The digitization process plays a crucial role in eliminating tourism’s “low efficiency” developmental pitfall and addressing the conflict between high-caliber tourism development and the reduction of carbon emissions. The study quantified carbon emissions from tourism in the Yangtze River Economic Belt of China using both the carbon footprint and the “bottom-up” approach and developed a panel threshold model to empirically evaluate the nonlinear effect of the digital economy on tourism carbon emissions. The results show that the effect of the digital economy on carbon emissions in tourism will vary in structure depending on the degree of tourist concentration and the concentration of residents in tourist areas. Particularly, considering varying levels of tourism concentration and the resident population density, the overall impact of the digital economy on carbon emissions from tourism exhibits a reversed “V” type single threshold characteristic. If the concentration of the tourism sector falls below 1.08 or its resident population density is under 389.9, digital tourism growth exacerbates carbon emissions, resulting in incremental impacts of 3.3 and 2.38, respectively. If the concentration of the tourism sector exceeds 1.08 or its resident population density surpasses 389.90, the collective impact of digital tourism growth will be maximized, and advancing the digital economy will aid in lowering carbon emissions in the tourism sector, yielding incremental impacts of -3.94 and -2.17, respectively. The impact of the digital economy on diminishing carbon emissions within the tourism sector primarily focuses on transportation and tourism-related activities. Achieving a harmonious interplay between tourism’s digital evolution and the reduction of carbon emissions requires not only the focused growth of the digital economy, but also the strategic direction of tourism businesses and the concentration of populations, thereby disrupting the inflexible trend of tourism carbon emissions clustering.