Sustainable Recovery or Carbon Rebound: Provincial Tourism Carbon Emission Efficiency in China Based on a Common-Frontier SBM and LMDI Decomposition

China’s dual-carbon commitment makes provincial tourism carbon efficiency a pressing policy question, but provincial evidence stops at 2019, and revenue-based estimates embed revenue in both the emission measure and the efficiency model. This study replaces revenue-share stripping coefficients with activity-volume coefficients for transport and accommodation and measures provincial tourism carbon emission efficiency with a common-frontier slacks-based measure (SBM) with undesirable outputs; because energy input is back-calculated from emissions, the score is a frontier-relative carbon-productivity measure. Tapio decoupling and a logarithmic mean Divisia index (LMDI) decomposition are convergent readings of a single accounting framework. (1) National domestic-tourism direct operational emissions fell from 107.6 Mt in 2019 to 43.7 Mt in 2022 and rebounded to 101.0 Mt in 2024 and about 117 Mt in 2025, above the 2019 peak. (2) With per-activity coefficients fixed, scale effects explain 91–97% of national emission changes, and real carbon intensity in 2023 was essentially unchanged from 2019. (3) On reported provincial statistics, efficiency fell from 0.560 to 0.456 across 26 provinces, but reception statistics drifted by about 29% relative to national totals; under a like-for-like caliber adjustment, the change is −0.013 (p = 0.84). The recovery was a scale-driven carbon rebound without detectable efficiency gains.