To what extent can interannual CO2 variability constrain carbon cycle sensitivity to climate change in CMIP5 Earth System Models?
We analyze the carbon–climate feedback in eight Earth System Models (ESMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5).We focus on tropical land carbon change and find decreases (-31.02 to -169.32 GtC K-1),indicating tropical ecosystems will release carbon as temperature warms,thus contributing to a positive feedback identified in earlier studies.We further investigate the relationship between tropical land carbon change and sensitivity of historical atmospheric CO2 growth rate to tropical temperature variability,and find a weak linear relationship.This sensitivity for most models is stronger than observed.We further use this ”emergent constraint” ”Cox et al.,2013” to constrain uncertainties in model-projected future carbon–climate changes,and find little effect in narrowing the model-spread,but the mean sensitivity is slightly smaller.This contrasts with earlier C4MIP results,highlighting the challenge in constraining future projections by modern observations and necessity for evaluating such relationships continuously.
carbon-climate feedback interannual CO2 variability Earth System Models CMIP5
Jun Wang Ning Zeng Yimin Liu Qing Bao
State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics, Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center,Univ State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics,
国内会议
北京
英文
1-13
2014-10-01（万方平台首次上网日期，不代表论文的发表时间）