text: where H.is the heat content of the land-ocean-atmosphere system . Equation 1-1 describes the change in the heat content where f is the radiative forcing at the tropopause, T is the change in surface temperature in response to a change in heat content, and is the climate feedback parameter (Schneider and Dickinson, 1974), also known as the climate sensitivity parameter, which denotes the rate at which the climate system returns the added forcing to space as infrared radiation or as reflected solar radiation (by changes in clouds, ice and snow, etc.).?