Almost all the terras and oceanias with organic (even multicellular) life on them have carbon dioxide as the main component in their atmospheres. Why? That does not make sense. On Earth, plants consume carbon dioxide through photosynthesis, but on those exoplanets (even some planets that are mostly green on their lands), it seems that process doesn't work at all. To be honest, I never seen any life-supporting planet with CO2 less than 50% in their atmospheres in SpaceEngine before.