Forests are an important carbon sink, conserving native forests rather than llogging them results in reduced carbon emissions. Oldgrowth forests store the most carbon. Research has found that forests converted to plantation
are expected to take more than 50 years to recover only 50% of their full carbon carrying capacity. It would take at least 150 years for a forest’s carbon carrying capacity to return to greater than 90% of its pre-logged levels.
Carbon Dioxide emissions in Tasmania annually due to logging and land-clearing are 25.5million tonnes, this is equivalent to the emissions of 6.2 million cars with an estimated social cost of $2.1billion.
“The loss of natural forests around the world contributes more to global emissions each year than the ransport sector. Curbing deforestation (landclearing) is a highly cost-effective way to reduce emissions;
large scale international pilot programmes to explore the best ways to do this could get underway very quickly.”
Stern Review into Climate Change, October 2006
(Extracted from Tasmanian Greens submission on Gunns’ proposed Pulp Mill)
CARBON IN FORESTS
Forests sequester carbon slowly but accumulate very large stores over long periods, often hundreds of years. his carbon is stored in the above ground wood, the roots and in the soil as organic matter. Much of this carbon is released to the atmosphere when the forest is logged. A new forest will gradually replace this lost carbon, but a orest that is regularly harvested will have on average much less carbon than an undisturbed forest
A study examining the effects of logging Mountain Ash (Eucalyptus regnans) in Victoria and Tasmania by Dean et l. (2003) showed that Mountain Ash forests can store up to 1,200 tonnes of carbon per hectare when fully ature. By contrast, re-growth forests on 80 year rotations were found to store on average around 400 tonnes of arbon per hectare.. It has been suggested that roughly 267 tonnes of carbon per hectare will be lost from E.delegatensis and E. obliqua forests when they are converted from mature to regrowth forests.
(Roxburgh, S.H. et al, 2003)
THE NEED TO ACCOUNT FOR CARBON LOSSES
Australia accounts for its greenhouse gas emissions according to the rules established by the Kyoto Protocol to he United Nations Framework Convention on Climate Change. The rules stipulate that when land that was orested in 1990 is converted to an alternative land-use (including a plantation), the resultant greenhouse gas missions must be added to the national inventory.It is reasonable to assume that Australia will adopt either a carbon tax or an emission trading system to impose a rice on greenhouse gas emissions, as the European Union has done. Once this occurs, emissions from any source will impose a cost on the economy. For example, increases in emissions from native forest logging will need to be offset by reduced emissions from other sectors, such as electricity generation.
QUANTITY AND COST OF EMISSIONS
It has been estimated approximately 200,000 hectares of native forest will be cleared over 25 years as feedstock or Gunns’ proposed Pulp Mill. 200,000 hectares each eventually emitting roughly 267 tonnes of carbon yields a total of about 53.3Mt of carbon, equivalent to 195.5Mt of CO2. Permits to emit this quantity of CO2 in Europe today would cost at least 4.5 billion Australian dollars.It is clear that there is a risk that greenhouse gas emissions from native forest logging will pose a significant long term cost on the wider Australian economy.
