Figure 4.

Estimates of global mean climate feedbacks from observations of interannual variability (blue triangles), from CMIP5 and CMIP6 model simulations of global warming in response to an abrupt CO₂ quadrupling (colored circles—orange: Vial et al., 2013; green: Caldwell et al., 2016; red: Colman & Hanson, 2017; and purple: Zelinka et al., 2020) and from this assessment (black squares). Error bars on climate model feedback estimates span the one standard deviation range across models. Observational estimates are derived using a combination of ERA‐Interim meteorological fields and CERES TOA radiative fluxes (Loeb et al., 2009) covering the period March 2000 to December 2010 (Dessler, 2013). Error bars on the observational estimates are 1‐sigma uncertainties, accounting for autocorrelation. Individual feedbacks are computed by multiplying temperature‐mediated changes in relevant fields by radiative kernels (Huang et al., 2017; Shell et al., 2008; Soden et al., 2008). Error bars on values from this assessment correspond to 1‐sigma uncertainties. Note that Planck feedback estimates are offset by 2.5 W m⁻² K⁻¹ from their actual values in order that they appear within the plot range.