Climate warming effect of disposal fates of harvested wood products

The objective of this research was to understand how the long-term climate warming effect of harvested wood products (HWP) changed as the proportional distribution of disposed products across three primary pathways (incineration, recycling, and landfilling) varied while accounting for the possibility of multiple recycling steps. The climate warming effect is defined as greenhouse gas (GHG) emissions from the disposal of carbon content in HWP, not including emissions from processing the disposed HWP and substitution effects. Emissions were estimated over 100 years from the year of the original HWP disposal. For solid HWP, the climate warming effect decreased, for any given recycling fraction, as the landfill fraction decreased. The opposite, however, occurred for paper HWP. Recycling reduced the climate warming effect of solid HWP by "pushing" some of the emissions outside of the assessment period. For paper HWP, recycling did not change the climate warming effect unless the assessment period was relatively short. These findings can be used to assess the effect of a given combination of disposal fates of HWP, including the final disposal of non-recyclable HWP, and indicate whether it exceeds the effect of instantaneously releasing the HWP carbon content as CO₂.