1 United Nations. Report of the Conference of the Parties on its Sixteenth Session, Cancun, 29 November to 10 December 2010 Document FCCC/CP/2010/7/Add. 1; http://unfccc.int/resource/docs/2010/cop16/eng/07a01.pdf (2011)

2 Zickfeld, K., Eby, M., Matthews, H. D. & Weaver, A. J. Setting cumulative emissions targets to reduce the risk of dangerous climate change. Proc. Natl Acad. Sci. USA 106, 16129–16134 (2009)

3 Meinshausen, M. et al. Greenhouse-gas emission targets for limiting global warming to 2 °C. Nature 458, 1158–1162 (2009)

4 Allen, M. R. et al. Warming caused by cumulative carbon emissions towards the trillionth tonne. Nature 458, 1163–1166 (2009)

5 Meehl, G. A. et al. Relative outcomes of climate change mitigation related to global temperature versus sea-level rise. Nature Clim. Change 2, 576–580 (2012)

6 Orr, J. C. et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681–686 (2005)

7 Steinacher, M., Joos, F., Frölicher, T. L., Plattner, G.-K. & Doney, S. C. Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model. Biogeosciences 6, 515–533 (2009)

8 Running, S. W. A measurable planetary boundary for the biosphere. Science 337, 1458–1459 (2012)

9 Knox, J., Hess, T., Daccache, A. & Wheeler, T. Climate change impacts on crop productivity in Africa and South Asia. Environ. Res. Lett. 7, 034032 (2012)

10 Forster, P. et al. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Ch. 2 129–234 (Cambridge Univ. Press, 2007)

11 Rogelj, J., Meinshausen, M. & Knutti, R. Global warming under old and new scenarios using IPCC climate sensitivity range estimates. Nature Clim. Change 2, 248–253 (2012)

12 Knorr, W., Prentice, I. C., House, J. I. & Holland, E. A. Long-term sensitivity of soil carbon turnover to warming. Nature 433, 298–301 (2005)

13 Fung, I., Doney, S., Lindsay, K. & John, J. Evolution of carbon sinks in a changing climate. Proc. Natl Acad. Sci. USA 102, 11201–11206 (2005)

14 Moss, R. H. et al. The next generation of scenarios for climate change research and assessment. Nature 463, 747–756 (2010)

15 Weyant, J. R., de la Chesnaye, F. C. & Blanford, G. J. Overview of EMF-21: multigas mitigation and climate policy. Energ. J. (Spec. Iss. 3),. 1–32 (2006)

16 Grübler, A. et al. Integrated assessment of uncertainties in greenhouse gas emissions and their mitigation: introduction and overview. Technol. Forecast. Soc. 74, 873–886 (2007)

17 Calvin, K. et al. The role of Asia in mitigating climate change: results from the Asia modeling exercise. Energy Econ. 34 (3). S251–S260 (2012)

18 United Nations. United Nations Framework Convention on Climate Change Document FCCC/INFORMAL/84 GE. 05–62220 (E) 200705; http://unfccc.int/resource/docs/convkp/conveng.pdf (1992)

19 IPCC. Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Changehttp://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html (IPCC, 2007)

20 Rockström, J. et al. A safe operating space for humanity. Nature 461, 472–475 (2009)

21 Rougier, J. Probabilistic inference for future climate using an ensemble of climate model evaluations. Clim. Change 81, 247–264 (2007)

22 Tomassini, L. et al. Uncertainty and risk in climate projections for the 21st century: comparing mitigation to non-intervention scenarios. Clim. Change 103, 399–422 (2010)

23 Doney, S. C., Fabry, V. J., Feely, R. A. & Kleypas, J. A. Ocean acidification: the other CO2 problem. Annu. Rev. Mar. Sci. 1, 169–192 (2009)

24 Fabry, V. J., McClintock, J. B., Mathis, J. T. & Grebmeier, J. M. Ocean acidification at high latitudes: the bellwether. Oceanography 22, 160–171 (2009)

25 Kleypas, J. A. et al. Geochemical consequences of increased atmospheric carbon dioxide on coral reefs. Science 284, 118–120 (1999)

26 Hoegh-Guldberg, O. et al. Coral reefs under rapid climate change and ocean acidification. Science 318, 1737–1742 (2007)

27 Yara, Y. et al. Ocean acidification limits temperature-induced poleward expansion of coral habitats around Japan. Biogeosciences 9, 4955–4968 (2012)

28 Powlson, D. S. et al. Soil management in relation to sustainable agriculture and ecosystem services. Food Policy 36, S72–S87 (2011)

29 Boden, T. & Andres, B. Global CO2 emissions from fossil-fuel burning, cement manufacture, and gas flaring: 1751–2009. Data set. (Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2012); http://cdiac.ornl.gov/ftp/ndp030/global.1751_2009.ems

30 Harrould-Kolieb, E. R. & Herr, D. Ocean acidification and climate change: synergies and challenges of addressing both under the UNFCCC. Clim. Policy 12, 378–389 (2012)

31 Church, J. A. et al. Revisiting the Earth’s sea-level and energy budgets from 1961 to 2008. Geophys. Res. Lett. 38, L18601 (2011)

32 Meinshausen, M. et al. The RCP greenhouse gas concentrations and their extension from 1765 to 2300. Clim. Change 109, 213–241 (2011)

33 Yamamoto-Kawai, M., McLaughlin, F. A., Carmack, E. C., Nishino, S. & Shimada, K. Aragonite undersaturation in the Arctic Ocean: effects of ocean acidification and sea ice melt. Science 326, 1098–1100 (2009)

34 Chan, N. C. S. & Connolly, S. R. Sensitivity of coral calcification to ocean acidification: a meta-analysis. Glob. Change Biol. 19, 282–290 (2013)

35 Schneider, K. & Erez, J. The effect of carbonate chemistry on calcification and photosynthesis in the hermatypic coral Acropora eurystoma . Limnol. Oceanogr. 51, 1284–1293 (2006)

36 Pandolfi, J. M., Connolly, S. R., Marshall, D. J. & Cohen, A. L. Projecting coral reef futures under global warming and ocean acidification. Science 333, 418–422 (2011)

37 Johnson, M. D. & Carpenter, R. C. Ocean acidification and warming decrease calcification in the crustose coralline alga Hydrolithon onkodes and increase susceptibility to grazing. J. Exp. Mar. Biol. Ecol. 434-435, 94–101 (2012)

38 Frieler, K. et al. Limiting global warming to 2 °C is unlikely to save most coral reefs. Nature Clim. Change 3, 165– 170. (2013)

39 Joos, F., Frölicher, T. L., Steinacher, M. & Plattner, G.-K. Ocean Acidification (eds Gattuso, J.-P. & Hansson, L. ) Ch. 14, 319–338 (Oxford Univ. Press, 2011)

40 Hickler, T. et al. CO2 fertilization in temperate FACE experiments not representative of boreal and tropical forests. Glob. Change Biol. 14, 1531–1542 (2008)

41 Strassmann, K. M., Joos, F. & Fischer, G. 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. Tellus B 60, 583–603 (2008)

42 Müller, S. A., Joos, F., Edwards, N. R. & Stocker, T. F. Water mass distribution and ventilation time scales in a cost-efficient, three-dimensional ocean model. J. Clim. 19, 5479–5499 (2006)

43 Parekh, P., Joos, F. & Müller, S. A. A modeling assessment of the interplay between aeolian iron fluxes and iron-binding ligands in controlling carbon dioxide fluctuations during antarctic warm events. Paleoceanography 23, PA4202 (2008)

44 Ritz, S. P., Stocker, T. F. & Joos, F. A coupled dynamical ocean-energy balance atmosphere model for paleoclimate studies. J. Clim. 24, 349–375 (2011)

45 Ritz, S. P., Stocker, T. F. & Severinghaus, J. P. Noble gases as proxies of mean ocean temperature: sensitivity studies using a climate model of reduced complexity. Quat. Sci. Rev. 30, 3728–3741 (2011)

46 Sitch, S. et al. Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model. Glob. Change Biol. 9, 161–185 (2003)

47 Spahni, R., Joos, F., Stocker, B. D., Steinacher, M. & Yu, Z. C. Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century. Clim. Past Discuss. 8, 5633–5685 (2012)

48 McKay, M. D., Beckman, R. J. & Conover, W. J. A comparison of three methods for selecting values of input variables in the analysis of output from a computer code. Technometrics 21, 239–245 (1979)

49 Joos, F. et al. Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate Change (IPCC) emission scenarios. Glob. Biogeochem. Cycles 15, 891–907 (2001)