Suppressed Late‐20th Century Warming in CMIP6 Models Explained by Forcing and Feedbacks

For the 1960–2000 period, latest generation of climate models (Coupled Model Intercomparison Project Phase 6 [CMIP6]) shows less global mean surface temperature change relative to pre-industrial than that seen in observations. In contrast, previous (CMIP5) performed well over this period. It has been hypothesized suppressed late-20th Century warming CMIP6 is caused by a stronger aerosol forcing. However, we find be only part story. Not forcing marginally more negative compared CMIP5, greenhouse gas also weaker CMIP5. These differences are amplified sensitivity between CMIP5 and ensemble, which leads both cooling 1960–1990 induced from 1990, returning post-2000 toward observed level.