Les calculs radiatifs du GIEC ne tiennent pas compte des nuages.

Sachant que là où il y a des nuages, ils bloquent 100% des IR.
Source : WG1AR5_Chapter08_FINAL.pdf §8.3.1 page 676
"Most intercomparison studies of the RF of GHGs are for clear-sky and
aerosol-free conditions; the introduction of clouds would greatly com-
plicate the targets of research and are usually omitted in the intercom-
parison exercises of GCM radiation codes and LBL codes (e.g., Collins
et al., 2006; Iacono et al., 2008). "