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EXECUTIVE SUMMARY (continued)
Carbon storage rates per hectare in grazing systems are low, but these systems
cover very large areas. Net carbon uptake can be achieved through reversion
of degrading processes (overgrazing, erosion, acidification and salinization)-a
strategy that also tends to increase productivity. Increased carbon storage
can also occur through enhanced plant productivity by fertilization of nutrient-limited
locations, introduction of better adapted grass and legume species, and irrigation
in water-limited situations. Changes in grazing and fire management can also
increase soil and biomass carbon pools. The increases in woody biomass that
usually follow a reduction in fire frequency may have adverse impacts on grazing
productivity, other production values, and biodiversity. Monitoring the extensive
but relatively small per-unit area changes in grassland carbon stocks is technically
challenging. The net assessment must include changes in CH4,
N2O, and ozone-precursor emissions (Section
4.4.3).
Drainage of wetlands can reduce methane emissions, but it results in a rapid
emission of carbon dioxide. Re-flooding of previously drained wetlands allows
carbon to be stored, but only at a slow rate-which can result in domination
of the radiative forcing benefit by the restored methane emission. These offsetting
impacts make full and symmetrical accounting of wetland management a difficult
and complex problem (Sections 4.4.6, 4.7.2).
The chapter identifies several activities that can occur under different land
use and cover conditions. These activities therefore are difficult to separate
out under most land-cover mapping schemes (Section 4.3.2)
that separate the landscape into areas of cropland, grassland, forest, and so
forth. These activities include agroforestry and biofuel production-which are
options for growing a different mix of crops on crop, grass, or forest land-and
restoration of severely degraded soils.
The use of agricultural and forest crops to produce biofuels reduces the use
of fossil fuels-currently by the equivalent of about 1 Gt C yr-1
and potentially by up to 10 Gt C yr-1. If biomass crops were deployed
at this maximum level, they would be a major land use. The fossil fuel replacement
effect is captured under existing reporting rules, but the direct effects of
land conversion to biofuel crops (which can be positive or negative) are not.
The latter could be included under Article 3.3 (where forest crops were planted
on former cropland) and/or under Article 3.4 (where growing grasses or short-rotation
woody crops for biofuels were defined as a cropping change). Modern biofuel
technology could contribute to sustainable development and GHG mitigation and
may reduce GHG levels sooner than other energy sector measures, at low cost.
Agroforestry can increase carbon sequestration while creating positive environmental
and social impacts such as improved biodiversity and farm income security. It
includes conversion of land recently derived from forest to agroforests rather
than to croplands or pastures, restoration of nutrient-depleted lands using
trees, and improvement of productivity in current agroforestry systems in tropical
and temperate regions. At present, the application of agroforestry is largely
limited to non-Annex I countries.
Restoration of severely degraded soils can produce significant increases in
soil and biomass carbon per unit area. In general, restoration activities also
improve biodiversity, promote sustainable productivity, and reduce air and water
pollution. Their adoption will often require some form of additional incentives
because the immediate benefits to land managers can be negligible or negative.
If relapse is avoided by addressing the causes of the original degradation,
the carbon pools formed are effectively permanent. Reclamation, restoration,
and removal of the causes of severe land degradation are almost always expensive,
so no more than a few percent of the affected area can or will realize this
potential. Fully reclaimed land can be put to a variety of uses and offers the
opportunity to adopt many of the sequestration methods discussed in this Special
Report for increasing the carbon sink still further.
To facilitate the assessment of existing proposals and future proposals as
they arise, we have suggested a decision framework that can be adapted to assist
in the consideration of issues such as verifiability, additionality, permanence,
and additional impacts (see Table 4-2).
| Table 4-2: Some options and implications associated
with selected questions that may arise in deciding how to implement Article
3.4. |
|
| Selected Question |
|
Options and Implications |
|
| Which additional activities should be included under Article
3.4? (Section 4.3.1) |
|
A few selected activities
- Decisions on criteria for inclusion are needed; may require regional
flexibility.
- Careful definition of each activity is needed; makes regional flexibility
challenging.
- May reduce cost and difficulty of near-term accounting.
|
| |
All activities that affect GHG emissions and sinks
- Allows more flexibility in definitions and criteria.
- May contribute to full carbon accounting.
- May provide more accurate reflection of a Party's total GHG impact.
- May have a more significant effect on first-period reports (Section
4.3.4).
- If coupled with activity-based reporting (see below), requires development
of more activity rate factors.
|
| Should "activities" be broadly or narrowly defined? (Section
4.3.2) |
|
Broadly (i.e., cropland management or forest management)
- Definitions of different activities can be fairly general and adapted
to regional differences.
- Double-counting potential is reduced.
- Land-based measures of stock change are well-adapted.
- Full carbon accounting may be more feasible.
- Indirect effects and/or background variability may need to be calculated.
|
| |
Narrowly (i.e., conservation tillage or forest fertilization)
- Definitions of activities need to be unambiguous, implementable, and
verifiable.
- May tend to favor activity-based rather than land-based accounting
methods (see below).
- May make non-CO2 estimates easier where
activities are clearly associated with non-CO2
emissions.
|
| Should additional activities be measured by land-based or
activity-based accounting methods? (Section 4.3.3) |
|
Land-based (i.e., sampling of C pools at start and end of accounting
period)
- Statistical sampling methods for different pools are well-established.
Cost varies with degree of precision demanded and frequency of measurement
required. Methods can be transparent and results verifiable.
- Will not measure non-CO2 emissions.
- If coupled with broad definition of activity, statistical sampling
of large areas (e.g., a regional forest or agricultural area) at two
points in time could capture net effect of emissions and sinks, eliminating
need to track separate activities on individual forest patches or agricultural
fields. Offers one possible method of reducing difficulty in tracking
Articles 3.3 and 3.4 forest activities separately.
- Statistical sampling could capture on-site effects of activities such
as biofuel production or agroforestry.
- If coupled with a narrow definition of activity, reduces the problem
of tracking individual activities from place to place or year to year
but increases problem of separating effects of different activities.
|
| |
Activity-based (i.e., area of activity times calculated rate of impact)
- May be more suited if decisions are made to include only a limited
group of narrowly defined additional activities under Article 3.4.
- Could be adapted where a particular narrow activity (i.e., conservation
tillage) was promoted by incentives and records were kept on amount
applied by participating farmers.
- Where more than one activity occurs on a particular piece of land,
carbon impacts of different activities may be difficult to verify.
- Requires development of emission or sink factors for each activity
in each region. Some factors may need to be tied to specific land uses
or soil types under some conditions.
- Can be used to estimate non-CO2 emissions.
- Methods can be transparent, but verification of seasonal activities
may be difficult or impossible at a later time.
|
| |
Some combination of the two methods
- May provide an opportunity to better fit an accounting method to different
activities and/or available data.
- Activity-based methods or default values could provide a transition
method while a Party established new institutional capacity.
- If land-based measures were used to estimate changes in carbon pools,
activity-based measures might be used to calculate associated non-CO2
effects to achieve more complete accounting.
- Could provide a different approach for verification (i.e., land-based
approach could measure total effect after several activity-based estimates
had been applied to one piece of land or over several years of application).
- Where land-based measures were used, an associated activity-based
estimate could be one means of adjusting measured carbon stock change
to compensate for indirect effects or natural variability.
|
| Should soil carbon stocks be included in the accounting? (Section
4.2) |
|
Yes
- This pool contains large amounts of carbon, is the major pool in agricultural
(cropland and grassland) situations, and soil carbon stocks can be altered
(+ or -) by management or land-use change.
- Incentives to improve soil carbon also tend to help improve soil quality,
productivity, and sustainability of agricultural and forestry systems.
- Soil surveys and periodic monitoring needed. Methods are readily available
from a scientific viewpoint but require investment and may be currently
lacking in some areas, suggesting technology transfer and/or transition
strategies to produce adequate data in short term.
|
| |
No
- Need for soil surveys and soil monitoring is reduced.
- Major carbon transfers between atmosphere and biosphere (emissions
and sinks) will go unreported.
- Opportunities to provide incentives for improving agricultural system
sustainability, expanding agroforestry, producing biofuels, or restoring
severely degraded land may be lost.
- Incentives for development of more cost-effective ways to monitor
soil carbon (e.g., remote sensing) are reduced.
|
| Should forest products be included as an additional activity
under Article 3.4? (Section 4.5.6) |
|
Yes
- Contributes to full accounting, if that is a desired goal.
- Decisions on accounting methods are needed.
- Activity- or flux-based accounting methods appear more feasible for
this activity, as opposed to land-based accounting.
- A more complete accounting of the total carbon impact of certain forest
management strategies (e.g., utilization vs. protection) could result.
- Incentives may be increased for using wood in place of higher energy-using
substitutes in construction.
- Incentives may be increased for recycling and extending product life.
|
| |
No
- Land-based accounting, if used on forest areas, need not attempt to
track fate of forest products after they leave site.
- Full carbon implication of forest management options such as extended
rotations is not captured.
- Fewer incentives will be created to use wood in construction, to recycle,
and to extend product life.
- Accounting in terms of trade between Parties will not be required.
|
| Should wetland restoration or drainage be included as an additional
activity? (Sections 4.4.6 and 4.7.2) |
|
Yes
- May capture effect of locally important land-use activities.
- May require activity-based accounting methods to be developed that
can estimate both CO2 and CH4
impacts.
- In some cases, results may be different than expected in terms of
climate-forcing impact.
- Associated impacts may be more important than climate impacts in affecting
land-use and management decisions.
|
| |
No
- Reduces complexity of monitoring and accounting systems.
- Probably has minor effect on national accounting totals for Parties.
- May miss opportunities to encourage wetland management that has other
environmental benefits.
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