Vulnerability and interaction between tourism and climate change are among the most important issues discussed recently. In this context, this study focuses primarily on how CO2 emissions, the main source of global warming and climate change, react to tourism developments. To this end, the impact of tourism developments on CO2 emissions in the most visited countries is examined from 1995 to 2014 by conducting the continuously updated fully modified (CUP-FM) and the continuously updated bias-corrected (CUP-BC) estimators. Empirical results indicate that tourism arrivals have an increasing effect on CO2 emissions, while tourism receipts have a reducing effect on CO2 emissions. Results also reveal a possible co-movement and causal relationship between tourism developments and CO2 emissions in the long-run.