dc.contributor.author | Cox, PM | |
dc.contributor.author | Huntingford, C | |
dc.contributor.author | Williamson, MS | |
dc.date.accessioned | 2018-10-23T13:07:36Z | |
dc.date.issued | 2018-01-18 | |
dc.description.abstract | Equilibrium climate sensitivity (ECS) remains one of the most important unknowns in climate change science. ECS is defined as the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level of CO2. Despite its rather idealized definition, ECS has continuing relevance for international climate change agreements, which are often framed in terms of stabilization of global warming relative to the pre-industrial climate. However, the 'likely' range of ECS as stated by the Intergovernmental Panel on Climate Change (IPCC) has remained at 1.5-4.5 degrees Celsius for more than 25 years. The possibility of a value of ECS towards the upper end of this range reduces the feasibility of avoiding 2 degrees Celsius of global warming, as required by the Paris Agreement. Here we present a new emergent constraint on ECS that yields a central estimate of 2.8 degrees Celsius with 66 per cent confidence limits (equivalent to the IPCC 'likely' range) of 2.2-3.4 degrees Celsius. Our approach is to focus on the variability of temperature about long-term historical warming, rather than on the warming trend itself. We use an ensemble of climate models to define an emergent relationship between ECS and a theoretically informed metric of global temperature variability. This metric of variability can also be calculated from observational records of global warming, which enables tighter constraints to be placed on ECS, reducing the probability of ECS being less than 1.5 degrees Celsius to less than 3 per cent, and the probability of ECS exceeding 4.5 degrees Celsius to less than 1 per cent. | en_GB |
dc.description.sponsorship | This work was supported by the European Research Council (ERC) ECCLES project, grant agreement number 742472 (P.M.C.); the EU Horizon 2020 Research Programme CRESCENDO project, grant agreement number 641816 (P.M.C. and M.S.W.); the EPSRC-funded ReCoVER project (M.S.W.); and the NERC CEH National Capability fund (C.H.). | en_GB |
dc.identifier.citation | Vol. 553, pp. 319 - 322 | en_GB |
dc.identifier.doi | 10.1038/nature25450 | |
dc.identifier.uri | http://hdl.handle.net/10871/34396 | |
dc.language.iso | en | en_GB |
dc.publisher | Springer Nature | en_GB |
dc.relation.url | https://www.ncbi.nlm.nih.gov/pubmed/29345639 | en_GB |
dc.rights | © 2018 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. | en_GB |
dc.subject | Carbon Dioxide | en_GB |
dc.subject | Global Warming | en_GB |
dc.subject | History, 19th Century | en_GB |
dc.subject | History, 20th Century | en_GB |
dc.subject | History, 21st Century | en_GB |
dc.subject | Models, Theoretical | en_GB |
dc.subject | Observation | en_GB |
dc.subject | Probability | en_GB |
dc.subject | Temperature | en_GB |
dc.title | Emergent constraint on equilibrium climate sensitivity from global temperature variability | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2018-10-23T13:07:36Z | |
exeter.place-of-publication | England | en_GB |
dc.description | This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this record | en_GB |
dc.identifier.journal | Nature | en_GB |