New USFS Data on Forest GHGs

The USFS Northern Research Station has a new report, “Greenhouse gas emissions and removals from forest land, woodlands, and urban trees in the United States, 1990-2018,” that offers national and state-level data.”Forest land, harvested wood products (HWPs), and urban trees within the land sector collectively represent the largest net carbon (C) sink in the United States, offsetting more than 11 percent of total GHG emissions annually.”

Here’s a summary national table:

We’ve discussed C stocks in Oregon forests here. In the report’s appendix, Table 370: C Stocks in Forest Land Remaining Forest Land (MMT C), Oregon, the C stocks are shown increasing slowly and steadily, from 2,860 MMT in 1990 to 3,186 MMT in 2019.

2 thoughts on “New USFS Data on Forest GHGs”

  1. Consider impact of 1994 Owl Plan on federal lands in OR. Pvt industrial lands continue to operate at net loss of forest carbon.

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  2. It strikes me as very odd to count harvested wood products as a carbon sink without also accounting for the emissions from all the tree parts and other forest carbon that is transferred to the atmosphere as a result of logging. Production and use of wood products are in fact a net source of GHG emissions, NOT a net sink. Logging also kills trees, stops photosynthesis, and initiates decay of trees that would otherwise continue to grow and absorb MORE carbon, so logging represents a significant forgone opportunity to store more carbon on the landscape. This is significant because forests, including on public land, are storing far less than their biological potential for carbon.

    Shanks (2008) said “There are also losses of carbon that occur during the creation of forest products. These losses to decay and wood products make carbon sequestration slower when harvesting is allowed. The young timberlands that replace older harvested lands grow quickly, but hold less in total carbon stores than their older counterparts; the net sequestration from forest products adds to total carbon stores, but does not come close to the vast amounts of carbon stored in non-harvested older timberlands. This finding differs from other papers that have shown that the highest carbon mitigation can be reached when high productivity lands are used exclusively for wood products creation (Marland and Marland, 1992). The wood products considered in these studies were either long lasting or used for fuel purposes. Allowing harvested timber to be allocated to all types of wood products increases carbon emissions and results in no harvest regimes sequestering more carbon.” Alyssa V. Shanks. 2008. Carbon Flux Patterns on U.S. Public Timberlands Under Alternative Timber Harvest Policies. MS Thesis. March 2008. http://ir.library.oregonstate.edu/dspace/bitstream/1957/8326/1/A_Shanks_Thesis_04%2002%2008_final.pdf.

    The UK Royal Academy of Engineering (Royal Society) looked at the potential for wood buildings to serve as a method of Greenhouse Gas Removal (GGR) and found —
    Generally, the lifespan of wooden buildings and lifetime emissions associated with electricity and heating costs are comparable to that of concrete and steel structures149. … Life cycle assessment studies of the carbon emissions saved by timber building relative to steel and concrete have been inconclusive153,154. … [A]t the end of their lives the wooden infrastructure materials would have to be repurposed for the carbon to remain captured, which may be a challenge if adopted at scale. … [I]ncreased afforestation will compete with agricultural
    land. … There is an additional risk that processing and transportation reduce the extent of the benefits of this GGR method. … The benefits of extending the longevity and security of carbon storage, originally created through forestation, in the built environment needs to be recognised by carbon accounting agreements. … Incentives for tree planting and sustainable forest management would be needed to significantly expand the scale of building with wood. … As with BECCS, if biomass used for building is imported, there will need to be international agreement about the country that can claim the carbon credit and a mechanism to monitor the storage.
    Royal Society 2018. Greenhouse gas removal. https://royalsociety.org/~/media/policy/projects/greenhouse-gas-removal/royal-society-greenhouse-gas-removal-report-2018.pdf citing (149) Aye L, Ngo T, Crawford RH, Gammampila R, Mendis P. Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable building modules. Energy and Buildings. 2012 Apr;47:159–68. Available from: http://dx.doi.org/10.1016/j.enbuild.2011.11.049; (153) Buchanan AH, Honey BG. Energy and carbon dioxide implications of building construction. Energy and Buildings. 1994 Jan;20(3):205–17. http://dx.doi.org/10.1016/0378-7788(94)90024-8; (154) Gustavsson L, Sathre R. Variability in energy and carbon dioxide balances of wood and concrete building materials. Building and Environment. 2006 Jul;41(7):940–51. http://dx.doi.org/10.1016/j.buildenv.2005.04.008.

    Substitution of wood for more fossil carbon intensive building materials has been projected to result in major climate mitigation benefits often exceeding those of the forests themselves. A reexamination of the fundamental assumptions underlying these projections indicates long-term mitigation benefits related to product substitution may have been overestimated 2- to 100-fold. This suggests that while product substitution has limited climate mitigation benefits, to be effective the value and duration of the fossil carbon displacement, the longevity of buildings, and the nature of the forest supplying building materials must be considered. … Conversion of older, high carbon stores forests to short rotation plantations would over the long term likely lead to more carbon being added to the atmosphere despite some of the harvested carbon being stored and production substitution occurring.
    Mark E Harmon 2019. Have product substitution carbon benefits been overestimated? A sensitivity analysis of key assumptions. Environ. Res. Lett. in press https://doi.org/10.1088/1748-9326/ab1e95.

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