The Age, May 24, 2011
STOPPING logging in old-growth forests, particularly in southern Australia, is one of the best ways of making timely cuts to Australia's greenhouse gas emissions, according to the Climate Commission's first report.
Established forests store much more carbon dioxide than plantations, so cutting them down releases more heat-trapping gases, it concluded.
''In general, forests with high carbon storage capacities are those in relatively cool, moist climates that have fast growth coupled with low decomposition rates, and older, complex, multi-aged and layered forests with minimal human disturbance,'' the report said.
''This framework underscores the importance of eliminating harvesting of old-growth forests as perhaps the most important policy measure that can be taken to reduce emissions from land ecosystems.''
If Australia is to stabilise and reduce its emissions in time to make a contribution to global efforts to slow climate change, storing more carbon in the landscape is classified as a useful interim measure while the nation weans itself off fossil fuel-based electricity production. Ending logging ''yields some quick gains while the slower process of transforming energy and transport systems unfolds''.
Over the past century, between 15 and 20 per cent of global carbon dioxide emissions were released by chopping down forests and clearing scrub, the report notes, citing the CSIRO and international research.
In Australia, recent estimates show that eucalyptus forests in cooler regions such as southern NSW, Victoria and Tasmania have a carbon-carrying capacity of about 640 tonnes a hectare. In their natural condition, about 33 billion tonnes of CO2 can be stored in these forests, but about 56 er cent of them have been logged.
If the logged areas were allowed to grow undisturbed again, about 7.5 billion tonnes of additional carbon dioxide could be stored in them again.