College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China.
PLoS One. 2013 Aug 26;8(8):e71975. doi: 10.1371/journal.pone.0071975. eCollection 2013.
China has been experiencing rapid urbanization in parallel with its economic boom over the past three decades. To date, the organic carbon storage in China's urban areas has not been quantified. Here, using data compiled from literature review and statistical yearbooks, we estimated that total carbon storage in China's urban areas was 577 ± 60 Tg C (1 Tg = 10(12) g) in 2006. Soil was the largest contributor to total carbon storage (56%), followed by buildings (36%), and vegetation (7%), while carbon storage in humans was relatively small (1%). The carbon density in China's urban areas was 17.1 ± 1.8 kg C m(-2), about two times the national average of all lands. The most sensitive variable in estimating urban carbon storage was urban area. Examining urban carbon storages over a wide range of spatial extents in China and in the United States, we found a strong linear relationship between total urban carbon storage and total urban area, with a specific urban carbon storage of 16 Tg C for every 1,000 km(2) urban area. This value might be useful for estimating urban carbon storage at regional to global scales. Our results also showed that the fraction of carbon storage in urban green spaces was still much lower in China relative to western countries, suggesting a great potential to mitigate climate change through urban greening and green spaces management in China.
中国在过去三十年经历了经济繁荣和快速城市化的进程。迄今为止，中国城市地区的有机碳储量尚未被量化。在这里，我们使用文献综述和统计年鉴汇编的数据，估计 2006 年中国城市地区的总碳储量为 577 ± 60 Tg C（1 Tg = 10(12) g）。土壤是总碳储量的最大贡献者（56%），其次是建筑物（36%）和植被（7%），而人类的碳储量相对较小（1%）。中国城市地区的碳密度为 17.1 ± 1.8 kg C m(-2)，约为全国所有土地平均水平的两倍。在估计城市碳储量时，最敏感的变量是城市面积。我们在中国和美国的广泛空间范围内考察了城市碳储量，发现总城市碳储量与总城市面积之间存在很强的线性关系，每 1000 平方公里城市面积的总城市碳储量为 16 Tg C。这个值对于在区域到全球范围内估计城市碳储量可能是有用的。我们的结果还表明，中国城市绿地的碳储量占比仍远低于西方国家，这表明中国通过城市绿化和绿地管理来缓解气候变化具有巨大潜力。
