BGD Biogeosciences Discussions BGD Biogeosciences Discuss. 1810-6285 Göttingen, Germany 10.5194/bgd-11-2083-2014 Challenges and opportunities to reduce uncertainty in projections of future atmospheric CO<sub>2</sub>: a combined marine and terrestrial biosphere perspective Dalmonech D. 1 Foley A. M. 2 3 Anav A. 4 Friedlingstein P. https://orcid.org/0000-0003-3309-4739 4 Friend A. D. https://orcid.org/0000-0002-9029-1045 2 Kidston M. 5 Willeit M. https://orcid.org/0000-0003-3998-6404 6 Zaehle S. 1 Biogeochemical Integration Department, Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745 Jena, Germany Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, UK Cambridge Centre for Climate Change Mitigation Research, Department of Land Economy, University of Cambridge, Cambridge, UK College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK Laboratoire des Sciences du Climat et l'Environnement, Gif-sur-Yvette, France Potsdam Institute for Climate Impact Research, Potsdam, Germany European Commission GREENCYCLESII - Anticipating climate change and biospheric feedbacks within the Earth system to 2200 (238366) 04 02 2014 11 2 2083 2153 Copyright: © 2014 D. Dalmonech et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://bg.copernicus.org/preprints/11/2083/2014/bgd-11-2083-2014.html The full text article is available as a PDF file from https://bg.copernicus.org/preprints/11/2083/2014/bgd-11-2083-2014.pdf

Atmospheric CO<sub>2</sub> and climate projections for the next century vary widely across current Earth system models (ESMs), owing to different representations of the interactions between the marine and land carbon cycle on the one hand, and climate change and increasing atmospheric CO<sub>2</sub> on the other hand. Several efforts have been made in the last years to analyse these differences in detail in order to suggest model improvements. Here we review these efforts and analyse their successes, but also the associated uncertainties that hamper the best use of the available observations to constrain and improve the ESMs models. The aim of this paper is to highlight challenges in improving the ESMs that result from: (i) uncertainty about important processes in terrestrial and marine ecosystems and their response to climate change and increasing atmospheric CO<sub>2</sub>; (ii) structural and parameter-related uncertainties in current land and marine models; (iii) uncertainties related to observations and the formulations of model performance metrics. We discuss the implications of these uncertainties for reducing the spread in future projections of ESMs and suggest future directions of work to overcome these uncertainties.

 References Abramowitz, G.: Towards a benchmark for land surface models, Geophys. Res. Lett., 32, L22702, <a href="http://dx.doi.org/10.1029/2005GL024419">https://doi.org/10.1029/2005GL024419</a>, 2005.%in list Abramowitz, G.: Model independence in multi-model ensemble prediction, Australian Meteorological and Oceanographic Journal, 59, 3–6, 2010. Ainsworth, E. A. and Long, S. P.: What have we learned from 15 years of free-air CO<sub>2</sub> enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO<sub>2</sub>., New Phytol., 165, 351–371, <a href="http://dx.doi.org/10.1111/j.1469-8137.2004.01224.x">https://doi.org/10.1111/j.1469-8137.2004.01224.x</a>, 2005.%in list Allen, M., Stott, P., Mitchell, J., Schnur, R., and Delworth, T.: Quantifying the uncertainty in forecasts of anthropogenic climate change, Nature, 407, 617–620, <a href="http://dx.doi.org/10.1038/35036559">https://doi.org/10.1038/35036559</a>, 2000.%in list Allison, S. D. and Martiny, J. B. H.: Resistance, resilience, and redundancy in microbial communities, P. Natl. Acad. Sci. USA, 105, 11512–11519, 2008.%in list Anav, A., Menut, L., Khvorostyanov, D., and Výovy, N.: Impact of tropospheric ozone on the Euro-Mediterranean vegetation, Glob. Change Biol., 17, 2342–2359, <a href="http://dx.doi.org/10.1111/j.1365-2486.2010.02387.x">https://doi.org/10.1111/j.1365-2486.2010.02387.x</a>, 2011.%in list Anav, A., Friedlingstein, P., Kidston, M., Bopp, L., Ciais, P., Cox, P., Jones, C., Jung, M., Myneni, R., and Zhu, Z.: Evaluating the land and ocean components of the global carbon cycle in the Cmip5 Earth system models, J. Climate, 26, 6801–6843, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00417.1">https://doi.org/10.1175/JCLI-D-12-00417.1</a>, 2013a. Anav, A., Murray-Tortarolo, G., Friedlingstein, P., Sitch, S., Piao, S., and Zhu, Z.: Evaluation of land surface models in reproducing satellite derived leaf area index over the high-latitude Northern Hemisphere – Part 2: Earth system models, Remote Sens., 5, 3637–3661, <a href="http://dx.doi.org/10.3390/rs5083637">https://doi.org/10.3390/rs5083637</a>, 2013b. Anderson, T. R.: Plankton functional type modelling: running before we can walk?, J. Plankton Res., 27, 1073–1081, 2005.%in list Annan, J. D., Hargreaves, J. C., Ohgaito, R., Abe-Ouchi, A., and Emori, S.: Efficiently constraining climate sensitivity with paleoclimate simulations, Sci. Online Lett. Atmos., 1, 181–184, 2005. Arora, V. K. and Matthews, H. D.: Characterizing uncertainty in modeling primary terrestrial ecosystem processes, Global Biogeochem. Cy., 23, 1–14, <a href="http://dx.doi.org/10.1029/2008GB003398">https://doi.org/10.1029/2008GB003398</a>, 2009.%in list Arora, V. K., Scinocca, J. F., Boer, G. J., Christian, J. R., Denman, K. L., Flato, G. M., Kharin, V. V., Lee, W. G., and Merryfield, W. J.: Carbon emission limits required to satisfy future representative concentration pathways of greenhouse gases, Geophys. Res. Lett., 38, 3–8, <a href="http://dx.doi.org/10.1029/2010GL046270">https://doi.org/10.1029/2010GL046270</a>, 2011.%in list Arora, V. K., Boer, G. J., Friedlingstein, P., Eby, M., Jones, C. D., Christian, J. R., Bonan, G., Bopp, L., Brovkin, V., Cadule, P., Hajima, T., Ilyina, T., Lindsay, K., Tjiputra, J. F., and Wu, T.: Carbon-concentration and carbon-climate feedbacks in CMIP5 Earth system models, J. Climate,26, 5289–5314, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00494.1">https://doi.org/10.1175/JCLI-D-12-00494.1</a>, 2013. Asner, G. P. and Alencar, A.: Drought impacts on the Amazon forest: the remote sensing perspective, New Phytol., 187, 569–578, <a href="http://dx.doi.org/10.1111/j.1469-8137.2010.03310.x">https://doi.org/10.1111/j.1469-8137.2010.03310.x</a>, 2010.%in list Atkin, O. K. and Tjoelker, M. G.: Thermal acclimation and the dynamic response of plant respiration to temperature, Trends Plant Sci., 8, 343–351, 2003.%in list Atkin, O. K., Bruhn, D., Hurry, V. M., and Tjoelker, M. G.: Evans Review No. 2: the hot and the cold: unravelling the variable response of plant respiration to temperature, Funct. Plant Biol., 32, 87–105, <a href="http://dx.doi.org/10.1071/FP03176">https://doi.org/10.1071/FP03176</a>, 2005.%in list Barton, A. D., Pershing, A. J., Litchman, E., Record, N. R., Edwards, K. F., Finkel, Z. V., Kiørboe, T., and Ward, B. A.: The biogeography of marine plankton traits, Ecol. Lett., 16, 522–534, <a href="http://dx.doi.org/10.1111/ele.12063">https://doi.org/10.1111/ele.12063</a>, 2013.%in list Behrenfeld, M. J. and Falkowski, P. G.: Photosynthetic rates derived from satellite-based chlorophyll concentration, Limnol. Oceanogr., 42, 1–20, 1997.%in list Berger, J. O., De Oliveira, V., and Sanso, B.: Objective Bayesian analysis of spatially correlated data, J. Am. Stat. Assoc., 96, 1361–1374, 2001.%in list Berman-Frank, I., Chen, Y., Gao, Y., Fennel, K., Follows, M. J., Milligan, A. J., and Falkowski, P.: Feedback between the nitrogen, carbon and oxygen cycles, in: Nitrogen in the Marine Environment, Elsevier Inc, Amsterdam, the Netherlands, 1539–1563, 2008. Blyth, E., Clark, D. B., Ellis, R., Huntingford, C., Los, S., Pryor, M., Best, M., and Sitch, S.: A comprehensive set of benchmark tests for a land surface model of simultaneous fluxes of water and carbon at both the global and seasonal scale, Geosci. Model Dev., 4, 255–269, <a href="http://dx.doi.org/10.5194/gmd-4-255-2011">https://doi.org/10.5194/gmd-4-255-2011</a>, 2011. Bony, S., Colman, R., Kattsov, M. V., Allan, R. P., Bretherton, C. S., Dufresne, J.-L., Hall, A., Hallegatte, S., Holland, M. M., Ingram, W. J., Randall, D. A., Soden, B. J., Tselioudis, G., and Webb, M. J.: How well do we understand and evaluate climate change feedback processes?, J. Climate, 19, 3445–3482, 2006.%in list Booth, B. B. B., Jones, C. D., Collins, M., Totterdell, I. J., Cox, P. M., Sitch, S., Huntingford, C., Betts, R. A., Harris, G. R., and Lloyd, J.: High sensitivity of future global warming to land carbon cycle processes, Environ. Res. Lett., 7, 024002, <a href="http://dx.doi.org/10.1088/1748-9326/7/2/024002">https://doi.org/10.1088/1748-9326/7/2/024002</a>, 2012.%in list Bopp, L., Monfray, P., Aumont, O., Dufresne, J.-L., Treut, H. Le, Madec, G., Terray, L., and Orr, C. J.: Potential impact of climate change on marine export production, Global Biogeochem. Cy., 15, 81–99, 2001.%in list Bopp, L., Resplandy, L., Orr, J. C., Doney, S. C., Dunne, J. P., Gehlen, M., Halloran, P., Heinze, C., Ilyina, T., Séférian, R., Tjiputra, J., and Vichi, M.: Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models, Biogeosciences, 10, 6225–6245, <a href="http://dx.doi.org/10.5194/bg-10-6225-2013">https://doi.org/10.5194/bg-10-6225-2013</a>, 2013. Boyd, P. W. and Doney, S. C.: Modelling regional responses by marine pelagic ecosystems to global climate change, Geophys. Res. Lett., 29, 1–4, 2002.%in list Braakhekke, M. C., Beer, C., Hoosbeek, M. R., Reichstein, M., Kruijt, B., Schrumpf, M., and Kabat, P.: SOMPROF: a vertically explicit soil organic matter model, Ecol. Model., 222, 1712–1730, <a href="http://dx.doi.org/10.1016/j.ecolmodel.2011.02.015">https://doi.org/10.1016/j.ecolmodel.2011.02.015</a>, 2011.%in list Braconnot, P., Harrison, S. P., Otto-Bliesner, B., Abe-Ouchi, A., Jungclaus, J., and Peterschmitt, J.-Y.: The Paleoclimate Modeling Intercomparison Project contribution to CMIP5, CLIVAR Exchanges, No. 56, International CLIVAR Project Office, Southampton, UK, 15–19, 2011. Braconnot, P., Harrison, S. P., Kageyama, M., Bartlein, P. J., Masson-Delmotte, V., Abe-Ouchi, A., Otto-Bliesner, B., and Yan Zhao, Y.: Evaluation of climate models using palaeoclimatic data, Nature Clim. Change, 2, 417–424, <a href="http://dx.doi.org/10.1038/NCLIMATE1456">https://doi.org/10.1038/NCLIMATE1456</a>, 2012. Buitenhuis, E. T., Vogt, M., Moriarty, R., Bednaršek, N., Doney, S. C., Leblanc, K., Le Quéré, C., Luo, Y.-W., O'Brien, C., O'Brien, T., Peloquin, J., Schiebel, R., and Swan, C.: MAREDAT: towards a world atlas of MARine Ecosystem DATa, Earth Syst. Sci. Data, 5, 227–239, <a href="http://dx.doi.org/10.5194/essd-5-227-2013">https://doi.org/10.5194/essd-5-227-2013</a>, 2013. Cadule, P., Friedlingstein, P., Bopp, L., Sitch, S., Jones, C. D., Ciais, P., Piao, S. L., and Peylin, P.: Benchmarking coupled climate-carbon models against long-term atmospheric CO<sub>2</sub> measurements, Global Biogeochem. Cy., 24,GB2016, <a href="http://dx.doi.org/10.1029/2009GB003556">https://doi.org/10.1029/2009GB003556</a>, 2010. Cane, M. A., Braconnot, P., Clement, A., Gildor, H., Joussaume, S., Kageyama, M., Khodri, M., Paillard, D., Tett, S., and Zorita, E.: Progress in paleoclimate modeling, J. Climate, 19, 5031–5057, <a href="http://dx.doi.org/10.1175/JCLI3899.1">https://doi.org/10.1175/JCLI3899.1</a>, 2006. Chapin III, F. S., McFarland, J., David McGuire, A., Euskirchen, E. S., Ruess, R. W., and Kielland, K.: The changing global carbon cycle: linking plant-soil carbon dynamics to global consequences, J. Ecol., 97, 840–850, <a href="http://dx.doi.org/10.1111/j.1365-2745.2009.01529.x">https://doi.org/10.1111/j.1365-2745.2009.01529.x</a>, 2009.%in list Chavez, F. P., Messi, M., and Pennington, J. T.: Marine Primary production in relation to climate variability and change, Annu. Rev. Mar. Sci., 3, 227–260, <a href="http://dx.doi.org/10.1146/annurev.marine.010908.163917">https://doi.org/10.1146/annurev.marine.010908.163917</a>, 2011. Chelton, D. B., Gaube, P., Schlax, M. G., Early, J. J., and Samelson, R. M.: The influence of nonlinear mesoscale eddies on near-surface oceanic chlorophyll, Science, 334, 328–332, 2011.%in list Chikamoto, Y., Kimoto, M., Ishii, M., Mochizuki, T., Sakamoto, T., Tatebe, H., Komuro, Y., Watanabe, M., Nozawa, T., Shiogama, H., Mori, M., Yasunaka, S., and Imada, Y.: An overview of decadal climate predictability in a multi-model ensemble by climate model MIROC, Clim. Dynam., 40, 1201–1222, <a href="http://dx.doi.org/10.1007/s00382-012-1351-y">https://doi.org/10.1007/s00382-012-1351-y</a>, 2012. Coleman, K. and Jenkinson, S.: ROTHC-26.3, a model for the turnover of carbon in soils, Herts, Rothamsted Research, Harpenden, Hertfordshire, UK, available online at: <a href="http://www.uni-kassel.de/w_dec/Modellierung/wdec-rothc_manual.pdf">http://www.uni-kassel.de/w_dec/Modellierung/wdec-rothc_manual.pdf</a>, 1999. Collatz, G. J., Ball, J. T., Grivet, C., and Berry, J. A.: Physiological and environmental regulation of stomatal conductance, photosynthesis and transpiration: a model that includes a laminar boundary layer, Agr. Forest Meteorol., 54, 107–136, 1991.%in list Collatz, G. J., Ribas-Carbo, M., and Berry, J. A.: Coupled photosynthesis-stomatal conductance model for leaves of C4 plants, Funct. Plant Biol., 19, 519–538, 1992.%in list Collins, M., Booth, B. B. B., Glen, B. B., James, R. H., Sexton, D. M. H., and Webb, M. J.: Climate model errors, feedbacks and forcings: a comparison of perturbed physics and multi-model ensembles, Clim. Dynam., 1737–1766, <a href="http://dx.doi.org/10.1007/s00382-010-0808-0">https://doi.org/10.1007/s00382-010-0808-0</a>, 2011. Collins, M., Chandler, R. E., Cox, P. M., Huthnance, J. M., Rougier, J., and Stephenson, D. B.: Quantifying future climate change, Nature Clim. Change, 2, 403–409, <a href="http://dx.doi.org/10.1038/nclimate1414">https://doi.org/10.1038/nclimate1414</a>, 2012. Collins, W. J., Bellouin, N., Doutriaux-Boucher, M., Gedney, N., Halloran, P., Hinton, T., Hughes, J., Jones, C. D., Joshi, M., Liddicoat, S., Martin, G., O'Connor, F., Rae, J., Senior, C., Sitch, S., Totterdell, I., Wiltshire, A., and Woodward, S.: Development and evaluation of an Earth-System model – HadGEM2, Geosci. Model Dev., 4, 1051–1075, <a href="http://dx.doi.org/10.5194/gmd-4-1051-2011">https://doi.org/10.5194/gmd-4-1051-2011</a>, 2011. Cox, P. and Jones, C.: Illuminating the modern dance, Nature, 321, 19–21, 2008.%in list Cox, P. M., Betts, R. A., Jones, C. D., Spall, S. A., and Totterdell, I. J.: Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model, Nature, 408, 184–187, <a href="http://dx.doi.org/10.1038/35041539">https://doi.org/10.1038/35041539</a>, 2000.%in list Cox, P. M., Pearson, D., Booth, B. B., Friedlingstein, P., Huntingford, C., Jones, C. D., and Luke, C. M.: Sensitivity of tropical carbon to climate change constrained by carbon dioxide variability, Nature, 494, 341–344, <a href="http://dx.doi.org/10.1038/nature11882">https://doi.org/10.1038/nature11882</a>, 2013.%in list Craine, J. M., Fierer, N., McLauchlan, K. K., and Elmore, A. J.: Reduction of the temperature sensitivity of soil organic matter decomposition with sustained temperature increase, Biogeochemistry, 113, 359–368, <a href="http://dx.doi.org/10.1007/s10533-012-9762-8">https://doi.org/10.1007/s10533-012-9762-8</a>, 2012.%in list Cramer, W., Bondeau, A., Woodward, F. I., Prentice, I. C., Betts, R. A., Brovkin, V., Cox, P. M., Fisher, V., Foley, J. A., Friend, A. D., Kucharik, C., Lomas, M. R., Ramankutty, N., Sitch, S., Smith, B., White, A., and Young-Molling, C.: Global response of terrestrial ecosystem structure and function to CO<sub>2</sub> and climate change: results from six dynamic global vegetation models, Glob. Change Biol., 7, 357–373, <a href="http://dx.doi.org/10.1046/j.1365-2486.2001.00383.x">https://doi.org/10.1046/j.1365-2486.2001.00383.x</a>, 2001.%in list Curry, J.: Reasoning about climate uncertainty, Climatic Change, 108, 723–732, <a href="http://dx.doi.org/10.1007/s10584-011-0180-z">https://doi.org/10.1007/s10584-011-0180-z</a>, 2011.%in list Dahlke, C., Loew, A., and Reick, C.: Robust identification of global greening phase patterns from remote sensing vegetation products, J. Climate, 25, 8289–8307, <a href="http://dx.doi.org/10.1175/JCLI-D-11-00319.1">https://doi.org/10.1175/JCLI-D-11-00319.1</a>, 2012.%in list Dalmonech, D. and Zaehle, S.: Towards a more objective evaluation of modelled land-carbon trends using atmospheric CO<sub>2</sub> and satellite-based vegetation activity observations, Biogeosciences, 10, 4189–4210, <a href="http://dx.doi.org/10.5194/bg-10-4189-2013">https://doi.org/10.5194/bg-10-4189-2013</a>, 2013. Dargaville, R. J., Heimann, M., McGuire, A. D., Prentice, I. C., Kicklighter, D. W., Joos, F., Clein, J. S., Esser, G., Foley, J., Kaplan, J., Meier, R. A., Melillo, J. M., Moore, B., Ramankutty, N., Reichenau, T., Schloss, A., Sitch, S., Tian, H., Williams, L. J., and Wittenberg, U.: Evaluation of terrestrial carbon cycle models with atmospheric CO<sub>2</sub> measurements: results from transient simulations considering increasing CO<sub>2</sub>, climate, and land-use effects, Global Biogeochem. Cy., 16, 1092, <a href="http://dx.doi.org/10.1029/2001GB001426">https://doi.org/10.1029/2001GB001426</a>, 2002. Davidson, E. A. and Janssens, I. A.: Temperature sensitivity of soil carbon decomposition and feedbacks to climate change, Nature, 440,165–173, <a href="http://dx.doi.org/10.1038/nature04514">https://doi.org/10.1038/nature04514</a>, 2006. Denman, K. L., Brasseur, G., Chidthaisong, A., Ciais, P., Cox, P. M., Dickinson, R. E., Hauglustaine, D., Heinze, C., Holland, E., Jacob, D., Lohmann, U., Ramachandran, S., da Silva Dias, P. L., Wofsy, S. C., and Zhang, X.: Couplings between changes in the climate system and biogeochemistry, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, UK, New York, NY, USA,499–587, 2007. Doblas-Reyes, F. J., Hagedorn, R., and Palmer, T. N.: The rationale behind the success of multi-model ensembles in seasonal forecasting – Part 2: Calibration and combination, Tellus A, 57, 234–252, 2005.%in list Doney, S. C., Lindsay, K., Caldeira, K., Campin, J.-M., Drange, H., Dutay, J.-C., Follows, M., Gao, Y., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Madec, G., Maier-Reimer, E., Marshall, J. C., Matear, R. J., Monfray, P., Mouchet, A., Najjar, R., Orr, J. C., Plattner, G.-K., Sarmiento, J., Schlitzer, R., Slater, R., Totterdell, I. J., Weirig, M.-F., Yamanaka, Y., and Yool, A.: Evaluating global ocean carbon models: the importance of realistic physics, Global Biogeochem. Cy., 18, GB3017, <a href="http://dx.doi.org/10.1029/2003GB002150">https://doi.org/10.1029/2003GB002150</a>, 2004. Doney, S. C., Fabry, V. J., Feely, R. A., and Kleypas, J. A.: Ocean acidification: the other CO<sub>2</sub> problem, Annu. Rev. Mar. Sci., 1, 169–192, <a href="http://dx.doi.org/10.1146/annurev.marine.010908.163834">https://doi.org/10.1146/annurev.marine.010908.163834</a>, 2009a. Doney, S. C., Lima, I., Moore, J. K., Lindsay, K., Behrenfeld, M. J., Westberry, T. K., Mahowald, N., Glover, D. M., and Takahashi, T.: Skill metrics for confronting global upper ocean ecosystem-biogeochemistry models against field and remote sensing data, J. Marine Syst., 76, 95–112, <a href="http://dx.doi.org/10.1016/j.jmarsys.2008.05.015">https://doi.org/10.1016/j.jmarsys.2008.05.015</a>, 2009b.%in list Dufresne, J., Foujols, M. A., Denvil, M., Caubel, S., Benshila, H., Bony, R., Bopp, S., and Braconnot, L.: Climate change projections using the IPSL-CM5 Earth system model: from CMIP3 to CMIP5, Clim. Dynam., 40, 2123–2165, 2013.%in list Dunne, J. P., John, J., Adcroft, A. J., Griffies, A. M., Hallberg, R. W., Shevliakova, E., Stouffer, R. J., Cooke, W., Dunne, K. A., Harrison, M. J., Krasting, J. P., Makyshev, S. L., Milly, P. C. D., Phillipps, P. J., Sentman, L. T., Samuels, B. L., Spelman, M. J., Winton, M., Wittenberg, A. T., and Zadeh, N.: GFDL's ESM2 global coupled climate – carbon Earth system models – Part 1: Physical formulation and baseline simulation characteristics, J. Climate, 25, 6646–6665, <a href="http://dx.doi.org/10.1175/JCLI-D-11-00560.1">https://doi.org/10.1175/JCLI-D-11-00560.1</a>, 2012.%in list Dutkiewicz, S., Follows, M. J., and Bragg, J. G.: Modeling the coupling of ocean ecology and biogeochemistry, Global Biogeochem. Cy., 23, 1–15, <a href="http://dx.doi.org/10.1029/2008GB003405">https://doi.org/10.1029/2008GB003405</a>, 2009.%in list Eliseev, A. V. and Mokhov, I. I.: Carbon cycle–climate feedback sensitivity to parameter changes of a zero-dimensional terrestrial carbon cycle scheme in a climate model of intermediate complexity, Theor. Appl. Climatol., 89, 9–24, <a href="http://dx.doi.org/10.1007/s00704-006-0260-6">https://doi.org/10.1007/s00704-006-0260-6</a>, 2006.%in list Fabry, V. J., Seibel, B. A., Feely, R. A., and Orr, J. C.: Impacts of ocean acidification on marine fauna and ecosystem processes, ICES J. Mar. Sci., 65, 414–432, 2008. FAO/IIASA/ISRIC/ISSCAS/JRC: Harmonized World Soil Database (version 1.1), FAO, Rome, Italy, IIASA, Laxenburg, Austria, 2009. Fatichi, S., Leuzinger, S., and Körner, C.: Moving beyond photosynthesis: from carbon source to sink-driven vegetation modeling, New Phytol.,<a href="http://dx.doi.org/10.1111/nph.12614">https://doi.org/10.1111/nph.12614</a>,2013. Farquhar, G. D., von von Caemmerer, S., and Berry, J. A.: A biochemical model of photosynthetic CO<sub>2</sub> assimilation in leaves of C3 species, Planta, 149, 78–90, 1980.%in list Fisher, R., Mcdowell, N., Purves, D., Moorcroft, P., Sitch, S., Cox, P., Huntingford, C., Meir, P., and Woodward, F. I.: Assessing uncertainties in a second-generation dynamic vegetation model caused by ecological scale limitations, New Phytol., 187, 666–681, 2010.%in list Foley, A. M., Dalmonech, D., Friend, A. D., Aires, F., Archibald, A., Bartlein, P., Bopp, L., Chappellaz, J., Cox, P., Edwards, N. R., Feulner, G., Friedlingstein, P., Harrison, S. P., Hopcroft, P. O., Jones, C. D., Kolassa, J., Levine, J. G., Prentice, I. C., Pyle, J., Vázquez Riveiros, N., Wolff, E. W., and Zaehle, S.: Evaluation of biospheric components in Earth system models using modern and palaeo observations: the state-of-the-art, Biogeosciences Discuss., 10, 10937–10995, <a href="http://dx.doi.org/10.5194/bgd-10-10937-2013">https://doi.org/10.5194/bgd-10-10937-2013</a>, 2013. Frank, D. C., Esper, J., Raible, C. C., Buentgen, U., Trouet, V., Stocker, B., and Joos, F.: Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate, Nature, 463, 527–530, <a href="http://dx.doi.org/10.1038/nature08769">https://doi.org/10.1038/nature08769</a>, 2010.%in list Frankenberg, C., Fisher, J. B., Worden, J., Badgley, G., Saatchi, S. S., Lee, J.-E., Toon, G. C., Butz, A., Jung, M., Kuze, A., and Yokota, T.: New global observations of the terrestrial carbon cycle from GOSAT: Patterns of plant fluorescence with gross primary productivity, Geophys. Res. Lett., 38, L17706, <a href="http://dx.doi.org/10.1029/2011GL048738">https://doi.org/10.1029/2011GL048738</a>, 2011. Friedlingstein, P. and Prentice, I. C.: Carbon – climate feedbacks: a review of model and observation based estimates, Current Opinion in Environmental Sustainability, 2, 251–257, <a href="http://dx.doi.org/10.1016/j.cosust.2010.06.002">https://doi.org/10.1016/j.cosust.2010.06.002</a>, 2010. Friedlingstein, P., Cox, P., Betts, R., Bopp, L., von Bloh, W., Brovkin, V., Cadule, P., Doney, S., Eby, M., Fung, I., Bala, G., John, J., Jones, C., Joos, F., Kato, T., Kawamiya, M., Knorr, W., Lindsay, K., H. D., M., Raddatz, T., Rayner, P., Reick, C., Roeckner, E., Schnitzler, K.-G., Schnur, R., Strassmann, K., Weaver, A. J., C., Y., and Zeng, N.: Climate – carbon cycle feedback analysis: results from the C 4 MIP model intercomparison, J. Climate, 19, 3337–3353, 2006.%in list Friedlingstein, P., Meinshausen, M., Arora, V., Jones, C., Anav, A., Liddicoat, S., and Knutti, R.: Uncertainties in CMIP5 climate projections due to carbon cycle feedbacks, J. Climate, 27, 511–526, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00579.1">https://doi.org/10.1175/JCLI-D-12-00579.1</a>, 2014. Friedrichs, M. A. M., Dusenberry, J. A., Anderson, L. A., Armstrong, R. A., Chai, F., Christian, J. R., Doney, S. C., Dunne, J., Fujii, M., Hood, R., McGillicuddy, D. J., Moore, J. K., Schartau, M., Spitz, Y. H., and Wiggert, J. D.: Assessment of skill and portability in regional marine biogeochemical models: role of multiple planktonic groups, J. Geophys. Res., 112, C08001, <a href="http://dx.doi.org/10.1029/2006JC003852">https://doi.org/10.1029/2006JC003852</a>, 2007.%in list Friedrichs, M. A. M., Carr, M.-E., Barber, R. T., Scardi, M., Antoine, D., Armstrong, R. A., Asanuma, I., Behrenfeld, M. J., Buitenhuis, E. T., Chai, F., Christian, J. R., Ciotti, A. M., Doney, S. C., Dowell, M., Dunne, J., Gentili, B., Gregg, W., Hoepffner, N., Ishizaka, J., Kameda, T., Lima, I., Marra, J., Mélin, F., Moore, J. K., Morel, A., O'Malley, R. T., O'Reilly, J., Saba, V. S., Schmeltz, M., Smyth, T. J., Tjiputra, J., Waters, K., Westberry, T. K., and Winguth, A.: Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean, J. Marine Syst., 76, 113–133, <a href="http://dx.doi.org/10.1016/j.jmarsys.2008.05.010">https://doi.org/10.1016/j.jmarsys.2008.05.010</a>, 2009.%in list Friend, A. D., Lucht, W., Rademacher, T. T., Keribin, R., Betts, R., Cadule, P., Ciais, P., Clark, D. B., Dankers, R., Falloon, P. D., Ito, A., Kahana, R., Kleidon, A., Lomas, M. R., Nishina, K., Ostberg, S., Pavlick, R., Peylin, P., Schaphoff, S., Vuichard, N., Warszawski, L.,Wiltshire, A. and Woodward, F. I.: Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO<sub>2</sub>, P. Natl. Acad. Sci. USA, in press, <a href="http://dx.doi.org/10.1073/pnas.1222477110">https://doi.org/10.1073/pnas.1222477110</a>, 2013. Fung, I. Y., Doney, S. C., Lindsay, K., and John, J.: Evolution of carbon sinks in a changing climate, P. Natl. Acad. Sci. USA, 102, 11201–11206, 2005.%in list Galbraith, D., Levy, P. E., Sitch, S., Huntingford, C., Cox, P., Williams, M., and Meir, P.: Multiple mechanisms of Amazonian forest biomass losses in three dynamic global vegetation models under climate change., New Phytol., 187, 647–665, <a href="http://dx.doi.org/10.1111/j.1469-8137.2010.03350.x">https://doi.org/10.1111/j.1469-8137.2010.03350.x</a>, 2010.%in list Gibbs, H. K.: Olson's major world ecosystem complexes ranked by carbon in live vegetation: an updated database using the GLC 2000 land cover product, available online at: <a href="http://cdiac.ornl.gov/epubs/ndp/ndp017/ndp017b.html">http://cdiac.ornl.gov/epubs/ndp/ndp017/ndp017b.html</a>, 2006. Gillett, N. P., Arora, V. K., Flato, G. M., Scinocca, J. F., and Von Salzen, K.: Improved constraints on 21st-century warming derived using 160 years of temperature observations, Geophys. Res. Lett., 39, 1–5, <a href="http://dx.doi.org/10.1029/2011GL050226">https://doi.org/10.1029/2011GL050226</a>, 2012.%in list Giorgi, F. and Mearns, L. O.: Probability of regional climate change based on the Reliability Ensemble Averaging (REA) method, Geophys. Res. Lett., 30, 1629,<a href="http://dx.doi.org/10.1029/2003GL017130">https://doi.org/10.1029/2003GL017130</a>, 2003. Gleckler, P. J., Taylor, K. E., and Doutriaux, C.: Performance metrics for climate models, J. Geophys. Res., 113, D06104, <a href="http://dx.doi.org/10.1029/2007JD008972">https://doi.org/10.1029/2007JD008972</a>, 2008.%in list Gnanadesikan, A., Dunne, J. P., Key, R. M., Matsumoto, K., Sarmiento, J. L., Slater, R. D., and Swathi, P. S.: Oceanic ventilation and biogeochemical cycling: Understanding the physical mechanisms that produce realistic distributions of tracers and productivity, Global Biogeochem. Cy., 18, GB4010, <a href="http://dx.doi.org/10.1029/2003GB002097">https://doi.org/10.1029/2003GB002097</a>, 2004. Gobron, N., Pinty, B., Taberner, M., Mélin, F., Verstraete, M. M., and Widlowski, J.-L.: Monitoring the photosynthetic activity of vegetation from remote sensing data, Adv. Space Res., 38, 2196–2202, <a href="http://dx.doi.org/10.1016/j.asr.2003.07.079">https://doi.org/10.1016/j.asr.2003.07.079</a>, 2006.%in list Goldstein, M. and Rougier, J.: Reified Bayesian modelling and inference for physical systems, J. Stat. Plan. Infer., 139, 1221–1239, <a href="http://dx.doi.org/10.1016/j.jspi.2008.07.019">https://doi.org/10.1016/j.jspi.2008.07.019</a>, 2009.%in list Gregg, W. W. and Casey, N. W.: Global and regional evaluation of the SeaWiFS chlorophyll data set, Remote Sens. Environ., 93, 463–479, 2004.%in list Gregg, W. W., Friedrichs, M. A. M., Robinson, A. R., Rose, K. A., Schlitzer, R., Thompson, K. R., and Doney, S. C.: Skill assessment in ocean biological data assimilation, J. Marine Syst., 76, 16–33, <a href="http://dx.doi.org/10.1016/j.jmarsys.2008.05.006">https://doi.org/10.1016/j.jmarsys.2008.05.006</a>, 2009.%in list Gregory, J. M., Jones, C. D., Cadule, P., and Friedlingstein, P.: Quantifying carbon cycle feedbacks, J. Climate, 22, 5232–5250, <a href="http://dx.doi.org/10.1175/2009JCLI2949.1">https://doi.org/10.1175/2009JCLI2949.1</a>, 2009.%in list Gruber, N.: The marine nitrogen cycle: overview and challenges, Nitrogen in the marine environment, 1–50, 2008. Guenet, B., Cadule, P., Zaehle, S., Piao, S. L., Peylin, P., Maignan, F., Ciais, P., and Friedlingstein, P.: Does the integration of the dynamic nitrogen cycle in a terrestrial biosphere model improve the long-term trend of the leaf area index?, Clim. Dynam.,40, 2535-2548,2013. Gurney, K. R., Law, R. M., Denning, A. S., Rayner, P. J., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fan, S., Fung, I. Y., Gloor, M., Heimann, M., Higuchi, K., John, J., Maki, T., Maksyutov, S., Masarie, K., Peylin, P., Prather, M., Pak, B. C., Randerson, J., Sarmiento, J., Taguchi, S., Takahashi, T., and Yuen, C.-W.: Towards robust regional estimates of CO<sub>2</sub> sources and sinks using atmospheric transport models, Nature, 415, 626–630, <a href="http://dx.doi.org/10.1038/415626a">https://doi.org/10.1038/415626a</a>, 2002.%in list Hagedorn, R., Doblas-Reyes, F. J., and Palmer, J. R.: The rationale behind the success of multi-model ensembles in seasonal forecasting – I. Basic concept, Tellus A, 57, 219–233, 2005.%in list Hallegraeff, G. M.: Ocean climate change, phytoplankton community responses, and harmful algal blooms: a formidable predictive challenge, J. Phycol., 235, 220–235, <a href="http://dx.doi.org/10.1111/j.1529-8817.2010.00815.x">https://doi.org/10.1111/j.1529-8817.2010.00815.x</a>, 2010.%in list Harrison, S. P. and Prentice, C. I.: Climate and CO<sub>2</sub> controls on global vegetation distribution at the last glacial maximum: analysis based on palaeovegetation data, biome modelling and palaeoclimate simulations, Glob. Change Biol., 9, 983–1004, 2003.%in list Hashioka, T., Vogt, M., Yamanaka, Y., Le Quéré, C., Buitenhuis, E. T., Aita, M. N., Alvain, S., Bopp, L., Hirata, T., Lima, I., Sailley, S., and Doney, S. C.: Phytoplankton competition during the spring bloom in four Plankton Functional Type Models, Biogeosciences Discuss., 9, 18083–18129, <a href="http://dx.doi.org/10.5194/bgd-9-18083-2012">https://doi.org/10.5194/bgd-9-18083-2012</a>, 2012. Heimann, M., Esser, G., Haxeltine, A., Kaduk, J., Kicklighter, D. W., Knorr, W., Kohlmaier, G. H., Mcguire, A. D., Melillo, J., Moore III, B., Otto, R. D., Prentice, I. C., Sauf, W., Schloss, A., Sitch, S., Wittenberg, U., and Wurth, G.: Evaluation of terrestrial carbon cycle models through simulations of the seasonal cycle of atmospheric First results of a model intercomparison study, Global Biogeochem. Cy., 12, 1–24, 1998.%in list Hemming, D., Betts, R., and Collins, M.: Sensitivity and uncertainty of modelled terrestrial net primary productivity to doubled CO<sub>2</sub> and associated climate change for a relatively large perturbed physics ensemble, Agr. Forest Meteorol.,180,79–88, <a href="http://dx.doi.org/10.1016/j.agrformet.2011.10.016">https://doi.org/10.1016/j.agrformet.2011.10.016</a>, 2011. Henson, S. A., Sarmiento, J. L., Dunne, J. P., Bopp, L., Lima, I., Doney, S. C., John, J., and Beaulieu, C.: Detection of anthropogenic climate change in satellite records of ocean chlorophyll and productivity, Biogeosciences, 7, 621–640, <a href="http://dx.doi.org/10.5194/bg-7-621-2010">https://doi.org/10.5194/bg-7-621-2010</a>, 2010. Holland, E. A., Neff, J. C., Townsend, A. R., and McKeown, B.: Uncertainties in the temperature sensitivity of decomposition in tropical and subtropical ecosystems: implications for models, Global Biogeochem. Cy., 14, 1137–1151, <a href="http://dx.doi.org/10.1029/2000GB001264">https://doi.org/10.1029/2000GB001264</a>, 2000.%in list Houghton, R. A., House, J. I., Pongratz, J., van der Werf, G. R., DeFries, R. S., Hansen, M. C., Le Quéré, C., and Ramankutty, N.: Carbon emissions from land use and land-cover change, Biogeosciences, 9, 5125–5142, <a href="http://dx.doi.org/10.5194/bg-9-5125-2012">https://doi.org/10.5194/bg-9-5125-2012</a>, 2012. Huntingford, C., Fisher, R. A., Mercado, L., Booth, B. B. B., Sitch, S., Harris, P. P., Cox, M., Jones, C. D., Betts, R. A., Malhi, Y., Harris, G. R., Collins, M., Cox, P. M., and Moorcroft, P.: Towards quantifying uncertainty in predictions of Amazon " dieback ", Philos. T. Roy. Soc. B, 363, 1857–1864, <a href="http://dx.doi.org/10.1098/rstb.2007.0028">https://doi.org/10.1098/rstb.2007.0028</a>, 2008.%in list Huntingford, C., Lowe, J. A., Booth, B. B. B., Jones, C. D., Harris, G. R., Gohar, L. K., and Meir, P.: Contributions of carbon cycle uncertainty to future, Tellus B, 61, 355–360, <a href="http://dx.doi.org/10.1111/j.1600-0889.2009.00414.x">https://doi.org/10.1111/j.1600-0889.2009.00414.x</a>, 2009.%in list Huntingford, C., Jones, P. D., Livina, V. N., Lenton, T. M., and Cox, P. M.: No increase in global temperature variability despite changing regional patterns, Nature, 500, 327–330, <a href="http://dx.doi.org/10.1038/nature12310">https://doi.org/10.1038/nature12310</a>, 2013.%in list Hungate, B. A., Dijkstra, P., Wu, Duval, B. D., Day, F. P., Johnson, D. W., Megonigal, J. P., Brown, A. L. P., and Garland, J. L.: Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO<sub>2</sub> exposure in a subtropical oak woodland, New Phytol., 200, 753–766, 2013.%in list Ilyina, T., Six, K. D., Segschneider, J., and Maier-reimer, E.: Global ocean biogeochemistry model HAMOCC: model architecture and performance as component of the MPI-Earth system model in different CMIP5 experimental realizations, Journal of Advances in Modeling Earth Systems, 5, 287–315, <a href="http://dx.doi.org/10.1029/2012MS000178">https://doi.org/10.1029/2012MS000178</a>, 2013. Jolliff, J. K., Kindle, J. C., Shulman, I., Penta, B., Friedrichs, M. A. M., Helber, R., and Arnone, R. A.: Summary diagrams for coupled hydrodynamic-ecosystem model skill assessment, J. Marine Syst., 76, 64–82, <a href="http://dx.doi.org/10.1016/j.jmarsys.2008.05.014">https://doi.org/10.1016/j.jmarsys.2008.05.014</a>, 2009.%in list Jones, B. C. D., Cox, P., Huntingford, C., Centre, H., and Office, M.: Uncertainty in climate – carbon-cycle projections associated with the sensitivity of soil respiration to temperature, Tellus B, 55, 642–648, 2003.%in list Jones, C. D., Collins, M., Cox, P., and Pall, S. A.: The carbon cycle response to ENSO: a coupled climate – carbon cycle model study, J. Climate, 14, 4113–4129, 2001.%in list Jones, C. D., Cox, P. M., and Huntingford, C.: Climate-carbon cycle feedbacks under stabilization: uncertainty and observational constraints, Tellus B, 58, 603–613, <a href="http://dx.doi.org/10.1111/j.1600-0889.2006.00215.x">https://doi.org/10.1111/j.1600-0889.2006.00215.x</a>, 2006.%in list Jones, C., McConnell, C., and Coleman, K.: Global climate change and soil carbon stocks; predictions from two contrasting models for the turnover of organic carbon in soil, Glob. Change Biol., 11, 154–166, <a href="http://dx.doi.org/10.1111/j.1365-2486.2004.00885.x">https://doi.org/10.1111/j.1365-2486.2004.00885.x</a>, 2005.%in list Jones, C., Robertson, E., Arora, V., Friedlingstein, P., Shevliakova, E., Bopp, L., Brovkin, V., Hajima, T., Kato, E., Kawamiya, M., Liddicoat, S., Lindsay, K., Reick, C. H., Roelandt, C., Segschneider, J., and Tjiputra, J.: Twenty-first-century compatible CO<sub>2</sub> emissions and airborne fraction simulated by CMIP5 Earth system models under four representative concentration pathways, J. Climate, 26, 4398–4413, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00554.1">https://doi.org/10.1175/JCLI-D-12-00554.1</a>, 2013.%in list Jung, M., Reichstein, M., Margolis, H. A., Cescatti, A., Richardson, A. D., Arain, M. A., Arneth, A., Bernhofer, C., Bonal, D., Chen, J., Gianelle, D., Gobron, N., Kiely, G., Kutsch, W., Lasslop, G., Law, B. E., Lindroth, A., Merbold, L., Montagnani, L., Moors, E. J., Papale, D., Sottocornola, M., Vaccari, F., and Williams, C.: Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations, J. Geophys. Res., 116, G00J07, <a href="http://dx.doi.org/10.1029/2010JG001566">https://doi.org/10.1029/2010JG001566</a>, 2011.%in list Kattge, J., Díaz, S., Lavorel, S., Prentice, I. C., Leadley, P., Bönisch, G., Garnier, E., Westoby, M., Reich, P. B., Wright, I. J., Cornelissen, J. H. C., Violle, C., Harrison, S. P., Van Bodegom, P. M., Reichstein, M., Enquist, B. J., Soudzilovskaia, N. A., Ackerly, D. D., Anand, M., Atkin, O., Bahn, M., Baker, T. R., Baldocchi, D., Bekker, R., Blanco, C. C., Blonder, B., Bond, W. J., Bradstock, R., Bunker, D. E., Casanoves, F., Cavender-Bares, J., Chambers, J. Q., Chapin Iii, F. S., Chave, J., Coomes, D., Cornwell, W. K., Craine, J. M., Dobrin, B. H., Duarte, L., Durka, W., Elser, J., Esser, G., Estiarte, M., Fagan, W. F., Fang, J., Fernández-Méndez, F., Fidelis, A., Finegan, B., Flores, O., Ford, H., Frank, D., Freschet, G. T., Fyllas, N. M., Gallagher, R. V., Green, W. A., Gutierrez, A. G., Hickler, T., Higgins, S. I., Hodgson, J. G., Jalili, A., Jansen, S., Joly, C. A., Kerkhoff, A. J., Kirkup, D., Kitajima, K., Kleyer, M., Klotz, S., Knops, J. M. H., Kramer, K., Kühn, I., Kurokawa, H., Laughlin, D., Lee, T. D., Leishman, M., Lens, F., Lenz, T., Lewis, S. L., Lloyd, J., Llusià, J., Louault, F., Ma, S., Mahecha, M. D., Manning, P., Massad, T., Medlyn, B. E., Messier, J., Moles, A. T., Müller, S. C., Nadrowski, K., Naeem, S., Niinemets, Ü., Nöllert, S., Nüske, A., Ogaya, R., Oleksyn, J., Onipchenko, V. G., Onoda, Y., Ordoñez, J., Overbeck, G., Ozinga, W. A., Patiño, S., Paula, S., Pausas, J. G., Peñuelas, J., Phillips, O. L., Pillar, V., Poorter, H., Poorter, L., Poschlod, P., Prinzing, A., Proulx, R., Rammig, A., Reinsch, S., Reu, B., Sack, L., Salgado-negret, B., Sardans, J., Shiodera, S., Shipley, B., Siefert, A., Sosinski, E., Soussana, J. F., Swaine, E., Swenson, N., Thompson, K., Thornton, P., Waldram, M., Weiher, E., White, M., White, S., Wright, S. J., Yguel, B., Zaehle, S., Zanne, A. E. and Wirth, C. : TRY – a global database of plant traits, Glob. Change Biol., 17, 2905–2935, <a href="http://dx.doi.org/10.1111/j.1365-2486.2011.02451.x">https://doi.org/10.1111/j.1365-2486.2011.02451.x</a>, 2011.%in list Keenan, T. F., Davidson, E., Moffat, A. M., Munger, W., and Richardson, A. D.: Using model-data fusion to interpret past trends, and quantify uncertainties in future projections, of terrestrial ecosystem carbon cycling, Glob. Change Biol., 18, 2555–2569, <a href="http://dx.doi.org/10.1111/j.1365-2486.2012.02684.x">https://doi.org/10.1111/j.1365-2486.2012.02684.x</a>, 2012.%in list Kelley, D. I., Prentice, I. C., Harrison, S. P., Wang, H., Simard, M., Fisher, J. B., and Willis, K. O.: A comprehensive benchmarking system for evaluating global vegetation models, Biogeosciences, 10, 3313–3340, <a href="http://dx.doi.org/10.5194/bg-10-3313-2013">https://doi.org/10.5194/bg-10-3313-2013</a>, 2013. Kidston, M., Matear, R., and Baird, M. E.: Parameter optimisation of a marine ecosystem model at two contrasting stations in the Sub-Antarctic Zone, Deep-Sea Res. Pt. II, 58, 2301–2315, <a href="http://dx.doi.org/10.1016/j.dsr2.2011.05.018">https://doi.org/10.1016/j.dsr2.2011.05.018</a>, 2011. Kirschbaum, M. U. F.: Does enhanced photosynthesis enhance growth: lessons learned from CO<sub>2</sub> enrichment studies, Plant Physiol., 155, 117–124, 2011.%in list Knorr, W.: Annual and interannual CO<sub>2</sub> exchanges of the terrestrial biosphere: process-based simulations and uncertainties, Global Ecol. Biogeogr., 9, 225–252, 2000.%in list Knutti, R. and Tomassini, L.: Constraints on the transient climate response from observed global temperature and ocean heat uptake, Geophys. Res. Lett., 35, 1–5, <a href="http://dx.doi.org/10.1029/2007GL032904">https://doi.org/10.1029/2007GL032904</a>, 2008.%in list Knutti, R., Meehl, G. A., Allen, M. R., and Stainforth, D. A.: Constraining climate sensitivity from the seasonal cycle in surface temperature, J. Climate, 19, 4224–4233, 2006.%in list Knutti, R., Allen, M. R., Friedlingstein, P., Gregory, J. M., Hegerl, G. C., Meehl, G. A., Meinshausen, M., Murphy, J. M., Plattner, G.-K., Raper, S. C. B., Stocker, T. F., Stott, P. A., Teng, H., and Wigley, T. M. L.: A review of uncertainties in global temperature projections over the twenty-first century, J. Climate, 21, 2651–2663, <a href="http://dx.doi.org/10.1175/2007JCLI2119.1">https://doi.org/10.1175/2007JCLI2119.1</a>, 2008.%in list Koffi, E. N., Rayner, P. J., Scholze, M., and Beer, C.: Atmospheric constraints on gross primary productivity and net ecosystem productivity: results from a carbon-cycle data assimilation system, Global Biogeochem. Cy., 26,GB1024, <a href="http://dx.doi.org/10.1029/2010GB003900">https://doi.org/10.1029/2010GB003900</a>, 2012. Körner, C., Asshoff, R., Bignucolo, O., Hättenschwiler, S., Keel, S. G., Peláez-Riedl, S., Pepin, S., Siegwolf, R. T. W., and Zotz, G.: Carbon flux and growth in mature deciduous forest trees exposed to elevated CO<sub>2</sub>, Science, 309, 1360–1362, <a href="http://dx.doi.org/10.1126/science.1113977">https://doi.org/10.1126/science.1113977</a>, 2005.%in list Kositsup, B., Montpied, P., Kasemsap, P., Thaler, P., Améglio, T., and Dreyer, E.: Photosynthetic capacity and temperature responses of photosynthesis of rubber trees (Hevea brasiliensis Müll. Arg.) acclimate to changes in ambient temperatures, Trees, 23, 357–365, <a href="http://dx.doi.org/10.1007/s00468-008-0284-x">https://doi.org/10.1007/s00468-008-0284-x</a>, 2008. Langdon, C., Broecker, W. S., Hammond, D. E., Glenn, E., Fitzsimmons, K., Nelson, S. G., Peng, T.-H., Hajdas, I., and Bonani, G.: Effect of elevated CO<sub>2</sub> on the community metabolism of an experimental coral reef, Global Biogeochem. Cy., 17,1011, <a href="http://dx.doi.org/10.1029/2002GB001941">https://doi.org/10.1029/2002GB001941</a>,2003. Lengaigne, M., Menkes, Ǽ. C., Andre, J., and Madec, Ǽ. G.: Influence of the oceanic biology on the tropical Pacific climate in a coupled general circulation model, Clim. Dynam., 28, 503–516, <a href="http://dx.doi.org/10.1007/s00382-006-0200-2">https://doi.org/10.1007/s00382-006-0200-2</a>, 2007.%in list Lermusiaux, P. F. J.: Uncertainty estimation and prediction for interdisciplinary ocean dynamics, J. Comput. Phys., 217, 176–199, 2006.%in list Lines, E. R., Coomes, D. A., and Purves, D. W.: Influences of forest structure, climate and species composition on tree mortality across the eastern US, PLoS ONE, 5, e13212, <a href="http://dx.doi.org/10.1371/journal.pone.0013212">https://doi.org/10.1371/journal.pone.0013212</a>, 2010. Litchman, E. and Klausmeier, C. A.: Trait-based community ecology of phytoplankton, Annu. Rev. Ecol. Evol. S., 39, 615–639, <a href="http://dx.doi.org/10.1146/annurev.ecolsys.39.110707.173549">https://doi.org/10.1146/annurev.ecolsys.39.110707.173549</a>, 2008.%in list Lloyd, J. and Farquhar, G. D.: Effects of rising temperatures and [CO<sub>2</sub>] on the physiology of tropical forest trees, Philos. T. Roy. Soc. B, 363, 1811–1817, <a href="http://dx.doi.org/10.1098/rstb.2007.0032">https://doi.org/10.1098/rstb.2007.0032</a>, 2008.%in list Lloyd, J. and Taylor, J.: On the temperature dependence of soil respiration, Funct. Ecol., 8, 315–323, 1994.%in list Long, M. C., Lindsay, K., Peacock, S., Moore, J. K., and Doney: Twentieth-century oceanic carbon uptake and storage in CESM1 (BGC), J. Climate, 1, 6775–6799, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00184.1">https://doi.org/10.1175/JCLI-D-12-00184.1</a>, 2013.%in list Longhurst, A., Sathyendranath, S., Platt, T., and Caverhill, C.: An estimate of global primary production in the ocean from satellite radiometer data, J. Plankton Res., 17, 1245–1271, 1995.%in list Lu, J. and Ji, J.: A simulation and mechanism analysis of long-term variations at land surface over arid/semi-arid area in north China, J. Geophys. Res., 111, 1–19, <a href="http://dx.doi.org/10.1029/2005JD006252">https://doi.org/10.1029/2005JD006252</a>, 2006.%in list Lu, M., Yang, Y., Luo, Y., Fang, C., Zhou, X., Chen, J., Yang, X., and Li, B.: Responses of ecosystem nitrogen cycle to nitrogen addition: a meta-analysis, New Phytol., 189, 1040–1050, 2011.%in list Luo, Y. Q., Hui, D. F., and Zhang, D. Q.: Elevated CO<sub>2</sub> stimulates net accumulations of carbon and nitrogen in land ecosystems: a meta-analysis, Ecology, 87, 53–63, 2006.%in list Luo, Y., Ogle, K., Tucker, C., Fei, S., Gao, C., LaDeau, S., Clark, J. S., and Schimel, D. S.: Ecological forecasting and data assimilation in a data-rich era, Ecol. Appl., 21, 1429–1442, 2011.%in list Luo, Y. Q., Randerson, J. T., Abramowitz, G., Bacour, C., Blyth, E., Carvalhais, N., Ciais, P., Dalmonech, D., Fisher, J. B., Fisher, R., Friedlingstein, P., Hibbard, K., Hoffman, F., Huntzinger, D., Jones, C. D., Koven, C., Lawrence, D., Li, D. J., Mahecha, M., Niu, S. L., Norby, R., Piao, S. L., Qi, X., Peylin, P., Prentice, I. C., Riley, W., Reichstein, M., Schwalm, C., Wang, Y. P., Xia, J. Y., Zaehle, S., and Zhou, X. H.: A framework for benchmarking land models, Biogeosciences, 9, 3857–3874, <a href="http://dx.doi.org/10.5194/bg-9-3857-2012">https://doi.org/10.5194/bg-9-3857-2012</a>, 2012. Luo, Y.-W., Doney, S. C., Anderson, L. A., Benavides, M., Berman-Frank, I., Bode, A., Bonnet, S., Boström, K. H., Böttjer, D., Capone, D. G., Carpenter, E. J., Chen, Y. L., Church, M. J., Dore, J. E., Falcón, L. I., Fernández, A., Foster, R. A., Furuya, K., Gómez, F., Gundersen, K., Hynes, A. M., Karl, D. M., Kitajima, S., Langlois, R. J., LaRoche, J., Letelier, R. M., Marañón, E., McGillicuddy Jr., D. J., Moisander, P. H., Moore, C. M., Mouriño-Carballido, B., Mulholland, M. R., Needoba, J. A., Orcutt, K. M., Poulton, A. J., Rahav, E., Raimbault, P., Rees, A. P., Riemann, L., Shiozaki, T., Subramaniam, A., Tyrrell, T., Turk-Kubo, K. A., Varela, M., Villareal, T. A., Webb, E. A., White, A. E., Wu, J., and Zehr, J. P.: Database of diazotrophs in global ocean: abundance, biomass and nitrogen fixation rates, Earth Syst. Sci. Data, 4, 47–73, <a href="http://dx.doi.org/10.5194/essd-4-47-2012">https://doi.org/10.5194/essd-4-47-2012</a>, 2012. Luo, Y., White, L. W., Canadell, J. G., DeLucia, E. H., Ellsworth, D. S., Finzi, A., Lichter, J., and Schlesinger, W. H.: Sustainability of terrestrial carbon sequestration: a case study in Duke Forest with inversion approach, Global Biogeochem. Cy., 17, 1021, <a href="http://dx.doi.org/10.1029/2002GB001923">https://doi.org/10.1029/2002GB001923</a>, 2003.%in list MacDougall, A. H., Avis, C. A., and Weaver, A. J.: Significant contribution to climate warming from the permafrost carbon feedback, Nat. Geosci., 5, 719–721, <a href="http://dx.doi.org/10.1038/ngeo1573">https://doi.org/10.1038/ngeo1573</a>, 2012.%in list Malakoff, D.: Researchers struggle to assess responses to ocean acidification, Science, 338, 27–28, 2012.%in list Malhi, Y., Aragao, L. E. O. C., Galbraith, D., Huntingford, C., Fisher, R., Zelazowski, P., Sitch, S., Mcsweeney, C., and Meir, P.: Exploring the likelihood and mechanism of a climate-change-induced dieback of the, P. Natl. Acad. Sci. USA, 106, 20610–20615, 2009.%in list Manizza, M., Buitenhuis, E. T., and Le Quéré, C.: Sensitivity of global ocean biogeochemical dynamics to ecosystem structure in a future climate, Geophys. Res. Lett., 37,L13607, <a href="http://dx.doi.org/10.1029/2010GL043360">https://doi.org/10.1029/2010GL043360</a>,2010. Masson, D. and Knutti, R.: Climate model genealogy, Geophys. Res. Lett., 38, L08703, <a href="http://dx.doi.org/10.1029/2011GL046864">https://doi.org/10.1029/2011GL046864</a>, 2011.%in list Matear, R. J.: Parameter optimization and analysis of ecosystem models using simulated annealing: a case study at Station P, J. Mar. Res., 53, 571–607, 1995.%in list Matthews, H. D., Eby, M., Ewen, T., Friedlingstein, P., and Hawkins, B. J.: What determines the magnitude of carbon cycle-climate feedbacks?, Global Biogeochem. Cy., 21, 1–12, <a href="http://dx.doi.org/10.1029/2006GB002733">https://doi.org/10.1029/2006GB002733</a>, 2007.%in list Melillo, J. M., Butler, S., Johnson, J., Mohan, J., Steudler, P., Lux, H., Burrows, E., Bowles, F., Smith, R., Scott, L., Vario, C., Hill, T., Burton, A., Zhou, Y.-M., and Tang, J.: Soil warming, carbon-nitrogen interactions, and forest carbon budgets., P. Natl. Acad. Sci. USA, 108, 9508–9512, <a href="http://dx.doi.org/10.1073/pnas.1018189108">https://doi.org/10.1073/pnas.1018189108</a>, 2011.%in list Melnikov, N. B. and O'Neill, B. C.: Learning about the carbon cycle from global budget data, Geophys. Res. Lett., 33, L02705, <a href="http://dx.doi.org/10.1029/2005GL023935">https://doi.org/10.1029/2005GL023935</a>, 2006.%in list Moore, J., Lindsay, K., Doney, S., Long, M., and Misumi, K.: Marine ecosystem dynamics and biogeochemical cycling in the Community Earth System Model [CESM1(BGC)]: comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 Scenarios, J. Climate, 26, 9291–9312, <a href="http://dx.doi.org/10.1175/JCLI-D-12-00566.1">https://doi.org/10.1175/JCLI-D-12-00566.1</a>, 2013. Murphy, J. M., Sexton, D. M. H., Barnett, D. N., Jones, G. S., Webb, M. J., Collins, M., and Stainforth, D. A.: Quantification of modelling uncertainties in a large ensemble of climate change simulations, Nature, 430, 768–772, <a href="http://dx.doi.org/10.1038/nature02770.1.">https://doi.org/10.1038/nature02770.1.</a>, 2004. Nachtergaele, F., van Velthuizen, H., Verekst, L., and Widberg, D.: Harmonized World Soil Database v1.2., 2012. Norby, R. J., Warren, J. M., Iversen, C. M., Medlyn, B. E., McMurtrie, R. E.: CO<sub>2</sub> enhancement of forest productivity constrained by limited nitrogen availability, P. Natl. Acad. Sci. USA, 107, 19368–19373, 2010.%in list Oleson, K. W., Lawrence, D. M., Gordon, B., Flanner, M. G., Kluzek, E., Peter, J., Levis, S., Swenson, S. C., Thornton, E., Dai, A., Decker, M., Dickinson, R., Feddema, J., Heald, C. L., Lamarque, J., Niu, G., Qian, T., Running, S., Sakaguchi, K., Slater, A., Stöckli, R., Wang, A., Yang, L., Zeng, X., and Zeng, X.: Technical Description of version 4.0 of the Community Land Model (CLM), 2010. Oren, R., Ellsworth, D. S., Johnsen, K. H., Phillips, N., Ewers, B. E., Maier, C., Schäfer, K. V., McCarthy, H., Hendrey, G., McNulty, S. G., and Katul, G. G.: Soil fertility limits carbon sequestration by forest ecosystems in a CO<sub>2</sub>-enriched atmosphere, Nature, 411, 469–472, 2001.%in list ORNL-DAAC, Global Soil Data Task Group: Global Gridded Surfaces of Selected Soil Characteristics (IGBP-DIS). [Global Gridded Surfaces of Selected Soil Characteristics (International Geosphere-Biosphere Programme – Data and Information System)]. Data set, available at: <a href="http://www.daac.ornl.gov">http://www.daac.ornl.gov</a> from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA, <a href="http://dx.doi.org/10.3334/ORNLDAAC/569">https://doi.org/10.3334/ORNLDAAC/569</a>, 2000. Oschlies, A.: Model-derived estimates of new production: new results point towards lower values, Deep-Sea Res. Pt. II, 48, 2173–2197, 2001. Oschlies, A. and Garçon, V.: Eddy-induced enhancement of primary production in a model of the North Atlantic Ocean, Nature, 394, 266–269, 1998.%in list Palmer, J. R. and Totterdell, I. J.: Production and export in a global ocean ecosystem model, Deep-Sea Res. Pt. I, 48, 1169–1198,2001. Parton, W. J., Scurlock, J. M. O., Ojima, D. S., Scholes, R. J., Kirchner, T., Seastedt, T., and Garcia, E.: Observations and modeling of biomass and soil organic matter dynamics for the grassland biome worldwide, Global Biogeochem. Cy., 7, 785–809, 1993.%in list Petersen, A. C.: The Precautionary Principle, Knowledge Uncertainty, and Environmental Assessment, Paper for NOB/NIG workshop "Knowledge Uncertainty", 30–31 October 2002, Erasmus University Rotterdam, available online at: <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.108.721&rep=rep1&type=pdf">http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.108.721&rep=rep1&type=pdf</a>, 2002. Pfeil, B., Olsen, A., Bakker, D. C. E., Hankin, S., Koyuk, H., Kozyr, A., Malczyk, J., Manke, A., Metzl, N., Sabine, C. L., Akl, J., Alin, S. R., Bates, N., Bellerby, R. G. J., Borges, A., Boutin, J., Brown, P. J., Cai, W.-J., Chavez, F. P., Chen, A., Cosca, C., Fassbender, A. J., Feely, R. A., González-Dávila, M., Goyet, C., Hales, B., Hardman-Mountford, N., Heinze, C., Hood, M., Hoppema, M., Hunt, C. W., Hydes, D., Ishii, M., Johannessen, T., Jones, S. D., Key, R. M., Körtzinger, A., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lenton, A., Lourantou, A., Merlivat, L., Midorikawa, T., Mintrop, L., Miyazaki, C., Murata, A., Nakadate, A., Nakano, Y., Nakaoka, S., Nojiri, Y., Omar, A. M., Padin, X. A., Park, G.-H., Paterson, K., Perez, F. F., Pierrot, D., Poisson, A., Ríos, A. F., Santana-Casiano, J. M., Salisbury, J., Sarma, V. V. S. S., Schlitzer, R., Schneider, B., Schuster, U., Sieger, R., Skjelvan, I., Steinhoff, T., Suzuki, T., Takahashi, T., Tedesco, K., Telszewski, M., Thomas, H., Tilbrook, B., Tjiputra, J., Vandemark, D., Veness, T., Wanninkhof, R., Watson, A. J., Weiss, R., Wong, C. S., and Yoshikawa-Inoue, H.: A uniform, quality controlled Surface Ocean CO<sub>2</sub> Atlas (SOCAT), Earth Syst. Sci. Data, 5, 125–143, <a href="http://dx.doi.org/10.5194/essd-5-125-2013">https://doi.org/10.5194/essd-5-125-2013</a>, 2013. Piao, S., Sitch, S., Ciais, P., Friedlingstein, P., Peylin, P., Wang, X.,Ahlström, A., Anav, A., Canadell, J. G., Cong, N., Huntingford, C., Jung, M., Levis, S., Levy, P. E., Li, J., Lin, X., Lomas, M. R., Lu, M., Luo, Y., Ma, Y., Myneni, R. B., Poulter, B., Sun, Z., Wang, T., Viovy, N., Zaehle, S. and Zeng, N. :Evaluation of terrestrial carbon cycle models for their response to climate variability and to CO<sub>2</sub> trends, Glob. Change Biol.,19, 2117–2132, <a href="http://dx.doi.org/10.1111/gcb.12187">https://doi.org/10.1111/gcb.12187</a>, 2013. Post, W. M., Emanuel, W. R., Zinke, P. J., and Stangenberger, A. G.: Soil carbon pools and world life zones, Nature, 298, 156–159, 1982.%in list Poulter, B., Hattermann, F., Hawkins, E. D., Zaehle, S., Sitch, S., Restrepo-Coupe, N., Heyder, U., and Cramer, W.: Robust dynamics of Amazon dieback to climate change with perturbed ecosystem model parameters, Glob. Change Biol.,16(9), 1–19, <a href="http://dx.doi.org/10.1111/j.1365-2486.2009.02157.x">https://doi.org/10.1111/j.1365-2486.2009.02157.x</a>, 2010. Poorter, H. and Navas, M. L.: Plant growth and competition at elevated CO<sub>2</sub>: on winners, losers and functional groups, New Phytol., 157, 175–198, 2003.%in list Purves, D. and Pacala, S.: Predictive models of forest dynamics, Science, 320, 1452, <a href="http://dx.doi.org/10.1126/science.1155359">https://doi.org/10.1126/science.1155359</a>, 2008.%in list Qian, H., Joseph, R., and Zeng, N.: Enhanced terrestrial carbon uptake in the northern high latitudes in the 21st century from the coupled carbon cycle climate model intercomparison project model projections, Global Biogeochem. Cy., 16, 641–656, <a href="http://dx.doi.org/10.1111/j.1365-2486.2009.01989.x">https://doi.org/10.1111/j.1365-2486.2009.01989.x</a>, 2010.%in list Le Quéré, C.: Trends in the land and ocean carbon uptake, Current Opinion in Environmental Sustainability, 2, 219–224, <a href="http://dx.doi.org/10.1016/j.cosust.2010.06.003">https://doi.org/10.1016/j.cosust.2010.06.003</a>, 2010. Le Quere, C., Harrison, S. P., Prentice, I. C., Buitenhuis, E. T., Aumont, O., Bopp, L., Claustre, H., Cotrim Da Cunha, L., Geider, R., Giraud, X., Klaas, C., Kohfeld, K., Legendre, L., Manizza, M., Platt, T., Rivkin, R. B., Sathyendranath, S., Uitz, J., Watson, A. J., and Wolf-Gladrow, D.: Ecosystem dynamics based on plankton functional types for global ocean biogeochemistry models, Glob. Change Biol., 11, 2016–2040, <a href="http://dx.doi.org/10.1111/j.1365-2486.2005.01004.x">https://doi.org/10.1111/j.1365-2486.2005.01004.x</a>, 2005.%in list Le Quéré, C., Andres, R. J., Boden, T., Conway, T., Houghton, R. A., House, J. I., Marland, G., Peters, G. P., van der Werf, G. R., Ahlström, A., Andrew, R. M., Bopp, L., Canadell, J. G., Ciais, P., Doney, S. C., Enright, C., Friedlingstein, P., Huntingford, C., Jain, A. K., Jourdain, C., Kato, E., Keeling, R. F., Klein Goldewijk, K., Levis, S., Levy, P., Lomas, M., Poulter, B., Raupach, M. R., Schwinger, J., Sitch, S., Stocker, B. D., Viovy, N., Zaehle, S., and Zeng, N.: The global carbon budget 1959–2011, Earth Syst. Sci. Data, 5, 165–185, <a href="http://dx.doi.org/10.5194/essd-5-165-2013">https://doi.org/10.5194/essd-5-165-2013</a>, 2013. Raddatz, T. J., Reick, C. H., Knorr, W., Kattge, J., Roeckner, E., Schnur, R., Schnitzler, K.-G., Wetzel, P., and Jungclaus, J.: Will the tropical land biosphere dominate the climate–carbon cycle feedback during the twenty-first century?, Clim. Dynam., 29, 565–574, <a href="http://dx.doi.org/10.1007/s00382-007-0247-8">https://doi.org/10.1007/s00382-007-0247-8</a>, 2007.%in list Randerson, J. T., Hoffman, F. M., Thornton, P. E., Mahowald, N. M., Lindsay, K., Lee, Y.-H., Nevison, C. D., Doney, S. C., Bonan, G., Stöckli, R., Covey, C., Running, S. W., and Fung, I. Y.: Systematic assessment of terrestrial biogeochemistry in coupled climate-carbon models, Glob. Change Biol., 15, 2462–2484, <a href="http://dx.doi.org/10.1111/j.1365-2486.2009.01912.x">https://doi.org/10.1111/j.1365-2486.2009.01912.x</a>, 2009.%in list Raupach, M., Rayner, P. J., Barrett, D. J., Defries, R. S., Heimann, M., Ojima, D. S., Quegan, S., and Schmullius, C. C.: Model – data synthesis in terrestrial carbon observation: methods, data requirements and data uncertainty specifications, Glob. Change Biol., 11, 378–397, <a href="http://dx.doi.org/10.1111/j.1365-2486.2005.00917.x">https://doi.org/10.1111/j.1365-2486.2005.00917.x</a>, 2005.%in list Rayner, P. J., Koffi, E., Scholze, M., Kaminski, T.,and Dufresne, J., L.: Constraining predictions of the carbon cycle using data, Philos. T. Roy. Soc. A, 369, 1955–1966, <a href="http://dx.doi.org/10.1098/rsta.2010.0378">https://doi.org/10.1098/rsta.2010.0378</a>, 2011.%in list Refsgaard, J. C. and Henriksen, H. J.: Modelling guidelines – terminology and guiding principles, Adv. Water Resour., 27, 71–82, <a href="http://dx.doi.org/10.1016/j.advwatres.2003.08.006">https://doi.org/10.1016/j.advwatres.2003.08.006</a>, 2004.%in list Reichler, T. and Kim, J.: How well do coupled models simulate today's climate?, B. Am. Meteorol. Soc., 89, 303–311, 2008.%in list Ricciuto, D. M., Davis, K. J., and Keller, K.: A Bayesian calibration of a simple carbon cycle model: the role of observations in estimating and reducing uncertainty, Global Biogeochem. Cy., 22, 1–15, <a href="http://dx.doi.org/10.1029/2006GB002908">https://doi.org/10.1029/2006GB002908</a>, 2008.%in list Ricciuto, D. M., King, A. W., Dragoni, D., and Post, W. M.: Parameter and prediction uncertainty in an optimized terrestrial carbon cycle model: effects of constraining variables and data record length, J. Geophys. Res., 116, 1–17, <a href="http://dx.doi.org/10.1029/2010JG001400">https://doi.org/10.1029/2010JG001400</a>, 2011.%in list Riebesell, U., Schulz, K. G., Bellerby, R. G. J., Botros, M., Fritsche, P., Meyerhoefer, M., Neill, C., Nondal, G., Oschlies, A., Wohlers, J., and Zoellner, E.: Enhanced biological carbon consumption in a high CO<sub>2</sub> ocean, Nature, 450, 545–549, <a href="http://dx.doi.org/10.1038/nature06267">https://doi.org/10.1038/nature06267</a>, 2007.%in list Riebesell, U., Koertinger, A., and Oschlies, A.: Sensitivities of marine carbon fluxes to ocean change, P. Natl. Acad. Sci. USA, 106, 20602–20609, 2009.%not in Rowlands, D. J., Frame, D. J., Ackerley, D., Aina, T., Booth, B. B. B., Christensen, C., Collins, M., Faull, N., Forest, C. E., Grandey, B. S., Gryspeerdt, E., Highwood, E. J., Ingram, W. J., Knight, S., Lopez, A., Massey, N., Mcnamara, F., Meinshausen, N., Piani, C., Rosier, S. M., Sanderson, B. M., Smith, L. A., Stone, D. A., Thurston, M., Yamazaki, K., Yamazaki, Y. H., and Allen, M. R.: Broad range of 2050 warming from an observationally constrained large climate model ensemble, Nat. Geosci., 5, 256–260, <a href="http://dx.doi.org/10.1038/ngeo1430">https://doi.org/10.1038/ngeo1430</a>, 2012.%in list Saatchi, S. S., Houghton, R. A., Alvala, R. C. D. S., Soares, J. V., and Yu, Y.: Distribution of aboveground live biomass in the Amazon basin, Glob. Change Biol., 13, 816–837, 2007.%in list Sailley, S. F., Vogt, M., Doney, S. C., Aita, M. N., Bopp, L., Buitenhuis, E. T., Hashioka, T., Lima, I., Le Quéré, C., and Yamanaka, Y.: Comparing food web structures and dynamics across a suite of global marine ecosystem models, Ecol. Model., 261–262, 43–57, Sala, A., Woodruff, D. R., and Meinzer, F. C.: Carbon dynamics in trees: feast or famine?, Tree Physiol., 32, 764–775, <a href="http://dx.doi.org/10.1093/treephys/tpr143">https://doi.org/10.1093/treephys/tpr143</a>, 2012. Sanderson, B. M. and Knutti, R.: On the interpretation of constrained climate model ensembles, Geophys. Res. Lett., 39,L16708, <a href="http://dx.doi.org/10.1029/2012GL052665">https://doi.org/10.1029/2012GL052665</a>, 2012. Sarmento, H., Montoya, J. M., Vázquez-Domínguez, E., Vaqué, D., and Gasol, J. M.: Warming effects on marine microbial food web processes: how far can we go when it comes to predictions?, Philos. T. Roy. Soc. B, 365, 2137–2149, <a href="http://dx.doi.org/10.1098/rstb.2010.0045">https://doi.org/10.1098/rstb.2010.0045</a>, 2010. Sarmiento, J. L., Hughes, T. M. C., Stouffer, R. J., and Syukuro, M.: Simulated response of the ocean carbon cycle to anthropogenic climate warming, Nature, 393, 1–2, 1998.%in list Sarmiento, J. L., Slater, R., Barber, R., Bopp, L., Doney, S. C., Hirst, A. C., Kleypas, J., Matear, R., Mikolajewicz, U., Monfray, P., Soldatov, V., Spall, S. A., and Stouffer, R.: Response of ocean ecosystems to climate warming, Global Biogeochem. Cy., 18,GB3003,<a href="http://dx.doi.org/10.1029/2003GB002134">https://doi.org/10.1029/2003GB002134</a>, 2004. Sato, H., Itoh, A., and Kohyama, T.: SEIB – DGVM: A new Dynamic Global Vegetation Model using a spatially explicit individual-based approach, Ecol. Model., 200, 279–307, <a href="http://dx.doi.org/10.1016/j.ecolmodel.2006.09.006">https://doi.org/10.1016/j.ecolmodel.2006.09.006</a>, 2007.%in list Savtchenko, A., Ouzounov, D., Ahmad, S., Acker, J., Leptoukh, G., Koziana, J., and Nickless, D.: Terra and aqua MODIS products available from NASA GES DAAC, Adv. Space Res., 34, 710–714, <a href="http://dx.doi.org/10.1016/j.asr.2004.03.012">https://doi.org/10.1016/j.asr.2004.03.012</a>, 2004.%in list Scheffer, M., Brovkin, V., and Cox, P. M.: Positive feedback between global warming and atmospheric CO<sub>2</sub> concentration inferred from past climate change, Geophys. Res. Lett., 33, 2–5, <a href="http://dx.doi.org/10.1029/2005GL025044">https://doi.org/10.1029/2005GL025044</a>, 2006.%in list Schiebel, R. and Movellan, A.: First-order estimate of the planktic foraminifer biomass in the modern ocean, Earth Syst. Sci. Data, 4, 75–89, <a href="http://dx.doi.org/10.5194/essd-4-75-2012">https://doi.org/10.5194/essd-4-75-2012</a>, 2012. Schmittner, A., Oschlies, A., Matthews, H. D., and Galbraith, E. D.: Future changes in climate, ocean circulation, ecosystems, and biogeochemical cycling simulated for a business-as-usual CO<sub>2</sub> emission scenario until year 4000 AD, Global Biogeochem. Cy., 22, 1–21, <a href="http://dx.doi.org/10.1029/2007GB002953">https://doi.org/10.1029/2007GB002953</a>, 2008.%in list Schmittner, A., Urban, N. M., Shakun, J. D., Mahowald, N. M., Clark, P. U., Bartlein, P. J., Mix, A. C., and Rosell-Melé, A.: Climate sensitivity estimated from temperature reconstructions of the last glacial maximum, Science, 334, 1385–1388, <a href="http://dx.doi.org/10.1126/science.1203513">https://doi.org/10.1126/science.1203513</a>, 2011.%in list Shaver, G. R., Canadell, J. G., Chapin III, F. S., Gurevitch, J., Harte, J., Henry, G., Ineson, P., Jonasson, S., Melillo, J., Pitelka, L., and Rustasd, L.: Global warming and terrestrial ecosystems: a conceptual framework for analysis, BioScience, 50, 871–882, <a href="http://dx.doi.org/10.1641/0006-3568(2000)050[0871:GWATEA]2.0.CO;2">https://doi.org/10.1641/0006-3568(2000)050[0871:GWATEA]2.0.CO;2</a>, 2000. Shevliakova, E., Pacala, S. W., Malyshev, S., Hurtt, G. C., Milly, P. C. D., Caspersen, J. P., Sentman, L. T., Fisk, J. P., Wirth, C., and Crevoisier, C.: Carbon cycling under 300 years of land use change: importance of the secondary vegetation sink, Global Biogeochem. Cy., 23, 1–16, <a href="http://dx.doi.org/10.1029/2007GB003176">https://doi.org/10.1029/2007GB003176</a>, 2009.%in list Shiogama, H., Emori, S., Hanasaki, N., Abe, M., Masutomi, Y., and Takahashi, K.: Observational constraints indicate risk of drying in the Amazon basin, Nature Communications, 3, 253–257, <a href="http://dx.doi.org/10.1038/ncomms1252">https://doi.org/10.1038/ncomms1252</a>, 2011. Simard, M., Pinto, N., Fisher, J. B., and Baccini, A.: Mapping forest canopy height globally with spaceborne lidar, J. Geophys. Res.-Biogeo., 116, G04021, <a href="http://dx.doi.org/10.1029/2011JG001708">https://doi.org/10.1029/2011JG001708</a>, 2011. Sitch, S., Cox, P. M., Collins, W. J., and Huntingford, C.: Indirect radiative forcing of climate change through ozone effects on the land-carbon sink, Nature, 448, 791–794, <a href="http://dx.doi.org/10.1038/nature06059">https://doi.org/10.1038/nature06059</a>, 2007.%in list Sitch, S., Huntingford, C., Gedney, N., Levy, P. E., Lomas, M., Piao, S. L., Betts, R., Ciais, P., Cox, P., Friedlingstein, P., Jones, C. D., Prentice, I. C., and Woodward, F. I.: Evaluation of the terrestrial carbon cycle, future plant geography and climate-carbon cycle feedbacks using five Dynamic Global Vegetation Models (DGVMs), Glob. Change Biol., 14, 2015–2039, <a href="http://dx.doi.org/10.1111/j.1365-2486.2008.01626.x">https://doi.org/10.1111/j.1365-2486.2008.01626.x</a>, 2008.%in list Sitch, S., Friedlingstein, P., Gruber, N., Jones, S. D., Murray-Tortarolo, G., Ahlström, A., Doney, S. C., Graven, H., Heinze, C., Huntingford, C., Levis, S., Levy, P. E., Lomas, M., Poulter, B., Viovy, N., Zaehle, S., Zeng, N., Arneth, A., Bonan, G., Bopp, L., Canadell, J. G., Chevallier, F., Ciais, P., Ellis, R., Gloor, M., Peylin, P., Piao, S., Le Quéré, C., Smith, B., Zhu, Z., and Myneni, R.: Trends and drivers of regional sources and sinks of carbon dioxide over the past two decades, Biogeosciences Discuss., 10, 20113–20177, <a href="http://dx.doi.org/10.5194/bgd-10-20113-2013">https://doi.org/10.5194/bgd-10-20113-2013</a>, 2013. Smith, M. J., Purves, D. W., Vanderwel, M. C., Lyutsarev, V., and Emmott, S.: The climate dependence of the terrestrial carbon cycle, including parameter and structural uncertainties, Biogeosciences, 10, 583–606, <a href="http://dx.doi.org/10.5194/bg-10-583-2013">https://doi.org/10.5194/bg-10-583-2013</a>, 2013. Smith, N. G. and Dukes, J. S.: Plant respiration and photosynthesis in global-scale models: incorporating acclimation to temperature and CO<sub>2</sub>, Glob. Change Biol., 19, 45–63, <a href="http://dx.doi.org/10.1111/j.1365-2486.2012.02797.x">https://doi.org/10.1111/j.1365-2486.2012.02797.x</a>, 2013.%in list Soden, B. J. and Held, I. M.: An assessment of climate feedbacks in coupled ocean – atmosphere models, J. Climate, 19, 3354–3360, 2006.%in list Stainforth, D. A., Allen, M. R., Tredger, E.R, Smith, L. A.: Confidence, uncertainty, and decision-support relevance in climate prediction, Philos. T. Roy. Soc. A, 365, 2145–2161, 2007.%in list Stauffer, B., Fluckiger, J., Monnin, E., Schwander, J., Barnola, J. M., and Chappellaz, J.: Atmospheric CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O records over the past 60 000 years based on the comparison of different polar ice cores, Ann. Glaciol., 35, 202–208, 2002.%in list Steinacher, M., Joos, F., Frölicher, T. L., Bopp, L., Cadule, P., Cocco, V., Doney, S. C., Gehlen, M., Lindsay, K., Moore, J. K., Schneider, B., and Segschneider, J.: Projected 21st century decrease in marine productivity: a multi-model analysis, Biogeosciences, 7, 979–1005, <a href="http://dx.doi.org/10.5194/bg-7-979-2010">https://doi.org/10.5194/bg-7-979-2010</a>, 2010. Stow, C. A., Jolliff, J., McGillicuddy, D. J., Doney, S. C., Allen, J. I., Friedrichs, M. A. M., Rose, K. A., and Wallhead, P.: Skill assessment for coupled biological/physical models of marine systems, J. Marine Syst., 76, 4–15, <a href="http://dx.doi.org/10.1016/j.jmarsys.2008.03.011">https://doi.org/10.1016/j.jmarsys.2008.03.011</a>, 2009.%in list Tagliabue, A., Bopp, L., and Gehlen, M.: The response of marine carbon and nutrient cycles to ocean acidification: large uncertainties related to phytoplankton physiological assumptions, Global Biogeochem. Cy., 25, GB3017,<a href="http://dx.doi.org/10.1029/2010GB003929">https://doi.org/10.1029/2010GB003929</a>, 2011. Takahashi, T., Sutherland, S. C., and Kozyr, A.: Global ocean surface water partial pressure of CO<sub>2</sub> database: measurements performed during 1968–2008 (version 2008), ORNL/CDIAC-152, NDP-088r, 2009. Taylor, K. E., Stouffer, R. J., and Meehl, G. A.: An overview of CMIP5 and the experiment design, B. Am. Meteorol. Soc., 93,485–498,<a href="http://dx.doi.org/10.1175/BAMS-D-11-00094.1">https://doi.org/10.1175/BAMS-D-11-00094.1</a>, 2011. Taucher, J. and Oschlies, A.: Can we predict the direction of marine primary production change under global warming?, Geophys. Res. Lett., 38, 1–6, <a href="http://dx.doi.org/10.1029/2010GL045934">https://doi.org/10.1029/2010GL045934</a>, 2011.%in list Taylor, K. E., Stouffer, R. J., and Meehl, G. A.: An overview of CMIP5 and the experiment design, B. Am. Meteorol. Soc., 93, 485–498, <a href="http://dx.doi.org/10.1175/BAMS-D-11-00094.1">https://doi.org/10.1175/BAMS-D-11-00094.1</a>, 2012.%in list Tebaldi, C. and Knutti, R.: The use of the multi-model ensemble in probabilistic climate projections, Philos. T. Roy. Soc. A, 365, 2053–2075, <a href="http://dx.doi.org/10.1098/rsta.2007.2076">https://doi.org/10.1098/rsta.2007.2076</a>, 2007.%in list Tebaldi, C., Mearns, L., Nychka, D., and Smith, R.: Regional probabilities of precipitation change: a Bayesian analysis of multimodel simulations, Geophys. Res. Lett., 31, L24213, <a href="http://dx.doi.org/10.1029/2004GL021276">https://doi.org/10.1029/2004GL021276</a>, 2004.%in list Thomas, M. K., Kremer, C. T., Klausmeier, C. A., and Litchman, E.: A global pattern of thermal adaptation in marine phytoplankton, Science, 338, 1085–1088, <a href="http://dx.doi.org/10.1126/science.1224836">https://doi.org/10.1126/science.1224836</a>, 2012.%in list Thum, T., Räisänen, P., Sevanto, S., Tuomi, M., Reick, C., Vesala, T., Raddatz, T., Aalto, T., Järvinen, H., Altimir, N., Pilegaard, K., Nagy, Z., Rambal, S., and Liski, J.: Soil carbon model alternatives for ECHAM5/JSBACH climate model: evaluation and impacts on global carbon cycle estimates, J. Geophys. Res., 116, G02028, <a href="http://dx.doi.org/10.1029/2010JG001612">https://doi.org/10.1029/2010JG001612</a>, 2011.%in list Tjiputra, J. F., Roelandt, C., Bentsen, M., Lawrence, D. M., Lorentzen, T., Schwinger, J., Seland, Ø., and Heinze, C.: Evaluation of the carbon cycle components in the Norwegian Earth System Model (NorESM), Geosci. Model Dev., 6, 301–325, <a href="http://dx.doi.org/10.5194/gmd-6-301-2013">https://doi.org/10.5194/gmd-6-301-2013</a>, 2013. Todd-Brown, K. E. O., Randerson, J. T., Post, W. M., Hoffman, F. M., Tarnocai, C., Schuur, E. A. G., and Allison, S. D.: Causes of variation in soil carbon simulations from CMIP5 Earth system models and comparison with observations, Biogeosciences, 10, 1717–1736, <a href="http://dx.doi.org/10.5194/bg-10-1717-2013">https://doi.org/10.5194/bg-10-1717-2013</a>, 2013. Tucker, C., Pinzon, J., Brown, M., Slayback, D., Pak, E., Mahoney, R., Vermote, E., and El Saleous, N.: An extended AVHRR 8-km NDVI dataset compatible with MODIS and SPOT vegetation NDVI data, Int. J. Remote Sens., 26, 4485–4498, <a href="http://dx.doi.org/10.1080/01431160500168686">https://doi.org/10.1080/01431160500168686</a>, 2005.%in list Urban, N. M. and Keller, K.: Probabilistic hindcasts and projections of the coupled climate, carbon cycle and Atlantic meridional overturning circulation system: a Bayesian fusion of century-scale observations with a simple model, Tellus A, 62, 737–750, <a href="http://dx.doi.org/10.1111/j.1600-0870.2010.00471.x">https://doi.org/10.1111/j.1600-0870.2010.00471.x</a>, 2010.%in list Van Asselt, M. B. A. and Rotmans, J.: Uncertainty in integrated assessment modelling, Climatic Change, 54, 75–105, 2002.%in list Volodin, E. M., Dianskii, N. A., and Gusev, A. V: Simulating Present Day Climate with the INMCM4. 0 Coupled Model of the Atmospheric and Oceanic General Circulations, Izv. Atmos. Ocean. Phy.+, 46, 414–431, <a href="http://dx.doi.org/10.1134/S000143381004002X">https://doi.org/10.1134/S000143381004002X</a>, 2010. Watanabe, M., Shiogama, H., Yokohata, T., Kamae, Y., Yoshimori, M., Ogura, T., Annan, J. D., Hargreaves, J. C., Emori, S., and Kimoto, M.: Using a multiphysics ensemble for exploring diversity in cloud–shortwave feedback in GCMs, J. Climate, 25, 5416–5431, <a href="http://dx.doi.org/10.1175/JCLI-D-11-00564.1">https://doi.org/10.1175/JCLI-D-11-00564.1</a>, 2012.%in list Watanabe, S., Hajima, T., Sudo, K., Nagashima, T., Takemura, T., Okajima, H., Nozawa, T., Kawase, H., Abe, M., Yokohata, T., Ise, T., Sato, H., Kato, E., Takata, K., Emori, S., and Kawamiya, M.: MIROC-ESM 2010: model description and basic results of CMIP5-20c3m experiments, Geosci. Model Dev., 4, 845–872, <a href="http://dx.doi.org/10.5194/gmd-4-845-2011">https://doi.org/10.5194/gmd-4-845-2011</a>, 2011. Way, D. A. and Sage, R. F.: Thermal acclimation of photosynthesis in black spruce [Picea mariana (Mill.) B. S. P.], Plant Cell Environ., 31, 1250–1262, <a href="http://dx.doi.org/10.1111/j.1365-3040.2008.01842.x">https://doi.org/10.1111/j.1365-3040.2008.01842.x</a>, 2008.%in list Wieder, W. R., Bonan, G. B., and Allison, S. D.: Global soil carbon projections are improved by modelling microbial processes, Nature Clim. Change, 3, 909–912, 2013. Willeit, M., Ganopolski, A., Dalmonech, D., Foley, A. M., and Feulner, G.: Time-scale and state dependence of the carbon-cycle feedback to climate, Clim. Dynam., in review, 2014. Woodwell, G. M., Mackenzie, F. T., Houghton, R. A., Apps, M., Gorham, E., and Davidson, E.: Biotic feedbacks in the warming of the earth, Clim. change, 40, 495–518, 1998. Wu, Z., Dijkstra, P., Koch, G. W., Penuelas, J., and Hungate, B. A.: Responses of terrestrial ecosystems to temperature and precipitation change: a meta-analysis of experimental manipulation, Glob. Change Biol., 17, 927–942, 2011.%in list Yokohata, T., Annan, J. D., Collins, M., Jackson, C. S., Shiogama, H., Watanabe, M., Emori, S., Yoshimori, M., Abe, M., Webb, M. J., and Hargreaves, J. C.: Reliability and importance of structural diversity of climate model ensembles, Clim. Dynam.,41,2745–2763, <a href="http://dx.doi.org/10.1007/s00382-013-1733-9">https://doi.org/10.1007/s00382-013-1733-9</a>, 2013. Yurova, A. Y., Volodin, E. M., I. G., A., Chertov, O. G., and Komarov, A. S.: Effects of variations in simulated changes in soil carbon contents and dynamics on future climate projections, Glob. Change Biol., 16, 823–835, <a href="http://dx.doi.org/10.1111/j.1365-2486.2009.01992.x">https://doi.org/10.1111/j.1365-2486.2009.01992.x</a>, 2010.%in list Zaehle, S. and Dalmonech, D.: Carbon–nitrogen interactions on land at global scales: current understanding in modelling climate biosphere feedbacks, Current Opinion in Environmental Sustainability, 3, 311–320, <a href="http://dx.doi.org/10.1016/j.cosust.2011.08.008">https://doi.org/10.1016/j.cosust.2011.08.008</a>, 2011. Zaehle, S., Sitch, S., and Smith, B.: Effects of parameter uncertainties on the modeling of terrestrial biosphere dynamics, Global Biogeochem. Cy., 19, GB3020, <a href="http://dx.doi.org/10.1029/2004GB002395">https://doi.org/10.1029/2004GB002395</a>, 2005. Zaehle, S., Friedlingstein, P., and Friend, A. D.: Terrestrial nitrogen feedbacks may accelerate future climate change, Geophys. Res. Lett., 37, L01401, <a href="http://dx.doi.org/10.1029/2009GL041345">https://doi.org/10.1029/2009GL041345</a>, 2010. Zaehle, S., Medlyn, B. E., De Kauwe, M. G., Walker, A. P., Dietze, M. C., Hickler, T., Luo, Y., Wang, Y.-P., El-Masri, B., Thornton, P., Jain, A., Wang, S., Warlind, D., Weng, E., Parton, W., Iversen, C. M., Gallet-Budynek, A., McCarthy, H., Finzi, A., Hanson, P. J., Prentice, I. C., Oren, R., and Norby, R. J.: Evaluation of eleven terrestrial carbon-nitrogen cycle models against observations from two temperate free-air CO<sub>2</sub> enrichment studies, New Phytol., in press, <a href="http://dx.doi.org/10.1111/nph.12697">https://doi.org/10.1111/nph.12697</a>, 2014. Zahariev, K., Christian, J. R., and Denman, K. L.: Preindustrial, historical, and fertilization simulations using a global ocean carbon model with new parameterizations of iron limitation, calcification, and N<sub>2</sub> fixation, Prog. Oceanogr., 77, 56–82, <a href="http://dx.doi.org/10.1016/j.pocean.2008.01.007">https://doi.org/10.1016/j.pocean.2008.01.007</a>, 2008.%in list Zeng, N., Qian, H., Munoz, E., and Iacono, R.: How strong is carbon cycle-climate feedback under global warming?, Geophys. Res. Lett., 31, 1–5, <a href="http://dx.doi.org/10.1029/2004GL020904">https://doi.org/10.1029/2004GL020904</a>, 2004.%in list Zeng, N., Mariotti, A., and Wetzel, P.: Terrestrial mechanisms of interannual CO<sub>2</sub> variability, Global Biogeochem. Cy., 19, GB1016,<a href="http://dx.doi.org/10.1029/2004GB002273">https://doi.org/10.1029/2004GB002273</a>, 2005. Zhou, J., Xue, K., Xie, J., Deng, Y., Wu, L., Cheng, X., Fei, S., Deng, S., He, Z., Nostrand, J. D. Van and Luo, Y.: Microbial mediation of carbon-cycle feedbacks to climate warming, Nature Clim. Change, 2, 106–110, <a href="http://dx.doi.org/10.1038/nclimate1331">https://doi.org/10.1038/nclimate1331</a>, 2011. Zhu, Z., Bi, J., Pan, Y., Ganguly, S., Anav, A., Xu, L., Samanta, A., Piao, S., Nemani, R., and Myneni, R.: Global data sets of Vegetation Leaf Area Index (LAI)3g and Fraction of Photosynthetically Active Radiation (FPAR)3g derived from Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) for the period 1981 to 2011, Remote Sens., 5, 927–948, <a href="http://dx.doi.org/10.3390/rs5020927">https://doi.org/10.3390/rs5020927</a>, 2013. Ziehn, T., Kattge, J., Knorr, W., and Scholze, M.: Improving the predictability of global CO<sub>2</sub> assimilation rates under climate change, Geophys. Res. Lett., 38, L10404, <a href="http://dx.doi.org/10.1029/2011GL047182">https://doi.org/10.1029/2011GL047182</a>, 2011.%in list