查看文章

Forests and forest products contribute to climate change mitigation by sequestering carbon into forests, storing part of the carbon in harvested wood products (HWPs) and by avoiding fossil-based greenhouse gas (GHG) emissions in substitution for alternative materials and energy. Often, there are trade-offs in sequestering carbon into forests and harvesting trees for substitution, which means that these two strategies cannot be optimized at the same time. Which strategy is the most effective depends on a number of assumptions including the time horizon, metrics to characterize the climate effects, the development of forest carbon stocks, the way harvested wood is processed and used, and the alternative products to be substituted.

Assessing the climate effects of the use of wood, changes in carbon stocks in forests and HWPs, as well as changes in fossil carbon emissions should be considered coherently. To do that, two systems are compared; the one with the studied wood use, and its reference system without the wood use being studied. In this report, the focus was on assessing carbon stock changes in HWPs and fossil emission substitution due to using HWPs and wood-based fuels in place of non-wood materials and fuels. The key knowledge and challenges encountered in the assessment and characterization of carbon storage in harvested wood products, substitution effects and the effect of cascading use of wood on them were summarized and discussed. Finally, some practical guidelines to conduct an assessment on an annual basis at a multiproduct and company level and over the life cycle at the product level were provided.