Comparison between Three Downscaled Land Use and Land Cover Products under Different Shared Socio-Economic Pathways
Land use and land cover changes (LULCCs) play a center role in the societal and earth system modelling. The Integrated Assessment Models (IAMs), which run at the regional scale, are used to simulate the human system dynamics, including the regional LULC demand. Meanwhile, the Earth System Models (ESMs) require gridded LULCC data to study the effects of LULCC on biogeophysics, biogeochemistry and climate. Therefore, it is of great importance to develop LULCC downscaling tools to link the IAMs with ESMs. A limited number of such tools, which downscale the regional LULC to grid scale, are available in literature. A systemic comparison of different downscaling tools is still lacking. The comparison can help our understanding of past and future LULCC, and also lead to model improvements. In this study, we use the Spatial Dynamic Allocation Model to downscale the LULC data under different Socio-Economic Pathway scenarios, and compare the downscaled results with two other land use and land cover downscaling results under the same scenarios: the Demeter model downscaled data and the Land-Use Harmonization 2. We discuss the possible reasons for the differences in LULCCs calculated based on different downscaling tools. This study provides a comprehensive understanding of different global LULCC products that can help to improve the ESM simulations for LULCC.