National GHG inventories are often compiled using specialist software, such as the IPCC Inventory Software or ALU Software. The ALU Software has functions to implement the Tier 2 equations for livestock emission sources, and activity data can be directly input into the ALU Software. The IPCC Inventory Software currently (Version 2.54) does not have the function to implement the IPCC Tier 2 equations for livestock emissions. Tier 2 livestock emissions must be calculated in another software and the population data and Tier 2 emission factors are then entered into the IPCC Inventory Software.
Tier 2 livestock inventories are therefore often compiled using custom-made spreadsheets. One benefit of using custom-made spreadsheets is that inventory compilers have a clear view of exactly how the calculations are made. However, there are many equations to programme into the spreadsheet, and there is a risk of errors in either the programmed equations or the units. For example, when milk fat content (%) should be entered as a %, it is correct to enter “4”, but not correct to enter “4%”.
To support inventory compilation using custom-made spreadsheets, a Microsoft Excel spreadsheet is available for download above. The spreadsheet contains draft templates for calculation of emissions from the sources shown in the table below. The templates in the spreadsheet should be adjusted to reflect the inventory structure and can be further edited to reflect any country-specific adjustments to how the IPCC equations are implemented. The ALU Software, which can also calculate Tier 2 emissions, can be used as a cross-check for estimates made using custom-made spreadsheets. The spreadsheet is Tool A.2 in the Livestock Activity Data Guidance (L-ADG) published by the GRA and CCAFS.
Emission sources included in the spreadsheet templates
|Category code and name*||Gases||Source for equations implemented|
|3A1a Enteric fermentation, cattle||CH4||IPCC (2006) Vol. 4 Ch. 10|
|3A1c Enteric fermentation, sheep||CH4||IPCC (2006) Vol. 4 Ch. 10|
|3A2a Manure management, cattle||CH4, N2O||IPCC (2006) Vol. 4 Ch. 10|
|3A2c Manure management, sheep||CH4, N2O||IPCC (2006) Vol. 4 Ch. 10|
|3C4 Direct N2O emissions from managed soils (urine and dung N deposited on pasture only)**||N2O||IPCC (2006) Vol. 4 Ch. 11|
|3C5 Indirect N2O emissions from managed soils (urine and dung N deposited on pasture only)**||N2O||IPCC (2006) Vol. 4 Ch. 11|
|3C6 Indirect N2O emissions from manure management||N2O||IPCC (2006) Vol. 4 Ch. 10|
**The templates do not include equations for estimating emissions from application of animal manure to managed soils.