In understanding the climate dynamics and to comprehend and analyse the global carbon cycle several models have been developed during the years, most of them are quite complex, even though there are also mid-complexity models (MMx, x=1,2,3,4) like MAGICC and FAIR. The formers are middle complex models, which are tuned with respect to more complex models (Global circulation models). This work shows the results obtained with a simpler model (SMx, x=1,2) considering actual measured data and formulating proper state equations. Through all the model calculations only yearly averages will be considered due to an interest in long-term dynamics, seasonal and daily/nightly variations are cancelled.