Sea Ice–Albedo Feedback and Nonlinear Arctic Climate Change - Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications - page 110

Plate 1. Schematic of the top-of-atmosphere absorbed shortwave radiation (red) and OLR (blue) as a function of surface
temperature. The solid red absorbed shortwave profile is stable because the surface albedo transition occurs over a range
of temperatures greater than ΔT C and so is less steeply sloped than the OLR curve. The dashed profile is unstable since
the transition occurs over a smaller range of temperatures, leading to a region where increased shortwave absorption
exceeds OlR cooling as temperature increases (a net positive feedback). Within this temperature range is a “forbidden”
zone where no equilibrium is possible under changes in forcing. (Forcing changes can be thought of as moving the blue
OLR curve left or right without changing its slope.)