Abstract:

This research delves into refining the method of carbon budget accounting for land use, which is crucial for advancing low-carbon land utilization and aiding in achieving China's dual carbon goals. Utilizing geospatial big data, the study accounts for the carbon budget of China's land use from 2008 to 2020 across various land use types and examines their spatio-temporal trends. Key findings reveal a consistent annual increase in carbon emissions from land use, with minor changes in carbon sequestration. Construction land represents the predominant carbon source, while agricultural land has reached its carbon peak. Ecological land offsets only about 7% of carbon emissions, and soil carbon stocks are mostly experiencing net losses. The study also highlights significant spatial clustering and lock-in effects, with high carbon emissions from construction land often found in resource-rich or economically developed cities, and major grain-producing areas showing high agricultural carbon emissions. High carbon sequestration areas in ecological lands are located on both sides of the "Hu Line" and in the southeast, with soil carbon stock losses generally higher in the east. The study underscores the immense pressure of achieving carbon peak in land use across various city types, with active and passive peaks, plateau phases, and cities yet to reach their carbon peak constituting 10%, 5%, 31%, and 54%, respectively. The findings advocate for the adoption of geospatial big data-driven refined management of land resources, formulating low-carbon land use transition strategies tailored to different regions and land use types, thereby facilitating the optimization of low-carbon national land space and carbon neutrality.

Key words: land use carbon budget, refinement, carbon accounting, carbon peak, spatio-temporal characteristics