What it is
Cloud radiative feedback is the largest single source of uncertainty in climate projections. The authors built a pattern-based analytical framework that ties the percentage change in tropical cloud fraction to sea surface temperature warming patterns, then used recent observations to constrain it in two stages, with the SST pattern effect explaining 79% of the remaining model spread. The result is a total cloud feedback of 0.49 plus or minus 0.27 W m-2 K-1 and an equilibrium climate sensitivity of 4.08 plus or minus 0.97 K.
Why it matters
Because clouds dominate the disagreement between climate models, tightening their feedback tightens everything downstream. This observationally grounded constraint reduces intermodel cloud-feedback uncertainty by 59% and surface-warming uncertainty by 33%. The central climate sensitivity of 4.08 plus or minus 0.97 K sits toward the higher end of the accepted range, implying more warming per unit CO2 than mid-range estimates.
Underlined numbers link to their source. Every metric and quoted figure is listed under Sources and data below.
Filed underclimate, cloud feedback, climate sensitivity, emergent constraint, SST patterns