The magnitude of the stock changes from additional activities that might
be included under Article 3.4 rests, inter alia, on any decisions that remain
to be made in the process of implementing the Kyoto Protocol. A consideration
of carbon stocks changes and net emissions of greenhouse gas emissions associated
with additional activities on managed lands entails synthesizing available
technical and scientific data, outlining the outcomes of one policy scenario,
and assessing the aggregate impact of policies and other factors. The scientific
literature to support such an analysis is currently quite limited. [4.3]
One such scenario is presented in Table 4,
to illustrate in a general sense the potential scope for carbon stock increases
through some broadly defined activities. It provides data and information
on carbon stock changes for some candidate activities under Article 3.4 for
the year 2010. This scenario relies on three components relating to the candidate
activities: 1) an estimate of current relevant land areas (column 2); 2) an
assumed percentage of those lands on which an activity would be applied in
2010 (column 3); and 3) a research-derived estimate of the annual rate of
carbon stock increase per hectare (column 4). The uptake rate is multiplied
by the applicable land area to approximately calculate the change in carbon
stock in the year 2010 (column 5).
Table 4, rather than providing precise projections,
reports calculated stock changes assuming an ambitious policy agenda that
promotes the application of activities to a significantly greater share of
the relevant land base than would have otherwise occurred. The assumed percentage
of lands on which the activity is applied is derived from considered professional
judgment based on existing literature of what a range of sustained and effective
initiatives, which vary across countries, could achieve. The share of land
on which the activity is actually applied in 2010 depends to a great extent
on the accounting system under Article 3.4, the evolving economic and social
aspects of the activity, and landowner response to incentives, among other
factors. Thus, the total annual stock changes in Table
4 (column 5) are likely to be on the high side.
Table 4 estimates do not necessarily represent
credits under Article 3.4 of the Kyoto Protocol, even if such levels of stock
change are achieved, because the Protocol may include approaches that limit
the applicability of these calculations.
Table 4 illustrates the estimated carbon stock changes from example additional
activities within Annex I and globally, assuming roughly similar levels of
policy support. For example, Table 4 suggests
that although conversion of cropland to grassland can provide a relatively
large carbon stock increase per hectare converted, forest management improvements,
which can be applied over a larger land base, may provide relatively larger
total annual increases. Very different estimates in changes of emissions and
removals associated with options for additional land use, land-use change,
and forestry activities would result from different definitions of additional
activities that might be agreed under Article 3.4, different accounting approaches,
and different decisions that might be taken on implementation rules for Article
3.4.
There is potential for carbon uptake into biomass, which may be stored over
a time period of decades in wood products. Furthermore, biomass used for energy
purposes, based on waste by-products of wood/crops or from trees/crops grown
expressly for this purpose, has the potential to lead to a reduction in net
greenhouse gas emissions by substituting for fossil fuels. [1.4.3,
1.4.4]
Table 4 does not account for the possibly significant
non-CO2 greenhouse gas emissions and removals that could be influenced by
the candidate activities. For example, the rates do not reflect net emissions
of CH4 or N2O from agricultural practices or wetlands/permafrost management.
The table also does not include the carbon stock impact of the use of biofuels
and the changing wood product pools, and consideration of forest management
does not include avoided deforestation, which is dealt with in Table
3.
