Dynamic Assessment of Carbon Storage Function and Forecasting of Its Future Potential in Beijing’s Green Belt

Urban green belts (GBs) have multiple functions of providing ecosystem carbon storage services, improving urban microclimate, and inhibiting urban sprawl. However, there is a paucity of studies to assess the dynamics of the ecosystem carbon storage function of the GB around the city and forecast its future potential. Our study analyzed the dynamic changes of carbon stock in Beijing’s GB during 2000 to 2020 and predicted the GB’s carbon storage potential in 2035 by coupling the InVEST and FLUS models. Results showed that Beijing’s GB carbon storage decreased from 14.45 to 10.59 Mt from 2000 to 2020. The carbon density of the GB in Beijing from 2000 to 2010 was greater than that of the non-GB areas, indicating that the GB had a substantial carbon storage function. The carbon stock in Beijing’s GB showed the spatial characteristics that the high carbon stock zones were located in the western part of the GB under 3 scenarios in 2035. The overall carbon stock in 2035 under the economic development scenario was 35.60 Mt, with the largest reduction from 2020, 1.78 Mt. The spatial layout, morphology, and structure of urban GB had a notable effect on carbon storage function, and the protection and spatial regulation of urban GB systems should be strengthened in the future in terms of urban–rural development and planning, the morphology and scale of GB, and institution and public support.