Estimate of Impact on Inventory Due to Different Data Sources and Methodologies
Kiyotaka TAHARA, Toshinori KOJIMA, Atsushi INABA
For the production of refrigerators, CO2 emissions was estimated as affected by variations in estimation of CO2 emissions from electricity production, and differences in the process data and system boundaries used in the bottom-up approach. The results indicate that the amount of CO2 emitted in raw materials production was influenced by variations in CO2 per kWh electricity consumed, but the ratio of CO2 emis-sions from direct processrelated sources was not influenced. The amount of CO2 emis-sions in material production and the ratio of CO2 emissions in material production were influenced by the process data and system boundaries used in the calculations. In particular, as the process of aluminum ingots lead to large CO2 emissions, it is necessary to carefully consider the system boundary definition use when comparing estimates obtained from different data sources.
The estimated CO2 emissions obtained via the bottom-up approach was then compared to that obtained using the Input-Output table analysis. The total CO2 emissions and the relative contribution of different sources in material production were influenced. It is also important to note that the calculated value using the Input-Output table is smaller than that from the bottom-up approach. It is reason that the data in the Input-Output table do not go into sufficient detail.