3.3.2.3. Options for Reducing Discrepancies between Actual and Reported Carbon
Stock Changes
Additional rules could be used to avert some of the type I and type II discrepancies
described in Section 3.3.2.2, where actual and reported
stock changes do not match. Two possible ways of doing this are as follows:
- By limiting "reforestation lands" that fall under Article 3.3 through the
use of additional time rules. For example, reforestation could exclude establishment
of tree cover on land that was non-forest for less than a specified period
of time (e.g., 10 years) after deforestation or land that was forest at a
specific point in time (e.g., 1990). If a densely stocked forest with 200
t C ha-1 is deforested in 1991, for example, and reforested 5 years later,
no carbon credits could be claimed in the commitment period. One problem,
however, is shown by the following example: Assume deforestation of a stand
with little carbon (e.g., 20 t C ha-1 in 1991) and reforestation 5 years later
with vigorously growing trees, with stocks increasing to 50 t C ha-1 in 2012.
Even though this activity reduces atmospheric CO2, it would be excluded by
the use of a time rule. This approach addresses only the type I discrepancy.
- By not limiting "reforestation lands" but limiting the amount of credits
and debits for these lands. There are at least two ways to do this:
- Credit for reforestation in areas deforested after 1990 or 1997, for
example, could be excluded. With a stand of 200 t C ha-1 deforested after
1997, no credits would be possible for subsequent reforestation. In the
foregoing example of an initial stand at 20 t C and the carbon stocks
at 50 t C in the commitment period, no credits would be possible. This
approach addresses only the type I discrepancy.
- Credits for reforestation in areas deforested after 1990 could be limited;
debits for afforestation and reforestation lands could be limited. This
approach addresses both type I and type II discrepancies.
- Avoiding the type I discrepancy. For land deforested between
1990 and 2007, carbon credits for reforestation could be awarded only
for increased carbon stocks above the level of carbon stocks present
on the land prior to deforestation (or in 1990) (D-R Rule). This approach
would eliminate an incentive to deforest land then reforest it to
claim carbon credits during the commitment period, thereby avoiding
that type I discrepancy in b2 on the facing page (note that ARD land
is assumed to be able to switch from the "deforestation" to the "reforestation"
category). This approach entails a moderate increase in data requirements
because information about the carbon stock prior to deforestation
or in 1990 is needed. The first sentence of Article 3.4 asks for data
on carbon stocks in 1990, but it is not clear whether these data have
to be geo-referenced; thus, it is not clear whether such data are
of use here.
- Avoiding the type II discrepancy. Carbon debits in afforestation
and reforestation could be limited to the amount of net credits (i.e.,
credits minus debits) received for carbon accumulating on the same
land (A/R Debit Rule). This approach would avoid the type II discrepancy
in b3 on the facing page, and it does not create additional data needs.
The purpose is to cap debits for reforestation activities (that sequestered
carbon between 1990 and 2008) followed by harvesting in the first
few commitment periods. It ensures that activities that increase carbon
stocks in the long term are not counted as debits under Article 3.3.
Particularly in the first few commitment periods, there are carbon
stocks on afforestation/reforestation lands that would not be credited
because they accrue before 2008. Any harvest loss in a commitment
period, however, would count to the extent that carbon is lost (see
Section 3.3.2.2). In the first commitment period,
the A/R Debit Rule would disallow debits because no credits have been
assigned previously and because the stocks are most likely higher
than they were before the initiation of the afforestation/ reforestation
activity. As subsequent commitment periods occur, an increasingly
greater share of carbon sequestering on afforestation/ reforestation
lands will have been credited, so the allowable debit for harvest
also increases. In any event, the net credit (credit minus debit)
over time for a unit of land would not be negative.
- The FAO scenario with land-based approach I (stock changes
over the full commitment period are accounted). With a harvest in
2009 and replanting in 2010, carbon losses from the harvest would
be accounted through the 2008-2012 stock change. If the A/R Debit
Rule were applied, however, there would be no debit in the first commitment
period, even though stocks have decreased. In the FAO scenario with
the land-based approach, the debits would be set to zero.
The amount of land included in the "reforestation" category would not
be affected by these two rules. Their main effect is on carbon stock
changes, not all of which would necessarily count even if an area is
"reforested since 1990."
The carbon discrepancies in items a1 and c1 could be avoided through the use
of the Degradation/Aggradation definitional scenario or possibly the Biome scenario.
The discrepancy in item a2 could be minimized through contiguous commitment
periods. The problem outlined in b4 could be avoided by defining "reforestation"
to include planting or regrowth of individual trees in an existing stand. Issue
d1 could be addressed through the way a forest is defined.
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