As soon as a tree starts to grow, it absorbs carbon dioxide and thus acts against the climate crisis. Its biomass consists of about 45% of the atom carbon, i.e. ‘C’. The CO₂ molecule consists of one carbon atom and two oxygen atoms with a molecular weight of 44, because C has a molecular weight of 12 and oxygen one of 16. When a tree has reached a biomass of 1,000 kg, it has converted 1,650 kg of CO₂ from the atmosphere through photosynthesis (1000×0.45×44/12).