A Summary of the Revised 1996 IPCC Guidelines
for National Greenhouse Gas Inventories
Background
This report summarises additions and revisions to the 1995 IPCC Guidelines for National
Greenhouse Gas Inventories (1995 IPCC Guidelines). It also describes efforts made by theIPCC to harmonise methods with others. The additions and revisions were accepted by theIPCC at its Twelfth Session held in Mexico City (11-13 September 1996) after acceptance by
Working Group I at its Sixth Session held in Mexico City (10 September 1996) in accordancewith IPCC procedures. They are called the Revised 1996 IPCC Guidelines for National
Greenhouse Gas Inventories. Within this report, a revision of an existing methodology ordefault data is referred to as a ‘revision’, ‘revised method’ or ‘revised data’. Additional
methods and default data are defined as ‘new’ methods or ‘new data’.

Land-use Change and Forestry Chapter
1.
Several revisions to the methods for the Land-use Change and Forestry Chapter areprovided. One such revision is to the method for estimating CO2 fluxes from soils, asdescribed below.
2.
The revisions to the Land-use Change and Forestry Chapter greatly extend and improve
the range and quality of default data, particularly for the tropics, where national forestry
statistics are sometimes less accessible than in the temperate or boreal regions. The revisions
can be summarised by changes in (a) default data and in (b) methods, as follows:(a) Default data
Classification system for land cover types: A revised system more consistent with sources ofnational, regional and international data, such as forest conversion rates and forest inventories
was developed. The revised classification system better reflects the diversity of forest types.
For the tropics, three classes of forests have been replaced with six, based on differences inrainfall amount, seasonality, and altitude.
Rates of forest conversion: New FAO default data are provided for each country and forest
type according to the proposed land-cover classification system. These data have been
compiled for the tropics for the 1980-90 period. Such revisions were incorporated because
country-level data are often difficult to obtain for many tropical countries; the 1995 IPCC
Guidelines contain no such data.
Aboveground biomass for native tropical forests: Emissions estimates from land-use change
and forestry can be highly sensitive to such input data and therefore a priority was given to
improving aboveground biomass data. Since publication of the 1995 IPCC Guidelines, better
datasets have become available drawing upon larger regional studies. The revisions now
include a large database of default values for Africa, America, and Asia for the revised landcover classification system. Additional data based on individual forest inventories (suitablefor converting to biomass) for many tropical countries are also included. None of the default
values are separated into primary and secondary forests (as in 1995 IPCC Guidelines) because

it was felt by experts that this was not a practical classification, given the variability ofdefinitions in different regions.
Rates of tropical forest regrowth: Revised default data are given for forest regrowth; the data
are related to the biomass data and are reported for the three tropical regions by forest type,according to the revised classification system.
(b) Methods
Estimation of net CO2 emissions from soil carbon: In the 1995 IPCC Guidelines, CO2
estimates are based upon the product of the rate of change in area of a given land-use and therate of change of soil carbon. The revised method estimates changes in soil carbon pools
associated with altered land-use or land management practices. Thus, all categories ofagriculturally-impacted lands, including conversions of forest or other vegetation toagriculture, land abandonment, shifting cultivation and permanent agriculture, are included in
the methodology. A default stock method is employed to estimate CO2 fluxes associated with
agricultural activities for a 20-year inventory period. This area of the IPCC Methodology has
been much improved because better scientific data is now available. The revised method ismore compatible with potential policy analysis.

References
Australian Methodology for the Estimation of Greenhouse Gas Emissions and Sinks (1996).
Joint EMEP/CORINAIR Atmospheric Emission Inventory Guidebook (1996), 1st Edition,
European Environmental Agency.
1995 IPCC Guidelines for National Greenhouse Gas Inventories, Reporting Instructions(Volume 1); Workbook (Volume 2); Reference Manual (Volume 3).

LIST OF ABBREVIATIONSCO2CH4N2O
SO2NOxCONH3NMVOCCarbon dioxide
MethaneNitrous oxideSulphur dioxide
Sum of nitrogen oxide and nitrogen dioxide
Carbon monoxideAmmonia
Non-methane volatile organic compounds

For further information, please contact:Ms. Bo Lim
IPCC Support Unit for Emission Inventories
OECD, Environment Directorate
2, rue André Pascal
75775 Paris Cedex 16France
Tel: (+33 1) 45 24 78 94
Fax: (+33 1) 45 24 78 76
Email: Bo.Lim@oecd.org