Regional and seasonal radiative forcing by perturbations to aerosol and ozone precursor emissions
Open Access
- 9 November 2016
- journal article
- research article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 16 (21), 13885-13910
- https://doi.org/10.5194/acp-16-13885-2016
Abstract
Predictions of temperature and precipitation responses to changes in the anthropogenic emissions of climate forcers require the quantification of the radiative forcing exerted by those changes. This task is particularly difficult for near-term climate forcers like aerosols, methane, and ozone precursors because their short atmospheric lifetimes cause regionally and temporally inhomogeneous radiative forcings. This study quantifies specific radiative forcing, defined as the radiative forcing per unit change in mass emitted, for eight near-term climate forcers as a function of their source regions and the season of emission by using dedicated simulations by four general circulation and chemistry-transport models. Although differences in the representation of atmospheric chemistry and radiative processes in different models impede the creation of a uniform dataset, four distinct findings can be highlighted. Firstly, specific radiative forcing for sulfur dioxide and organic carbon are stronger when aerosol–cloud interactions are taken into account. Secondly, there is a lack of agreement on the sign of the specific radiative forcing of volatile organic compound perturbations, suggesting they are better avoided in climate mitigation strategies. Thirdly, the strong seasonalities of the specific radiative forcing of most forcers allow strategies to minimise positive radiative forcing based on the timing of emissions. Finally, European and shipping emissions exert stronger aerosol specific radiative forcings compared to East Asia where the baseline is more polluted. This study can therefore form the basis for further refining climate mitigation options based on regional and seasonal controls on emissions. For example, reducing summertime emissions of black carbon and wintertime emissions of sulfur dioxide in the more polluted regions is a possible way to improve air quality without weakening the negative radiative forcing of aerosols.Funding Information
- European Commission (282688)
This publication has 94 references indexed in Scilit:
- Analysis of present day and future OH and methane lifetime in the ACCMIP simulationsAtmospheric Chemistry and Physics, 2013
- Pre-industrial to end 21st century projections of tropospheric ozone from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)Atmospheric Chemistry and Physics, 2013
- Radiative forcing of the direct aerosol effect from AeroCom Phase II simulationsAtmospheric Chemistry and Physics, 2013
- Radiative forcing due to stratospheric water vapour from CH4 oxidationGeophysical Research Letters, 2007
- Abatement of Greenhouse Gases: Does Location Matter?Climatic Change, 2006
- Gas/aerosol partitioning 2. Global modeling resultsPublished by American Geophysical Union (AGU) ,2002
- Gas/aerosol partitioning: 1. A computationally efficient modelJournal of Geophysical Research: Atmospheres, 2002
- New estimates of radiative forcing due to well mixed greenhouse gasesGeophysical Research Letters, 1998
- Time scales in atmospheric chemistry: Theory, GWPs for CH4 and CO, and runaway growthGeophysical Research Letters, 1996
- Cloud condensation nucleus‐sulphate mass relationship and cloud albedoJournal of Geophysical Research: Atmospheres, 1994