but also by enhancing climate change globally. This paper presents a robust method based on the Green Tourism Supply Chain Management (GTSCM) concept, which can be used to estimate the effect on the environment that can be attributed to each link of the supply chain. The overall approach is based on Life Cycle Impact Assessment (LCIA) theory and corresponding models. A case study to demonstrate the applicability of this approach is presented for two large seaside hotels located in Chalkidiki, Greece. Chalkidiki is the most popular tourist destination in Northern Greece. A LCIA questionnaire was developed and input data for the Life Cycle Assessment (LCA) obtained from the hotel managers. For this LCA SimaPro 8 software was used. The LCIA methods chosen were Eco-indicator 99 and CML 2001. The effect on fossil fuel consumption of both hotels due to their use of local transport and electricity was considerable but less than that needed for transporting the tourists by air to Chalkidiki. This paper clearly indicates that LCA and Life Cycle Thinking (LCT) can form the basis for promoting GTSCM in the tourism industry.