For purposes of this Special Report, in a given land area and time period,
a full carbon accounting system would consist of a complete accounting for
changes in carbon stocks across all carbon pools. Applying full carbon accounting
to all land in each country would, in principle, yield the net carbon exchange
between terrestrial ecosystems and the atmosphere. However, the Kyoto Protocol
specifies, among other things, that attention focus onto those land areas
subject to "direct human-induced" activities since 1990 (Article 3.3) or human-induced
activities (Article 3.4). [2.3.2.5]
3.1. Forests, Afforestation, Reforestation, and Deforestation
There are many possible definitions of a "forest" and approaches to the
meaning of the terms "afforestation," "reforestation," and "deforestation"
(ARD). The choice of definitions will determine how much and which land in
Annex I countries are included under the provisions of Article 3.3, lands
associated with activities included under Article 3.3 (hereafter "lands under
Article 3.3"). The amount of land included will have implications for the
changes in carbon stocks accounted for under Article 3.3. [2.2.2,
2.2.3, 3.2, 3.5.2,
3.5.3]
Seven definitional scenarios were developed that combine definitions of
forest and ARD and reflect a range of approaches that can be taken. The scenarios
are not intended to be exhaustive. They can be split into two representative
groups, which are discussed in the SPM: 1) scenarios in which only a forest/non-forest
conversion (i.e., a land-use change triggers accounting under Article 3.3)
(e.g., IPCC Definitional Scenario), and 2) scenarios in which land-cover change
or activities trigger accounting under Article 3.3 (e.g., FAO Definitional
Scenario). [2.2.2, 2.2.3,
3.2, 3.5.2, 3.5.3,
Table 3-4]
Countries have defined forests and other wooded lands, for a number of national
and international purposes, in terms of (i) legal, administrative, or cultural
requirements; (ii) land use, (iii) canopy cover, or (iv) carbon density (essentially
biomass density). Such definitions were not designed with the Kyoto Protocol
in mind and, thus, they may not necessarily suffice for the particular needs
of Articles 3.3 and 3.4. [2.2.2, 3.2]
Forest definitions based on legal, administrative, or cultural considerations
have limitations for carbon accounting as they may bear little relationship
to the amount of carbon at a site. [2.2.2, 3.2]
Most definitions of forest are based in part on a single threshold of minimum
canopy cover. However, such definitions may allow changes in carbon stocks
to remain unaccounted under Article 3.3. For example, if a high threshold
for canopy cover (e.g., 70% canopy cover) is used in the definition of a forest,
then many areas of sparse forest and woodland could be cleared or could increase
in cover without the losses or gains in carbon being counted under Article
3.3. If a low threshold is set (e.g., 10% canopy cover), then dense forest
could be heavily degraded and significant amounts of carbon released, without
the actions being designated as deforestation. Similarly, a forest, for example
with 15% canopy cover, could be considerably enhanced without the actions
qualifying as reforestation or afforestation under Article 3.3. Approaches
to partly address these problems may include, inter alia, using national,
regional, or biome-specific thresholds (e.g., a low canopy cover for savannas
and a high canopy cover for moist forests). [2.2.2,
3.2, 3.3.2]
Definitions of forests based on carbon-density thresholds have similar issues
with respect to thresholds as canopy cover-based definitions. [2.2.2]
There are a number of approaches to definitions of afforestation, reforestation,
and deforestation. One approach involves the concept of land-use change. Deforestation
can be defined as the conversion of forest land to non-forest land. Reforestation
and afforestation can be defined as the conversion of non-forested lands to
forests with the only difference being the length of time during which the
land was without forest. [2.2.3, 3.2]
An alternative definition of deforestation might be based on a decrease
in the canopy cover or carbon density by a given amount or crossing one of
a sequence of thresholds. Similarly, afforestation and reforestation could
be defined in terms of an increase in canopy cover or carbon density. None
of these definitions involves the concept of a land-use change. [2.2.2,
3.2]
Definitions of a forest based strictly on actual canopy cover without consideration
of potential canopy cover could lead to harvesting and shifting agriculture
being referred to as deforestation and to regeneration being referred to as
reforestation, thus creating additional areas of lands under Article 3.3.
If the definition of a forest was based on the potential canopy cover at maturity
under planned land-use practices, harvesting/regeneration activities may not
fall under Article 3.3. [2.2.2, 2.2.3,
3.2]
Some commonly used definitions of reforestation include the activity of
regenerating trees immediately after disturbance or harvesting where no land-use
change occurs. If, for example, the definition of deforestation or the accounting
system do not include disturbance and harvesting, then emissions from a harvested
stand will not be accounted for. In this particular example, uptake due to
regeneration would be accounted for, resulting in potentially significant
credits for which a corresponding net removal of carbon from the atmosphere
would not occur. This issue could be considered when developing the accounting
system. [2.2.3.2]
There are several consequences of using definitions that lead to the creation
of lands under Article 3.3 by the harvest-regeneration cycle (i.e., where
harvesting is included in the definition of deforestation, or regeneration
is included in the definition of reforestation). For example, a forest estate
managed on a sustainable-yield basis where an area of forest is cut in a regular
cycle (e.g., 1/50th of the forest is harvested and regenerated each year on
a 50-year rotation cycle) may be in approximate carbon balance. However, in
this case, only those stands harvested or regenerated since 1990 would be
considered lands under Article 3.3. The regrowth (carbon sink) on these lands
will be less than the carbon emissions due to harvesting until all stands
of the estate are lands under Article 3.3. Different definitional and accounting
approaches would have different accounting consequences. For example:
If emissions from harvesting during a commitment period are counted
(land-based approach I; see Table 3), then
during the first and subsequent commitment periods a net debit could arise
from a managed forest estate that is approximately in carbon balance.
If emissions from harvesting during a commitment period prior to regeneration
are not counted (land-based approach II; see Table
3), then during the first and subsequent commitment periods a net
credit would generally arise from a managed forest estate that is approximately
in carbon balance. This may be offset to some extent by delayed emissions
from soils and harvest residues.
If emissions from harvesting during a commitment period are not counted
(activity-based approach; see Table 3), then
during the first and subsequent commitment periods a net credit would
arise from regeneration in a managed forest estate that is approximately
in carbon balance. It would be practically very difficult to separate
changes in soil carbon pools associated with harvesting and regeneration
activities.
In each of these approaches the accounted stock changes would generally
be different from the actual net exchange of carbon between this example
forest estate and the atmosphere during a commitment period. [3.2,
3.5.2]
Afforestation is usually defined as the establishment of forest on land
that has been without forest for a period of time (e.g., 20-50 years or more)
and was previously under a different land use. The precise period that distinguishes
afforested from reforested land is not important in accounting for lands covered
under Article 3.3 provided afforestation and reforestation are treated identically
under the Protocol, as they are in the Revised 1996 IPCC Guidelines for National
Greenhouse Gas Inventories.2
[2.2.3, 3.3.2]
Article 3.3 encompasses ARD activities that have occurred since 1990 but
recognizes only verifiable carbon stock changes in each commitment period.
This has several implications. For example:
For lands deforested between 1990 and the beginning of the first commitment
period only a fraction of carbon stock changes (such as those from delayed
carbon emissions from soil and wood products if they are accounted) will
occur during the commitment period and would be debited under Article
3.3. If these lands are subsequently reforested then there may be an increase
in carbon stocks during the commitment period and a credit under Article
3.3. This would mean that the credit received would not match the actual
carbon stock changes or the net exchanges of carbon with the atmosphere
since 1990.
Another accounting issue could arise when land is reforested or afforested
between 1990 and 2008 but stocks are reduced either by harvesting or natural
disturbance during a commitment period. Even though the forest area and
possibly carbon stocks may have increased since 1990, a debit could be
recorded in a commitment period. This creates the possibility of a negative
incentive for establishing forests well in advance of the first commitment
period, because any stock increase prior to 2008 would not be credited
but the later loss of this stock would be debited.
Such outcomes could possibly be addressed through different combinations
of definitional and accounting approaches. [3.3.2]
There are definitional and carbon accounting issues concerning drawing a
clear boundary between natural phenomena and human-induced activities, when,
for example, significant forest losses occur as a result of fires or disturbances
such as pest outbreaks. In cases involving lands under Article 3.3 or 3.4
where fires or pest outbreaks occur in a forest, a question is whether accounting
should, inter alia: (i) count neither the loss nor subsequent uptake of carbon
(which reflects the actual net change in carbon stocks on those lands and
exchange of carbon with the atmosphere in the long term, but creates problems
in continuing to account for the area burnt/defoliated as lands under Article
3.3 or 3.4); (ii) count both the loss and subsequent uptake of carbon (which
reflects the actual net change in carbon stocks on those lands and exchange
of carbon with the atmosphere, but creates an initial carbon debit for the
Party concerned); (iii) count only the loss of carbon (which would overestimate
the actual losses of carbon stocks, not represent the exchanges of carbon
with the atmosphere, and create future accounting problems), or (iv) count
only the subsequent uptake (which would fail to reflect the actual changes
in carbon stock and would not represent the exchanges of carbon with the atmosphere,
and would provide carbon credits for the Party concerned). [2.2.3.3]
In cases involving lands that do not fall under Articles 3.3 or 3.4, where
fires or pest outbreaks trigger land-use change, the consequences are similar
to deforestation. If similar vegetation cover is allowed to regenerate, such
disturbances may not lead to a long-term change in carbon stocks. [2.4.4,
2.2.3, 2.3.3]
