IPCC Good Practice Guidance IPCC Good Practice Guidance and Uncertainty Management in and Uncertainty Management in

National Greenhouse Gas National Greenhouse Gas InventoriesInventories

UNFCCC Workshop on the Preparation of National Communications from non-Annex I Parties

April 26-30, 2004, Manila

Leandro BuendiaProgramme Officer, IPCC-NGGIP-TSU

(lbuendia@iges.or.jp)

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.

Decision 17/CP.8

MethodologiesPara 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.

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.

Contents

Background InformationWhat is good practice guidance Contents of the ReportKey Source CategoryPolicy RelevanceConclusion

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

Background Information

IPCC Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories (GPG2000)

Published in 2000

What is good practice guidance?

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

in which uncertainties are reduced as far as is practicable

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

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

Further aims, to produce inventories which are:

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

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

1. Methodological Issues Choice of method Choice of emission factors Choice of activity

2. Completeness

3. Developing a Consistent Time series

4. Uncertainty Assessment

5. Reporting and Documentation

6. Inventory Quality Assurance/Quality Control

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

Doesthe country manage

cattle, buffalo, sheep, goats, camels, mules/asses, swine, or other

livestock?

Report‘Not Occurring’

No

Is enteric fermentation a key source category?

(Note 1)

Ask for each species: Is this

sub-source category significant?

(Note 2)

Yes

Yes

Estimate emissionsfor the speciesusing Tier 2

Ask for each species: Are data available with which to

perform a Tier 2 estimate?

Estimate emissions for the species

using Tier 1

Figure 4.2 Decision Tree for CH4 Emissions from Enteric Fermentation

No

No

No

Yes Yes

2. Completeness advice to ensure complete estimates

3. Developing a Consistent Time series advice to ensure consistency throughout

the time series

4. Uncertainty Assessment provide default values for uncertainty

ranges

5. Reporting and Documentation provide what information is necessary

for the specific source category

6. Inventory Quality Assurance/Quality Control guidance and procedures to enable

cross-checks during inventory compilations

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

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

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

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)

Annex 2 Verification

discusses international and scientific aspects, options or tools for inventory verification

includes practical guidance for verification of emissions inventories

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

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 country’s total inventory of direct greenhouse gases in terms of the absolute level of emissions, the trend in emissions, or both.”

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

“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.”

…How do we identify Key Source Categories?

Key Source Category Analysis

Quantitative Approach – relationship between the level and trend of each source category’s emissions and total national emissions (Level and Trend Assessments)

Qualitative Approach – considers other criteria that are not easily assessed through a quantitative analysis.

Decision tree to identify key source categories

No

Yes

No

Are inventory data available for

more than one year?

Arecountry-specific

uncertainty estimates available for each category

estimate?

Determine key categories using the Tier 2 Level and Trend Assessments,

incorporating national uncertainty estimates and evaluating qualitative

criteria

Determine key categories using the Tier 1 Level Assessment and

evaluating qualitative considerations

Determine key categories using the Tier 1 Level and Trend

Assessments and evaluating qualitative criteria

Yes

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

Table 7.2: Spreadsheet for the Tier 1 Analysis – Level Assessment

AIPCC

SourceCategories

BDirect

GreenhouseGas

CBase YearEstimate

DCurrent

YearEstimate

ELevel

Assessment

FCumulative

Total

TOTAL

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 unitsColumn D – Current year emissions estimates from the most recent national inventory, in CO2-equivalent unitsColumn E: Level Assessment from Equation 7.1Column F: Cumulative total of Column E

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.

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

Tier 1 Method Trend Assessment

Equation 7.2Source 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

Table 7.3: Spreadsheet for the Tier 1 Analysis – Trend Assessment

AIPCC

SourceCategories

BDirect

GreenhouseGas

CBase YearEstimate

DCurrent

YearEstimate

ETrend

Assessment

F%

Contrib’n toTrend

GCumulative

Total ofColumn F

TOTAL

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 unitsColumn D – Current year emissions estimates from the most recent national inventory, in CO2-equivalent unitsColumn E: Trend Assessment from Equation 7.2 recorded as an absolute numberColumn F: Percentage contribution to the total trend of the national inventoryColumn G: Cumulative Total of Column F

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 <0.01 8 0.58

Mobile Combustion: Aviation CO2 50.5 50.1 <0.01 6 0.64

Mobile Combustion: Road & Other CO2 338.1 381.0 <0.01 5 0.69

CH4 Emissions from Solid Waste Disposal Sites CH4 56.2 66.7 <0.01 4 0.73

Fugitive Emissions from Oil & Gas Operations CH4 34.5 35.1 <0.01 3 0.76

Mobile Combustion: Marine CO2 16.4 15.4 <0.01 3 0.79

PFC Emissions from Aluminum Production PFC 4.9 2.9 <0.01 3 0.82

Mobile Combustion: Road & Other N2O 13.0 16.9 <0.01 2 0.84

HFC-23 Emissions from HCFC-22 Manufacture HFC 9.5 8.2 <0.01 2 0.87

CH4 Emissions from Enteric Fermentation in Livestock CH4 32.7 34.1 <0.01 2 0.89

Direct N2O Emissions from Agricultural Soils N2O 46.6 53.7 <0.01 2 0.91

CO2 Emissions from Stationary Combustion – Coal CO2 481.6 533.3 <0.01 2 0.92

N2O Emissions from Adipic Acid Production N2O 4.7 3.9 <0.01 1 0.94

SF6 from Magnesium Production SF6 1.7 3.0 <0.01 1 0.95

PFC, HFC & SF6 Emissions from semicon. manuf. several 0.2 1.3 <0.01 1 0.96

…… …… …… …… …… ……

TOTAL 1632.1 1813.6 0.05 1.00

Table 7.A3. Source Category Analysis Summary (US Inventory)

AIPCC Source Categories

BDirect Green-

house Gas

CKey Source Category Flag

DIf Column C is Yes, Criteria for identifi-cation

EComments

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

……

Qualitative Approaches to identify key source categories

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

Criteria to consider that are not easily assessed through a quantitative analysis:

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 96GLsuses same functional forms for the equations, or

their equivalentallows for correction of any errors or deficiencies

that have been identified in the 96GLs

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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