Policy-Driven Land Use Optimization for Carbon Neutrality: A PLUS-InVEST Model Coupling Approach in the Chengdu–Chongqing Economic Circle

In the context of global “dual carbon” objectives, land use dynamics exhibit a strong correlation with regional carbon storage. Facing significant ecological–economic conflicts, the Chengdu–Chongqing Economic Circle in western China necessitates multi-scenario modeling of carbon storage. This research integrates the PLUS model (simulation accuracy Kappa = 0.84) and InVEST model to project land use and carbon storage trajectories under natural development (NDS), urban development (UDS), carbon peak (CPS), and carbon neutrality (CNS) scenarios from 2030 to 2060, leveraging historical data from 2000 to 2020. The results show the following: (1) The study area is dominated by forest land and cultivated land (accounting for more than 90%). From 2000 to 2020, cultivated land decreased, and construction land increased; construction land continued to expand under all future scenarios. (2) Carbon storage showed a trend of first increasing and then decreasing, reaching 4974.55 × 106 t in 2020 (an increase of 4.0 × 106 t compared with 2000). The peak carbon storage in the CPS scenario reached 5015.18 × 106 t, and the overall spatial pattern was “high around and low in the middle”. (3) The CPS achieved a carbon peak through intensive land use and ecological restoration, and the CNS further strengthened carbon sink protection and promoted carbon neutrality. Constructing a multi-scenario coupling model chain provides a new method for regional carbon management, which has important guiding significance for the low-carbon development of the Chengdu–Chongqing Twin Cities Economic Circle.