Forced temperature changes contaminate a natural variability constraint on climate sensitivity

Journal Article · 31 October 2018 · Nature (London)

DOI: https://doi.org/10.1038/nature25450 · OSTI ID:1477151

Po-Chedley, Stephen ^[1]; Proistosescu, Cristian ^[2]; Armour, Kyle C. ^[3]; Santer, Benjamin D. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2. Univ. of Washington, Seattle, WA (United States). Joint Inst. for the Study of the Atmosphere and the Ocean
3. Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences and School of Oceanography

A paper by Cox et al. introduces Ψ, “a theoretically informed metric of global temperature variability”, which scales with equilibrium climate sensitivity (ECS) across 16 General Circulation Models (GCMs). They report that Ψ provides a strong constraint on ECS, ruling out both high and low values. Our analysis shows that this constraint is sensitive to the GCMs considered, primarily reflects forced climate response rather than climate variability, and does not narrow uncertainty in ECS. It is therefore premature to rule out the possibility of large ECS values.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1477151
• Report Number(s): LLNL-JRNL-748281; 933072
• Journal Information: Nature (London), Journal Name: Nature (London) Vol. 563; ISSN 0028-0836
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United States
• Language: English