The inventory taken includes the GHG mentioned in the IPCC 2007 fourth assessment report, such as carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, perfluorocarbons, fluorinated ether, perfluoropolyether, hydrovarbon and other substances that are controlled and monitored by the Montreal Protocol.
The calculation of GHG emission of this assessment is done by proceeding the quantification in accordance with the method of emission inventory; the assessment estimates the impact based on the carbon emissions within a hundred year after the product is formed, the calculation is as follows:
GHG Emissions = Activity Data x Emissions Factors x GWP value (IPCC 2007)
- Activity Data
- There are two types of data namely Primary Activity Data and Secondary Data; the primary activity data is the emission figure obtained by multiplying the measure taken from the life-cycle of a product by the emission factor; the secondary data is the figure obtained outside of the product life-cycle, which, according to PAS 2050:2011, is applicable when primary activity data is unable to obtain or impracticable.
- Emission Factor
- An emission factor is a representative value that attempts to relate the quantity of a pollutant, in this case carbon dioxide, released to the atmosphere with an activity associated.
- Global Warming Potential (GWP)
- The global warming potential of a GHG refers to the total contribution to global warming resulting from the emission of one unit of that GHG relative to one unit of the reference gas.