The climate sector of the FeliX model integrates the results of all other sectors and translates them into global average temperature change in the atmosphere and oceans.
The model divides these systems into five separate reservoirs of heat and carbon (one atmospheric/upper ocean + four deep oceanic layers), each of which is in thermal contact with the reservoir layers above and below it. Each layer is characterized by a heat capacity (C, Wikipedia) and a heat transfer coefficient (h, Wikipedia), which determine the propagation of heat through the total system. These parameters are defined and discussed in the FeliX Model Report [pp. 84-92].
The radiative forcing due to CO2, N2O, CH4, and other greenhouse gases is calculated from the atmospheric concentration of each of these pollutants. Radiative forcing from carbon dioxide is based on endogenous predictions, while all others are set to RCP 4.5. Total atmospheric radiative forcing is shown above at right along with RCP projections and historical data from IIASA's RCP database.
The heat trapped by greenhouse gases is either transferred to deep ocean layers or results in global atmospheric temperature change. The plot below projects atmospheric temperature change relative to the global preindustrial average along with historical data from the NASA Goddard Institute for Space Studies (GISS) and the Hadley Center's Climactic Research Unit. For comparison, the range of warming associated with each RCP is shown at right. Historical data is used to calibrate the model, while RCP projections are used for scenario validation.