.nullnonmarkingreturn “.null9.null.null6.null2013.null11 .nullPROGRESSUS INQUISITIONES DE MUTATIONE CLIMATISVol. 9 No. 6November 2013doi10.3969/j.issn.1673-1719.2013.06.004.nullnonmarkingreturn, .nullnonmarkingreturn , .nullnonmarkingreturn,.null . 2.nullnonmarkingreturn “ .nullnonmarkingreturn .null 2013-07-24.nullnonmarkingreturn .null.nullnonmarkingreturn “.null71173131.nullnonmarkingreturn.nullnonmarkingreturn “2 China Meteorological Administration, Beijing 100081, China; 3 College of Global Change and Earth System Science, BeijingNormal University, Beijing 100875, ChinaAbstract The 2.null target has become a political consensus among global community. The translation from thetemperature rise target to international and national carbon budget should be built upon consistent scientific findings.The current studies on Earth system models, mitigation trajectories and allocation schemes still lack necessaryconsistency to reach political consensus. The decision-making basis for a top-down climate regime is not ready. Themost practical way is to further enhance bottom-up national mitigation pledges through ratcheting assessment, witha view to share the mitigation burden in an equitable manner.Key words climate change; uncertainty; emission space; climate negotiationTeng Fei1, He Jiankun1, Gao Yun2, Dong Wenjie3[8][7][10][9]Allen M R, Frame D J, Huntingford C, et al. Warming caused bycumulative carbon emissions towards the trillionth tonne [J]. Nature, 2009,458 7242 1163-1166Meinshausen M, Meinshausen N, Hare W, et al. Greenhouse-gas emissiontargets for limiting global warming to 2.null[J]. Nature, 2009, 458 72421158-1162IPCC. Climate change 2007 the physical science basis [M]. CambridgeCambridge University Press, 2007Gillett N P, Arora V K, Matthews D, et al. Constraining the ratio of globalwarming to cumulative CO2emissions using CMIP5 simulations [J].Journal of Climate, 2013, 26 6844-6858IPCC. Climate change 2007 mitigation of climate change [M].Cambridge Cambridge University Press, 2007.nullnonmarkingreturn “*,-./. .nullnonmarkingreturn “.nullnonmarkingreturn [M]. .nullnonmarkingreturn .nullnonmarkingreturn “, 2011Meinshausen M, Raper S C B, Wigley T M L. Emulating coupledatmosphere-ocean and carbon cycle models with a simpler model,MAGICC6-Part 1 model description and calibration [J]. AtmosphericChemistry and Physics, 2011, 11 4 1417-1456Meinshausen M, Wigley T M L, Raper S C B. Emulating atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6-Part 2applications [J]. Atmospheric Chemistry and Physics, 2011, 11 4 1457-1471Clarke L, Edmonds J, Krey V, et al. International climate policyarchitectures overview of the EMF 22 international scenarios [J]. EnergyEconomics, 2009, 31 S64-S81Rogelj J, Hare W, Lowe J, et al. Emission pathways consistent with a2.null global temperature limit [J]. Nature Climate Change, 2011, 1 8413-418Rogelj J, Meinshausen M, Knutti R. Global warming under old and newscenarios using IPCC climate sensitivity range estimates [J]. NatureClimate Change, 2012, 2 4 248-253Winkler H, Jayaraman T, Pan J H, et al. Equitable access to sustainabledevelopment contribution to the body of scientific knowledge [M]. BASICexpert group, 2011.nullnonmarkingreturn “. .nullnonmarkingreturn “ .nullnonmarkingreturn “.nullnonmarkingreturn [M]. .nullnonmarkingreturn .nullnonmarkingreturn “, 2012.nullnonmarkingreturn , .nullnonmarkingreturn, .nullnonmarkingreturn. .nullnonmarkingreturn “*,-./.null[J]. .nullnonmarkingreturn “ .nullnonmarkingreturn “nonmarkingreturn, 2009 6 47-53.nullnonmarkingreturn , .nullnonmarkingreturn , .nullnonmarkingreturn, .null. .nullnonmarkingreturn “*,-[J]. .nullnonmarkingreturn “, 2009, 5 6 362-368.nullnonmarkingreturn , .nullnonmarkingreturn , .nullnonmarkingreturn , .null. 2050.nullnonmarkingreturn CO2.nullnonmarkingreturn .nullnonmarkingreturn .nullnonmarkingreturn [J]..nullnonmarkingreturn D.null .nullnonmarkingreturn , 2009 8 1009-1027.nullnonmarkingreturn , .nullnonmarkingreturn , .nullnonmarkingreturn , .null. .nullnonmarkingreturn “*.null,.nullnonmarkingreturn “[J]. .nullnonmarkingreturn D.null .nullnonmarkingreturn , 2009 12 1659-1671.nullnonmarkingreturn , .nullnonmarkingreturn. .nullnonmarkingreturn “ .nullnonmarkingreturn “.nullnonmarkingreturn “[J]. .nullnonmarkingreturn “, 2009 5 83-98Tannert C, Elvers H-D, Jandrig B. The ethics of uncertainty. In the lightof possible dangers, research becomes a moral duty [J]. EMBO Reports,2007, 8 10 892-896[11][12][13][14][15][16][17][18][19][20][21][22][23][6][5]