New Perspectives on CO2 Radiative Forcing

CO2 radiative forcing has been well studied and relatively well simulated for decades. Recent years, however, have seen a *deepening* of our understanding of CO2 forcing, largely facilitated by a simplified analytical model of CO2 forcing in which CO2 forcing arises from the temperature contrast between the stratosphere and surface/lower atmosphere. We present the basic of this model, and then highlight recent work applying this model to better understand various aspects of CO2 forcing, including its state dependence, logarithmic scaling, quantum-mechanical foundations, and (perhaps most notably) its inter-model spread.