Table 9.

Sources of uncertainty and associated data.

Source of Uncertainty	Specific Factor	Years	Relevant products	90% CI
Conversion factors	mbf:ccf	1906-1979	Timber products	± 30%
	mbf:ccf	1980-2009	Timber products	± 15%
	ccf:MgC	1906-2009	Primary products	± 5%
Reported harvest	Harvest in mbf	1906-1945	Timber products	± 30%
	Harvest in mbf	1946-1979	Timber products	± 20%
	Harvest in mbf or ccf	1980-2009	Timber products	± 15%
Product distribution	Roundwood to softwood sawtimber	1906-1979	Timber products	± 30%
	Roundwood to softwood sawtimber	1980-2009	Timber products	± 15%
	Softwood sawtimber to lumber	1906-1949	Timber products	± 30%
	Softwood sawtimber to lumber	1950-1979	Timber products	± 20%
	Softwood sawtimber to lumber	1980-2009	Timber products	± 15%
	Lumber going to new housing	1906-2009	Primary products	± 15%
	Panels going to new housing	1906-2009	Primary products	± 15%
	Residues going to pulp	1906-2009	Primary products	± 15%
Product decay	Product half-life or storage factor	1906-2009	All end-use	± 15%
	Fraction of discards to landfills	1906-2009	Discarded	± 15%
	Landfill decay limits	1906-2009	Landfilled	± 15%
	Landfill half-life	1906-2009	Landfilled	± 15%