The purpose of this study is to evaluate the eight ISIMIP2a biome models against independent estimates of long-term net carbon fluxes (i.e. Net Biome Productivity, NBP) over terrestrial ecosystems for the recent four decades (1971–2010). We evaluate modeled global NBP against 1) the updated global residual land sink (RLS) plus land use emissions (ELUC) from the Global Carbon Project (GCP), presented as R + L in this study by Le Quéré et al (2015), and 2) the land CO2 fluxes from two atmospheric inversion systems: Jena CarboScope s81_v3.8 and CAMS v15r2, referred to as FJena and FCAMS respectively. The model ensemble-mean NBP (that includes seven models with land-use change) is higher than but within the uncertainty of R + L, while the simulated positive NBP trend over the last 30 yr is lower than that from R + L and from the two inversion systems. ISIMIP2a biome models well capture the interannual variation of global net terrestrial ecosystem carbon fluxes. Tropical NBP represents 31 ± 17% of global total NBP during the past decades, and the year-to-year variation of tropical NBP contributes most of the interannual variation of global NBP. According to the models, increasing Net Primary Productivity (NPP) was the main cause for the generally increasing NBP. Significant global NBP anomalies from the long-term mean between the two phases of El Niño Southern Oscillation (ENSO) events are simulated by all models (p < 0.05), which is consistent with the R + L estimate (p = 0.06), also mainly attributed to NPP anomalies, rather than to changes in heterotrophic respiration (Rh). The global NPP and NBP anomalies during ENSO events are dominated by their anomalies in tropical regions impacted by tropical climate variability. Multiple regressions between R + L, FJena and FCAMS interannual variations and tropical climate variations reveal a significant negative response of global net terrestrial ecosystem carbon fluxes to tropical mean annual temperature variation, and a non-significant response to tropical annual precipitation variation. According to the models, tropical precipitation is a more important driver, suggesting that some models do not capture the roles of precipitation and temperature changes adequately.
Laboratoire des Sciences du Climat et de l’Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France;Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN/IPSL, 4 place Jussieu, 75005 Paris, France;Author to whom any correspondence should be addressed.;Laboratoire des Sciences du Climat et de l’Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France;Laboratoire des Sciences du Climat et de l’Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France;Sino-French Institute of Earth System Sciences, College of Urban and Environmental Sciences, Peking University, 100871 Beijing People’s Republic of China;Sino-French Institute of Earth System Sciences, College of Urban and Environmental Sciences, Peking University, 100871 Beijing People’s Republic of China;Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, Maryland, United States of America;College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QE, United Kingdom;Laboratoire des Sciences du Climat et de l’Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France;Unité de Modélisation du climat et des Cycles Biogéochimiques, UR SPHERES, Université de Liège, Quartier Agora, Allée du Six Août 19 C, B-4000 Liège, Belgium;Unité de Modélisation du climat et des Cycles Biogéochimiques, UR SPHERES, Université de Liège, Quartier Agora, Allée du Six Août 19 C, B-4000 Liège, Belgium;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany;Unité de Modélisation du climat et des Cycles Biogéochimiques, UR SPHERES, Université de Liège, Quartier Agora, Allée du Six Août 19 C, B-4000 Liège, Belgium;Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt am Main, Germany;Department of Physical Geography, Goethe-University, Frankfurt am Main, Germany;National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan;College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QE, United Kingdom;Laboratoire de Physique Atmosphérique et Planétaire, UR SPHERES, Université de Liège, Quartier Agora, Allée du Six Août 19 C, B-4000 Liège, Belgium;National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany;Geography Department, Humboldt-Universität zu Berlin, D-10099 Berlin, Germany;International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, United States of America;Sino-French Institute of Earth System Sciences, College of Urban and Environmental Sciences, Peking University, 100871 Beijing People’s Republic of China;Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, Maryland, United States of America;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany;Max Planck Institute for Biogeochemistry, Postfach 10 01 64, D-07701 Jena, Germany;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany;Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt am Main, Germany;International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, United States of America;Laboratoire des Sciences du Climat et de l’Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France;International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, United States of America;Department of Atmospheric and Oceanic Sciences, University of Maryland, College Park, Maryland, United States of America;Potsdam Institute for Climate Impact Research, D-14412 Potsdam, Germany
Recommended Citation:
Jinfeng Chang,Philippe Ciais,Xuhui Wang,et al. Benchmarking carbon fluxes of the ISIMIP2a biome models[J]. Environmental Research Letters,2017-01-01,12(4)