Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models
<p>Feedbacks play a fundamental role in determining the magnitude of the response of the climate system to external forcing, such as from anthropogenic emissions. The latest generation of Earth system models includes aerosol and chemistry components that interact with each other and with the b...
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Format: | Article |
Language: | English |
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Copernicus Publications
2021-01-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | https://acp.copernicus.org/articles/21/1105/2021/acp-21-1105-2021.pdf |
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record_format |
Article |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
G. Thornhill W. Collins D. Olivié R. B. Skeie A. Archibald A. Archibald S. Bauer R. Checa-Garcia S. Fiedler G. Folberth A. Gjermundsen L. Horowitz J.-F. Lamarque M. Michou J. Mulcahy P. Nabat V. Naik F. M. O'Connor F. Paulot M. Schulz C. E. Scott R. Séférian C. Smith T. Takemura S. Tilmes K. Tsigaridis K. Tsigaridis J. Weber |
spellingShingle |
G. Thornhill W. Collins D. Olivié R. B. Skeie A. Archibald A. Archibald S. Bauer R. Checa-Garcia S. Fiedler G. Folberth A. Gjermundsen L. Horowitz J.-F. Lamarque M. Michou J. Mulcahy P. Nabat V. Naik F. M. O'Connor F. Paulot M. Schulz C. E. Scott R. Séférian C. Smith T. Takemura S. Tilmes K. Tsigaridis K. Tsigaridis J. Weber Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models Atmospheric Chemistry and Physics |
author_facet |
G. Thornhill W. Collins D. Olivié R. B. Skeie A. Archibald A. Archibald S. Bauer R. Checa-Garcia S. Fiedler G. Folberth A. Gjermundsen L. Horowitz J.-F. Lamarque M. Michou J. Mulcahy P. Nabat V. Naik F. M. O'Connor F. Paulot M. Schulz C. E. Scott R. Séférian C. Smith T. Takemura S. Tilmes K. Tsigaridis K. Tsigaridis J. Weber |
author_sort |
G. Thornhill |
title |
Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models |
title_short |
Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models |
title_full |
Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models |
title_fullStr |
Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models |
title_full_unstemmed |
Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models |
title_sort |
climate-driven chemistry and aerosol feedbacks in cmip6 earth system models |
publisher |
Copernicus Publications |
series |
Atmospheric Chemistry and Physics |
issn |
1680-7316 1680-7324 |
publishDate |
2021-01-01 |
description |
<p>Feedbacks play a fundamental role in determining the magnitude of the
response of the climate system to external forcing, such as from
anthropogenic emissions. The latest generation of Earth system models
includes aerosol and chemistry components that interact with each other and
with the biosphere. These interactions introduce a complex web of feedbacks
that is important to understand and quantify.</p>
<p>This paper addresses multiple pathways for aerosol and chemical feedbacks in
Earth system models. These focus on changes in natural emissions (dust, sea
salt, dimethyl sulfide, biogenic volatile organic compounds (BVOCs) and
lightning) and changes in reaction rates for methane and ozone chemistry.
The feedback terms are then given by the sensitivity of a pathway to climate
change multiplied by the radiative effect of the change.</p>
<p>We find that the overall climate feedback through chemistry and aerosols is
negative in the sixth Coupled Model Intercomparison Project (CMIP6) Earth
system models due to increased negative forcing from aerosols in a climate
with warmer surface temperatures following a quadrupling of <span class="inline-formula">CO<sub>2</sub></span>
concentrations. This is principally due to increased emissions of sea salt
and BVOCs which are sensitive to climate change and cause strong
negative radiative forcings. Increased chemical loss of ozone and methane
also contributes to a negative feedback. However, overall methane lifetime is
expected to increase in a warmer climate due to increased BVOCs. Increased
emissions of methane from wetlands would also offset some of the negative
feedbacks. The CMIP6 experimental design did not allow the methane lifetime
or methane emission changes to affect climate, so<span id="page1106"/> we found a robust negative
contribution from interactive aerosols and chemistry to climate sensitivity
in CMIP6 Earth system models.</p> |
url |
https://acp.copernicus.org/articles/21/1105/2021/acp-21-1105-2021.pdf |
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doaj-13a27c7c269d4e36a79f7adbb3f3cc952021-01-27T07:28:12ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242021-01-01211105112610.5194/acp-21-1105-2021Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system modelsG. Thornhill0W. Collins1D. Olivié2R. B. Skeie3A. Archibald4A. Archibald5S. Bauer6R. Checa-Garcia7S. Fiedler8G. Folberth9A. Gjermundsen10L. Horowitz11J.-F. Lamarque12M. Michou13J. Mulcahy14P. Nabat15V. Naik16F. M. O'Connor17F. Paulot18M. Schulz19C. E. Scott20R. Séférian21C. Smith22T. Takemura23S. Tilmes24K. Tsigaridis25K. Tsigaridis26J. Weber27Department of Meteorology, University of Reading, Reading, UKDepartment of Meteorology, University of Reading, Reading, UKNorwegian Meteorological Institute, Oslo, NorwayCICERO – Centre for International Climate and Environmental Research Oslo, Oslo, NorwayDepartment of Chemistry, University of Cambridge, Cambridge, UKNational Centre for Atmospheric Science, Cambridge, UKNASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY, USA, USALaboratoire des Sciences du Climat et de l'Environnement, IPSL, CEA-CNRS-UVSQ, Gif-sur-Yvette, FranceMax-Planck-Institute for Meteorology, Hamburg, GermanyMet Office Hadley Centre, Exeter, UKNorwegian Meteorological Institute, Oslo, NorwayGFDL/NOAA, Princeton University, Princeton, NJ, USANational Centre for Atmospheric Research, Boulder, CO, USACNRM, Meteo-France, Toulouse CEDEX, FranceMet Office Hadley Centre, Exeter, UKCNRM, Meteo-France, Toulouse CEDEX, FranceGFDL/NOAA, Princeton University, Princeton, NJ, USAMet Office Hadley Centre, Exeter, UKGFDL/NOAA, Princeton University, Princeton, NJ, USANorwegian Meteorological Institute, Oslo, NorwaySchool of Earth and Environment, University of Leeds, Leeds, UKCNRM, Meteo-France, Toulouse CEDEX, FranceSchool of Earth and Environment, University of Leeds, Leeds, UKResearch Institute for Applied Mechanics, Kyushu University, Fukuoka, JapanNational Centre for Atmospheric Research, Boulder, CO, USANASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY, USA, USACenter for Climate Systems Research, Columbia University, New York, NY, USADepartment of Chemistry, University of Cambridge, Cambridge, UK<p>Feedbacks play a fundamental role in determining the magnitude of the response of the climate system to external forcing, such as from anthropogenic emissions. The latest generation of Earth system models includes aerosol and chemistry components that interact with each other and with the biosphere. These interactions introduce a complex web of feedbacks that is important to understand and quantify.</p> <p>This paper addresses multiple pathways for aerosol and chemical feedbacks in Earth system models. These focus on changes in natural emissions (dust, sea salt, dimethyl sulfide, biogenic volatile organic compounds (BVOCs) and lightning) and changes in reaction rates for methane and ozone chemistry. The feedback terms are then given by the sensitivity of a pathway to climate change multiplied by the radiative effect of the change.</p> <p>We find that the overall climate feedback through chemistry and aerosols is negative in the sixth Coupled Model Intercomparison Project (CMIP6) Earth system models due to increased negative forcing from aerosols in a climate with warmer surface temperatures following a quadrupling of <span class="inline-formula">CO<sub>2</sub></span> concentrations. This is principally due to increased emissions of sea salt and BVOCs which are sensitive to climate change and cause strong negative radiative forcings. Increased chemical loss of ozone and methane also contributes to a negative feedback. However, overall methane lifetime is expected to increase in a warmer climate due to increased BVOCs. Increased emissions of methane from wetlands would also offset some of the negative feedbacks. The CMIP6 experimental design did not allow the methane lifetime or methane emission changes to affect climate, so<span id="page1106"/> we found a robust negative contribution from interactive aerosols and chemistry to climate sensitivity in CMIP6 Earth system models.</p>https://acp.copernicus.org/articles/21/1105/2021/acp-21-1105-2021.pdf |