Indicator 4.1.3 - Net change in forest products carbon
core indicator


As demonstrated by several of the indicators under Criterion 5, Canada's extensive and diverse forests support a strong forest industry. Together, primary and secondary timber products, and nontimber forest products, contribute several billion dollars to the country's GDP and directly and indirectly employ hundreds of thousands of Canadians.

When forests are harvested to extract timber products, the carbon contained in the trees is transferred to these products. Once transferred, it can remain sequestered in these products for days, years, or decades. Therefore, although forest harvesting does not release carbon to the atmosphere immediately, decayed or burned timber forest products will eventually release their carbon to the atmosphere. It is important to understand the carbon life cycle in forest products to improve knowledge of the potential impact of this carbon on Canada's overall carbon balance. This increased level of understanding will, in turn, facilitate the development of national strategies to mitigate the impacts of carbon emissions on climate change.

The length of the life cycle of the carbon stored in forest products will generally depend on the way they were manufactured and on their final use. For example, pulp and paper carbon can have a very short life cycle if burned, or a relatively long life cycle if sent to landfills with very low decomposition rates.

This indicator is based on the tracking of the main forest products in Canada and includes sawn-wood, wood-based panels, other industrial roundwood, paper and paperboard, and market pulp. It provides an estimate of the change in carbon stocks in forest products located in Canada. New estimates may emerge as internationally agreed accounting procedures for harvested wood products are developed to report on international agreements such as the Kyoto Protocol. For this indicator, net change in forest product carbon considers the net carbon contribution from imports and exports, and from losses to the atmosphere from forest products located in Canada.

Since the calculation of the change in carbon includes imports and exports, increases or decreases in this indicator do not necessarily indicate the actual exchange of carbon with the atmosphere. Emissions to the atmosphere related to the fate of imports are included while emissions related to the fate of exports are not included. The methodology and some of the data used for this report were provided by Environment Canada (Dominique Blain, Environment Canada, personal communication, 2005). All data on domestic production and trade were extracted from the FAOSTAT public database, except for market pulp data, which are obtained from the Pulp and Paper Products Council (2004).

The calculation of forest product carbon stock change is expressed as:

commodity consumption - emissions

where

commodity consumption = domestic production + imports - exports

and

emissions = emissions from current year production + emissions from products already in long-term storage.

Since the net change in forest product carbon is influenced by the decay of products added in previous years, the estimates reported for 2000-2003 can be improved by including the earliest data on the production and trade of forest products. For the estimates of inherited emissions reported here for 2002-2003, production and trade data were backtracked to 1961, the earliest year for which data were available in the FAOSTAT public database (FAOSTAT, FAO Statistical Databases 2005).

The change in forest products carbon is shown in Figure 4.1d. The net change of carbon is the result of the current year balance (current consumption carbon stock change) combined with the emissions from previous years (inherited emissions). Forest products carbon stocks have been increasing over the period (positive numbers indicate an increasing stock). The increase was highest in 1990 at 5 Mt carbon per year, lowest in 1992, and increasing since 1992 to just over 4.5 Mt carbon per year in 2003. The variation in the indicator is explained by changes in product consumption throughout the period (Figure 4.1e). Inherited emissions gradually increase throughout the period. As these inherited emissions are influenced by the inputs to forest product stocks in previous years, this value is sensitive to how long before the period data is available. Including trade before 1961 is being considered to improve the estimate of inherited emissions. The impact of this will likely reduce net increase in forest product carbon stocks. Another factor affecting this estimate is that manufacturing and trade data of finished products are not included. Representation of these products would tend to increase the change in forest product carbon stocks.



Figure 4.1d Change in forest products carbon in Canada from 1990 to 2003.



Figure 4.1e Commodity consumption (domestic production + imports - exports) in Canada from 1990 to 2003.

Although the carbon stock changes from forest products are relatively small compared with those from the forest ecosystem, they are still an important component within the overall carbon cycle. To further improve the data used to produce this indicator, factors such as the availability of historic data, the inclusion of other commodities, and consistency with the methodology used for Indicators 4.1.1 and 4.1.2 (linking with the output of the new Canadian Carbon Budget Model that is being developed) (Apps et al. 1999) are being considered.