Long-term climate commitments projected with climate-carbon cycle models

Eight earth system models of intermediate complexity (EMICs) are used to project climate change commitments for the recent Intergovernmental Panel on Climate Change’s (IPCC’s) Fourth Assessment Report (AR4). Simulations are run until the year 3000 A.D. and extend substantially farther into the future than conceptually similar simulations with atmosphere–ocean general circulation models (AOGCMs) coupled to carbon cycle models. In this paper the following are investigated: 1) the climate change commitment in response to stabilized greenhouse gases and stabilized total radiative forcing, 2) the climate change commitment in response to earlier CO2 emissions, and 3) emission trajectories for profiles leading to the stabilization of atmospheric CO2 and their uncertainties due to carbon cycle processes. Results over the twenty-first century compare reasonably well with results from AOGCMs, and the suite of EMICs proves well suited to complement more complex models. Substantial climate change commitments for sea level rise and global mean surface temperature increase after a stabilization of atmospheric greenhouse gases and radiative forcing in the year 2100 are identified. The additional warming by the year 3000 is 0.6–1.6 K for the low-CO2 IPCC Special Report on Emissions Scenarios (SRES) B1 scenario and 1.3–2.2 K for the high-CO2 SRES A2 scenario. Correspondingly, the post-2100 thermal expansion commitment is 0.3–1.1 m for SRES B1 and 0.5–2.2 m for SRES A2. Sea level continues to rise due to thermal expansion for several centuries after CO2 stabilization. In contrast, surface temperature changes slow down after a century. The meridional overturning circulation is weakened in all EMICs, but recovers to nearly initial values in all but one of the models after centuries for the scenarios considered. Emissions during the twenty-first century continue to impact atmospheric CO2 and climate even at year 3000. All models find that most of the anthropogenic carbon emissions are eventually taken up by the ocean (49%–62%) in year 3000, and that a substantial fraction (15%–28%) is still airborne even 900 yr after carbon emissions have ceased. Future stabilization of atmospheric CO2 and climate change requires a substantial reduction of CO2 emissions below present levels in all EMICs. This reduction needs to be substantially larger if carbon cycle–climate feedbacks are accounted for or if terrestrial CO2 fertilization is not operating. Large differences among EMICs are identified in both the response to increasing atmospheric CO2 and the response to climate change. This highlights the need for improved representations of carbon cycle processes in these models apart from the sensitivity to climate change. Sensitivity simulations with one single EMIC indicate that both carbon cycle and climate sensitivity related uncertainties on projected allowable emissions are substantial.

[1]  D. Randall,et al.  Climate models and their evaluation , 2007 .

[2]  T. Stocker,et al.  Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium , 2005 .

[3]  Atul K. Jain,et al.  Climate Sensitivity Uncertainty and the Need for Energy Without CO2 Emission , 2003, Science.

[4]  R. Dickinson,et al.  Couplings between changes in the climate system and biogeochemistry , 2007 .

[5]  Katrin J. Meissner,et al.  The role of land surface dynamics in glacial inception: a study with the UVic Earth System Model , 2003 .

[6]  Chris D. Jones,et al.  Impact of climate-carbon cycle feedbacks on emissions scenarios to achieve stabilisation , 2006 .

[7]  L. Perelman,et al.  A finite-volume, incompressible Navier Stokes model for studies of the ocean on parallel computers , 1997 .

[8]  Mark E. Borsuk,et al.  Robust Bayesian uncertainty analysis of climate system properties using Markov chain Monte Carlo methods , 2007 .

[9]  Yuexin Liu,et al.  Modeling the emissions of nitrous oxide (N₂O) and methane (CH₄) from the terrestrial biosphere to the atmosphere , 1996 .

[10]  A. Hirst,et al.  Changes in dissolved oxygen in the Southern Ocean with climate change , 2000 .

[11]  Julia C. Hargreaves,et al.  Using ensemble prediction methods to examine regional climate variation under global warming scenarios , 2006 .

[12]  Fortunat Joos,et al.  Stabilisation of atmospheric greenhouse gases: Physical, biological, and socio-economic implications , 1997 .

[13]  Martijn Gough.  Climate change , 2009, Canadian Medical Association Journal.

[14]  Fortunat Joos,et al.  Metrics to assess the mitigation of global warming by carbon capture and storage in the ocean and in geological reservoirs , 2004 .

[15]  Atul K. Jain,et al.  Stability: Energy for a Greenhouse Planet Advanced Technology Paths to Global Climate , 2008 .

[16]  T. Stocker,et al.  Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium , 2005 .

[17]  Klaus S. Lackner,et al.  A Guide to CO2 Sequestration , 2003, Science.

[18]  W. G. Strand,et al.  How Much More Global Warming and Sea Level Rise? , 2005, Science.

[19]  M. Maqueda,et al.  Sensitivity of a global sea ice model to the treatment of ice thermodynamics and dynamics , 1997 .

[20]  T. Wigley,et al.  Analytical solution for the effect of increasing CO2 on global mean temperature , 1985, Nature.

[21]  M. Maqueda,et al.  Performance of a second‐order moments advection scheme in an Ocean General Circulation Model , 2006 .

[22]  E. Dlugokencky,et al.  Atmospheric chemistry and greenhouse gases , 2001 .

[23]  Pierre Friedlingstein,et al.  Contributions of past and present human generations to committed warming caused by carbon dioxide. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[24]  James D. Annan,et al.  Efficiently Constraining Climate Sensitivity with Ensembles of Paleoclimate Simulations , 2005 .

[25]  James D. Annan,et al.  An efficient climate forecasting method using an intermediate complexity Earth System Model and the ensemble Kalman filter , 2004 .

[26]  T. Stocker,et al.  The effects of subgrid-scale parameterizations in a zonally averaged ocean model , 2000 .

[27]  T. Wigley,et al.  Analytical solution for the effect of increasing CO2 on global mean temperature , 1985, Nature.

[28]  S. Rahmstorf,et al.  The earth system model of intermediate complexity CLIMBER-3α. Part I: description and performance for present-day conditions , 2005 .

[29]  T. Wigley.  The Climate Change Commitment , 2005, Science.

[30]  M. Scholze,et al.  Constraining temperature variations over the last millennium by comparing simulated and observed atmospheric CO2 , 2003 .

[31]  A. Kattenberg,et al.  ECBILT: a dynamic alternative to mixed boundary conditions in ocean models , 1998 .

[32]  Jonathan M. Gregory,et al.  The Role of Climate Sensitivity and Ocean Heat Uptake on AOGCM Transient Temperature Response , 2002 .

[33]  Jan S. Fuglestvedt,et al.  A simple model for scenario studies of changes in global climate: Version 1.0 , 1999 .

[34]  Stefano Schiavon,et al.  Climate Change 2007: The Physical Science Basis. , 2007 .

[35]  Nicolas Gruber,et al.  The Oceanic Sink for Anthropogenic CO2 , 2004, Science.

[36]  R. Dickinson,et al.  The land surface climatology of the community land model coupled to the NCAR community climate model , 2002 .

[37]  André Berger,et al.  Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations , 1992 .

[38]  Andrei P. Sokolov,et al.  A flexible climate model for use in integrated assessments , 1998 .

[39]  Victor Brovkin,et al.  Carbon cycle, vegetation, and climate dynamics in the Holocene: Experiments with the CLIMBER‐2 model , 2002 .

[40]  A. R. Price,et al.  Millennial timescale carbon cycle and climate change in an efficient Earth system model , 2006 .

[41]  G. Fischer,et al.  Simulating effects of land use changes on carbon fluxes: past contributions to atmospheric CO2 increases and future commitments due to losses of terrestrial sink capacity , 2008 .

[42]  H. L. Miller,et al.  Global climate projections , 2007 .

[43]  Y. Yoshida,et al.  Long-term climate response to stabilized and overshoot anthropogenic forcings beyond the twenty-first century , 2006 .

[44]  H. Damon Matthews.  Emissions targets for CO2 stabilization as modified by carbon cycle feedbacks , 2006 .

[45]  K. Bryan.  A Numerical Method for the Study of the Circulation of the World Ocean , 1997 .

[46]  Ian G. Enting,et al.  Future emissions and concentrations of carbon dioxide: Key ocean / atmosphere / land analyses , 1994 .

[47]  Andrei P. Sokolov,et al.  A Three-Dimensional Ocean-Seaice-Carbon Cycle Model and its Coupling to a Two-Dimensional Atmospheric Model: Uses in Climate Change Studies , 2005 .

[48]  Uwe Mikolajewicz,et al.  Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model , 2007 .

[49]  Gian-Kasper Plattner,et al.  Feedback mechanisms and sensitivities of ocean carbon uptake under global warming , 2001 .

[50]  Stephen Sitch,et al.  Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate Change (IPCC) Emission Scenarios , 2001 .

[51]  Reservoir time-scales for anthropogenic CO2 in the atmosphere: commentary , 1996 .

[52]  Andrei P. Sokolov,et al.  A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration , 2005 .

[53]  G. Meehl,et al.  OVERVIEW OF THE COUPLED MODEL INTERCOMPARISON PROJECT , 2005 .

[54]  I. G. Enting,et al.  On the use of smoothing splines to filter CO2 data , 1987 .

[55]  Peter M. Cox,et al.  An analogue model to derive additional climate change scenarios from existing GCM simulations , 2000 .

[56]  Thomas F. Stocker,et al.  A latitude-depth, circulation-biogeochemical ocean model for paleoclimate studies. Development and sensitivities , 1998 .

[57]  J. Houghton,et al.  Climate change 2001 : the scientific basis , 2001 .

[58]  W. Collins,et al.  Global climate projections , 2007 .

[59]  Christopher B. Field,et al.  Current status and past trends of the global carbon cycle , 2004 .

[60]  L. Harvey.  Effect of ocean mixing on the transient climate response to a CO2 increase: Analysis of recent model results , 1986 .

[61]  Chris D. Jones,et al.  Modelling vegetation and the carbon cycle as interactive elements of the climate system , 2002 .

[62]  C. D. Keeling,et al.  Atmospheric CO 2 records from sites in the SIO air sampling network , 1994 .

[63]  S. Gerber,et al.  Sensitivity of a dynamic global vegetation model to climate and atmospheric CO2 , 2004 .

[64]  Two decades of ocean CO2 sink and variability , 2003 .

[65]  William H. Lipscomb,et al.  An energy-conserving thermodynamic model of sea ice , 1999 .

[66]  M. Latif,et al.  Evaluation of Different Methods to Assess Model Projections of the Future Evolution of the Atlantic Meridional Overturning Circulation , 2007 .

[67]  David William Keith,et al.  Climate Strategy with Co2 Capture from the Air , 2006 .

[68]  L. Harvey,et al.  Declining Temporal Effectiveness of Carbon Sequestration: Implications for Compliance with the United National Framework Convention on Climate Change , 2004 .

[69]  J. Edmonds,et al.  Economic and environmental choices in the stabilization of atmospheric CO2 concentrations , 1996, Nature.

[70]  M. Claussen,et al.  EMIC Intercomparison Project (EMIP–CO2): comparative analysis of EMIC simulations of climate, and of equilibrium and transient responses to atmospheric CO2 doubling , 2005 .

[71]  Reto Knutti,et al.  Probabilistic climate change projections for CO2 stabilization profiles , 2005 .

[72]  Philippe Huybrechts,et al.  Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles , 2002 .

[73]  David W. Keith,et al.  Climate Strategy with Co2 Capture from the Air , 2001 .

[74]  Thomas F. Stocker,et al.  The Stability of the Thermohaline Circulation in Global Warming Experiments , 1999 .

[75]  Corinne Le Quéré,et al.  Observations: Oceanic Climate Change and Sea Level , 2007 .

[76]  L. Harvey.  A Semianalytic Energy Balance Climate Model with Explicit Sea Ice and Snow Physics , 1988 .

[77]  H. Matthews.  Emissions targets for CO2 stabilization as modified by carbon cycle feedbacks , 2006 .

[78]  F. Joos,et al.  A Paleo-perspective on changes in atmospheric CO2 and climate , 2004 .

[79]  Victor Brovkin,et al.  CLIMBER-2: a climate system model of intermediate complexity. Part I: model description and performance for present climate , 2000 .

[80]  Syukuro Manabe,et al.  Simulated response of the ocean carbon cycle to anthropogenic climate warming , 1998, Nature.

[81]  Thomas F. Stocker,et al.  A Zonally Averaged, Coupled Ocean-Atmosphere Model for Paleoclimate Studies , 1992 .

[82]  L. Perelman,et al.  Hydrostatic, quasi‐hydrostatic, and nonhydrostatic ocean modeling , 1997 .

[83]  M. Winton,et al.  A Reformulated Three-Layer Sea Ice Model , 2000 .

[84]  Jorge L. Sarmiento,et al.  Oceanic Carbon Dioxide Uptake in a Model of Century-Scale Global Warming , 1996, Science.

[85]  Frank Lunkeit,et al.  Earth system models of intermediate complexity: closing the gap in the spectrum of climate system models , 2002 .

[86]  A. McGuire,et al.  Interactions between carbon and nitrogen dynamics in estimating net primary productivity for potential vegetation in North America , 1992 .

[87]  L. François,et al.  Sensitivity of a global oceanic carbon cycle model to the circulation and to the fate of organic matter: preliminary results , 1996 .

[88]  L. Harvey.  A two‐dimensional ocean model for long‐term climatic simulations: Stability and coupling to atmospheric and sea ice models , 1992 .

[89]  S. Manabe,et al.  Response of a Coupled Ocean–Atmosphere Model to Increasing Atmospheric Carbon Dioxide: Sensitivity to the Rate of Increase , 1999 .

[90]  I. C. Prentice,et al.  Carbon balance of the terrestrial biosphere in the Twentieth Century: Analyses of CO2, climate and land use effects with four process‐based ecosystem models , 2001 .

[91]  L. Lackner,et al.  A guide to CO_2 sequestration , 2003 .

[92]  J. Dufresne,et al.  Positive feedback between future climate change and the carbon cycle , 2001 .

[93]  F. Tubiello,et al.  Reservoir timescales for anthropogenic CO2 in the atmosphere , 1994, Tellus. Series B, Chemical and physical meteorology.

[94]  R. Reynolds,et al.  Forced and unforced ocean temperature changes in Atlantic and Pacific tropical cyclogenesis regions , 2006, Proceedings of the National Academy of Sciences.

[95]  Sergey Paltsev,et al.  MIT Integrated Global System Model (IGSM) Version 2: Model Description and Baseline Evaluation , 2005 .

[96]  David Archer,et al.  Fate of fossil fuel CO2 in geologic time , 2005 .

[97]  Corinne Le Quéré,et al.  An efficient and accurate representation of complex oceanic and biospheric models of anthropogenic carbon uptake , 1996 .

[98]  D. Streets,et al.  Dangerous human-made interference with climate: a GISS modelE study , 2006, physics/0610115.

[99]  David Archer,et al.  Multiple timescales for neutralization of fossil fuel CO2 , 1997 .

[100]  F. Woodward,et al.  Global response of terrestrial ecosystem structure and function to CO2 and climate change: results from six dynamic global vegetation models , 2001 .

[101]  Thomas F. Stocker,et al.  Influence of CO2 emission rates on the stability of the thermohaline circulation , 1997, Nature.

[102]  Robert J. Scholes,et al.  The Carbon Cycle and Atmospheric Carbon Dioxide , 2001 .

[103]  V. Brovkin,et al.  A continuous climate-vegetation classification for use in climate-biosphere studies , 1997 .

[104]  D. Etheridge,et al.  Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn , 1996 .

[105]  Marika M. Holland,et al.  The UVic earth system climate model: Model description, climatology, and applications to past, present and future climates , 2001, Data, Models and Analysis.

[106]  Nebojsa Nakicenovic,et al.  Scenarios, targets, gaps and costs , 2004 .

[107]  F. Joos,et al.  Global warming and marine carbon cycle feedbacks on future atmospheric CO2 , 1999, Science.

[108]  R. Schnur,et al.  Climate-carbon cycle feedback analysis: Results from the C , 2006 .

[109]  Victor Brovkin,et al.  CLIMBER-2: a climate system model of intermediate complexity. Part II: model sensitivity , 2001 .

[110]  G. Meehl,et al.  Constraining Climate Sensitivity from the Seasonal Cycle in Surface Temperature , 2006 .

[111]  Robert Marsh,et al.  Uncertainties due to transport-parameter sensitivity in an efficient 3-D ocean-climate model , 2005 .

[112]  Nathan P. Gillett,et al.  Natural and anthropogenic climate change: incorporating historical land cover change, vegetation dynamics and the global carbon cycle , 2004 .

[113]  A. Manning,et al.  Global oceanic and land biotic carbon sinks from the Scripps atmospheric oxygen flask sampling network , 2006 .

[114]  Andrei P. Sokolov,et al.  Consequences of Considering Carbon–Nitrogen Interactions on the Feedbacks between Climate and the Terrestrial Carbon Cycle , 2008 .

[115]  T. Fichefet,et al.  A zonally averaged, three-basin ocean circulation model for climate studies , 1994 .

[116]  K. Lambeck,et al.  Effect of isostatic rebound on modelled ice volume variations during the last 200 kyr , 2001 .

[117]  T. Stocker,et al.  Influence of the Thermohaline Circulation on Projected Sea Level Rise , 2000 .

[118]  Ronald G. Prinn,et al.  Effects of ozone on net primary production and carbon sequestration in the conterminous United States using a biogeochemistry model , 2004 .

[119]  A. Semtner.  A MODEL FOR THE THERMODYNAMIC GROWTH OF SEA ICE IN NUMERICAL INVESTIGATIONS OF CLIMATE , 1975 .

[120]  R. Houghton.  The annual net flux of carbon to the atmosphere from changes in land use 1850–1990* , 1999 .

[121]  Bas Eickhout,et al.  Impacts of future land cover changes on atmospheric CO2 and climate , 2005 .

[122]  J. Townshend,et al.  Carbon emissions from tropical deforestation and regrowth based on satellite observations for the 1980s and 1990s , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[123]  Jonathan M. Gregory,et al.  The climate response to CO2 of the Hadley Centre coupled AOGCM with and without flux adjustment , 1997 .

[124]  A. McGuire,et al.  Global climate change and terrestrial net primary production , 1993, Nature.

[125]  Peter H. Stone,et al.  Efficient Three-Dimensional Global Models for Climate Studies: Models I and II , 1983 .

[126]  Decrease of emissions required to stabilize atmospheric CO2 due to positive carbon cycle–climate feedbacks , 2005 .

[127]  P. Gent,et al.  Isopycnal mixing in ocean circulation models , 1990 .

[128]  Christopher B. Field,et al.  The global carbon cycle: integrating humans, climate and the natural world. , 2004 .

[129]  Chris D. Jones,et al.  Climate-carbon cycle feedbacks under stabilization: uncertainty and observational constraints , 2006 .

[130]  E. Driesschaert.  Climate change over the next millennia using LOVECLIM, a new Earth system model including the polar ice sheets , 2005 .

[131]  Stephen Sitch,et al.  Role of land cover changes for atmospheric CO2 increase and climate change during the last 150 years , 2004 .

[132]  S S I T C H,et al.  Evaluation of Ecosystem Dynamics, Plant Geography and Terrestrial Carbon Cycling in the Lpj Dynamic Global Vegetation Model , 2022 .

[133]  F. Joos,et al.  The substitution of high‐resolution terrestrial biosphere models and carbon sequestration in response to changing CO2 and climate , 1999 .

[134]  R. Houghton,et al.  Why are estimates of the terrestrial carbon balance so different? , 2003 .

[135]  I. C. Prentice,et al.  Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model , 2003 .

[136]  R. Betts,et al.  Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model , 2000, Nature.

[137]  J. Berry,et al.  A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species , 1980, Planta.