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Carbon and Forests: The Big Picture

By Jerry Vanclay

Energy generated by burning forestry waste and other biomass sources should be recognised as renewable.

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As Australia prepares to pay for its carbon emissions, the challenge is to ensure wise behavioural change rather than “game-playing”. There is a danger that advocates for forests will over-emphasise their capacity for carbon farming, to the detriment of the overall carbon balance.

The two major pools of carbon – in the biosphere and the geosphere – have very different characteristics in terms of cycle time, natural ebb and flow, and reversibility.

In the biosphere – trees, plants and soil – carbon cycles naturally. The volume of carbon cycled globally each year – largely associated with the Northern Hemisphere winter – is about ten times anthropogenic emissions. Trees grow for decades and sometimes centuries, eventually dying to release their carbon. Any carbon flows from the biosphere are reversible because new forests can be created efficiently.

Carbon in the geosphere – oil and coal – tends to remain sequestered for millennia unless it is unearthed by human activity, after which it permanently enters the biosphere. The alternative – commercial-scale geosequestration – is an aspiration rather than a reality. My view is that carbon capture and storage is the new perpetual motion machine: the idea that we can mine coal, burn it and bury the CO2 emissions underground with an efficiency better than a carbon tax is, at this stage, pure fantasy.

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The full text of this article can be purchased from Informit.

Jerry Vanclay is Professor of Sustainable Forestry and Head of the School of Environmental Science and Management at Southern Cross University, Lismore.