区域碳固持服务供需关系动态分析——以北京为例

Mapping the Changes in Supply and Demand of Carbon Sequestration Service:A Case Study in Beijing

陆地生态系统的碳固持服务能直接固定大气中的CO_2,有效减缓全球变暖趋势。该服务的供需平衡对于区域的可持续发展至关重要。目前,以空间显式的方法,定量评估城市尺度上碳固持服务供需关系动态的研究还比较少。因此,论文以北京市为例,分别选取CASA模型计算的植被净初级生产力,以及IPCC清单法和城市碳代谢法计算的人为CO_2排放量,表征碳固持服务的供应和需求量。在此基础上,分析了北京市2000和2013年碳固持服务的供需变化。结果显示,2000年北京市碳固持服务供不应求,供需比为53.5%。空间分布上,中心城区的碳固持服务供需失衡,西部和北部地区的碳固持服务则供大于求。2000—2013年,北京市碳固持服务的供需关系趋于紧张,供需比降至38.5%。碳固持服务供需关系变紧张的主要原因是碳排放总量的增加。其中,来自城市居民生活和交通运输过程的碳排放增长最多。基于此,建议在需求端加快产业转移、促进节能减排,在供应端加大生态环境保护力度、保障区域的可持续发展。

Carbon sequestration service provided by terrestrial ecosystem can mitigate climate change by directly absorbing atmospheric CO2. The balance between the supply and demand of carbon sequestration service is crucial for sustainable development in urban areas. However, spatially explicit and quantitative investigation of the changes in the supply and demand of this ecosystem service is relatively rare. In this study, the CASA model was adopted to measure the net primary productivity to represent the supply of carbon sequestration service. Meanwhile, the IPCC Guideline Inventory as well as the carbon metabolism method were used to measure the anthropogenic CO2 emissions to represent the demand of carbon sequestration service. Then, the balance of the supply and demand of carbon sequestration service in 2000 and 2013 were analyzed. The results showed that the supply of carbon sequestration service in 2000 was in short, the overall supply/demand ratio being 53.5%. Spatially, the demand of the service was far beyond the supply of the service in the central districts whereas the situation was opposite in the northern and western districts. In 2013, the gap between the supply and demand of the service was even larger that the supply/demand ratio dropped to 38.5%. Spatially, the gap between the supply and demand was widened in the central districts. The widened gap was mainly due to the increase in CO2 emissions accompanying with urbanization process. Specifically, CO2 emissions from household use and transportation contributed most to the increase. Therefore, it is highly recommended to enhance ecological conservation, improve the efficiency of energy consumption and accelerate the transformation of industrial structure for a more sustainable development path in Beijing.