Absorption is mostly by vegetation on land and by the oceans.
Growing trees absorb as much CO2 from the atmosphere as they release when vegetation rots. But the widespread clearing of forests has released substantial amounts of CO2 into the atmosphere. On the other hand, there is increasing eviden ce of a CO2 'fertilisation effect'. Many forests, especially outside the tropics, may now be net absorbers of CO2 because the rising concentrations of CO2 in the air encourage them to grow faster. Scientists have not yet balanced the modern carbon cycle.