CLIM SEN

This selection specifies which of four possible values of the climate sensitivity determines the global warming curve which SCENGEN uses to scale the GCM patterns of climate change. The climate sensitivity is defined as the equilibrium (or eventual) global-mean warming that occurs in response to a unit radiative forcing change. It is commonly expressed in terms of the response to CO2 forcing alone, as the equilibrium warming for a doubling of the CO2 concentration (deltaT2x).

The four options shown by SCENGEN relate back to values used by MAGICC and are: high (deltaT2x = 4.5degC), mid (2.5degC), low (1.5degC) and user (user-defined). If the user did not make a user selection for the climate sensitivity in MAGICC, then the user-defined value will be 2.5degC, the mid-range value specified by IPCC. As the user clicks on different values of this parameter, the global-mean deltaT value (highlighted in red), which corresponds to the actual warming for the selected time interval, will change accordingly.

Note that the User climate sensitivity can only be selected when the User set of MAGICC PARAMETERS has been selected first.