Land Use Carbon Budget Pattern and Carbon Compensation Mechanism of Counties in the Pearl River Basin: A Perspective Based on Fiscal Imbalance

Implementing watershed carbon compensation under the constraint of fiscal imbalance is a crucial approach for China to achieve its “dual carbon” goals. Focusing on 257 counties within the Pearl River Basin (PRB), this paper first measured and modified the land use carbon emissions, carbon absorption, and the land use carbon budget (LUCB) from 2005 to 2020. Subsequently, their spatiotemporal patterns and the changes before and after the modifications were analyzed. Finally, this paper determined the subject–object, value, and priority order of carbon compensation using the modified LUCB as the baseline value, and a carbon compensation mechanism that combines vertical and horizontal directions was constructed. The following findings were obtained: (1) At the time scale, the proportion of construction land and forestland in the land use structure increased, and carbon emissions, carbon absorption, and the LUCB showed an overall upward trend from 2005 to 2020. (2) At the spatial scale, the areas with high carbon emissions and carbon deficits were mainly located in the lower reaches of the basin, whereas the areas with high carbon absorption and carbon surpluses were widely distributed in the upper and middle reaches. The carbon deficit in urban municipal districts and resource-based counties was relatively serious. (3) In 2020, the total amount of carbon compensation in the PRB was CNY −8088.61 million. The number of counties that needed to be paid and compensated was 75 and 182, respectively. The carbon compensation mechanism constructed in this paper can provide a reference for other countries and regions with financial imbalances to achieve regional carbon neutrality.