格网尺度的重庆市碳补偿研究——基于土地利用视角

Grid scale measurement of carbon compensationin Chongqing City:Based on the perspective of land use

【目的】完善碳补偿机制是应对气候变化、助力碳中和目标实现的重要行动。基于土地利用变化,从格网尺度建立行政单元内部间的碳补偿机制,可为区域低碳协调发展提供科学参考。【方法】本文基于5 km×5 km的格网单元,采用土地覆盖及社会经济数据对2000—2020年重庆市碳源/汇进行核算,探究碳源/汇的时空演变规律,以修正后的净碳排放量作为基准值对碳补偿价值进行研究,最后探讨重庆市实现碳补偿的路径。【结果】(1)研究期间,重庆市碳排放量呈现持续增加的态势,总计增长3729.07万t;碳吸收量缓慢增加,总计增长5.93万t。(2)碳排放呈现以中心城区为高值中心,向两翼逐渐降低的“核心—外围”空间结构,碳排放减少区域以长寿区为主,增加区域则主要在渝北、九龙坡、沙坪坝和巴南西北部;碳吸收总体呈现出“两翼高、中部低”的分布特征,奉节、云阳和万州等区县一带为碳吸收增长区,渝东北以及中心城区的部分地区为碳吸收减少区。(3)碳补偿支付区集中在中心城区、梁平中部、开州东南部和丰都西南部等地,总计支付金额为233702.58万元;获补区主要分布在两翼地区和主城都市区内部少量区域,总计获补金额为140638.72万元。【结论】重庆市碳排放远大于碳吸收,格网化碳补偿价值存在空间异质性。建议根据实际情况制定差异化的资金补偿政策,保障碳获补地区的经济利益,强调碳支付区的生态保护责任,多途径推进跨区县的横向生态补偿,协同促进生态保护与经济发展的双赢。

[Objective]Improving the carbon compensation mechanism is an important action tocope with climate change and realize the goal of carbon neutrality.At the grid scale,theestablishment of carbon compensation between administrative units can provide a reference forregional low-carbon coordinated development based on land use change.[Methods]Using landcover and socioeconomic data at a grid scale of 5 km×5 km,this study calculated the carbon source/sink of land use in Chongqing from 2000 to 2020,and then explored the spatiotemporal evolutioncharacteristics of the carbon source/sink.Further more,the carbon compensation value with therevised net carbon emissions was estimated.Finally,the path for Chongqing to achieve carboncompensation was discussed.[Results]During the research period,carbon emissions in Chongqingshowed a continuous increase,with a total increase of 37.29 million tons.The carbon absorptionwas slowly increasing,with a total increase of 0.059 million tons.The carbon emissions showed a“core-periphery”spatial structure with the central urban area as the high-value center and graduallydecreasing towards the two wings.The areas with reduced carbon emissions were mainly inChangshou,while the areas with increased emissions mainly occurred in Yubei,Jiulongpo,Shapingba,and the northwest of Ba’nan.The carbon absorption showed a distribution pattern of“high in two wings and low in the middle”in general.Fengjie,Yunyang,and Wanzhou were areasof carbon sink growth,while the northeast of Chongqing and some areas in the central urban areashowed the reduction of carbon sink.The carbon compensation paying areas were concentrated inthe central urban area,central Liangping,southeastern Kaizhou,and southwestern Fengdu,with atotal payment amount of 2.337 billion yuan.The regions that can receive carbon compensationwere mainly distributed in the two wings and a small number within the main urban area,with atotal amount of 1.406 billion yuan.[Conclusion]Carbon emissions in Chongqing far exceedcarbon absorption,and there exists spatial heterogeneity in the carbon compensation value at thegrid scale.It is recommended to formulate differentiated compensation funding policies accordingto the actual situation,so as to ensure the economic interests of carbon compensation receivingareas and emphasize the ecological protection responsibility of carbon compensation paying areas.It is also necessary to promote cross-regional and county-level horizontal ecological compensationthrough multiple channels,and create a win-win situation between ecological protection andeconomic development.