12.2 Data and Methodologies
12.2.1 Estimation Model for Direct/Indirect CO 2 Emissions
12.2.1.1 Definition of Direct and Indirect CO 2 Emissions
CO 2 emissions fall into two types, direct emissions and indirect emissions. Easier to
measure are the direct emissions that we are responsible for. These include the
amount of gas and kerosene we use in our houses and the amount of petrol or diesel
we burn in our cars. Getting the CO 2 figures right for gas, petrol and diesel is quite
straightforward, because a standard amount is released when each fuel is burnt. CO 2
in the electricity production process is emitted at power plants. Thus, it is defined as
the direct emissions of the industrial sector. In contrast, the indirect emissions for
households are defined as the CO 2 emissions allocated to the regions where the
energy is consumed according to the expenditure of money on the items for
households’daily life. In this study, the boundary of CO 2 emissions was extended
to fuel production for household fuel use, agriculture for food production, and other
production for consumption items including energy use for both production and
transportation processes. The electricity, gas and kerosene used in houses were
allocated as direct emissions of households. The petrol or diesel consumption was
allocated to car registration place as direct emissions. It is useful to make a clear
distinction among the CO 2 emissions caused by household consumption and to
formulate an effective policy for the reduction of the total GHG emissions.
We defined the direct and indirect CO 2 emissions as below.
1. Direct emissions: CO 2 emissions from different CO 2 emitting regions of each
sector,
2. Indirect emissions: CO 2 emissions from the regions where the commodities are
consumed according to expenditure of money on the items for households’
daily life.
12.2.1.2 Data
With regard to the emission intensity (emission factor) data, we employed Embodied Energy and Emission Intensity Data (3EID). These data contain embodied
environmental burden intensity data calculated using Japanese input-output tables.
The Japanese input-output tables consist of approximately 400 commodity sectors.
They represent the economic relationships among these sectors based on annual
transactions. 3EID includes data on direct and indirect energy consumption or CO 2
emissions (i.e. environmental burden) from unit production activity (equivalent to
1 million yen). In this study, we employed the CO 2 emission intensity data
estimated from consumer prices excluding imports. The emission intensity by
prefecture and household type was calculated by Tanaka et al. (2008)’s method
mentioned above.
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K. Nakamichi et al.
12.2.1 Estimation Model for Direct/Indirect CO 2 Emissions
12.2.1.1 Definition of Direct and Indirect CO 2 Emissions
CO 2 emissions fall into two types, direct emissions and indirect emissions. Easier to
measure are the direct emissions that we are responsible for. These include the
amount of gas and kerosene we use in our houses and the amount of petrol or diesel
we burn in our cars. Getting the CO 2 figures right for gas, petrol and diesel is quite
straightforward, because a standard amount is released when each fuel is burnt. CO 2
in the electricity production process is emitted at power plants. Thus, it is defined as
the direct emissions of the industrial sector. In contrast, the indirect emissions for
households are defined as the CO 2 emissions allocated to the regions where the
energy is consumed according to the expenditure of money on the items for
households’daily life. In this study, the boundary of CO 2 emissions was extended
to fuel production for household fuel use, agriculture for food production, and other
production for consumption items including energy use for both production and
transportation processes. The electricity, gas and kerosene used in houses were
allocated as direct emissions of households. The petrol or diesel consumption was
allocated to car registration place as direct emissions. It is useful to make a clear
distinction among the CO 2 emissions caused by household consumption and to
formulate an effective policy for the reduction of the total GHG emissions.
We defined the direct and indirect CO 2 emissions as below.
1. Direct emissions: CO 2 emissions from different CO 2 emitting regions of each
sector,
2. Indirect emissions: CO 2 emissions from the regions where the commodities are
consumed according to expenditure of money on the items for households’
daily life.
12.2.1.2 Data
With regard to the emission intensity (emission factor) data, we employed Embodied Energy and Emission Intensity Data (3EID). These data contain embodied
environmental burden intensity data calculated using Japanese input-output tables.
The Japanese input-output tables consist of approximately 400 commodity sectors.
They represent the economic relationships among these sectors based on annual
transactions. 3EID includes data on direct and indirect energy consumption or CO 2
emissions (i.e. environmental burden) from unit production activity (equivalent to
1 million yen). In this study, we employed the CO 2 emission intensity data
estimated from consumer prices excluding imports. The emission intensity by
prefecture and household type was calculated by Tanaka et al. (2008)’s method
mentioned above.
246
K. Nakamichi et al.