Emission pathways consistent with a 2 °c global temperature limit

ABSTRACT In recent years, international climate policy has increasingly focused on limiting temperature rise, as opposed to achieving greenhouse-gas-concentration-related objectives. The

agreements reached at the United Nations Framework Convention on Climate Change conference in Cancun in 2010 recognize that countries should take urgent action to limit the increase in

global average temperature to less than 2 °C relative to pre-industrial levels1. If this is to be achieved, policymakers need robust information about the amounts of future greenhouse-gas

emissions that are consistent with such temperature limits. This, in turn, requires an understanding of both the technical and economic implications of reducing emissions and the processes

that link emissions to temperature. Here we consider both of these aspects by reanalysing a large set of published emission scenarios from integrated assessment models in a risk-based

climate modelling framework. We find that in the set of scenarios with a ‘likely’ (greater than 66%) chance of staying below 2 °C, emissions peak between 2010 and 2020 and fall to a median

level of 44 Gt of CO2 equivalent in 2020 (compared with estimated median emissions across the scenario set of 48 Gt of CO2 equivalent in 2010). Our analysis confirms that if the mechanisms

needed to enable an early peak in global emissions followed by steep reductions are not put in place, there is a significant risk that the 2 °C target will not be achieved. Access through

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CONTENT BEING VIEWED BY OTHERS NEAR-TERM TRANSITION AND LONGER-TERM PHYSICAL CLIMATE RISKS OF GREENHOUSE GAS EMISSIONS PATHWAYS Article 13 December 2021 ESTIMATING THE TIMING OF GEOPHYSICAL

COMMITMENT TO 1.5 AND 2.0 °C OF GLOBAL WARMING Article 06 June 2022 UNCERTAINTY IN NON-CO2 GREENHOUSE GAS MITIGATION CONTRIBUTES TO AMBIGUITY IN GLOBAL CLIMATE POLICY FEASIBILITY Article

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Google Scholar  Download references ACKNOWLEDGEMENTS The authors gratefully thank everyone involved in the UNEP _Emissions Gap Report_, and acknowledge the contributions of all modelling

groups that provided data and information, all co-authors from the UNEP _Emissions Gap Report_ and others who provided comments, in particular B. Knopf, G. Luderer, E. Sawin, B. O’Neill, B. 

Ward, N. Ranger, V. Bossetti and R. Knutti. J.R. was supported by the Swiss National Science Foundation (project 200021-135067). J.L. was supported by the Joint DECC/Defra Met Office Hadley

Centre Climate Programme (GA01101) and the AVOID programme (GA0215). AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Institute for Atmospheric and Climate Science, ETH Zurich,

Universitätstrasse 16, 8092 Zürich, Switzerland Joeri Rogelj * Potsdam Institute for Climate Impact Research (PIK), 14412 Potsdam, PO Box 60 12 03, Germany William Hare & Malte

Meinshausen * Climate Analytics GmbH, Telegrafenberg A26, 14412 Potsdam, Germany William Hare * Department of Meteorology, Met Office Hadley Centre, University of Reading, Reading RG6 6BB,

UK Jason Lowe * PBL Netherlands Environmental Assessment Agency, 3720 AH Bilthoven, PO Box 303, The Netherlands Detlef P. van Vuuren * Utrecht Sustainability Institute, Utrecht University,

Heidelberglaan 2, 3584 CS Utrecht, The Netherlands Detlef P. van Vuuren * Energy Program, International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, A-2361 Laxenburg,

Austria Keywan Riahi * Georges Lemaître Centre for Earth & Climate Research, Université Catholique de Louvain, Place de l’Université 1, B-1348 Louvain-la-Neuve, Belgium Ben Matthews *

National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan Tatsuya Hanaoka * Energy Research Institute, B1505, Jia. No. 11, Muxidibeili, Xichen Dist.,

Beijing 100038, China Kejun Jiang * School of Earth Sciences, University of Melbourne, Victoria 3010, Australia Malte Meinshausen Authors * Joeri Rogelj View author publications You can also

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publications You can also search for this author inPubMed Google Scholar * Ben Matthews View author publications You can also search for this author inPubMed Google Scholar * Tatsuya

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Scholar * Malte Meinshausen View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS J.R., W.H., J.L., K.R., B.M., M.M. and D.P.v.V. designed the

research. M.M. developed the climate model set-up. J.R. carried out the research. All authors discussed the results and contributed to writing the paper. CORRESPONDING AUTHOR Correspondence

to Joeri Rogelj. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial interests. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION (PDF 1835 KB) RIGHTS AND

PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Rogelj, J., Hare, W., Lowe, J. _et al._ Emission pathways consistent with a 2 °C global temperature limit. _Nature

Clim Change_ 1, 413–418 (2011). https://doi.org/10.1038/nclimate1258 Download citation * Received: 16 June 2011 * Accepted: 22 September 2011 * Published: 23 October 2011 * Issue Date:

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