The Tree Debate
Utilising tree sequestration as a method of creating carbon offsets has come under some media and industry fire. Here we list the common accusations, and provide a rebuttal in relation to Forests NSW NGACs.
Trees don't permanently remove carbon dioxide from the air
That is true, individual trees do not, and they run the risk of dying or being burnt down. When you buy an NGAC, you are paying for management of an entire forest, not for individual trees. The certification provides a legal guarantee that your carbon dioxide will remain sequestered for at least 100 years. This goes beyond Kyoto, which only requires 30 years.
Trees grown outside the tropics actually heat up the planet
Australian forests have a net cooling effect on climate, independent of the carbon they are removing from the carbon cycle, due to the evaporative cooling effects brought on by evapotranspiration. Dr. Sophie Bickford did some research into the claim that trees heat up the planet you can find the results here:
Is there enough water to sustain these trees in Australia?
Native trees have evolved to flourish in their local conditions. More than just flourish, they evolved to help balance their environment, for example native trees help combat soil salinity and deter errosion.
Aren't these trees already in the ground?
The carbon credits you purchase today are a result of sequestration in trees that are already in the ground. This is important because, if they were not then there would be no proof that 1 tonne of carbon dioxide was sequestered for each carbon credit sold. Further, trees can take 5 years or more to become net sequesterers (prior to this they can be net emitters of carbon dioxide). Hence, in order to be able to sell these carbon credits there must be incontravertible proof that the sequestration has occurred and will remain.
If the trees are already in the ground how can you prove additionality?
Under NGAC certification (and under Kyoto Standards) the trees must have been planted on land that was cleared prior to 1990. Hence all the carbon pools are new forests.
Why trees are great:
- Trees are the only proven method we currently have for actively removing carbon dioxide from the air. Geosequestration is still a dream. To solve the global warming problem we need to put back the trees as well as implement carbon saving and renewable energy schemes.
- Trees have many additional benefits. Native trees provide homes for native animals and assist with combating soil salinity.
Not all tree planting schemes are great
- Native monoculture and non-native forests are not good for our ecosystem. Don't solve one problem by creating another (Forests NSW carbon pools consist of trees that are native to the area in which they are planted).
- Uncertified tree planting schemes provide no guarantees of permanence, or that you are actually getting the sequestration you are paying for.