The Paris Climate Agreement is based on pledges from 195 countries to substantially reduce emissions of greenhouse gases (GHG) to prevent dangerous climate change. The tourism sector has likewise pledged to reduce its GHG emissions (-70% by 2050); however, current emission trends would result in a tripling in the same timeframe. In order to understand how the sector understands the decarbonisation challenge, 17 senior tourism leaders were interviewed with regard to their perspectives on the risks and opportunities associated with climate change impacts and action. Respondents affirmed that the climate is already changing, fuelled by human activities, including tourism, and that its impacts on society and tourism will be largely negative and devastating in some regions. Opinion was divided regarding mitigation timelines, the compatibility of continued tourism growth with Paris Climate Agreement decarbonisation goals, and the role of technology and governance in reducing emissions. The paper examines leaders' perspectives in terms of "belief systems" that interpret information in decision-making, as well as forms of agnogenesis; this is, the fabrication of uncertainty to justify non-action. Belief systems and agnogenesis are thought to represent important barriers to progress on the decarbonisation of tourism, as they are for the global low-carbon transition.