The rapid development of tourism in emerging countries is a major contributor to the sector's growing greenhouse gas (GHG) emissions. An assessment of emissions produced by Brazilian tourists confirms this trend, and reveals the importance of each country's unique economic, social and environmental factors, which make it difficult to treat emerging countries as a homogenous group. This paper explores the possible futures of Brazilian tourism emissions by using various scenarios, starting with the reconstruction of submarkets based on transport modes and distances travelled, using national sources for the year 2010. A reference scenario shows that GHG emissions are likely to be multiplied by four by 2030 and by eight by 2050. Finally, alternative hypotheses on the driving forces behind Brazilians' domestic and international tourism are combined and used as building blocks to develop alternative scenarios. The outcome of reasonable mitigation options would maintain tourism's contribution to national greenhouse gas emissions in 2030 at a level comparable to those currently observed in highly developed countries. However, between 2030 and 2050, tourism emissions would continue to grow, whereas national emissions would diminish. Tourism could therefore become a major burden in national mitigation policies.