Pervasive Warming Bias in CMIP6 Tropospheric Layers

Earth and Space Science

R. McKitrick¹  J. Christy² 

[1] Department of Economics and Finance University of Guelph Guelph Ontario Canada;Earth System Science Center University of Alabama in Huntsville Huntsville AL USA;

关键词: troposphere;    global warming;    climate model testing;    trend estimation;    climate sensitivity;   

DOI  :  10.1029/2020EA001281

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown