Carbon offset companies sell you trees, that will absorb CO2 from the atmosphere for as long as the trees are alive. This is of cause a good thing, but does not equate to being carbon neutral. Young trees absorb little carbon, but the carbon absorption rate accelerates as the trees grow older and matures.

 

Hence, when the carbon offset companies claim that an activity generating 1100 kg (1.1 ton) of CO2 can be made carbon neutral by purchasing 1 tree, the activity is firstcarbon neutral after a very long time - assuming that the tree survives 80+ years.

 

We therefore have a delay before the carbon neutral state is achieved. If the activity generating 1100 kg of CO2 is repeated the following year and another tree planted, and so on, we actually find that there over a 100 year period is a net gain of CO2. Carbon emissions will continue to rise because the trees are unable to keep up with the level of emissions.

 

Carbon-info.org has developed a model that illustrates this point. If a person produces 1100 kg of CO2 each year during a 100 year period, and each year purchases a tree (as calculated by carbon offset companies) to absorb the carbon dioxide, there will actually over the 100 year period be a net gain of carbon dioxide in the atmosphere. Not exactly carbon neutral!