Simulated effect of sunshade solar geoengineering on the global carbon cycle

作     者：Jiu JIANG Han ZHANG Long CAO 

作者机构：Department of Atmospheric Sciences School of Earth Sciences Zhejiang University 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2018年第61卷第9期

页      面：1306-1315页

核心收录：

学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 070601[理学-气象学] 08[工学] 0708[理学-地球物理学] 0706[理学-大气科学] 0704[理学-天文学] 

基　　金：supported by the National Key Basic Research Program of China (Grant No. 2015CB953601) the National Natural Science Foundation of China (Grant Nos. 41675063 & 41422503) the Fundamental Research Funds for the Central Universities 

主　　题：Solar geoengineering Carbon cycle Climate change Ocean biogeochemistry 

摘      要：Solar geoengineering has been proposed as a potential mechanism to counteract global wanning. Here we use the University of Victoria Earth System Model （UVic） to simulate the effect of idealized sunshade geoengineering on the global carbon cycle. We conduct two simulations. The first is the A2 simulation, where the model is driven by prescribed emission scenario based on the SRES A2 COz emission pathway. The second is the solar geoengineering simulation in which the model is driven by the A2 CO2 emission scenario combined with sunshade solar geoengineering. In the model, solar geoengineering is represented by a spatially uniform reduction in solar insolation that is implemented at year 2020 to offset CO2-induced global mean surface temperature change. Our results show that solar geoengineering increases global carbon uptake relative to A2, in particular CO2 uptake by the terrestrial biosphere. The increase in land carbon uptake is mainly associated with increased net primary production （NPP） in the tropics in the geoengineering simulation, which prevents excess warming in tropics. By year 2100, solar geoengineering decreases A2-simulated atmospheric CO2 by 110 ppm （12%） and causes a 60% （251 Pg C） increase in land carbon accumulation compared to A2. Solar geoengineering also prevents the reduction in ocean oxygen concentration caused by increased ocean temperatures and decreased ocean ventilation, but reduces global ocean NPE Our results suggest that to fully access the climate effect of solar geoengineering, the response of the global carbon cycle should be taken into account.