海洋和陆地碳循环对二氧化碳正负排放响应的模拟研究OA北大核心CSTPCD

Human activities lead to increase in atmospheric CO2 concentrations and global warming,threatening human survival.As a potential method to mitigate global warming,CO2 removal has garnered extensive attention in recent years.We employed the University of Victoria Earth System Climate Model(UVic ESCM)to simulate and analyze the effects of both positive and negative CO2 pulses of various intensity on the carbon cycle starting from preindustrial equilibrium(CO2 concentration:285×10-6).The results show that in the 100 Pg C positive CO2 pulse emission scenario,100(1000)years after imposing the CO2 pulse,only 28%(18%)of the CO2 emission remains in the atmosphere,the ocean absorbs about 38%(61%)of the CO2 emission,the land absorbs about 34%(21%)of the CO2 emission.In the 100 Pg C negative CO2 pulse emission scenario,the ocean and the land releases CO2 to the atmosphere,weakening the effect of CO2 removal.100(1000)years after imposing the CO2 pulse,only 23%(12%)of the initial CO2 removal from the atmosphere remains,with 36%(65%)offset by ocean carbon release,41%(23%)offset by land carbon release.According to different positive and negative pulse scenarios,the cumulative airborne fraction in the positive pulse scenario is always higher than cumulative removal fraction in the negative pulse scenario of the same intensity,which indicates that the positive and negative pulse carbon emission scenario responses of the sea and land carbon cycles are asymmetric.It means that negative emissions of higher intensities are needed to offset the atmospheric CO2 concentration increases caused by positive emissions.