How well do we understand and evaluate climate change feedback processes?

• Published in: Journal of Climate
• Main Authors: Bony, S., Colman, R, Kattsov, VM, Allan, RP, Bretherton, CS, Dufresne, JL, Hall, A, Hallegatte, Stéphane, Holland, MM, Ingram, W, Randall, DA, Soden, BJ, Tselioudis, G, Webb, MJ
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Météo-France Paris, Météo France, Centre international de recherche sur l'environnement et le développement (CIRED), Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École des hautes études en sciences sociales (EHESS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: [SDU]Sciences of the Universe [physics]; Sea ice
• Online Access: https://hal-enpc.archives-ouvertes.fr/hal-00716782; https://hal-enpc.archives-ouvertes.fr/hal-00716782/document; https://hal-enpc.archives-ouvertes.fr/hal-00716782/file/%5B15200442%20-%20Journal%20of%20Climate%5D%20How%20Well%20Do%20We%20Understand%20and%20Evaluate%20Climate%20Change%20Feedback%20Processes%20.pdf; https://doi.org/10.1175/JCLI3819.1

International audience Processes in the climate system that can either amplify or dampen the climate response to an external perturbation are referred to as climate feedbacks. Climate sensitivity estimates depend critically on radiative feedbacks associated with water vapor, lapse rate, clouds, snow, and sea ice, and global estimates of these feedbacks differ among general circulation models. By reviewing recent observational, numerical, and theoretical studies, this paper shows that there has been progress since the Third Assessment Report of the Intergovernmental Panel on Climate Change in (i) the understanding of the physical mechanisms involved in these feedbacks, (ii) the interpretation of intermodel differences in global estimates of these feedbacks, and (iii) the development of methodologies of evaluation of these feedbacks ( or of some components) using observations. This suggests that continuing developments in climate feedback research will progressively help make it possible to constrain the GCMs' range of climate feedbacks and climate sensitivity through an ensemble of diagnostics based on physical understanding and observations.