Climate

Description
Shows the impact of changes in atmospheric concentrations of key greenhouse gases on the earth's global mean temperature (GMT).

Input variables

* Atmospheric concentrations of CO2 (from Carbon cycle module) * Atmospheric concentrations of NH4 (from Other greenhouse gases module) * Atmospheric concentrations of NO2 (from Other greenhouse gases module)

Key assumptions
The climate module is based on Fiddaman's FREE model. FREE took its climate assumptions without modification from the Dynamic Integrated model of Climate and the Economy (DICE), which is described in detail by Nordhaus (1994). DICE's climate module, in turn, was adapted from a prior model developed by Schneider and Thompson (1981).

The module assumes that warming occurs from three primary factors:

* Radiative forcing (RF) from atmospheric CO2 A doubling of atmospheric CO2 concentrations from pre-industrial levels is assumed to lead to an increase in mean global temperature (MGT) of 3 degrees Celsius (for more detail, see PCC TAR WG1, 2001, Table 6.2) * Radiative forcing from atmospheric NH4 and NO2 * Other factors, as described by Hansen et al. (2005), which are assumed to be exogenous (see Forcings in GISS models for a brief summary)

The module also takes into account heat transfer from the atmosphere and surface ocean to the deep ocean and cooling from outbound long wave radiation.

The assumptions of the climate module are described in greater detail in C-ROADS Simulator Reference Guide.

Output variables

* Increase in global meant temperature (GMT) above baseline year (feeds into Sea level rise module)