The relationship between the carbon dioxide concentration and selected mechanical properties were investigated on solid wood specimens. The carbon footprint is showing increasing tendency in the region where the examined trees were grown. Hence, the goal was to find any contact between this effect and selected mechanical properties of wood. The samples in this preliminary study were taken only from Norway spruce (Picea abies) and English oak (Quercus robur) trees, which were grown in Hungary. Compressive strength and hardness were determined from the pith to the bark in order to find any changes in the mechanical properties, which can be contact with the increased carbon dioxide concentration. The experiment shows that just in case of English oak has any relationship between the compression strength and the sample position in the stem. This connection can be explained with anatomical features, too. Therefore, added investigations are necessary (e.g. radial density profile determination).