Land use projections in China under global socioeconomic and emission scenarios: Utilizing a scenario-based land-use change assessment framework

Land-use changes under the shared socioeconomic pathways (SSPs) and the representative concentration pathways (RCPs) have been analyzed globally, but how regional and national land use respond to the global mitigation policies is seldom explored, which poses difficulties in regional environmental adaptation and decision-making. China, as a major food consuming and biofuel production country, would suffer great uncertainties in future land-use dynamics under the global scenarios. Here, we present a scenario-based land-use change assessment framework, integrating Global Change Assessment Model and Future Land Use Simulation Model, to evaluate the potential land use projections of China from 2010 to 2100. Eight scenarios with different combinations of SSPs and radiative forcing targets of RCPs are designed, to analyze the impacts of the global socioeconomic and emission assumptions on regional mitigations and land-use changes. We recalibrated the historical land use data and urban dynamics of China to improve the consistency of modeling results with the actual regional changes. Meanwhile, differences in land use dynamics are demonstrated by spatial downscaling, which are jointly affected by the global assumptions and local driving factors, showing a fierce competition between the crop and forest. We find that the regional crop changes are sensitive to the socioeconomic dynamics as well as the bioenergy production, while different carbon regimes drive the forest changes in unexpected ways. Besides, overall heterogeneous landscape patterns and similar spatial suitability maps are found in distributions of land-use change between the emission and socioeconomic scenarios. The results indicate that this framework embedded with the consideration of anthropogenic managements as well as the detailed interactions of local environments provides an effective way to investigate regional land use response to a range of alternative future pathways.