Overview

2019 REFINEMENT TO THE 2006
IPCC GUIDELINES FOR
NATIONAL GREENHOUSE GASINVENTORIESOVERVIEW

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

1Overview

Authors
Eduardo Calvo Buendia (Peru), Sabin Guendehou (Benin), Bundit Limmeechokchai (Thailand), Riitta Pipatti(Finland), Yasna Rojas (Chile), Rob Sturgiss (Australia), Kiyoto Tanabe (Japan), Tom Wirth (USA)
Daniela Romano (Italy), Jongikhaya Witi (South Africa), Amit Garg (India), Melissa M. Weitz (USA), Bofeng
Cai (China), Deborah A. Ottinger (USA), Hongmin Dong (China), James Douglas MacDonald (Canada),
Stephen Michael Ogle (USA), Marcelo Theoto Rocha (Brazil), Maria José Sanz Sanchez (Spain), Deborah M.
Bartram (USA), Sirintornthep Towprayoon (Thailand)

Review Editors
Dario Gómez (Argentina) and William Irving (USA)22019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

Contents
Overview
1

Introduction .............................................................................................................................................. 42

Background .............................................................................................................................................. 53

Key concepts unchanged from the 2006 IPCC Guidelines ...................................................................... 6

4

Coverage of the 2019 Refinement ............................................................................................................ 7

5

Relationship with the 2006 IPCC Guidelines ........................................................................................... 9

6

Specific developments in the 2019 Refinement ..................................................................................... 11

TablesTable 1

Types of refinement from inventory compliers’ perspective............................................................ 9

Boxes
Box 1

Significance and prioritization criteria ............................................................................................. 7

Box 2

Example of mapping table to relate the 2019 Refinement to the 2006 IPCC Guidelines (Vol.4) .. 102019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

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Overview

1 INTRODUCTION
The 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2006 IPCC Guidelines) which were
published in 2006 provide methodologies for estimating national inventories of anthropogenic emissions bysources and removals by sinks of greenhouse gases. This IPCC Methodology Report titled the 2019 Refinement
to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2019 Refinement) was published in 2019
to refine the 2006 IPCC Guidelines with the aim to provide an updated and sound scientific basis for supporting
the preparation and continuous improvement of national greenhouse gas inventories.
In order to achieve this overall aim, the 2019 Refinement:•

Provides supplementary methodologies for sources and sinks of greenhouse gases only where currently there
are gaps or where new technologies and production processes have emerged requiring elaborated
methodologies or for sources and sinks that were not well covered by the 2006 IPCC Guidelines;•

Provides updated default values of emission factors and other parameters based on the latest available
scientific information only where significant differences from the default values presented in the 2006 IPCC
Guidelines are identified;•

Provides additional or alternative up-to-date information and guidance, where possible, as clarification orelaboration of existing guidance in the 2006 IPCC Guidelines.

The 2019 Refinement does not revise the 2006 IPCC Guidelines, but updates, supplements and/or elaborates the2006 IPCC Guidelines where gaps or out-of-date science have been identified. It does not replace the 2006 IPCC
Guidelines, but should be used in conjunction with the 2006 IPCC Guidelines and, where indicated, with the2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands (Wetlands
Supplement).

42019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

2 BACKGROUND
The Bureau of IPCC Task Force on National Greenhouse Gas Inventories (TFB), at its 26th meeting held in
Ottawa, Canada in August 2014, concluded that:•

The 2006 IPCC Guidelines provide a technically sound methodological basis of national greenhouse gas
inventories, and therefore fundamental revision was unnecessary.

•

To maintain the scientific validity of the 2006 IPCC Guidelines, certain refinements might be required,taking into account scientific and other technical advances that had matured sufficiently since 2006.

Following these conclusions by the TFB and also in accordance with the approval by the IPCC at its 40th Session
held in Berlin, Germany in April 2014, the Task Force on National Greenhouse Gas Inventories (TFI) started atechnical assessment of IPCC inventory guidelines through an on-line questionnaire survey and four expert
meetings in 2015 and 2016 1,2,3,4.
The technical assessment revealed that there had been new scientific and empirical knowledge related to sources
and sinks of greenhouse gases as well as inventory management published since 2006 that the IPCC should take
into account, particularly with respect to data for emission factor development for some categories and gases.
Consequently, the TFB recognized the necessity and usefulness of refining the 2006 IPCC Guidelines, andconcluded that the refinement should be made as early as possible so as to help all the Parties to the United
Nations Framework Convention on Climate Change (UNFCCC) use good practice inventory methodologies
based on up-to-date scientific knowledge.
The IPCC, at its 43rd Session in Nairobi, Kenya in April 2016, approved the proposal made by the Co-Chairs of
TFI on “Refinement of 2006 IPCC Guidelines for National Greenhouse Gas Inventories, including production of
a Methodology Report(s)” 5 . At the same session, the IPCC decided to consider the outline of the new
Methodology Report(s) at the 44th Session of the IPCC in October 2016 and to consider the draft Methodology
Report(s) at a Plenary session of the IPCC in May 2019 6. Following this decision, a scoping meeting for a
Methodology Report(s) to refine the 2006 IPCC Guidelines was held in Minsk, Belarus in August 2016. The
outcome of the scoping meeting was approved by the TFB at its 28th meeting which was held immediately after
the scoping meeting, and submitted to the IPCC for consideration. Finally the IPCC, at its 44th Session in
Bangkok, Thailand in October 2016, decided to prepare the 2019 Refinement and adopted its scope and outline 7.

1 Expert Meeting for Technical Assessment of IPCC Inventory Guidelines (Energy, IPPU, Waste Sectors), 29 June - 1 July

2015, Geneva, Switzerland
2 Expert Meeting for Technical Assessment of IPCC Inventory Guidelines (AFOLU Sector), 13-16 July 2015, São Paulo,

Brazil
3 Expert meeting for Technical Assessment of IPCC Inventory Guidelines: follow-up on specified issues from the 2015

expert meetings, 25-26 April 2016, Wollongong, Australia
4 Expert

meeting for Technical Assessment of IPCC Inventory Guidelines (Cross-sectoral issues), 27-29 April 2016,
Wollongong, Australia

5 Decision IPCC/XLIII-8 “Update of methodologies on National Greenhouse Gas Inventories”
6 Decision IPCC/XLIII-7 “Sixth Assessment Report (AR6) Products. Strategic Planning”
7 Decision IPCC/XLIV-5 “Sixth Assessment Report (AR6) Products, Outline of the Methodology Report(s) to refine the2006 IPCC Guidelines for National Greenhouse Gas Inventories”

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

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3 KEY CONCEPTS UNCHANGED FROM THE
2006 IPCC GUIDELINES
The following key concepts should be noted when using the 2019 Refinement. These are consistent with the2006 IPCC Guidelines.
•

Guidance is provided for greenhouse gas inventory arrangements and management, data gathering,compilation, and reporting. Reporting refers to the presentation of emission inventory estimates in tables orother formats used to communicate inventory information. The guidance is relevant but not prescriptive withrespect to the reporting of national inventories under international agreements, and the use of reported
information under these agreements.

•

Reporting tables are provided in Volume 1 as part of general guidance for reporting. They are not intended
to prescribe specific reporting formats under the UNFCCC that should be developed and agreed by theParties to the UNFCCC.

•

Methods are provided for estimating emissions (and removals as appropriate) for each gas in mass units. It
does not recommend any specific metrics (e.g., GWP values) to calculate emission estimates in CO2
equivalent units. Some guidance (e.g., key category analysis) suggests calculation of emission estimates in
CO2 equivalent, for which inventory compilers may use any metrics that are designed to convert greenhousegas emissions into CO2 equivalent.

•

A tier represents a level of methodological complexity. Usually three tiers are provided. Tier 1 is the basic
method, Tier 2 intermediate and Tier 3 the most demanding in terms of complexity and data requirements.
Tiers 2 and 3 are sometimes referred to as higher tier methods and are generally considered to be moreaccurate on condition that adequate data are available to develop, evaluate and apply a higher tier method.

•

This guidance assists countries in compiling complete, national inventories of greenhouse gases. The
guidance has been structured so that any country, regardless of experience or resources, should be able toproduce reliable estimates of their emissions and removals of these gases. It uses the overarching frameworkand the concepts consistent with the 2006 IPCC Guidelines. National greenhouse gas inventories rely on a
few key concepts for which there is a common understanding (see Chapter 1, Volume 1). This helps ensurethat inventories are comparable between countries, do not contain double counting or omissions, and that thetime series reflect actual changes in emissions.

•

Some technical material is presented in appendices, where emissions or removals are poorly understood andwhere there is insufficient information available to develop reliable, globally applicable, default methods fora particular source or sink. Countries may use appendices as a basis for further methodological development,
but a national inventory can be considered complete without the inclusion of estimates for these sources.

6

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

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4 COVERAGE OF THE 2019 REFINEMENT
The 2019 Refinement covers all IPCC inventory sectors but refinements are included for only those categories
where the science was considered to have sufficiently advanced since 2006 or where new or additional guidance
was required. The specific categories that have been refined through this process were selected through atechnical assessment carried out in 2015 and 2016 and a subsequent scoping meeting held in August 2016 using
the significance and prioritization criteria shown in Box 1 8.

BOX 1
SIGNIFICANCE AND PRIORITIZATION CRITERIA

•

•
•

•

Significance of the source/sink and the gas within the sector on a global scale.
Sources significant only for a limited number of particular countries, currently or in theforeseeable future, may not meet this criterion. The adequacy of the existing guidance for aparticular category should be considered, as should the likelihood that new information would
lead to a definite improvement in the IPCC Guidelines.
Availability of relevant new scientific results.
Sufficient data availability and maturity of scientific advances since 2006 to provide a basis
for methodological development or refinement, including (1) ability to develop new or
updated default emission/removal factors; and (2) feasibility of obtaining the necessary data to
implement the methods.
Emergence of new sources or gases meeting these criteria.

The outline of the 2019 Refinement adopted by the IPCC was developed on the basis of the categories selected
through the process mentioned above. However, the IPCC also agreed on the following principles when theoutline was adopted.
•

Authors should develop modifications even for those chapters/sections/subsections where “No refinement”
is indicated in the approved table of contents, if deemed necessary to ensure consistency with therefinements made in the other chapters/sections/subsections.

•

Authors may conclude no refinement should be made even for the chapters/sections/subsections whererefinement is expected in this approved table of contents, after comprehensive review of available literature.

In addition to the greenhouse gases included in the 2006 IPCC Guidelines, the 2019 Refinement includes gases
for which global warming potential (GWP) values are given in one of the subsequent IPCC Assessment Reports,
unless the gases are covered by Annexes A through E of the Montreal Protocol. (Annex F of the Montreal
Protocol lists hydrofluorocarbons, which are included in the 2019 Refinement.) The 2019 Refinement also
provides estimation methods for halogenated greenhouse gases for which GWP values were not available from
IPCC Assessment Reports at the time the 2019 Refinement was developed. (See Volume 1, Chapter 8 andVolume 3, Chapters 6, 7, and 8 for examples of both sets of gases.)
The 2006 IPCC Guidelines contain links to information on methods used under other agreements andconventions, for the estimation of emissions of tropospheric precursors which may be used to supplement thereporting of emissions and removals of greenhouse gases. The 2019 Refinement follows this approach, and does
not provide methods for the estimation of emissions of tropospheric precursors (see Chapter 7, Volume 1).
The structure of the 2019 Refinement is the same as that of the 2006 IPCC Guidelines so as to make it easier for
inventory compilers to use the 2019 Refinement with the 2006 IPCC Guidelines. It comprises an Overview
Chapter (this chapter) and the following five volumes.
•

Volume 1: General Guidance and Reporting;•

Volume 2: Energy;

8

There are potential issues for future revision or refinement that are not addressed in the 2019 Refinement, including those
identified during the Technical Assessment in 2015-2016 but considered too early to work on, as well as those identified
after the approval of table of contents of the 2019 Refinement by the IPCC at its 44th Session in Bangkok, Thailand in
October 2016.

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

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Overview•

Volume 3: Industrial Processes and Product Use (IPPU);•

Volume 4: Agriculture, Forestry and Other Land Use (AFOLU);•

Volume 5: Waste.

Across all the volumes, some additional sections have been included. The guidance focuses on inventory
methodologies rather than on scientific discussions of the background material, for which references areprovided.

8

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

5 RELATIONSHIP WITH THE 2006 IPCC
GUIDELINESAs stated in Section 1 above, the 2019 Refinement does not revise the 2006 IPCC Guidelines, but updates,
supplements and/or elaborates the 2006 IPCC Guidelines where gaps or out-of-date science have been identified.
It does not replace the 2006 IPCC Guidelines, but should be used in conjunction with the 2006 IPCC Guidelines
and, where indicated, with the Wetlands Supplement. 9
In line with this principle, the 2019 Refinement was developed by:•

updating existing guidance in the 2006 IPCC Guidelines to address the needs explained in the first or second
bullet in Section 1 (Introduction) of this chapter. When updating a section or an entire chapter, in some cases
these sections or chapters have been entirely rewritten with new structure.

•elaborating existing guidance in the 2006 IPCC Guidelines to address the needs explained in the first or thirdbullet of Section 1 (Introduction) of this chapter.

•

adding completely new guidance on issues for which there is essentially no guidance in the 2006 IPCC
Guidelines to address the needs explained in the first bullet in Section 1 (Introduction) of this chapter.

With a view to helping inventory compilers understand the relationship between the 2019 Refinement and the2006 IPCC Guidelines, each volume has an annex titled “Mapping tables” to relate the 2019 Refinement to the2006 IPCC Guidelines. This annex in each volume provides a road map for relating sections, equations, tables,
figures and boxes in the 2019 Refinement to the 2006 IPCC Guidelines. In these annexes, types of refinement(update, new guidance, no refinement or removed) are clarified for chapters/sections/subsections from inventory
compilers’ perspective in order to help them understand how they should use the 2019 Refinement. The types ofrefinement used there are explained in Table 1 below.
TABLE 1TYPES OF REFINEMENT FROM INVENTORY COMPLIERS’ PERSPECTIVE
Type of refinement

Explanation

UpdateInventory compilers should use the chapter/section/subsection in the 2019 Refinement insteadof the corresponding chapter/section/subsection in the 2006 IPCC Guidelines.

New Guidance

Recognizing that there is no guidance in the 2006 IPCC Guidelines, inventory compilers
should use the chapter/section/subsection in the 2019 Refinement.

No Refinement

Inventory compliers should use the corresponding chapter/section/subsection in the 2006
IPCC Guidelines, because no refinement has been made in that chapter/section/subsection.

Removed

There were few cases where guidance/sections were removed because they were no longer
relevant.

Every chapter/section/subsection in the 2019 Refinement which is explained as “Update” or “New Guidance”
contains all necessary paragraphs, tables, figures, etc. including those unchanged from the 2006 IPCC
Guidelines, so that inventory compilers do not have to look back to the 2006 IPCC Guidelines.
In addition, with a view to ensure consistency with the 2006 IPCC Guidelines to the extent possible, efforts weremade to keep the numbering of tables, figures, boxes, equations the same as in the 2006 IPCC Guidelines. As aconsequence, the numbering of new/updated tables, figures, boxes, equations in the 2019 Refinement is notnecessarily in sequence.

9 The IPCC decided to produce the 2019 Refinement as a separate Methodology Report which should be used in conjunction

with the 2006 IPCC Guidelines. Consolidating all methodological guidance into a single Methodology Report would
require a new decision by the IPCC.

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

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BOX 2
EXAMPLE OF MAPPING TABLE TO RELATE THE 2019 REFINEMENT TO THE 2006 IPCC GUIDELINES (VOL.4)

U = Update, NG = New Guidance, NR = No Refinement"Good practice" is a key concept for inventory compilers to follow in preparing national greenhouse gas
inventories. The key concept does not change in the 2019 Refinement. The term "good practice" has been
defined, since 2000 when this concept was introduced 10 , as "a set of procedures intended to ensure thatgreenhouse gas inventories are accurate in the sense that they are systematically neither over- norunderestimates so far as can be judged, and that uncertainties are reduced so far as practicable". This definition
has gained general acceptance amongst countries as the basis for inventory development and its centrality has
been retained for the 2019 Refinement. Certain terms in the definition have been updated based on feedback fromthe statistics community, such that this definition can be also understood as "a set of procedures intended toensure that greenhouse gas inventories are accurate in the sense that they are systematically neither over- norunderestimates so far as can be judged, and that they are precise so far as practicable" in the context ofrefinement of Chapter 3 of Volume 1 11.
These requirements are intended to ensure that estimates of anthropogenic emissions by sources and removals bysinks, even if uncertain, are bona fide estimates, in the sense of not containing any biases that could have been
identified and eliminated, and that random errors have been reduced as far as practicable, given national
circumstances. Estimates of this type are presumably the best attainable, given current scientific knowledge andavailable resources. The 2019 Refinement also recognises the principles of transparency, accuracy, completeness,consistency and comparability defined in the 2006 IPCC Guidelines.

10 The definition was originally introduced with the Good Practice Guidance and Uncertainty Management in National

Greenhouse Gas Inventories published in 2000.
11 In the 2006 IPCC Guidelines, the term “uncertainty” was used with two meanings – a general one which is associated withboth accuracy and precision, and a specific one only as the inverse of precision. This definition text of “good practice”
which uses the term “precise” instead of “uncertainties” overcomes inconsistencies with general IPCC definition for
uncertainty, without changing the original concept of “good practice”.

102019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

6 SPECIFIC DEVELOPMENTS IN THE 2019
REFINEMENT
The 2019 Refinement contains the following specific developments, among others, since the 2006 IPCC
Guidelines:

Volum e 1 (General Guidance and Reporting)•National greenhouse gas inventory arrangements and management tools: The 2019 Refinement elaborates
guidance on establishing greenhouse gas inventory arrangements to support the development, improvement
and maintenance of national greenhouse gas inventories. This guidance is not designed to be prescriptive
given that the shape and form of greenhouse gas inventory arrangements depend on national circumstances.
Instead, the guidance provides approaches and examples of national greenhouse gas inventory arrangementsthat could be useful in establishing greenhouse gas inventory arrangements. In addition, institutionalarrangements include the interactions between institutions/organisations that are involved with thegreenhouse gas inventory inputs, compilation processes, and outputs. The 2019 Refinement provides new
guidance on generic inventory management tools such as workplans, improvement plans, data management
systems, quality systems, training and capacity building and documentation procedures. As it is the case forthe provided guidance on national greenhouse gas inventory arrangements, the management tools presented
in this new guidance should not be considered prescriptive. However, they provide some suggested
approaches and examples demonstrated to be useful when developing greenhouse gas inventory systems.
(Chapter 1)•

Data collection strategy: General guidance for collecting existing national/international data and new data iselaborated. The material can be used both by countries establishing a data collection strategy for the firsttime and by countries with established data collection procedures. It is also to be applicable to emission
factor, activity, and uncertainty data collection. (Chapter 2)•

Use of facility-level data in inventories: Detailed industrial facility-level data that are increasingly collected
for various goals such as tracking the progress of emission trading programmes or climate change policies
have the potential to be utilized in national greenhouse gas inventories. The challenge for inventory
compilers is assessing how best to integrate facility reported data to achieve improvements, especially ifthere are some outstanding coverage and completeness issues. The 2019 Refinement includes new guidanceon how best to use facility-level data that are not originally designed for national greenhouse gas inventory
compilation. A new decision tree for selecting facility-level data is provided as well as good practicereporting considerations associated with facility-level data used in the national greenhouse gas inventory.
(Chapter 2)•

Uncertainty analysis: The 2019 Refinement provides an update on uncertainties associated with activity data.
It also incorporates guidance on how to derive uncertainty estimates from activity data generated based on
random samples. This elaborated guidance has useful applications particularly in the AFOLU sector in
dealing with uncertainty estimates from land use surveys or forest cover surveys. The updated guidance also
includes key requirements for use of Approach 1 uncertainty assessment with examples. A practical stepby-step example demonstrating the use of Approach 2 uncertainty assessment (Monte-Carlo analysis) is also
provided to guide inventory compilers. (Chapter 3)•

Key category analysis: No major modifications with respect to the 2006 IPCC Guidelines have occurred but
a simplification of the equation to perform key category analysis using trend assessment (Approach 1) has
been implemented in the 2019 Refinement. General principles and guidance have been updated and an
updated trend approach is described. Priorities for maintenance and improvement of the inventory are
addressed, and new guidance in determining the appropriate level of disaggregation of greenhouse gas
estimates to identify key categories is provided. (Chapter 4)•

Non-linear interpolation: A new methodology for non-linear interpolation analysis has been added in the2019 Refinement, along with an example. This is relevant in cases where time series consistency is best
represented by multiplicative (exponential) rather than additive (linear) relationships. (Chapter 5)•

Comparison of greenhouse gas emission estimates with atmospheric measurements: Guidance oncomparison of greenhouse gas emission estimates with atmospheric measurement has been updated andelaborated to reflect the state of science for atmospheric measurements and their application to improving
national greenhouse gas inventories. These approaches can be used to provide additional scientificverification of inputs and results for particular categories and gases, and therefore help countries to target
areas of uncertainty. The most notable advances were achieved in the application of inverse models of
atmospheric transport for emission estimates at the national scale. Thus, atmospheric measurements are2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

11

Overview

being used to provide useful quality assurance of the national greenhouse gas emission estimates. The
guidance highlights key components and steps that can be applied when using atmospheric measurements
and inverse models for comparison with inventory emission estimates as part of a country’s overall QA/QC
and verification system as described in Chapter 6 of Volume 1. (Chapter 6)•

Use and reporting of models: The 2019 Refinement provides new guidance on the use and reporting ofmodels. This new guidance applies to complex models, generally Tier 3 approaches. A step-by-step
approach to report on the use of models in emission inventories is presented along with a checklist for
ensuring good practice in the use of complex, higher tier models in national greenhouse gas inventories.
(Chapter 6)•

Indirect greenhouse gas emissions: The 2019 Refinement includes a series of updates ranging from
improvements in the explanation of the methodology for indirect nitrous oxide (N2O) emissions from theatmospheric deposition of nitrogen in nitrogen oxides (NOx) and ammonia (NH3), detailed methodologicalguidance on treatment of carbon dioxide (CO2) inputs to the atmosphere from emissions of carboncontaining compounds, that are not already reported in GHG inventories an update on the backgroundscience on precursors and indirect emissions 12. The 2019 Refinement also incorporates new guidance on
non-biogenic sources of CO2 from the atmospheric oxidation of methane (CH4), carbon monoxide (CO), andnon-methane volatile organic compounds (NMVOCs), examples of NMVOCs from the different source
categories as well as guidance on carbon content of various materials and total solvent NMVOC emissions.
(Chapter 7)•

National GHG inventory coverage: The 2019 Refinement provides updated guidance on specific issues to betaken into account in national GHG inventories. The guidance now includes reporting of non-CO2 emissions
from the biochar production and CO2 and CH4 emissions from flooded land. Additionally, existing guidanceon reporting of captured biogenic CO2 was further clarified. (Chapter 8)

Volum e 2 (Energy)•

All methodological updates made in the 2019 Refinement are in the fugitive emissions categories. No
methodological updates were made for stationary combustion, mobile combustion, or other sources otherthan fugitives.

•

Fugitive CH4 and CO2 emissions from mining, processing, storage and transportation of coal: The 2019
Refinement includes guidance on fugitive CO2 emissions from underground and surface mines including
CO2 from methane utilization or flaring from underground coal mines. The 2019 Refinement adds yearspecific default input values for fugitive CH4 emissions from abandoned underground mines for 2017
through 2050 (previously the series of default values ended at 2016). A section on a basis for future
methodological development is presented in the Appendix for fugitive emissions from abandoned surface
mines and from coal exploration. (Chapter 4)•

Fugitive emissions from oil and natural gas systems: The 2019 Refinement includes updates to emission
factors to reflect the range of technologies and practices in use, including for unconventional oil and gas
exploration. Additional detail on the appropriate selection of factors considering technologies and practices
in place is provided. The 2019 Refinement includes methods and emission factors for abandoned wells. An
annex provides guidance on converting activity data inputs to the standard conditions applicable to theemission factors presented. Another annex provides data that allow compilers to disaggregate factors into
venting, leak, and flaring sources. As terminologies for technologies and practices can vary, an annex isprovided with definitions for key terms. (Chapter 4)•

Fugitive emissions from fuel transformation: The 2019 Refinement includes a new section on fugitive
emissions from fuel transformation, including methods for fugitive emissions from charcoal production,
biochar production, coke production, (including flaring), gasification transformation processes (coal toliquids, and gas to liquids), and methods in Appendix (biomass to liquids, biomass to gas, and wood pellet
production). These have been appropriately cross-referenced with Volume 3 (IPPU) and Volume 4(AFOLU). (Chapter 4)

12 Chapter 7 of Volume 1 refers to "inputs of CO to the atmosphere" to represent the unoxidized carbon contained in
2compounds (e.g., CO, NMVOCs, CH4) that are emitted from some anthropogenic activities. The CO2 is formed at a latertime in the atmosphere and not released directly from these activities

122019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

Volum e 3 (Industrial Processes and Product Use)•

New categories and new gases: The 2019 Refinement expands the scope of the 2006 IPCC Guidelines toinclude more manufacturing sectors identified as sources of greenhouse gases. These include production ofhydrogen, rare earth metals, and alumina, and waterproofing of circuit boards. In addition, a basis for future
methodological development is provided for fluorinated treatment of textiles, carpet, leather and paper.
Additional greenhouse gases identified in the IPCC Fourth and Fifth Assessment Reports, as well as otherreferences, are also included where anthropogenic sources have been identified. Greenhouse gases identified
in the IPCC Fourth and Fifth Assessment Reports include, for example, additional hydrofluorocarbons,
perfluorocarbons, and halogenated ethers, such as PFPMIE (a perfluoropolyether widely used as a heattransfer fluid in electronics manufacturing). (Chapters 3, 4, 6, 8)•

Updates: The guidance for several source categories has been updated. This includes the guidance for
production of nitric acid, fluorochemicals, iron and steel, aluminium, and electronics, and for the production
and use of refrigeration and air-conditioning equipment. (Chapters 3, 4, 6, 7) Important updates include:•For nitric acid, updates to the production process categories (e.g., to include dual-pressure processes)
and corresponding updates to the default emission factors for the Tier 2 method.

For fluorochemical production, updates to clarify the full range of emissions and their sources atfluorochemical production plants, updated default emission factors for the Tier 1 method, andupdates to the Tier 3 method to include emissions from equipment leaks and to provide more detailfor estimating emissions from process vents.



For iron and steel, updates to the guidance for metallurgical coke production to align it with the new
methods presented in the Energy Volume for fugitive emissions, and to present new methods suchas a Tier 1b simplified carbon balance method; updates to the methodological guidance for iron andsteel production to include improved decision-trees, a new Tier 2 method for methane emissions,
new Tier 3a (plant-specific carbon balance) and Tier 3b (based on emission measurements) methods
for carbon dioxide emissions, a new Tier 1 method for carbon dioxide emissions from flaring ofprocess gases, and new methods to estimate nitrous oxide emissions including a Tier 1 method foremissions from flaring of process gases. Default emission factors have been extensively updated,
and the Tier 2 material-specific carbon contents list has been extended and updated.

For aluminium, several updates to the guidance for estimating PFC emissions, including an updateto the smelting technology classes, updated default emission factors for the Tier 1 method, newguidance for estimating emissions from low-voltage anode effects, updated default emission factors
for the existing Tier 2 and Tier 3 (now Tier 2a and Tier 3a) methods for estimating emissions fromhigh-voltage anode effects (termed “anode effects” in the 2006 IPCC Guidelines), new Tier 2b andTier 3b methods for estimating emissions from high-voltage anode effects that better account for the
impact of anode effect duration, and a new Tier 3DM method for facility-specific direct
measurement of total PFC emissions. New guidance has also been added for estimating emissions
from the production of alumina through the Bayer-Sinter and Nepheline processes.

For electronics, new guidance on tracking gas consumption and on apportioning use to different
process types, updated and new Tier 2 methods that account for the size of manufactured wafers insemiconductor manufacturing, a new Tier 3b method for estimating emissions by developing
facility-specific emission factors at the stack level, new guidance on adapting Tier 2 methods toaccount for technological changes, new guidance for the sub-sector microelectromechanical systems(MEMS), and updates to the default emission factors for Tier 1 and Tier 2 methods, including an
expanded list of input gases, by-products, and fluorinated liquids.

For refrigeration and air conditioning, new “cook-book” style guidance on building an HFCemissions inventory (including guidance on data sources and on establishing the existing bank of
HFCs), and new and updated tables regarding the identity and distribution of substitutes for ozone
depleting substances (ODS) by application and by substance for both developing and developed
countries.

Updates to Figure 1.1 (Industrial Processes and Product Use categories): Figure 1.1 has been updated toreflect the changes described above by (1) adding subcategories for Hydrogen Production (2B10), Rare
Earths Production (2C7), Microelectromechanical Systems (2E4), and Waterproofing of Electronic Circuits(2G2c) to reflect the addition of new guidance for these subcategories; (2) adding several subcategories
under Fluorochemical Production to reflect the broad range of fluorochemical products, (3) updating thename of the Electronics subcategory previously called “TFT Flat Panel Display” to the more comprehensive“Display,” and (4) removing the subcategory “Heat Transfer Fluid” from the Electronics category, because
the fluorinated liquids previously covered by this subcategory may be used in any of the Electronics subsectors (Semiconductors, Displays, Photovoltaics, or MEMS), may be used for applications other than heat2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

13

Overviewtransfer (including for testing, soldering, and cleaning), and are identifiable through their chemical contents.
(Chapter 1)

Volum e 4 (Agricultur e, Forestry and Other Land Use)•Tier 3 model: Section on Tier 3 model has been refined to expand the guidance on how to parameterize andevaluate models, the integration of data to models, and means to increase its transparency. Case studies havebeen included to demonstrate how different countries have developed and worked with Tier 3 methods.
(Chapter 2)•

Interannual variability (IAV): A new section has been introduced to provide an option that may be used todisaggregate Managed Land Proxy (MLP) emissions and removals into those that are considered to result
from human effects and those that are considered to result from natural disturbances. This section may be ofinterest to countries with AFOLU sector emissions that have high IAV due to natural disturbances. The
section first addresses definitional issues, followed by a description of whether or not different
methodological approaches used to estimate carbon stock changes quantify the interannual variability ofemissions and removals. A generic approach to report the disaggregated contribution of natural disturbances
to the emissions and removals on managed lands is then provided, along with country-specific examples. For
those countries that choose to implement this disaggregation, it is good practice to report the total MLPemissions and removals as well as the disaggregated components. (Chapter 2)•

Biomass estimates: Biomass Tier 1 factors have been updated for Forest Land, Cropland and Settlements.
Guidance on Tier 1 methods for Cropland and Settlements has been refined and clarified. Guidance for timeseries consistency for Forest Land has also been updated. Factors for dead organic matter have been updated,and new sections on Tier 2 guidance for the use of allometric models and biomass maps have been
introduced. (Chapters 2, 4, 5, 8)•

Soil carbon: Tier 1 carbon stock change factors have been updated for tillage management, grassland
management and land use based on evolving understanding of management impacts on soils. Many of the
updated factors reflect a smaller impact of anthropogenic activity on soil carbon than default factors
provided in the 2006 IPCC Guidelines. Reference C stocks have also been updated based on an analysis of a
global dataset that produces more representative reference stocks for different soil types by climate regions.
The Tier 2 and Tier 3 methods have also been refined to estimate the impact of biochar amendments on soil
carbon stocks in mineral soils for cropland and grassland. More guidance is provided for developing Tier 2
stock change factors and Tier 3 methods. In addition, an alternative Tier 2 approach, i.e., steady-statemethod, been provided in the Cropland Remaining Cropland section of the report. (Chapters 2, 4, 5, 6, 7, 8)•

Rice cultivation: Tier 1 factors have been updated for the baseline emission factors, scaling factors for water
management regimes before and during cultivation periods, and conversion factors for organic amendments.
Default cultivation periods have also been added for estimating annual emission factors. (Chapter 5)•

Flooded Lands: New guidance is provided for CO2 and non-CO2 emissions from Land Converted to Flooded
Lands and Flooded Land Remaining Flooded Land. Methods for future development associated with thesesources were included in Appendix 2 and Appendix 3 of Volume 4 of the 2006 IPCC Guidelines. The
science has matured over the past decade and these sources are now included in the main guidance (insteadof appendices) of Chapter 7, Volume 4 of the 2019 Refinement for a more complete inventory of greenhousegas emissions from managed lands. The methods include estimation of total emissions following theManaged Land Proxy and an optional method to develop indicative estimates of the anthropogenic
component of total emissions 13. (Chapter 7)•

Livestock and manure management: Tier 1 emission factors have been updated considering current
productivity data and integrating differential emission factors and for high and low productivity systems.
Further, for major animal categories, Tier 1 parameters such as enteric fermentation EFs, volatile solids andnitrogen excretion are derived based on consistent data sources. The Tier 1 method to estimate CH4

13 In the outline of the 2019 Refinement approved by the IPCC at its 44th Session in Bangkok, Thailand in October 2016,

refinement was requested to update CO2 emission factors for land converted to flooded land (Wetlands) and to develop, on
the basis of comprehensive review of available literature, consistent methodologies that take into account factoring out ofemissions and removals that would otherwise occur in the absence of the flooded area for estimating CO2 and CH4
emissions from flooded lands (both land converted to flooded land and flooded land remaining flooded land). Methods
have been developed to comply with the direction from the 44th Session of the IPCC. These methods provide transparency
in terms of the total emissions from Flooded Land following the Managed Land Proxy, which is consistent with othermethodologies for the AFOLU sector, and an optional method to develop indicative estimates of the anthropogenic
component of total emissions for both Flooded Land Remaining Flooded Land and Land Converted to Flooded Land.

142019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Overview

emissions from manure management has been updated for consistency with N2O emissions. Certain Tier 2parameters have been refined. The methane conversion rate (Ym) for cattle and buffalo, varies based onanimal diet and level of productivity. The default methane conversion factor (MCF) values for animal waste
management systems are presented based on climatic regions, as opposed to annual temperatures, and asimple calculation model for deriving the MCF based on monthly temperature regimes has been presented.
Finally, improved guidance has been developed for the treatment of nitrogen transfers among livestock
emission source categories and transfers to agricultural soils. (Chapter 10)•

Soil N2O: Tier 1 estimates have been updated based on the latest science for direct and indirect emission
factors. A key development is the disaggregation of emission factors by climate region. (Chapter 11)•

Harvested wood products (HWPs): The methods and equations in the 2006 IPCC Guidelines have been
updated. The updated methods and equations better help inventory compilers to include the HWP poolestimates in greenhouse gas inventories using any of the approaches: 'stock-change' approach, 'production'
approach, ´simple-decay´ and 'atmospheric-flow' approach. (Chapter 12)

Volum e 5 (Waste)•

Waste generation, composition and management: The 2019 Refinement updates key parameters used in thefirst order decay (FOD) method including waste generation rate and waste composition by countries andregion using UN classification. The 2019 Refinement also provides default values and uncertainty of carbon
content, nitrogen content and degradable organic carbon (DOC) of domestic and industrial sludge. (Chapter
2)•

Estimation of CH4 emission from landfill: Guidance on the use of methane correction factor (MCF) in
different management conditions of solid waste disposal sites (SWDS) has been updated. New default
values for the MCF to estimate CH4 emissions from active aeration landfill have been provided by level oflandfill management (poorly and well managed). The IPCC Waste Model has been updated according to therefinement. Default values for the fraction of degradable organic carbon which decomposes (DOCf) for
different waste components and their uncertainties have been updated, and relevant guidance has been added.
(Chapter 3)•

Incineration and open burning of waste: Guidance on emission estimation from new technologies including
gasification and pyrolysis has been elaborated with provision of CH4 and N2O emission factors to ensure amore complete coverage of sources. Oxidation factor of municipal solid waste (MSW) open burning has
been updated. (Chapter 5)•CH4 emissions from wastewater treatment: Updated guidance is provided for the estimation of CH4 fromwastewater treatment, and updated emission factors for septic systems and centralised wastewater treatment
plants are provided. Updated emission factors are also provided for CH4 emissions from wastewater after
disposal of untreated wastewater or wastewater treatment effluent into aquatic environments. (Chapter 6)•

N2O emissions from wastewater treatment: New guidance and emission factors are provided for N2Oemissions from domestic and industrial wastewater treatment plants, and updated emission factors areprovided for N2O emissions from wastewater after disposal of untreated wastewater or wastewater treatment
effluent into aquatic environments. (Chapter 6)•

Non-biogenic (fossil) CO2 emissions from wastewater treatment and discharge: A discussion of nonbiogenic (fossil) CO2 emissions from wastewater treatment and discharge, where fossil organic carbon ispresent in wastewater or treatment sludge, is presented as an appendix as a basis for future methodologicaldevelopment. (Chapter 6)•

Discharge into aquatic environments: An alternate set of emission factors is provided for CH4 and N2Oemissions from wastewater after disposal of untreated wastewater or wastewater treatment effluent into
aquatic environments when the country has activity data to differentiate the conditions of the waterbody
receiving the discharge. (Chapter 6)

2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories

15