OVERVIEW OF THE IPCC
GUIDELINESThis document is one volume of the Revised 1996 IPCC Guidelines for
National Greenhouse Gas Inventories.
The series consists of three books:•THE GREENHOUSE GAS INVENTORY REPORTING INSTRUCTIONS•THE GREENHOUSE GAS INVENTORY WORKBOOK•THE GREENHOUSE GAS INVENTORY REFERENCE MANUAL

These books together provide the range of information needed to plan,
carry out and report results of a national inventory using the IPCC system.
The Reporting Instructions (Volume 1) provides step-by-step directions forassembling, documenting and transmitting completed national inventory dataconsistently, regardless of the method used to produce the estimates.
These instructions are intended for all users of the IPCC Guidelines andprovide the primary means of ensuring that all reports are consistent andcomparable.
The Workbook (Volume 2) contains suggestions about planning and getting
started on a national inventory for participants who do not have a national
inventory available already and are not experienced in producing suchinventories. It also contains step-by-step instructions for calculating
emissions of carbon dioxide (CO2) methane (CH4), nitrous oxide (N2O),
halocarbons (HFCs, PFCs), sulphur hexafluoride (SF6), ozone and aerosol
precursors, from six major emission source categories. It is intended tohelp experts in as many countries as possible to start developing inventories
and become active participants in the inventories programme.
The Reference Manual (Volume 3) provides a compendium of information on
methods for estimation of emissions for a broader range of greenhousegases and a complete list of source types for each. It summarises a range ofpossible methods for many source types. It also provides summaries of thescientific basis for the inventory methods recommended and gives extensive
references to the technical literature. It is intended to help participants at
all levels of experience to understand the processes which cause
greenhouse gas emissions and removals to occur and the estimation
methods used in compiling inventories.

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Contents of the IPCC Guidelines
All three volumes begin with the following sections:Acknowledgements
Preface
Overview of the IPCC Guidelines
The contents of each volume are as follows:
Volume 1: Greenhouse Gas Inventory Reporting Instructions
Introduction to the Reporting Instructions
Chapter 1: Understanding the Common Reporting Framework
Chapter 2: Reporting the National Inventory
Tables:Sectoral Report Tables
Summary Report Tables
Overview Table
Annex 1: Managing Uncertainties
Annex 2: IPCC and CORINAIR Source Categories
Glossary
Volume 2: Greenhouse Gas Inventory Workbook
Introduction to the Workbook
Module 1: Energy
Module 2: Industrial Processes
Module 3: Solvent and Other Product Use
Module 4: Agriculture
Module 5: Land-Use Change and Forestry
Module 6: Waste
Volume 3: Greenhouse Gas Inventory Reference Manual
Introduction to the Reference Manual
Chapter 1: Energy
Chapter 2: Industrial Processes
Chapter 3: Solvent and Other Product Use
Chapter 4: Agriculture
Chapter 5: Land-Use Change & Forestry
Chapter 6: Waste

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Before you start...
This diagram explains the stages needed to make a national inventory whichmeets IPCC standards.

Yes

Do you have a detailed
National Inventory?

NoAggregate/transform
data and put into
standard format as
outlined in the Reporting
Instructions

Plan inventory
Assemble data

Use manual work
sheets in Workbook

NoDo you want to use
IPCC Computer SoftwareYes

Use software andWorkbook

Reporting recommendations- documentation- verification- uncertainty
Use Reporting Instructions

Final National Inventory

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The flow diagram above illustrates how the different types of users(working at different levels of inventory detail) can use the various volumesof the Guidelines. You should recognise that reality is more complex than
this simple explanatory chart. Many countries may have some parts of theinventory complete at a high level of detail but may only be getting started
on other parts. It is quite likely that some users will need to do several
iterations of the thinking process reflected in the diagram with regard todifferent parts of their inventory.
The stages outlined in the flow diagram are:Question 1
Do you have a detailed national inventory?
Answer: Yes
If your country already has a complete national inventory, you should
transform the data it contains into a form suitable for use by IPCC. Thismeans transforming it into a standard format. In order to do this, use
Volume 1 of the IPCC Guidelines, Reporting Instructions. This gives details ofthe way in which data should be reported and documented.
Answer: NoYou should start to plan your inventory and assemble the data you willneed to complete the Worksheets in this book. Refer to the Getting Started
section of the Workbook.
AVAILABILITY/USE OF COMPUTERSOFTWARE

Question 2
Do you want to use the IPCC computer software?

IPCC computer software is available
with the IPCC Guidelines.
Thesoftware includes the same simple
default methods as presented in theWorkbook and the Sectoral andSummary Tables for reporting
inventories, as presented in theReporting Instructions. It is available
in English only.

Answer: Yes

This version of the software is being
produced in Excel 5.0.
If you would like to receive a copyof the software, send a letter or fax
to:
IPCC UNIT FOR GHG
INVENTORIES
Pollution Prevention and Control
Division
OECD, Environment Directorate
2, rue André-Pascal
75775 PARIS CEDEX 16
FRANCE
FAX: (33-1) 45 24 78 76

If you want to use the IPCC software, you will still follow the instructions
included in the Workbook to assemble the data you have collected into an
inventory (see margin box). You will use the software instead of the printed
worksheets to enter data.
Answer: No
If you do not use the IPCC software, use the Workbook and theWorksheets it contains to assemble the data you have collected into aninventory.
Finally...
Inventory data should be returned to IPCC in the form recommended in
the Reporting Instructions. It is important that, where you have used amethodology other than the IPCC Default Methodology, it is properly
documented. This will ensure that national inventories can be aggregatedand compared in a systematic way in order to produce a coherent regionaland global picture.

General Notes on the Guidelines
Scope:•OVERVIEW.4

The IPCC Guidelines are designed to estimate and report on national
inventories of anthropogenic greenhouse gas emissions and removals.

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In general terms “anthropogenic” refers to greenhouse gas emissions
and removals that are a direct result of human activities or are theresult of natural processes that have been affected by human activities.
Users may include any human-induced emissions and removals in theirinventory as long as they can be clearly documented and quantified.
•National inventories should include greenhouse gas emissions andremovals taking place within national (including administered)territories and offshore areas over which the country has jurisdiction.
There are, however, four qualifications of this principle in theGuidelines:(a) Emissions based upon fuel sold to ships or aircraft engaged ininternational transport should not be included in national totals
but reported separately.
(b) Emissions from road vehicles should be attributed to the country
where the fuel is loaded into the vehicle. The error in nationalemissions introduced in the case of road transport is expected tobe small.
(c) Emissions from the combustion or decay of wood and wood
products are assumed to take place in the country in which thewood was harvested and within a year of harvesting. This isbecause it has been determined that the most workable approachto estimating CO2 emissions and removals from forests is toaccount for changes in stocks of standing biomass in forests andother locations. The simple assumption is that wood removed
from stocks releases CO2 emissions in the year and in the country
where the wood was removed. While the IPCC method allows
for accounting of exports and carbon stored in products, it does
not yet provide a methodology, which is a priority for future work.
(d) In line with the principle of national emissions, the IPCC
methodology accounts for the bulk of greenhouse gas emissions
related to fuel combustion in the country in which those emissions
are released. The IPCC methodology for carbon stored in nonfuel products manufactured from fuels as raw materials takes into
account emissions released from those products during their use
or destruction. Emissions are attributed to the country where theconversion to non-energy products takes place, even when theproducts are traded internationally. This is believed to be a
relatively small net error, but it is also a priority for future work.

Data Quality and Time Frame:•The data available to estimate anthropogenic greenhouse gas emissions
resulting from fuel combustion are generally of a better quality than thedata available to estimate greenhouse gas emissions and removals in theareas of agriculture and land use change/forestry. Accordingly, while
the IPCC Guidelines request an emission figure for a single year in mostsource/sink sectors, three-year averages (with the base year in themiddle) are preferred in the areas of agriculture and land usechange/forestry. In addition, the IPCC Guidelines recognise thatgreenhouse gas emissions and removals in the area of land usechange/forestry can occur over an extended period of time once theactivity has been completed. For example, when estimating emissions

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from the abandonment of forests and grasslands, users are requested
to estimate emissions related to two time periods of previous activity:(a) 0 - 20 years ago, and (b) 20 - 100 years ago.
Default Method:•The IPCC Guidelines contain “default” methodologies for the estimationof greenhouse gas emissions and removals. Users are encouraged togo beyond these minimum default methods where possible, and report
the results.
The IPCC Guidelines also include a number of “default” assumptions anddata for use in the estimation of greenhouse gas emissions andremovals. This default information is included primarily to provide
users with a starting point from which they can develop their own
national assumptions and data. Indeed, national assumptions and data
are always preferred because the default assumptions and data may notalways be appropriate for specific national contexts.
In general, therefore, default assumptions and data should be used only
when national assumptions and data are not available. Section 2 of theIntroduction to the IPCC Greenhouse Gas Inventory Workbook
provides information on the quality of the default data available indifferent greenhouse gas source/sink categories. When it is indicatedthat the data available are of low quality, users should recognise thatthe default data do not provide a basis for the development of adefinitive inventory of that source/sink category.

•Many of the categories of greenhouse gas emissions and removals canbe estimated only with large ranges of uncertainty. Quite naturally,some national experts have developed methods which are designed toproduce ranges of estimates rather than point estimates for highly
uncertain categories. The IPCC Guidelines, however, require that users
provide a single point estimate for each gas and emissions/removalcategory. This is simply to make the task of compilation, comparisonand evaluation of national reports manageable. Users are encouraged
to provide uncertainty ranges or other statements of confidence orquality along with the point estimates. The procedures for reporting
uncertainty information are discussed in the Greenhouse Gas Inventory
Reporting Instructions.

Double Counting of Emissions:
The methods proposed for the estimation of emissions sometimes simplify
the inventory construction in order to use data which are more readily
available than those needed for a detailed and more precise approach. Incertain cases this may cause or increase the risk of double counting
emissions. There are two areas where this may occur in the Guidelines.
1)
All countries preparing CO2 inventories using the IPCC Guidelines
are asked to estimate the emissions from fuel combustion using the IPCC
Reference Approach either as the primary means of preparing theinventory or as a verification stage following the preparation of an inventory
using national methods. The Reference Approach is a simple procedure
which demands relatively little data and lends itself to wide-spread
application as a "common denominator".

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The Reference Approach provides an upper bound to CO2 emissions
inferred from the country's supply of fossil fuels by identifying the carbon
content, subtracting from it the carbon stored in non-energy products andproducts made from fuels used as raw material, adjusting for carbon which
remains unburnt and multiplying by 44/12. It is an upper bound1 becausesome of the carbon will be emitted in forms other than CO2, in part
because fuel combustion is not always complete but also because fuels mayleak or evaporate. Consequently the CO2 emissions figure obtained fromthe Reference Approach will include carbon emitted as CH4, CO or
NMVOC. At the same time the Guidelines encourage countries to estimate
separate inventories for these gases and when this is done these gases arereported twice, in their emitted form and as CO2. It is in this sense thatthey are "double counted".
Use of the Reference Approach carries with it two consequences whichshould be carefully noted.
Because the Reference Approach uses fossil fuel supply statistics as a basis
for determining the carbon supply•

Not all carbon based emissions from fossil fuel are reported twice.
The Reference Approach CO2 estimate will not include emissions
from combustion or release of fossil fuels for which the corresponding
quantities (activity data) are not included in national production or
import figures. Notable examples of activities which lead to emissions
not included are the venting of natural gases from coal mining andhandling and oil and gas production. Emissions from the flaring ofnatural gases are also excluded. As a result, when emissions fromthese activities are included in the relevant inventories using thefugitive emissions methodologies recommended in the Guidelines no"double counting" occurs.

•CO2 emissions from biomass used as fuels are excluded from the total
CO2 emissions figure. The restriction of the Reference Approach tofossil fuels results from the sustainable nature of biofuels. The CO2emissions are, however, reported for information purposes. Notethat non-CO2 emissions from biofuels are included in their respectiveinventories.

2)
Double counting may also occur when calculated emissions fromthe manufacture of products from fuels used as raw materials or from theuse of fuels for their physical properties (e.g. lubricants) include emissions
produced from the later destruction of these products. The double countwill be with any separate reporting within the Waste module of theGuidelines of emissions from destruction.
3)
When a national CO2 inventory is constructed from emissions
estimated for each source category using emission factors derived frommeasurements on combustion plant, care should be taken to include theCO2 equivalent of other fossil carbon based emissions from the source
1 In practice, because of inaccuracies in the supply statistics and/oremission factors, CO2 estimates from the Reference Approach may be lessthan those obtained by summing all CO2 emissions from the combustion offuel.

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category. In this manner, the resulting total CO2 emissions can becompared with the result of the CO2 Reference Approach as part of theinventory verification stage. If, however, CO2 emission factors, derived
from the carbon content of the fuel, are used then no addition of the CO2
equivalent of carbon gases is required.

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