A tree makes its food by taking in Carbon Dioxide from the air and water from the earth. Sunlight or solar energy then is required by the leaves for the preparation of the food. In turn the tree then gives off oxygen or the air we breathe.
By taking in Carbon Dioxide a tree stores Carbon, The stored Carbon is retained (even after it is milled into a timber product) until the wood decays and the Carbon is partially emitted, or is disposed of, through actions such as burning.
Bush fires for example are bad for the environment because some of the stored Carbon in the trees is emitted into the atmosphere.
Accordingly, it can be argued timber frames and other associated timber products in Australian homes can help fight climate change because these houses store lots of Carbon research has shown. Almost 100 million tones of Carbon is stored in timber in Australian homes, with about 2 million tonnes of Carbon Dioxide equivalent added each year as new houses are built, according to the research.
Given the longevity of housing, the average life of a house is 61 years, this sector has the greatest potential for long-term storage of Carbon in harvested wood products. “If the forest is sustainably managed and maintained, then the Carbon removed from the forest in products or released during harvesting is replaced through new growth” the researches said.
Historically, most wood used in houses was sourced from Australian native forest and imported timber, but 80% now comes from domestic softwood plantations.
However, despite the positive effect timber products in houses has on the environment, the annual extra Carbon stocks have declined over the last 20 years as more bricks, concrete, metal and plastics have been used to build houses. Unfortunately this situation is not aided by the way authorities treat timber under the 5 star energy (soon to be 6 stars) rating conditions, where the building fabric is rated only. The timber industry maintains a more holistic rating should be used, ie including the production of all building products used. Conversely, the study found if more wood was used, annual Carbon storage in houses could rise from 1.6 million tonnes in 2008 to a projected 4 million tones in 2050.
It is interesting to note and somewhat of a paradox, the federal government intends to argue for the inclusion of Carbon in wood products at the Copenhagen climate talks later this year, however, when it comes to energy ratings it is not considered at all.