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Titel |
Climate responses to anthropogenic emissions of short-lived climate pollutants |
VerfasserIn |
L. H. Baker, W. J. Collins, D. J. L. Olivié, R. Cherian, Ø. Hodnebrog, G. Myhre, J. Quaas |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 14 ; Nr. 15, no. 14 (2015-07-24), S.8201-8216 |
Datensatznummer |
250119926
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Publikation (Nr.) |
copernicus.org/acp-15-8201-2015.pdf |
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Zusammenfassung |
Policies to control air quality focus on mitigating emissions of aerosols and
their precursors, and other short-lived climate pollutants (SLCPs). On a
local scale, these policies will have beneficial impacts on health and crop
yields, by reducing particulate matter (PM) and surface ozone concentrations;
however, the climate impacts of reducing emissions of SLCPs are less
straightforward to predict. In this paper we consider a set of idealized,
extreme mitigation strategies, in which the total anthropogenic emissions of
individual SLCP emissions species are removed. This provides an upper bound
on the potential climate impacts of such air quality strategies.
We focus on evaluating the climate responses to changes in anthropogenic
emissions of aerosol precursor species: black carbon (BC), organic carbon
(OC) and sulphur dioxide (SO2). We perform climate integrations with four
fully coupled atmosphere–ocean global climate models (AOGCMs), and examine
the effects on global and regional climate of removing the total land-based
anthropogenic emissions of each of the three aerosol precursor species.
We find that the SO2 emissions reductions lead to the strongest response,
with all models showing an increase in surface temperature focussed in the
Northern Hemisphere mid and (especially) high latitudes, and showing a corresponding
increase in global mean precipitation. Changes in precipitation patterns are
driven mostly by a northward shift in the ITCZ (Intertropical Convergence Zone), consistent with the
hemispherically asymmetric warming pattern driven by the emissions changes.
The BC and OC emissions reductions give a much weaker response, and there is
some disagreement between models in the sign of the climate responses to
these perturbations. These differences between models are due largely to
natural variability in sea-ice extent, circulation patterns and cloud
changes. This large natural variability component to the signal when the
ocean circulation and sea-ice are free-running means that the BC and OC
mitigation measures do not necessarily lead to a discernible climate
response. |
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