Studies related to the evolution of exoplanet atmospheres are carried out in the frame of the COROT mission and are also related to the scientific precursor studies dedicated to the search of terrestrial exoplanets and the characterisation of their atmospheres by ESA's Darwin and NASA's Terrestrial Planet Finder (TPF) in the next decade. It is of great importance for the COROT team to know which kind of exoplanets the observatory will discover and if possibly detected big terrestrial exoplanets (COROT limitations: >2 Earth radii size; <0.5 AU orbital distance) may evolve a biosphere. The methods applied at IWF are derived from comparative planetology, which belongs to the scientific experience and modelling obtained from studies on Venus, Earth, Mars, Titan, and the giant planets. The main focus in this research addresses open questions of the stability of planetary atmospheres and the evolution of planetary water inventories.