AUSTRALIA: Greenhouse deal could put trees in black
Copyright 2001 The Weekend Australian
October 20, 2001
By Asa Wahlquist
TREE planting could become a vital part of the Australian economy if the federal Government signs the Kyoto accord, agreeing to limit our production of greenhouse gases.
The greenhouse effect is so-called because increased levels of carbon dioxide blanket the atmosphere, causing it to heat up in the same way glass causes a greenhouse to warm.
The major causes of greenhouse gases in Australia are, in order, electricity generation, agriculture, land clearing and transport fuels. Increased levels of carbon dioxide and other gases are forecast to lead to a temperature increase of between 1C and 6C over the next 70 years. The expected impacts include increased climate variability and reduced rainfall in parts of Australia.
Plants take up, or sequester, carbon dioxide, storing it in their leaves, branches, trunks and roots. Old trees help keep it out of the atmosphere.
On the other hand, clearing or burning timber releases carbon dioxide back into the atmosphere.
Under the Kyoto protocol, which at this stage is not legally binding, trees planted since 1990 would be included in the targets. The protocol also includes basic rules for greenhouse sinks -- such as revegetation, forest management or grazing land management -- to reduce or offset emissions.
Those sinks would become part of a system of carbon, or emission, trading. Emitters of greenhouse gases might be required to buy carbon credits to offset their emissions.
The Tokyo Electric Power Company has signed an agreement with State Forests of NSW to establish a forest for carbon sequestration over a 10-year period.
The initial agreement is for 1000 hectares of forest, with a target area of between 10,000 and 40,000 hectares, planted on land leased from private landholders.
A formal commonwealth market in carbon trading has not yet been established.
Likely guidelines on eligible plantings include trees that are potentially over two metres tall, in patches greater than one hectare, and with a foliage spread of 20 per cent of the ground area; on land that was cleared before January 1990; and vegetation established by human intervention, which includes regeneration from natural sources.
It is likely that large farm shelter belts and orchards (but not vineyards) planted since 1990 (on land cleared before 2000) are likely to be eligible. Planting trees on land cleared after January 2000 and the replacement of woody weeds and existing forests would not be eligible.
The Australian Greenhouse Office has developed a carbon accounting method that can predict actual sequestration, which can vary according to the type of tree, its age, and the climate and soil.
Most trees grow slowly at first, and sequester carbon fastest between about 10 and 20 years. They continue to sequester carbon, although much more slowly, when they are older, until growth is balanced by decay.
Actively growing Australian forests can sequester carbon at between 3.5 and 35 tonnes of carbon dioxide per hectare each year on average for the first 30 years after planting.
The Australian Greenhouse Office has mapped the carbon sequestration potential for different areas of Australia, and has graphed the carbon sequestration for forests with different potentials. The office says any arrangement for the sale of carbon would require accurate carbon measurements over time.
Detailed instructions for such measurements will be posted later this year under the Bush for Greenhouse project's field measurement procedures for carbon accounting program, on the Australian Greenhouse Office website:
www.greenhouse.gov.au