College of Land Management, Nanjing Agricultural University, Xuanwu District, Nanjing, Jiangsu Province, 210095, People's Republic of China.
National & Local Joint Engineering, Research Center for Rural Land Resources Use and Consolidation, Nanjing, 210095, China.
Environ Sci Pollut Res Int. 2023 Sep;30(43):96808-96826. doi: 10.1007/s11356-023-29111-6. Epub 2023 Aug 15.
Burgeoning urbanization is a defining challenge for global carbon emissions mitigation in the coming decades. In this context, achieving low-carbon urbanization remains an urgent issue that demands prompt solutions. The coupling and decoupling relationships between urbanization and carbon emissions play an important role in the coordination of urbanization development and carbon emissions reduction, which has rarely been explored in existing studies, especially in China at the county level. To address this gap, the coupling and decoupling relationship between the urbanization level (UL) and carbon emissions density (CED) was explored using an improved coupling degree model and the Tapio decoupling method in China at the county level from 2000 to 2020. The results showed that the UL and CED of China both exhibited increasing trends, and the spatial distribution was quite similar, with the UL increasing from 0.018 in 2000 to 0.028 in 2020 and the CED increasing from 95.163 ton/km in 2000 to 295.746 ton/km in 2020. The spatial distribution of hotspots in the UL change differed with time, whereas that in the CED change was relatively stable. However, both of them were concentrated in eastern China. The coupling degrees of the UL and CED in China were 0.348, 0.355, 0.369, 0.370, and 0.338 in 2000, 2005, 2010, 2015, and 2020, respectively, with the moderately unbalanced type (>35%) being dominant at the county level and mainly scattered in eastern China. The changes in the spatial distribution patterns of the 10 subcategories were quite limited, with the systematically balanced type being dominant (89%). The decoupling types of the UL and CED during 2000-2005, 2005-2010, and 2010-2015 were weak decoupling, while those in 2015-2020 were expansive negative decoupling. At the county level, the most significant transition occurred between expansive negative decoupling, strong decoupling, and strong negative decoupling. The proportion of strong decoupling type counties peaked in 2015-2020 (70.86%), whereas that of the strong negative decoupling type counties remained high (17.55%), scattering the country. These findings can advance policy enlightenment of low-carbon urbanization and green development for China against the backdrop of "30·60 dual carbon" goal.
城市化的快速发展是未来几十年全球碳减排面临的重大挑战。在这种情况下，实现低碳城市化仍然是一个紧迫的问题，需要及时解决。城市化与碳排放的耦合和脱耦关系在城市化发展与碳排放减排的协调中起着重要作用，这在现有研究中很少被探讨，特别是在中国县级层面。为了弥补这一空白，本文采用改进的耦合度模型和 Tapio 脱钩方法，以中国 2000-2020 年县级单元为研究对象，探讨了城市化水平（UL）与碳排放密度（CED）的耦合脱耦关系。结果表明，中国的 UL 和 CED 均呈上升趋势，空间分布十分相似，UL 从 2000 年的 0.018 增加到 2020 年的 0.028，CED 从 2000 年的 95.163 吨/千米增加到 2020 年的 295.746 吨/千米。UL 变化的热点空间分布随时间变化而不同，而 CED 变化的热点空间分布则相对稳定，但都集中在中国东部地区。2000-2020 年，中国 UL 和 CED 的耦合度分别为 0.348、0.355、0.369、0.370 和 0.338，县级层面以中度不平衡型（>35%）为主，主要分布在中国东部地区。10 个子类的空间分布格局变化有限，以系统平衡型（89%）为主。2000-2005 年、2005-2010 年和 2010-2015 年 UL 和 CED 的脱耦类型为弱脱耦，2015-2020 年为扩张负脱耦。在县级层面，扩张负脱耦、强脱耦和强负脱耦之间的转变最为显著。强脱耦类型县的比例在 2015-2020 年达到峰值（70.86%），而强负脱耦类型县的比例仍然较高（17.55%），分布在中国各地。这些发现可以为中国“30·60 双碳”目标背景下的低碳城市化和绿色发展提供政策启示。
