Greenhouse gas impacts of harvested wood products: Evaluation and development of methods

Greenhouse gas (GHG) impact of wood and paper products, in the following referred as harvested wood products (HWP), is twofold: 1) HWP form a renewable pool of wood-based carbon, whose changes act as carbon sink or source, 2) manufacture and whole lifecycle of HWP cause fossil carbon emissions. These fossil emissions are often smaller than those of rival products from nonrenewable sources, and thus material and energy substitution by HWP can cause a relative decrease in GHG emissions. This report considers both above components, but it focuses on impact 1) and specifically on the approaches and methods for estimating the balance of wood-based carbon in HWP. In estimation and reporting GHG emissions under the United Nations Framework Convention on Climate Change (UNFCCC), countries do in principle report all their fossil carbon emissions (including those of HWP lifecycle), whereas reporting principles of carbon balance in HWP, impact 1), is still open. At present only changes in forest biomass are reported whereas HWP stock is not assumed to change. Climate political debate has raised alternative and competing accounting approaches, which in totally different way allocate HWP emissions or removals between countries. The report discusses and compares the alternative approaches and provides numerical examples illustrating the position of various countries in above emissions allocation. After inclusion of HWP reporting under the UNFCCC, the next possible step could be to include HWP accounting in the commitments of the Kyoto Protocol. In this case, substantial barriers for international trade of HWP and use of renewable bioenergy might be formed, dependent on the choice of the HWP accounting approach. In this study a dynamic spreadsheet model of carbon balance in HWP was developed, which countries could use in their national emissions estimation and reporting under the UNFCCC. The model requires as basic input data the production and international trade rates of HWP, provided worldwide and since 1961 by the FAO database, which is easily accessible through the internet. The report presents a short description of the above model. In addition, a more robust method for estimation of national HWP stocks is presented, based on direct inventory of building stock. However, this method is not applicable in national reporting globally, basically due to lack of relevant statistics in most countries. The GHG impacts of type 2) are also shortly illustrated by Finnish case studies, two of which consider material substitution in Finnish new construction.