After decades of tourism research definitions and statistics of global tourism, flows are still not uniformly defined. A problem is that scholars, sector stakeholders and policy makers tend to have a biased image of the global tourism system. An important bias is the idea that international travel by air transport forms the core of global tourism. In this paper, we will show this to be incorrect. Due to this bias, several problems arise assessing the economic, social and ecological impacts of tourism and the role of transport and transport technology for the sustainable development of tourism, specifically with respect to its increasingly important role in climate change. This paper is based on research recently published in Sustainability (Peeters et al. 2012).