Scenarios for the Altamira cave CO₂ concentration from 1950 to 2100

A data-driven approach insensitive to the initial conditions was developed to extract governing equations for the concentration of CO₂ in the Altamira cave (Spain) and its two main drivers: the outside temperature and the soil moisture. This model was then reformulated in order to use satellite observations and meteorological predictions, as a forcing. The concentration of CO₂ inside the cave was then investigated from 1950 to 2100 under various scenarios. It is found that extreme levels of CO₂ were reached during the period 1950-1972 due to the massive affluence of visitors. It is demonstrated that it is possible to monitor the CO₂ in the cave in real time using satellite information as an external forcing. For the future, it is shown that the maximum values of CO₂ will exceed the levels reached during the 1980s and the 1990s when the CO₂ introduced by the touristic visits, although intentionally reduced, still enhanced considerably the micro corrosion of walls and pigments.