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| Titel |
Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise |
| VerfasserIn |
J. Schewe, A. Levermann, M. Meinshausen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 2, no. 1 ; Nr. 2, no. 1 (2011-03-08), S.25-35 |
| Datensatznummer |
250000458
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| Publikation (Nr.) |
 copernicus.org/esd-2-25-2011.pdf |
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| Zusammenfassung |
| We present climatic consequences of the Representative Concentration Pathways
(RCPs) using the coupled climate model CLIMBER-3α, which contains a
statistical-dynamical atmosphere and a three-dimensional ocean model. We
compare those with emulations of 19 state-of-the-art atmosphere-ocean general
circulation models (AOGCM) using MAGICC6. The RCPs are designed as standard
scenarios for the forthcoming IPCC Fifth Assessment Report to span the full
range of future greenhouse gas (GHG) concentrations pathways currently
discussed. The lowest of the RCP scenarios, RCP3-PD, is projected in
CLIMBER-3α to imply a maximal warming by the middle of the 21st
century slightly above 1.5 °C and a slow decline of temperatures
thereafter, approaching today's level by 2500. We identify two mechanisms
that slow down global cooling after GHG concentrations peak: The known
inertia induced by mixing-related oceanic heat uptake; and a change in
oceanic convection that enhances ocean heat loss in high latitudes, reducing
the surface cooling rate by almost 50%. Steric sea level rise under the
RCP3-PD scenario continues for 200 years after the peak in surface air
temperatures, stabilizing around 2250 at 30 cm. This contrasts with around
1.3 m of steric sea level rise by 2250, and 2 m by 2500, under the highest
scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m)
is found to exceed that of the sea surface by the second half of the
21st century under RCP3-PD. This intermediate-depth
warming persists for centuries even after surface temperatures have returned
to present-day values, with potential consequences for marine ecosystems,
oceanic methane hydrates, and ice-shelf stability. Due to an enhanced
land-ocean temperature contrast, all scenarios yield an intensification of
monsoon rainfall under global warming. |
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