The world’s tourism footprint has been quantified across the supply chain, with the carbon-intensive industry revealed as a significant and growing contributor to greenhouse gas (GHG) emissions. Small islands attract a disproportionate share of GHG emissions per capita, through international arrivals, while the US is responsible for the majority of tourism-generated emissions overall. The research fills a gap noted by United Nations bodies and notes that carbon-intensive air-travel is not included in international climate commitments.