Tourism in Antarctica is rapidly growing and diversifying, which raises concerns about its effects on the environment. Research and policy-making efforts have so far focused on the impacts on Antarctica's own ecosystems, whereas global impacts have all but been ignored. This article presents an inventory of greenhouse gas emissions produced by Antarctic tourism. Emissions are shown to be considerable, with aviation and cruises being the main sources. Tourism to the Antarctic ranks among the most energy-intensive segments in the tourism market. It is argued that greenhouse gas emissions should be included in environmental impact assessments. Improving the global environmental performance of Antarctic tourism is difficult, because of its exclusive dependency on long-haul trips.