百年尺度不同区域地表气温对CO_(2)浓度非均匀动态分布敏感度的研究

Regional Sensitivity of Surface Temperature to Nonuniform CO_(2) Concentration on the Century Scale

地球系统模式结果表明大气CO_(2)浓度的快速增加是气候变化重要的原因之一。卫星资料分析结果表明,大气CO_(2)浓度并非均一的,而是有明显的区域差异,以人类活动为主的碳排放会影响这一区域差异。这种空间差异如何影响区域地表气温对CO_(2)的敏感度,需要进一步深入系统的研究,利用地球系统模式BNU-ESM(Earth System Model of Beijing Normal University)进行数值模拟,并与观测数据进行比较,结果表明:在试验模拟结果2°C阈值内,非均匀CO_(2)浓度试验的CO_(2)浓度增加阈值范围小于均匀CO_(2)浓度试验结果,偏少约为4.3 ppm(106)。在区域尺度上,中国地表气温对CO_(2)敏感度普遍低于美国、欧洲以及北半球平均水平,这表明CO_(2)浓度空间差异对地表气温的敏感度的影响存在明显区域差异,很可能是CO_(2)浓度辐射效应与气候系统反馈过程的共同作用结果,这需要进一步研究。非均匀CO_(2)浓度对地表气温敏感度影响将会对碳中和目标下未来碳汇潜力精准估算提供科学支持。

Simulations from Earth System Model show that the rapid increase in atmospheric CO_(2) concentration is one of the major reasons for climate change.Satellite data analysis shows that the atmospheric CO_(2) concentration is globally nonuniform.There are evident regional discrepancies,mainly caused by anthropogenic carbon emissions.The impact of this spatial difference on global warming has not been thoroughly studied.We evaluated simulation results using the BNU-ESM(Earth System Model of Beijing Normal University)and compared the results with observational datasets.The results show that within a threshold of 2℃temperature increase between 1901 and 2100,the CO_(2) concentration increase forced by nonuniform CO_(2) concentration was less than that by uniform CO_(2) concentration,which was approximately 4.30 ppm.On the regional scale,the sensitivity of surface temperature to CO_(2) concentration in China is lower than that in the United States,Europe,and the Northern Hemisphere.This might result from the combined impacts of CO_(2)-radiative forcing and climate feedback across these regions;however,this requires future investigation.The impact of nonuniform CO_(2) concentration on surface temperature sensitivity could provide scientific support for estimating future carbon sinks under a carbon-neutral target.