The interaction between the vegetation and its physical environment has been a continuous process during the evolution of Earth. Oxigen (O2) and carbon dioxide (CO2) concentrations have varied across the different geologic periods partially due to the activity of photosynthetic organisms. At the moment of appearance of the Cyanobacteria, O2 was very scarce and CO2 concentration was close to 100-fold higher than the concentration at present. Photosynthesis lead to a global increase in O2 and decrease in CO2. The CO2 and O2 level changes may have favored the selection of photosynthetic enzime Rubisco (ribulose-1,5,-bisfosfate carboxilase/oxigenase) with an increasing affinity and selectivity for CO2. In fact, a certain correlation between CO2 and O2 levels present at the moment of appearance of different plant groups that exist today and Rubisco's affinity for CO2. However, the appearance of the carbon concentration mechanisms (whose function is to increase the CO2 concentration around Rubisco to supress photorespiration) had to be earlier than the decrease of CO2 and O2 levels. These mechanisms are not necessary under a high ambient CO2 concentration. Only local variations (not related to the global concentration) in the concentration of CO2 and O2 could explain their appearance. Therefore, the importance of the micro-environment in the evolution of photosynthetic organisms has to be studied and presents a challenge to the global approach of the so-called climatic change.