Acting as an enormous "carbon sink", trees soak up carbon dioxide from the air, producing life-giving oxygen in return. In fact, a medium-sized tree generates the same amount of oxygen
as each one of us needs to breathe.
In a tree, 'breathing' takes place in the leaf. Chlorophyll (the substance causing the green colour) absorbs the CO2 and uses it along with water to dissolve minerals taken up
through the roots. After the chemical reaction is completed, the leaf releases oxygen and water vapor through its pores.