Carbon dioxide in CESM2 is bigger than other models in CMIP6

[ysjoo]

I find that co2 in CESM2 is bigger than other cmip6 models.
1st figure is CO2 in GFDL-ESM4, 2nd figure is CO2 in CESM2, 3rd figure is CO2 in MRI-ESM2-0
I compared models, then CO2 of CESM2 is bigger than others.
But, co2mass of CEMS is same other models.
Why CO2 of CEMS is bigger than others?
CESM2 LENS is also big.