Franc Model

a framework for risk analysis of abrupt climate change


FRANC is a combined economic, climate, and carbon cycle model based on the DICE model by William Nordhaus. It is written in Fortran 90 with MPI to create an open source utility with the versatility to run on single or multiple processors. FRANC can use either the original climate module included in DICE or the combined climate/carbon cycle/MOC module SNEASY, a Simple Nonlinear EArth SYstem model. The economic/climate model is coupled with the evolutionary global optimization package DE, Differential Evolution.


  • Two versions are available:
    1. DICE with its original climate model
    2. DICE + SNEASY
  • Time step is variable, not limited to decadal steps.
  • Evolutionary optimization scheme handles nonconvex solution space.
  • Parameter ranges allow analysis of uncertainty.
  • Multiple states of the world show climate bifurcations.


FRANC is distributed under the GNU General Public License.


Download version 1