Observational constraints on mixed-phase clouds imply higher climate sensitivity

TitleObservational constraints on mixed-phase clouds imply higher climate sensitivity
Publication TypeJournal Article
Year of Publication2016
AuthorsTan, Ivy, Storelvmo Trude, and Zelinka Mark D.
JournalScience
Volume352
Number6282
Pages224–227
Date Published04/2016
Abstract

Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations.The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate.We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.

URLhttp://dx.doi.org/10.1126/science.aad5300
DOI10.1126/science.aad5300
Journal: Science
Number: 6282
Volume: 352

Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations.The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate.We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.

DOI: 10.1126/science.aad5300
Year of Publication: 2016
Citation:
Tan, I, T Storelvmo, and MD Zelinka.  2016.  "Observational constraints on mixed-phase clouds imply higher climate sensitivity."  Science 352(6282): 224–227, doi:10.1126/science.aad5300.