Harvested wood products in the context of climate change : A comparison of different models and approaches for the Norwegian greenhouse gas inventory

Emissions of greenhouse gases is accounted for and reported annually under the UNFCCC and the Kyoto protocol. In the current accounting system, emissions of CO2 from harvested wood products (HWP) are attributed to the year of harvest and the country of harvest. All harvested wood is thus assumed to be oxidised to CO2 in the year of harvesting, and no wood goes into long term storage. This is called the IPCC default approach. Much of the harvested wood will however be stored for a short or long period of time before it oxidises and this will cause a delayed emission of CO2. If more wood is stored than oxidised in a given year, harvested wood products will act as a sink and a removal of CO2 is recorded. However, if the consumption of wood decreases to a level below what is oxidised, harvested wood products will act as a source and emissions of CO2 is recorded. In Norway, as on many other countries, the stock of harvested wood products has been increasing for many years, and is likely to increase further. Including emissions/removals of CO2 from harvested wood products in the post Kyoto 2012 regime is under consideration by the UNFCCC, and in that context it is imperative to evaluate estimation models and approaches for the reporting/accounting (IPCC 2006a).The project received financial support from the Norwegian Pollution Control Authority (SFT)