CICERO Simple Climate Model (CICERO-SCM v1.1.1) – an improved simple climate model with a parameter calibration tool

Abstract. The CICERO Simple Climate Model (CICERO-SCM) is a lightweight, semi-empirical model of global climate. Here we present a new open-source Python port of the model for use in climate assessment and research. The new version of CICERO-SCM has the same scientific logic and functionality as the original FORTRAN version but it is considerably more flexible and open source via Github. We describe the basic structure, improvements compared to the previous FORTRAN version, together with technical descriptions of the global thermal dynamics and carbon cycle components and the emissions module, before presenting a range of standard figures demonstrating its application. A new parameter calibration tool is demonstrated to make an example calibrated parameter set to span and fit a simple target specification. CICERO-SCM is fully open source and available through GitHub (https://github.com/ciceroOslo/ciceroscm).