Denison, S orcid.org/0000-0002-3201-1375, Forster, PM orcid.org/0000-0002-6078-0171 and Smith, CJ orcid.org/0000-0003-0599-4633 (2019) Guidance on emissions metrics for nationally determined contributions under the Paris Agreement. Environmental Research Letters, 14 (12). 124002. ISSN 1748-9326
Abstract
Many nationally determined contributions (NDCs) under the Paris Agreement follow the established practice of specifying emissions levels in tonnes of CO2 equivalent emissions. The Global Warming Potential (GWP) is the emissions metric used most often to aggregate contributions from different greenhouse gases (GHGs). However, the climate impact of pathways expressed in this way is known to be ambiguous. For this reason, alternatives have been proposed but the ambiguity has not been quantified in the context of the Paris Agreement. Here we assess the variation in temperature using pathways consistent with the ambition of limiting temperature increases to well below 2 °C. These are taken from the IPCC Special Report on Global Warming of 1.5 °C (SR15). The CO2 emission levels are adjusted so that the pathways all have the same total CO2 equivalent emissions for a given emissions metric but have different proportions of short-lived and long-lived pollutants. We show that this difference affects projections by up to 0.17 °C when GWP100 is used. Options of reducing this ambiguity include using a different emissions metric or adding supplementary information in NDCs about the emissions levels of individual GHGs. We suggest the latter on the grounds of simplicity and because it does not require agreement on the use of a different emissions metric.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/. |
Keywords: | NDC; metric; GWP100; Paris Agreement; 2°C; 1.5°C; IPCC SR15 |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC NE/N006038/1 EU - European Union 820829 |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Oct 2019 10:56 |
Last Modified: | 20 Dec 2019 09:15 |
Status: | Published |
Publisher: | IOP Publishing |
Identification Number: | 10.1088/1748-9326/ab4df4 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:152360 |
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