Fo and δT are, respectively, the flux change at the top of the atmosphere, and the global surface air temperature change after the forcing is introduced with SST and SI fixed. Fo is the "quasi forcing" of Rotstayn and Penner. λ is the equilibrium climate sensitivity. Thus the fixed sea surface forcing, Fs, allows the tropospheric temperatue and the land surface, as long as the stratospheric temperature, to ajust to the presence of the forcing agent.