Harvested Wood Products in the U.S. National Greenhouse Gas Inventory: Methodology and Accounting

Harvested Wood Products: Topics Overview of U.S. Emissions and Removals U.S. Estimation Method and Results for Harvested Wood Products Accounting Approach

Emissions = 6,935 Tg CO2 eq.Removals = 691 Tg CO2 eq. Overview of U.S. Greenhouse Gas Emissions, 2002 HWP = 215 Tg CO2 eq.

U.S. Estimation Method Method details for the U.S.– –Track Inputs to, and outputs from carbon pools Begin in 1910, track to current time –Product carbon pools Products in use Products in dumps or solid waste disposal sites –Use forest sector model framework – the WOODCARB model to track all products from annual harvest to track imports/ exports

U.S. estimation example – tracking carbon in single family houses

Harvested Wood Products: Methodology Source: Heath and others, 1996; Skog and Nicholson, 1998 Disposition of Carbon in Harvested Wood - U.S. Average RemovalsEmissions

U.S. data Annual Data Requirements 1.Harvest statistics 2.Product production 3.Product exports and imports Coefficients 1.Factors to convert product units to carbon 2.Distribution of products to end uses 3.Use life of products in end uses 4.Portion of discarded wood to dumps vs SWDS vs burning 5.Portion of wood in permanent vs temporary storage in SWDS 6.Decay rates in dumps & SWDS The U.S. assumes the coefficients are the same for products used domestically and products exported

U.S. Product Lifetime Half lives for end uses (years) 1 family homes (pre-1980)80 1 family homes(post-1980)100 Multifamily homes70 Mobile homes20 Nonresidential construction67 Pallets6 Manufacturing12 Furniture30 Railroad ties30 Paper (free sheet)6 Paper (other)1 Wood and paper in SWDS Fraction that decays Solidwood3% Newsprint16% Coated paper18% Boxboard32% Office Paper38% Half life for portion that decays 20 years

Harvested Wood Products: Comparison of Approaches Stock Change or Flow Variables Tg CO2 eq. A Domestic Product Stock Change (from domestic RW) 212 B Exported Product Stock Change (from domestic RW) 3 CImported Product Stock Change36 DFlow of imports47 EFlow of exports25 Approaches: Production (A+B) =215 Stock Change (A+C) =248 Atmospheric Flow (A + C – (D – E))=227 U.S. HWP Removals in 2002 = 215 Tg CO2 eq. Variables from U.S. HWP Estimation Methods

Harvested Wood Products: Timeline September 2004, UNFCCC HWP workshop November 2004, IPCC Guidelines (GL) revisions, HWP experts meeting **December 2004, SBSTA 21** March 2005, 1 st review of IPCC GL revision by experts September 2004, 2 nd review of IPCC GL revision by experts and governments May 2006, SBSTA 24, IPCC GL revision presented to SBSTA

Conclusions HWP is an important sink in the U.S. Tracking HWP will highlight opportunities to better manage HWP pools Transparency can be improved if countries report stock changes associated with both imports and exports regardless of approach Encourage transparent reporting now, such that any approach can be applied in the future Accounting systems should be consistent with IPCC default There is a narrow window of opportunity to provide guidance to IPCC authors on HWP