Fig. 2: The spatial extents and magnitudes of the trends.
Cumulative area within the North Atlantic plus Northeast Pacific regions (Fig. 1) for which the decadal trend of the cloud radiative effect (CRE) falls between nil and the value indicated on the abscissa (A). The trends of the sea surface temperature (SST, B) and cloud droplet number concentration (Nd, C) in these locations are also shown. The black line corresponds to the observational data sets as described in “Observed cloud trends”. The gray lines refer to results from simulations with 24 Coupled Model Intercomparison Project Phase 6 (CMIP6) Earth System Models, which includes a subset of models that provided Nd. Results from simulations with the model CanAM5.1-PAM are shown in red, which incorporates the Twomey and Albrecht effects (Earth System Model simulations). Thick lines refer to ensemble mean results and dashed lines to the individual ensemble members. See “Observed cloud trends”, “Earth System Model simulations”, and the Supplementary Notes for details.
