Uncertainty [MGD Sections]

UNFCCC decisions and requirements
IPCC good practice guidance
Relationship to UNFCCC
GHGI coverage, approaches, methods and tiers
Design decisions relevant to national forest monitoring systems
Land cover, land use and stratification
Forest reference emission levels and forest reference levels
Quality assurance and quality control
Guiding principles – Requirements and design decisions
Estimation methods for REDD+ activities
Integration frameworks for estimating emission and removals
Selecting an integration framework
Activity data x emission/removal factor tools
Fully integrated tools
Practical considerations in choosing an integration tool
Guiding principles – Methods and approaches
Remote sensing observations
Coarse resolution optical data
Medium resolution optical data
High resolution optical data
L-band Synthetic aperture radar
C-band and X-band SAR
LIDAR
Global forest cover change datasets
Ground-based observations
National forest inventories
Auxiliary data
Guiding principles – Remote sensing and ground-based observations
Activity data
Methods for estimating activity data
Maps of forest/non-forest, land use, or forest stratification
Detecting areas of change
Additional map products from remote sensing
Estimating uncertainty of area and change in area
Estimating total emissions/removals and its uncertainty
REDD+ requirements and procedures
Reporting forest reference emission levels and forest reference levels
Technical assessment of forest reference emission levels and forest reference levels
Reporting results of REDD+ activities
Technical analysis of the REDD+ annex to the BUR
Additional advice on REDD+ reporting and verification
Guiding Principles – Reporting and verification of emissions and removals
Financial considerations
Country examples – Tier 3 integration
Use of global forest change map data
Relative efficiencies
Developing and using allometric models to estimate biomass

Record Keeping [MGD Sections]

Integration + Estimation [MGD Sections]

Ground Based Observations [MGD Sections]

2.2.3   Significance and key category analysis Previous topic Parent topic Child topic Next topic

Key category analysis (KCA) is IPCC’s method for deciding which emissions or removals categories to prioritize in preparation of the GHGI. A category is key if, when categories are ordered by magnitude, it is one of the categories contributing cumulatively to 95% of total national emissions or removals, or to 95% cumulatively of the trend in national emissions or removals. KCA is described and in section 5.4 of GPG2003 Opens in new window, and volume 1, Chapter 4 of the 2006GL Opens in new window. Since it is not known at the outset which categories are key, KCA may need to be iterative with the initial ordering undertaken using Tier 1 methods.
REDD+ activities are mostly not recognised categories in the IPCC inventory methodology, but in the case of deforestation, GPG2003 suggests adding up the forest to other land use conversions that contribute to deforestation, and treating deforestation as key if the result is larger than the smallest category considered to be key using the UNFCCC reporting categories. IPCC also provides qualitative criteria for identifying key categories, one of which is that categories for which emissions are being reduced, or removals enhanced, should be treated as key. To the extent that this qualitative criterion applies in the case of REDD+ activities, they could be treated as key, although there has been no COP decision on this.
In applying KCA(1), GPG2003 asks whether particular subcategories defined for this purpose are significant. The subcategories defined for these purposes are for CO2 are biomass, dead organic matter and soils(2). For IPCC, significant subcategories are those which contribute at least 25% to 30% of the emissions or removals in the parent category to which they belong. This does not mean that sub-categories may be omitted, but for subcategories which are not significant in this sense, countries may use Tier 1 methods if country specific data are not available. Identifying key subcategories assists in the allocation of resources to collect country specific data and in addition focuses efforts to reduce uncertainties related to these key subcategories.
Decisions 12/CP.17 Opens in new window and 13/CP.19 Opens in new window say that significant pools and activities should be included in FREL and/or FRLs, and that Parties have some flexibility not to include other pools and activities, considered not to be significant. For reasons of consistency, it is clear that inclusion of pools and activities should be the same in the FREL and/or FRL as for the subsequent emissions and removals estimates from REDD+ activities.
Drawing on a precedent from IPCC usage, significant pools could be taken to be those accounting for 25% to 30% or more of the GHG emissions or removals associated with a REDD+ activity(3). The analogy is not exact because IPCC uses the 25% to 30% level to define as significant pools for which default methodologies can be applied, even if the parent category to which they belong is a key category. This is not the same as deciding on potential omission of a pool consistent with decision 12/CP.17 Opens in new window and 13/CP.19 Opens in new window. Another possible (though not necessarily mutually exclusive) way to approach significance, based on a set of rules to help ensure a consistent policy signal, that achievement in emissions reductions or removals enhancement would not be overestimated and to prioritize the most relevant sources. For example:
  • the pool likely to be responsible for the largest cumulative emissions addressed by the REDD+ activity (or removals if the carbon stocks addressed by the activity are increasing) is the most significant.
  • other pools not already included can potentially be considered not significant if they behave in the same direction as the most significant pool (i.e. their carbon stocks increase or decrease when those from the most significant pool increase or decrease, respectively).
  • on the other hand, pools expected to behave differently compared with the most significant pool are considered potentially significant, for inclusion at the same time as the most significant pool, or for prioritization in a stepwise approach as better data become available.
For deforestation in tropical biomes, the most significant pool will often be biomass, except where forests are growing on organic soils. In the case of other activities, biomass could be regarded initially as the most significant pool and the other pools tested against this working hypothesis using IPCC methods summarized in the MGD, implemented at Tier 1 for test purposes. As an example, where covered by national forest definitions, for planted forests established on drained organic soils, soil organic carbon is very likely to be significant under the rules suggested above because the pool decreases as biomass increases. The expectation would be to include significant pools using country specific data (hence Tier 2), as these become available. Significance can be kept under review as national monitoring systems develop.
As with pools, for activities a possible consideration could be that the REDD+ activity likely to be responsible for the largest GHG emissions or removals be considered the most significant. Activities unlikely to be affected by displacement (causing greater emissions and/or reduced removals) due to action on the most significant activity could be considered not significant relative to the most significant activity. Activities likely to be affected by displacement due to action on the most significant activity would be considered potentially significant, for inclusion at the same time as the most significant activity, or for prioritization in a stepwise approach as better data become available. Evidence for displacement(4) would include consideration of how action on the most significant activity would affect the drivers of other activities, and hence the emissions and/or removals associated with them. The relationship to proxies may be relevant. Subsequent steps would also allow inclusion of the next largest activities whether or not affected by displacement from activities already included as significant. This process could continue until all activities justified as significant by the Party and considered under the technical assessment process were included.
The relative importance of emissions or removals associated with REDD+ activities may change over time (because of actions taken, evolution of drivers, newly acquired data or improved methods), so significance, where applied, should be reassessed periodically, e.g. as part of a stepwise approach, and in particular when assessing results.

 (1)
As set out in section 3.1.6 of GPG2003 Opens in new window the decision trees provided by GPG2003
 (2)
See table 3.1.3, page 3.20 of GPG2003 Opens in new window. For N2O the subcategories used for KCA are fire, soil organic matter mineralisation, nitrogen inputs and cultivation of organic soils. For CH4 the subcategory is fire.
 (3)
Other percentage levels could be used to define significant are possible; e.g. the FCPF Methodological Framework Opens in new window uses 10%.
 (4)
Noting that, according to decision 9/CP.19, paragraph 4 Opens in new window, countries should provide the most recent summary of information on how all of the safeguards (as referred to in decision 1/CP.16, appendix I, paragraph 2 Opens in new window), including actions to reduce displacement of emissions, have been addressed and respected before they can receive results-based payments.