IPCC Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories UNFCCC Workshop on the Preparation of National Communications from non-Annex I Parties April 26-30, 2004, Manila Leandro Buendia Programme Officer,

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IPCC Good Practice Guidance and Uncertainty
Management in National Greenhouse Gas
InventoriesUNFCCC Workshop on the Preparation
of National Communications from non-Annex I
PartiesApril 26-30, 2004, ManilaLeandro
BuendiaProgramme Officer, IPCC-NGGIP-TSU
(lbuendia_at_iges.or.jp)
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Decision 17/CP.8, Annex (Guidelines for the
Preparation of NC from non-Annex 1 Parties)

• Objectives
• Para 1b. To encourage the presentation of
  information in a consistent, transparent and
  comparable, as well as flexible, manner, taking
  into account specific national circumstances.

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Decision 17/CP.8

• Methodologies
• Para 11. Non-Annex 1 Parties are encouraged to
  apply the IPCC Good Practice Guidance and
  Uncertainty Management in National Greenhouse Gas
  Inventories, taking into account the need to
  improve transparency, consistency, comparability,
  completeness and accuracy in inventories.
• Para 12. Non-Annex I Parties are also
  encouraged, to the extent possible, to undertake
  any key source analysis as indicated in the IPCC
  good practice guidance to assist in developing
  inventories that better reflect their national
  circumstances.

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Decision 17/CP.8

• Reporting
• Para 24. Non-Annex I Parties are encouraged to
  provide information on the level of uncertainty
  associated with inventory data and their
  underlying assumptions, and to describe the
  methodologies used, if any, for estimating these
  uncertainties.

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Contents

• Background Information
• What is good practice guidance
• Contents of the Report
• Key Source Category
• Policy Relevance
• Conclusion

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Background Information

• June 1998 SBSTA 8 encouraged IPCC to give high
  priority to completing its work on uncertainty,
  as well as to prepare a report on good practices
  in inventory management and to submit a report on
  these issues for consideration by SBSTA, if
  possible by COP5
• October 1998 IPCC held a Planning Meeting in
  Paris to plan for the work
• January 1999 October 1999 Sectoral and
  Cross-sectoral Expert Meetings
• December 1999 - February 2000 First draft was
  reviewed by governments and experts
• May 2000 IPCC XVI accepted the GPG2000 Report
• June 2000 SBSTA 12 endorsed the GPG2000

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Background Information
IPCC Good Practice Guidance and Uncertainty
Management in National Greenhouse Gas
Inventories (GPG2000) Published in 2000
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What is good practice guidance?

• Good Practice Guidance (GPG) aims to assist
  countries in producing inventories

• that are neither over- nor underestimates so
  far as can be judged

• in which uncertainties are reduced as far as
  is practicable

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Further aims, to produce inventories which are

• transparent
• documented
• consistent over time
• complete
• comparable
• assessed for uncertainties
• subject to quality control and assurance
• efficient in the use of resources

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Structure of the GPG2000

• Preface
• Chapter 1 Introduction
• Chapter 2 Energy
• Chapter 3 Industrial Processes
• Chapter 4 Agriculture
• Chapter 5 Waste
• Chapter 6 Quantifying Uncertainties in Practice
• Chapter 7 Methodological Choice and Recalculation
• Chapter 8 Quality Assurance and Quality Control
• Annex 1 Conceptual Basis for Uncertainty Analysis
• Annex 2 Verification
• Annex 3 Glossary
• Annex 4 List of Participants

Source category good practice guidance
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Source category specific good practice guidance
(Chapters 2 to 5)

• Methodological Issues
• Choice of method
• Choice of emission factors
• Choice of activity
• Completeness
• Developing a Consistent Time series
• Uncertainty Assessment
• Reporting and Documentation
• Inventory Quality Assurance/Quality Control

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1. Methodological Issues

• Choice of Method
• estimation methods suited to national
  circumstances
• decision trees (which tier?)
• Choice of Emission Factors
• most suitable emission factors for inventory
  calculation (default values)
• Choice of Activity Data
• most suitable activity data for inventory
  calculation

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Figure 4.2 Decision Tree for CH4 Emissions from
Enteric Fermentation
Does the country manage cattle, buffalo, sheep,
goats, camels, mules/asses, swine, or
other livestock?
Report Not Occurring
No
Yes
Is enteric fermentation a key source
category? (Note 1)
No
Yes
Ask for each species Is this sub-source
category significant? (Note 2)
Ask for each species Are data available with
which to perform a Tier 2 estimate?
No
No
Yes
Yes
Estimate emissions for the species using Tier 2
Estimate emissions for the species using Tier 1
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• Completeness
• advice to ensure complete estimates
• Developing a Consistent Time series
• advice to ensure consistency throughout the time
  series
• Uncertainty Assessment
• provide default values for uncertainty ranges

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• Reporting and Documentation
• provide what information is necessary for the
  specific source category
• Inventory Quality Assurance/Quality Control
• guidance and procedures to enable cross-checks
  during inventory compilations

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Chapter 6 Quantifying Uncertainties in Practice

• describes GPG in estimating and reporting
  uncertainties associated with both annual
  estimates emissions
• identifies types of uncertainty from the
  viewpoint of the inventory practitioner and shows
  how to obtain expert judgment in a consistent
  manner
• provides two tiers for combining source category
  uncertainties into an uncertainty estimate for
  total national emissions

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Chapter 7 Methodological Choice and Recalculation

• how to identify key source categories in the
  national inventory
• how to systematically manage methodological
  change overtime and ensure that trends in
  national emissions are consistently estimated

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Chapter 8 Quality Assurance and Quality Control

• covers measurement standards, routine
  computational and completeness checks, and
  documentation and data archiving procedures to be
  applied to the inventory at the compilation
  stage.
• describes a system of independent review and
  auditing that could be implemented by inventory
  agencies
• covers only actions that inventory agencies could
  take in respect of their own inventories

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Annex 1 Conceptual Basis for Uncertainty Analysis

• deals with the concepts that underlie the
  practical advice on uncertainties provided in the
  Chapters 2 to 8 of the main report (statistical
  concepts, sources of uncertainties, applications)

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Annex 2 Verification

• discusses international and scientific aspects,
  options or tools for inventory verification
• includes practical guidance for verification of
  emissions inventories

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Annex 3 Glossary

• defines the terms of particular interest in the
  context of greenhouse gas inventories
• summarises mathematical definitions of selected
  statistical terms for convenient reference

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Key Source Category

• A key source category is one that is
  prioritized within the national inventory system
  because its estimate has a significant influence
  on a countrys total inventory of direct
  greenhouse gases in terms of the absolute level
  of emissions, the trend in emissions, or both.

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Why do we need to identify key source categories
in the national inventory?

• inventory development is a resource intensive
  enterprise
• in most cases, resources are limited and have to
  be prioritized
• certain source categories are particularly
  significant in their contribution to the overall
  uncertainty of the inventory

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How do we identify Key Source Categories?

• It is important to identify these key source
  categories so that the resources available for
  inventory preparation may be prioritized and the
  best possible estimates prepared for the most
  significant source categories.

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Key Source Category Analysis

• Quantitative Approach relationship between the
  level and trend of each source categorys
  emissions and total national emissions (Level and
  Trend Assessments)
• Qualitative Approach considers other criteria
  that are not easily assessed through a
  quantitative analysis.

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Decision tree to identify key source categories
No
Determine key categories using the Tier 1 Level
Assessment and evaluating qualitative
considerations
Are inventory data available for more than one
year?
Yes
Are country-specific uncertainty estimates
available for each category estimate?
Determine key categories using the Tier 1 Level
and Trend Assessments and evaluating qualitative
criteria
No
Yes
Determine key categories using the Tier 2 Level
and Trend Assessments, incorporating national
uncertainty estimates and evaluating qualitative
criteria
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Quantitative Approach -Tier 1 Method Level
Assessment

• Equation 7.1
• Source Category Level Assessment
• Source Category Estimate / Total Estimate
• Lx,t Ex,t / Et
• Where
• Lx,t is the Level Assessment for source x in year
  t
• Source Category Estimate (Ex,t ) is the emission
  estimate of source category x in year t
• Total Estimate (Et) is the total inventory
  estimate in year t

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Table 7.2 Spreadsheet for the Tier 1 Analysis
Level Assessment
Column A list of IPCC source categories (see
Table 7.1, Suggested IPCC Source
Categories) Column B Direct Greenhouse Gas (
CO2, CH4, N2O, etc.) Column C Base year
emissions estimates from the national inventory
data, in CO2-equivalent units Column D Current
year emissions estimates from the most recent
national inventory, in CO2-equivalent
units Column E Level Assessment from Equation
7.1 Column F Cumulative total of Column E
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How to decide using Table 7.2?

• Any source category that meets the 95 threshold
  in any year should be identified as a key source
  category.

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Tier 1 Analysis Level Assessment (US Inventory)
IPCC Source Categories Direct Greenhouse Gas Base Year Estimate Current Year Estimate Level Assessment Cumulative Total of LA
CO2 Emissions from Stationary Combustion - Coal CO2 481.6 533.3 0.29 0.29
Mobile Combustion Road Other CO2 338.1 381.0 0.21 0.50
CO2 Emissions from Stationary Combustion - Gas CO2 266.0 313.1 0.17 0.68
CO2 Emissions from Stationary Combustion Oil CO2 176.8 177.5 0.10 0.77
CH4 Emissions from Solid Waste Disposal Sites CH4 56.2 66.7 0.04 0.81
Direct N2O Emissions from Agricultural Soils N2O 46.6 53.7 0.03 0.84
Mobile Combustion Aircraft CO2 50.5 50.1 0.03 0.87
Fugitive Emissions from Oil and Gas Operations 34.5 35.1 0.02 0.89
CH4 Emissions from Enteric Fermentation in Domestic Livestock CH4 32.7 34.1 0.02 0.91
Indirect N2O Emissions from Nitrogen Used in Agriculture N2O 18.8 20.4 0.01 0.92
Fugitive Emissions from coal mining and handling CH4 24.0 18.8 0.01 0.93
CH4 Emissions from Manure management CH4 14.9 17.0 0.01 0.94
Mobile Combustion Road and Other N2O 13.0 16.9 0.01 0.95
Mobile Combustion Marine CO2 16.4 15.4 0.01 0.96

TOTAL 1632.1 1813.6 1.00
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Tier 1 Method Trend Assessment
Equation 7.2 Source Category Trend Assessment
(Source Category Level Assessment) x ?
(Source Category Trend Total Trend)? Tx,t
Lx,t ? ( Ex,t - Ex,o) / Ex,t - (Et - Eo)/
Et? Where Tx,t is the Trend Assessment which
is the contribution of the source category to the
overall inventory trend (absolute value) Lx,t is
the Level Assessment for source x in year t
(Equation 7.1) Ex,t and Ex,o are the emissions
estimates of source category x in years t and 0,
respectively Et and Eo are the total inventory
estimates in years t and 0, respectively
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Table 7.3 Spreadsheet for the Tier 1 Analysis
Trend Assessment
Column A list of IPCC source categories (see
Table 7.1, Suggested IPCC Source
Categories) Column B Direct Greenhouse Gas (
CO2, CH4, N2O, etc.) Column C Base year
emissions estimates from the national inventory
data, in CO2-equivalent units Column D Current
year emissions estimates from the most recent
national inventory, in CO2-equivalent
units Column E Trend Assessment from Equation
7.2 recorded as an absolute number Column F
Percentage contribution to the total trend of the
national inventory Column G Cumulative Total of
Column F
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Tier 1 Analysis Trend Assessment (US Inventory)
IPCC Source Categories Direct Greenhouse Gas Base Year Estimate Current Year Estimate Trend Assessment Contribution to trend Cumulative Total
CO2 Emissions from Stationary Combustion - Oil CO2 176.8 177.5 0.01 19 0.19
CO2 Emissions from Stationary Combustion - Gas CO2 266.0 313.1 0.01 17 0.36
Emissions from Subs. for Ozone Depleting substances Several 0.3 14.7 0.01 14 0.50
Fugitive Emissions from Coal Mining handling CH4 24.0 18.8 lt0.01 8 0.58
Mobile Combustion Aviation CO2 50.5 50.1 lt0.01 6 0.64
Mobile Combustion Road Other CO2 338.1 381.0 lt0.01 5 0.69
CH4 Emissions from Solid Waste Disposal Sites CH4 56.2 66.7 lt0.01 4 0.73
Fugitive Emissions from Oil Gas Operations CH4 34.5 35.1 lt0.01 3 0.76
Mobile Combustion Marine CO2 16.4 15.4 lt0.01 3 0.79
PFC Emissions from Aluminum Production PFC 4.9 2.9 lt0.01 3 0.82
Mobile Combustion Road Other N2O 13.0 16.9 lt0.01 2 0.84
HFC-23 Emissions from HCFC-22 Manufacture HFC 9.5 8.2 lt0.01 2 0.87
CH4 Emissions from Enteric Fermentation in Livestock CH4 32.7 34.1 lt0.01 2 0.89
Direct N2O Emissions from Agricultural Soils N2O 46.6 53.7 lt0.01 2 0.91
CO2 Emissions from Stationary Combustion Coal CO2 481.6 533.3 lt0.01 2 0.92
N2O Emissions from Adipic Acid Production N2O 4.7 3.9 lt0.01 1 0.94
SF6 from Magnesium Production SF6 1.7 3.0 lt0.01 1 0.95
PFC, HFC SF6 Emissions from semicon. manuf. several 0.2 1.3 lt0.01 1 0.96

TOTAL 1632.1 1813.6 0.05 1.00
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Table 7.A3. Source Category Analysis Summary (US
Inventory)
A IPCC Source Categories B Direct Green-house Gas C Key Source Category Flag D If Column C is Yes, Criteria for identifi-cation E Comments
ENERGY SECTOR
CO2 Emissions from Stationary Combustion - Coal CO2 Yes Level, Trend
CO2 Emissions from Stationary Combustion Oil CO2 Yes Level, Trend

INDUSTRIAL SECTOR
N2O Emissions from Adipic Acid Production N2O Yes Trend


AGRICULTURE SECTOR


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Qualitative Approaches to identify key source
categories
Criteria to consider that are not easily assessed
through a quantitative analysis

• Use of mitigation techniques and technologies
• Expecting high emission growth
• Categories with high uncertainty
• Exhibiting unexpectedly low or high emissions

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Policy Relevance

• GPG2000 does not revise or replace the 96GLs
• Provides reference that complements and is
  consistent with the 96GLs
• specific source categories are the same or can be
  traced back to categories in 96GLs
• uses same functional forms for the equations, or
  their equivalent
• allows for correction of any errors or
  deficiencies that have been identified in the
  96GLs

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Conclusions

• it is through good practice guidance and
  uncertainty management that a sound basis can be
  provided to produce more reliable estimates of
  the magnitude of absolute and trend uncertainties
  in GHG inventories than has been achieved
  previously
• whatever the level of complexity of the
  inventory, good practice provides improved
  understanding of how uncertainties may be managed
  to produce emissions estimates that are
  acceptable for the purposes of the UNFCCC (i.e.
  transparency, consistency, comparability,
  completeness and accuracy in inventories), and
  for the scientific work associated with GHG
  inventories.

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