Tourism is an increasingly significant contributor to greenhouse gas (GHG) emissions. Emissions growth in the sector is in substantial conflict with global climate policy goals that seek to mitigate climate change through significant emission reductions. This article discusses the role of various tourism sub-sectors in generating emissions, and technical and management options in reducing these. It concludes that given observed and anticipated emission growth rates, technology and management will not be sufficient to achieve even modest absolute emission reductions in the sector, pointing to the key role of social and behavioural change in realizing climatically sustainable tourism. The article also discusses some of the systemic barriers that have to be overcome in order for tourism to comply with post Kyoto Protocol global mitigation frameworks. The article concludes that radical change will be needed to reconcile the holiday and business travel demands of a growing world population with the climate policy targets of the international community, specifically restricting anthropogenic global warming to less than 2°C.