It may sound like a simple task. But it wasn’t and still isn’t. The duration of the six-month study eventually stretched to two years because scientists needed to first find the connection between forest carbon balances and the carbon balances of harvested wood products.
The challenge was that there were several wood products with varying lifecycles that were generating many different possibilities. Many assumptions would have a strong impact on the results of the study and scientists had the tough job of narrowing them down in number and arriving at credible robust conclusions.
Sampo Soimakallio, Head of Unit for SYKE, recalls the enormity of the task. “We don’t know for how long the products exist, what different purposes they are used for and what happens to them at the end of life – whether carbon is released or not. We also don't know what wood-based products really substitute in the market,” he lists.
“Even if we know all these, then there are still assumptions required about the carbon balance of harvested wood products and products that are substituted by them. That is difficult to define.”
Once that was defined, scientists began comparing two different systems - one with the wood use under study and a reference system without wood use. The focus of the research was narrowed down to assessing carbon stock changes in products made of wood, and fossil emission substitution due to using wood-based products and fuels instead of non-wood materials and fuels.
Light at the end of the tunnel
By April this year, scientists were able to conclude that it is possible to roughly assess the substitution and carbon storage effects of harvested wood products and wood-based energy caused by production stages at product and company levels.
Forests and forest products contribute to climate change mitigation by sequestering carbon into forests, storing part of the carbon in HWPs and by avoiding fossil-based greenhouse gas (GHG) emissions in substitutions for alternative materials and energy.
But this study reveals that the handling of carbon storage in wood and its substitution effects are intrinsically connected to wood harvested from forests. It also tells us why we need to coherently consider changes in fossil carbon emissions when assessing the climate effects of wood, as well as in carbon stocks in the forests and harvested wood products (HWPs) such as furniture, plywood, paper and paper-like products.
Most importantly, the study provides practical guidelines to conduct annual GHG balance assessments of the temporary carbon storage of wood products, the cascading use of wood and the substitution of wood for alternatives at a company-wide, multi-product and product lifecycle level.
“It's difficult to say in detail that this is the figure that should be used for a certain single product. It’s much more practical to define typical ranges and average values for different types of product groups,” explains Soimakallio.
He elaborates that it's important to understand where the hotspots are, such as why certain products are good or bad: “We can see what the important and least important factors are, as well as what should be improved to change the picture.”
A giant leap
This climate study complements UPM’s ongoing scientific efforts in promoting sustainability practices throughout its value chain. For instance, there have been cooperation projects with the Finnish Meteorological Institute and the Natural Resources Institute focusing on climate effects, as well as ongoing research conducted in Uruguay on methods for measuring soil carbon content.
“Over the years we have cooperated with scientific partners who are credible and transparent,” says Lundgren. “This product study, and other studies undertaken over the years, are all expanding our knowledge and contributing to the development of UPM’s climate approach.”
“As society looks to achieve net-zero, science is going to play a crucial role by providing us with facts so that we can contribute in a credible manner. Scientists have estimated the need to limit warming to 1.5C and, as companies and societies, we must listen to their warnings. It could change later for the better and we will need to adjust our ways accordingly. But if we don't develop something, then who will?” he asks.