Timber housing as a carbon sink?

Over on Treehugger, Warren McLaren wonders about the potential for timber housing to act as a carbon sink, referencing an Australian report (scroll down) on the topic. He writes:

And I remembered a report I saw last month in The Age newspaper that suggested that timber frame houses were excellent carbon sinks. Not a trick that steel can replicate. According to research:

Almost 100 million tonnes of carbon is stored in timber in Australian houses, with about 2 million tonnes of carbon dioxide equivalent added each year as new houses are built ...

That annual addition would absorb about 0.4% of Australia’s total greenhouse gas emissions (as measured in 2006), but has been on the decline as Australian houses have utilised more bricks, concrete, metal and plastics in the past 20 years. The study noted that were more wood used, “annual carbon storage in houses could rise from 1.6 million tonnes in 2008 to 4 million tonnes in 2050.”

He also notes:

The report, entitled “Dynamics of Carbon Stocks in Timber in Australian Residential Housing” does need to be considered with a degree of circumspect, because it was commissioned by industry body, Forest & Wood Products Australia, who obviously have a vested interested in higher timber use.

However, industry influence aside, the researchers at Melbourne University's Department of Forest and Ecosystem Science, and the NSW Department of Primary Industries did collate some intriguing figures. For instance, they calculated that whilst most wood used in houses was historically sourced from Australian native forest or imported timber, these days 80% is derived from domestic softwood plantations.