Ken Skog

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Comments onHWP estimation methods

• Ken Skog
• Kim Pingoud

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Methods Topics

• Method types
• Applicability of methods to approaches
• Data needs and availability
• Components(variables) needed to estimate for any
  approach

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Methods Types

• Flux data Input from surveys
• Output
• Use lifetimes to estimate outputs
• Use surveys to estimate outputs
• Stock data
• c) Estimate stock change between two inventories

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Methods Applicability
Stock Change Atmospheric Flow Production
Flux using lifetimes Need domestic life times Need domestic lifetimes Need domestic and export lifetimes
Flux using surveys of emissions Partial domestic coverage (not all emissions can be surveyed) (means to verify) Partial domestic coverage (not all emissions can be surveyed) (means to verify) Difficult need to separate domestic emissions survey into domestic and import wood sources
Stock change Partial coverage (e.g. buildings in country) (means to verify) Partial coverage (e.g. buildings in country) (means to verify Difficult need to separate inventory change into domestic and import wood sources
Notes Potential incomplete coverage of secondary wood products Potential incomplete coverage of secondary wood products Complete coverage for secondary products exports
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Data Availability
Data Sources
Harvest, production, trade FAO, country data
Conversion factors IPCC Forest GPG, country data
Lifetime for products in use Limited previous studies Need work validating against surveys of inventory
Disposition after use Limited need national estimates (possible aid from waste sector)
SWDS decay limits / lifetimes IPCC Waste sector guidelines GPG
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Variables needed to estimate for any approach
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Harvested Wood Products Stocks and flows
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Harvested Wood Products Comparison of Approaches
U.S. HWP Removals in 2002 59 Tg C Variables
from U.S. HWP Estimation Methods
Stock Change or Flow Variables Tg C
A Domestic Product Stock Change (from domestic RW) 58
B Exported Product Stock Change (from domestic RW) 1
C Imported Product Stock Change 10
D Flow of imports 13
E Flow of exports 7
Approaches Production (AB) 59 Stock Change
(AC) 68 Atmospheric Flow (A C (D
E)) 62