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| Titel |
Carbon-climate sensitivity: A well-constrained metric of the climate response to carbon emissions |
| VerfasserIn |
N. P. Gillett, H. D. Matthews, P. A. Stott, K. Zickfeld |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024638
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| Zusammenfassung |
| Climate sensitivity and transient climate response characterise climate feedbacks on the
response to equilibrium and transient changes in radiative forcing, but do not relate directly to
emissions of carbon dioxide, and do not account for carbon cycle feedbacks. Previous
experiments with climate-carbon models have shown that the time-integrated radiative
forcing per unit CO2 emission is approximately independent of the background CO2
concentration, due to reduced effectiveness of carbon sinks at higher CO2 concentration
cancelling the logarithmic dependence of radiative forcing on CO2 concentration; that the
allowable cumulative emissions for climate stabilisation are independent of the emissions
pathway; and that global mean temperature remains approximately constant on
multi-centennial timescales in simulations in which CO2 emissions cease completely.
Here we generalise these results to show that Carbon Climate Sensitivity (CCS),
defined as the ratio of temperature change to cumulative emissions, is approximately
independent of both the atmospheric concentration of CO2 and its rate of change, and is
well-constrained by observations to be in the range 1.0 – 2.0 K/EgC, consistent with
estimates based on climate-carbon models of 1.0 – 2.1 K/EgC. CCS therefore aggregates
information about climate feedbacks and carbon cycle feedbacks, and represents a
simple yet robust metric for comparing models. CCS may also have more general
applications in the fields of climate change mitigation and policy, since it allows
CO2-induced global mean temperature change to be inferred directly from emissions. |
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