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Title: Context for interpreting equilibrium climate sensitivity and transient climate response from the CMIP6 Earth system models

Journal Article · · Science Advances
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [1]; ORCiD logo [5]; ORCiD logo [6]; ORCiD logo [7]
  1. National Center for Atmospheric Research, Boulder, CO (United States)
  2. Met Office Hadley Centre, Exeter (United Kingdom)
  3. Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany); University of Bremen (Germany)
  4. Canadian Centre for Modelling and Analysis, Victoria (Canada)
  5. University of Arizona, Tucson, AZ (United States)
  6. PCMDI, Livermore, CA (United States)
  7. Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany)

For the current generation of earth system models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6), the range of equilibrium climate sensitivity (ECS, a hypothetical value of global warming at equilibrium for a doubling of CO2) is 1.8°C to 5.6°C, the largest of any generation of models dating to the 1990s. Meanwhile, the range of transient climate response (TCR, the surface temperature warming around the time of CO2doubling in a 1% per year CO2increase simulation) for the CMIP6 models of 1.7°C (1.3°C to 3.0°C) is only slightly larger than for the CMIP3 and CMIP5 models. Here we review and synthesize the latest developments in ECS and TCR values in CMIP, compile possible reasons for the current values as supplied by the modeling groups, and highlight future directions. Cloud feedbacks and cloud-aerosol interactions are the most likely contributors to the high values and increased range of ECS in CMIP6.

Research Organization:
University Corporation for Atmospheric Research, Boulder, CO (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
89243018SSC000007; AC52-07NA27344
OSTI ID:
1670779
Alternate ID(s):
OSTI ID: 1785916
Report Number(s):
LLNL-JRNL-812553
Journal Information:
Science Advances, Vol. 6, Issue 26; ISSN 2375-2548
Publisher:
AAASCopyright Statement
Country of Publication:
United States
Language:
English

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  • Knutti, Reto; Rugenstein, Maria A. A.
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Cited By (5)


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