Rheia: one final try at ground-up worldbuilding

[MrBragg]

thermohaline circulation, volcanic activity, solar flares , strenght of solar luminance, albedo reflection , possible meteoric impacts, biological activity density, axial tilt and planet orbit , greenhouse gases densities, in particular co2 concentration, carbon dioxide levels absorbed by oceans relative to its mass, vegetation land cover

A number of these actually are taken into account during the simulation. Solar flux (and star temp), albedo of different land types, vegetation cover, obliquity / eccentricity, and gas concentrations / pressures are all treated. There are certainly simplifications and systematic errors in the model outputs, but in terms of variables that get treated it does quite a thorough job and allows the effects of any one of these variables to be isolated and varied.