The case for using trees to offset fossil carbon dioxide has been that they will buy us time. That still is relevant
today and more so if New Zealand invests in a transition to a circular bioeconomy says Scion CEO Dr Julian Elder in
response to the Farms, forests and fossil fuels report released yesterday.
“Now is the time to be having the serious conversation about a new economy and build a national consensus on how our
country can grow its way to a sustainable, bio-resourced future.
“Forests, as part of a suite of tools, will always play a key role in removing carbon dioxide from the atmosphere. They
are something that we can get on with while we as a nation decide how to best reduce fossil emissions through developing
technologies and substitution options to reduce emissions.
“Forests store carbon for the life of the tree and thus are only part of the solution, yet harvested forests continue to
help reduce greenhouse gas emissions through the life of wood products like buildings and furniture,” he says.
Using sustainable wood in construction contributes to climate change mitigation. The manufacturing and processing
emissions for wood are lower than those of concrete, bricks and steel responsible for between eight and 15 per cent of
greenhouse gas emissions worldwide. Wooden materials extend carbon storage from the forest to the building – for
decades, or even centuries – while replanted trees continue the carbon sequestration process.
Innovative engineered wood products, such as cross laminated timber, allows bigger and taller wooden buildings to be
constructed and store more carbon. It is calculated that one cubic metre of cross-laminated timber stores 730 kilograms
of carbon.
It is important for the ‘built environment’ to balance its greenhouse gas emissions. A Scion study showed that Auckland
Council could achieve their emissions reduction target 25 per cent faster than
planned by applying ‘urban equilibrium’ principals (where timber buildings act like carbon pools) to their forecast
growth.
Using massive timber technologies, such as in large and tall buildings going up around the world, would provide other
benefits too. For example, substituting building materials would reduce manufacturing emissions by 38 to 65 per cent,
and prefabrication would reduce construction emissions by up to 13 per cent.
Other emissions savings would be made at end-of-life by landfilling the timber waste or using it as a substitute for
fossil fuels to generate energy. Scion research shows that if New Zealandswapsjust30 per centof ourpetroleum-basedliquid
fuel forcleaner, greenerbiofuel made from renewable feedstocks like fast growing trees,we would reduce greenhouse gas
emissions to the equivalent oftaking half the cars off the road.On the East Coast alone this would involveplanting one
and a half times more trees and investing$1billion into infrastructure,creating1,000 new jobs.