Stjern, CW, Samset, BH, Myhre, G et al. (17 more authors) (2017) Rapid Adjustments Cause Weak Surface Temperature Response to Increased Black Carbon Concentrations. Journal of Geophysical Research: Atmospheres, 122 (21). pp. 11462-11481. ISSN 2169-897X
Abstract
We investigate the climate response to increased concentrations of black carbon (BC), as part of the Precipitation Driver Response Model Intercomparison Project (PDRMIP). A tenfold increase in BC is simulated by nine global coupled‐climate models, producing a model median effective radiative forcing of 0.82 (ranging from 0.41 to 2.91) W m⁻², and a warming of 0.67 (0.16 to 1.66) K globally and 1.24 (0.26 to 4.31) K in the Arctic. A strong positive instantaneous radiative forcing (median of 2.10 W m⁻² based on five of the models) is countered by negative rapid adjustments (−0.64 W m⁻² for the same five models), which dampen the total surface temperature signal. Unlike other drivers of climate change, the response of temperature and cloud profiles to the BC forcing is dominated by rapid adjustments. Low‐level cloud amounts increase for all models, while higher‐level clouds are diminished. The rapid temperature response is particularly strong above 400 hPa, where increased atmospheric stabilization and reduced cloud cover contrast the response pattern of the other drivers. In conclusion, we find that this substantial increase in BC concentrations does have considerable impacts on important aspects of the climate system. However, some of these effects tend to offset one another, leaving a relatively small median global warming of 0.47 K per W m⁻²—about 20% lower than the response to a doubling of CO₂. Translating the tenfold increase in BC to the present‐day impact of anthropogenic BC (given the emissions used in this work) would leave a warming of merely 0.07 K.
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Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
Keywords: | black carbon; rapid adjustments; climate; semidirect |
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 US Department of Energy Project 1552083 NERC NE/N006038/1 ECMRWF European Centre Medium No ref number |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Nov 2017 11:50 |
Last Modified: | 28 Mar 2018 14:33 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1002/2017JD027326 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123582 |
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