Pervasive Warming Bias in CMIP6 Tropospheric Layers
Abstract
The tendency of climate models to overstate warming in the tropical troposphere has long been noted. Here we examine individual runs from 38 newly released Coupled Model Intercomparison Project Version 6 (CMIP6) models and show that the warm bias is now observable globally as well. We compare CMIP6 runs against observational series drawn from satellites, weather balloons, and reanalysis products. We focus on the 1979–2014 interval, the maximum span for which all observational products are available and for which models were run using historically observed forcings. For lower-troposphere and midtroposphere layers both globally and in the tropics, all 38 models overpredict warming in every target observational analog, in most cases significantly so, and the average differences between models and observations are statistically significant. We present evidence that consistency with observed warming would require lower model Equilibrium Climate Sensitivity (ECS) values.
- Authors:
-
[1];
[2]
- Department of Economics and Finance University of Guelph Guelph Ontario Canada
- Earth System Science Center University of Alabama in Huntsville Huntsville AL USA
- Publication Date:
- Research Org.:
- Univ. of Alabama, Huntsville, AL (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- OSTI Identifier:
- 1664589
- Alternate Identifier(s):
- OSTI ID: 1786787; OSTI ID: 1803668
- Grant/Contract Number:
- DE‐SC0019296; SC0019296
- Resource Type:
- Published Article
- Journal Name:
- Earth and Space Science
- Additional Journal Information:
- Journal Name: Earth and Space Science Journal Volume: 7 Journal Issue: 9; Journal ID: ISSN 2333-5084
- Publisher:
- American Geophysical Union (AGU)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; climate sensitivity; trend estimation; climate model testing; global warming; troposphere
Citation Formats
McKitrick, R., and Christy, J. Pervasive Warming Bias in CMIP6 Tropospheric Layers. United States: N. p., 2020.
Web. doi:10.1029/2020EA001281.
McKitrick, R., & Christy, J. Pervasive Warming Bias in CMIP6 Tropospheric Layers. United States. https://doi.org/10.1029/2020EA001281
McKitrick, R., and Christy, J. Wed .
"Pervasive Warming Bias in CMIP6 Tropospheric Layers". United States. https://doi.org/10.1029/2020EA001281.
@article{osti_1664589,
title = {Pervasive Warming Bias in CMIP6 Tropospheric Layers},
author = {McKitrick, R. and Christy, J.},
abstractNote = {The tendency of climate models to overstate warming in the tropical troposphere has long been noted. Here we examine individual runs from 38 newly released Coupled Model Intercomparison Project Version 6 (CMIP6) models and show that the warm bias is now observable globally as well. We compare CMIP6 runs against observational series drawn from satellites, weather balloons, and reanalysis products. We focus on the 1979–2014 interval, the maximum span for which all observational products are available and for which models were run using historically observed forcings. For lower-troposphere and midtroposphere layers both globally and in the tropics, all 38 models overpredict warming in every target observational analog, in most cases significantly so, and the average differences between models and observations are statistically significant. We present evidence that consistency with observed warming would require lower model Equilibrium Climate Sensitivity (ECS) values.},
doi = {10.1029/2020EA001281},
journal = {Earth and Space Science},
number = 9,
volume = 7,
place = {United States},
year = {2020},
month = {9}
}
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