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’.

Agriculture Chapter
1.
Three sections of this Chapter have been revised, that are, (1) methane emissions fromrice cultivation, (2) nitrous oxide emissions from agricultural soils and (3) manuremanagement. For the estimation of N2O emissions, the default methods and data are new.
2.
Methane Emissions from Rice Cultivation. In the 1995 IPCC Guidelines, theestimation of CH4 emissions from wetland rice cultivation is a function of the CH4 emission
factor, area of rice cultivated and the season length. One critical default parameter is the CH4
emission factor, which is based upon temperature. It was determined that the relationshipbetween CH4 emissions and soil temperature as assumed in the 1995 IPCC Guidelines wasno longer appropriate because new data suggest that the seasonally integrated CH4 flux
depends much more on the input of organic carbon, water regime, time and duration ofdrainage and soil type than on local temperature. The revised methodology is a function of theemission factor integrated over a cropping season for particular rice water regime, for a given
organic amendment, and of the annual harvested area cultivated under these conditions. The
latter is given by the cultivated area times the number of cropping seasons per year.
3.
The revisions to the method use internationally-agreed definitions for rice eco-systems
classified according to the water regime and a range of CH4 emission scaling factors relative
to continuously flooded rice eco-systems and for soils without organic amendment. A default
seasonally integrated emission factor is also provided for the continuously-flooded regime,
without-organic amendment.
4.
Nitrous Oxide Emissions from Agricultural Soils and Manure Management.
A
new default method for calculating national emissions of N2O from agriculture is provided.
The new N2O method is a revision of the method in the 1995 IPCC Guidelines. It includes
more sources of N2O from agricultural activities and makes explicit recommendations on
N2O emission factors. The new method accounts for the application of N-fertilisers to the soil
and N uptake in crops and subsequently tracks the flow of N as it moves through the(anthropogenic) animal and human food chain. Three categories of N2O sources are
distinguished in the new methodology, (1) direct emissions from agricultural soils, (2)emissions from animal production, and (3) N2O emissions indirectly induced by agriculturalactivities1. Because a larger number of sources and pathways are considered, the new N2O
methodology affects several source sectors. Emissions are reported in several sections of the1995 IPCC Guidelines, namely, Manure Management (Section 4.2, 1995 IPCC Guidelines),
Agricultural Soils (Section 4.5, 1995 IPCC Guidelines), and Waste (Section 6.3, 1995 IPCCGuidelines). The input data required can be obtained from FAO databases.
5.
The new method provides a comprehensive description of N2O emissions fromagriculturally-related activities by accounting for previously omitted N2O sources. Using thismethod, global N2O emission estimates imply that atmospheric N2O input from agriculturalproduction as a whole has apparently been previously underestimated by at least 70%. Nitrous
oxide emissions resulting from atmospheric deposition are assigned to the NO x or NH3
emitting country2.

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
SO2NOxCONH3NMVOC

Carbon dioxideMethane
Nitrous oxide
Sulphur dioxide
Sum of nitrogen oxide and nitrogen dioxide
Carbon monoxide
Ammonia
Non-methane volatile organic compounds

1It is however recognised that there are other sources of anthropogenic atmospheric inputs of N-compounds tosoils e.g., NOx from fuel combustion. Only compounds directly applied to agricultural soils are considered.
2In some countries and regions, other conventions related to long range transboundary air pollution areaddressing the issue of atmospheric transport and deposition in greater detail.

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