Newest batch of climate models (CMIP6) continue to over-predict global watrming

Source:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020EA001281

" Conclusions

The literature drawing attention to an upward bias in climate model warming responses in the tropical troposphere extends back at least 15 years now 

 (Karl et al., 2006). 

 

Rather than being resolved, the problem has become worse, since now every member of the CMIP6 generation of climate models exhibits an upward bias in the entire global troposphere as well as in the tropics. 

 

The models with lower ECS values have warming rates somewhat closer to observed but are still significantly biased upward and do not overlap observations. 

 

Models with higher ECS values also have higher tropospheric warming rates, and applying the emergent constraint concept implies that an ensemble of models with warming rates consistent with observations would likely have to have ECS values at or below the bottom of the CMIP6 range. 

 

Our findings mirror recent evidence from inspection of CMIP6 ECSs (Voosen, 2019) and paleoclimate simulations (Zhu et al., 2020), which also reveal a systematic warm bias in the latest generation of climate models."   

 

(arrows in the chart below are two different measurements of actual warming)