Keeping tourism's future within a climatically safe operating space

Introduction In recent decades, signs of the increasing human influence on the Earth’s systems have become stronger. Paul Crutzen (see e.g. Crutzen, 2002) and others even argue that we have entered a new geological epoch: the age of man or Anthropocene. Humankind has interfered with the Earth’s processes so much that the results will likely be clearly visible in the sediment layers that are currently forming. Scientific debate has shifted from discussing the justification of using the term to defining which anthropogenic signatures in the geological record fulfil the formal requirements for the recognition of such a new epoch (Lewis and Maslin, 2015). If these are fulfilled, the Holocene, with its stable and benign climate fostering humanity as we know it, is over and we have entered an epoch of human-caused change. The earthly processes that humans affect range from the global climate to local biota. Humanity has upset the climate system, primarily by burning fossil fuels. Humanity appropriates more than half the Earth’s primary production and uses a large share of the Earth’s land, leading to large-scale extinctions of plant and animal species as outlined by Michael C. Hall (this volume). In addition, the large-scale use of chemical fertilizers has fundamentally changed the nitrogen and phosphorous cycles. Growing populations and increasing irrigation have lowered ground water levels around the world (Ehrlich et al., 2012; Rockström et al., 2009). Humanity lives beyond the means that the Earth systems provide, which is not sustainable in the long run. The challenge is to reorganize society in such a way as to respect the planet’s ecological boundaries. Tourism will have to do its share. In this chapter, we discuss the role of tourism in affecting the earthly processes, in particular the climate system. The chapter presents the mitigation challenge that tourism is facing, and analyses if and how tourism can meet the necessary reduction targets while remaining an economically healthy sector