Qualitative model of the long-term carbon cycle: the rise of the vascular plant during the Paleozoic period and its dramatic effect on our atmosphere

By essence qualitative modelling is of great interest for education in science as mentioned in many papers. In line with this statement modelling the processes that ought to be taught to students, such as the ones involved in the large biochemical cycles, is essential. This paper presents a set of four models to support both the modelling of the longterm carbon cycle and the explanation of a critical event in the history of our planet, namely the large drop of the atmospheric CO2 during the second part of the Paleozoic period (450-300 million years ago). The main processes are captured in a library of model fragments. Different clustering of model fragments allows for building qualitative models with different scope. In collaboration with domain experts this paper presents the essential processes to generate a consistent explanation of the phenomenon.