 |
| Titel |
State-dependent climate sensitivity of the last 5 million years |
| VerfasserIn |
Peter Köhler, Bas De Boer, Anna von der Heydt, Lennert Stap, Roderik van de Wal |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105074
|
| Publikation (Nr.) |
 EGU/EGU2015-4520.pdf |
|
|
|
|
|
| Zusammenfassung |
| Equilibrium temperature rise in response to increase in radiative forcing is called equilibrium
climate sensitivity, an important quantity calculated by climate models to project
future warming. For model validation comparisons with estimates based on paleo
reconstructions are necessary. Here we use an energy balance model (Köhler et al., 2010)
to estimate climate sensitivity using CO2 proxy data together with model-based
reconstruction of land ice (de Boer et al., 2014) over the last 5 million years. We
find that equilibrium climate sensitivity containing the radiative forcing of CO2
and land ice albedo depends on the background climate. This state-dependency is
mainly contained in the non-linearity of the land-ice forcing. Results differ in detail if
based on ice core CO2 of the last 800,000 years covering mainly colder than present
climates (von der Heydt et al., 2014) or on CO2 proxies of the last 5 million years.
Nevertheless, the climate sensitivity of the warm Pliocene, a paleo-analogy for a
warmer future, is at least about a third higher than for preindustrial background
climates.
References:
de Boer, B., Lourens, L. J. & van de Wal, R. S. Persistent 400,000-year variability of
Antarctic ice volume and the carbon cycle is revealed throughout the Plio-Pleistocene. Nature
Communications 5, 2999 (2014). doi: 10.1038/ncomms3999.
Köhler, P. Bintanja, R., Fischer, H., Joos, F., Knutti, R., Lohmann, G. & Masson-Delmotte, V.
What caused Earth’s temperature variations during the last 800,000 years? Data-based
evidences on radiative forcing and constraints on climate sensitivity. Quaternary Science
Reviews 29, 129–145 (2010). doi: 10.1016/j.quascirev.2009.09.026.
von der Heydt, A. S., Köhler, P., van de Wal, R. S. & Dijkstra, H. A. On the state
dependency of fast feedback processes in (paleo) climate sensitivity. Geophysical Research
Letters 41, 6484–6492 (2014). doi: 10.1002/2014GL061121. |
|
|
|
|
|
|