Global mitigation potential of carbon stored in harvested wood products

Download Johnston_etal_PNAS_2019

Carbon stored in harvested wood products (HWPs) can affect national greenhouse gas (GHG) inventories, in which the production
and end use of HWPs play a key role. The Intergovernmental Panel
on Climate Change (IPCC) provides guidance on HWP carbon accounting, which is sensitive to future developments of socioeconomic factors including population, income, and trade. We
estimated the carbon stored within HWPs from 1961 to 2065 for
180 countries following IPCC carbon-accounting guidelines, consistent with Food and Agriculture Organization of the United Nations
(FAOSTAT) historical data and plausible futures outlined by the
shared socioeconomic pathways. We found that the global HWP
pool was a net annual sink of 335 Mt of CO2 equivalent (CO2e)·y−1
in 2015, offsetting substantial amounts of industrial processes
within some countries, and as much as 441 Mt of CO2e·y−1 by 2030
under certain socioeconomic developments. Furthermore, there is
a considerable sequestration gap (71 Mt of CO2e·y−1 of unaccounted carbon storage in 2015 and 120 Mt of CO2e·y−1 by 2065)
under current IPCC Good Practice Guidance, as traded feedstock
is ineligible for national GHG inventories. However, even under
favorable socioeconomic conditions, and when accounting for
the sequestration gap, carbon stored annually in HWPs is <1% of global emissions. Furthermore, economic shocks can turn the HWP pool into a carbon source either long-term—e.g., the collapse of the USSR—or short-term—e.g., the US economic recession of 2008/09. In conclusion, carbon stored within end-use HWPs varies widely across countries and depends on evolving market forces.