Environmental Engineering Reference
In-Depth Information
Japan has a better trade structure than China does through the analysis of certain
goods' carbon intensity with its export proportion.
9.3
Methodology
9.3.1 Methods of Calculating Carbon Intensity
Input-output Assessment and Life Cycle Assessment are the main ways of
calculating CO
2
emissions. The latter method is a quantification that studies the
requirements of energy and raw materials in the process of product life cycles.
Because of the great variety of products and complicated production processes,
however, it is difficult to analysis every product by using Life Cycle Assessment.
In contrast, Input-output Assessment can utilize input-output tables to evaluate
the direct and indirect carbon emissions of any product, thereby presenting the
correlation among sectors of the national economy. Because of the applicability of
Input-output Assessment, we use this method to calculate carbon intensity.
According to Input-output Assessment, the gross output
x
can be expressed as
8
:
Þ
1
y
x ¼ I A
ð
(9.1)
where
A
is
the direct consumption coefficient matrix, element
a
ij
¼ x
ij
/
x
j
,
i
,
j ¼
...
n
.
x
ij
denotes the intermediate input in the input-output table,
x
j
is
the total input of sector
j
,
I
is unit matrix, (
I A
)
1
is the Leontief inverse matrix,
and
y
is a column vector of final consumption.
In this paper,
DE
j
is direct carbon intensity of sector
j
, which represents the CO
2
emissions per unit value by each sector.
FE
j
is the full carbon intensity coefficient,
which denotes the overall CO
2
emissions of producing a unit value of each final
product.
1,
Þ
1
FE
j
¼ DE
j
I A
ð
;
ð
j ¼
1
;
2
;
...
n
Þ
(9.2)
Since intermediate products are produced overseas, so that some CO
2
emissions
are beyond national borders, we modify the model as follows
9
:
FE
j
0
Þ
1
¼ DE
j
I ρA
ð
;
ð
j ¼
1
;
2
;
...
n
Þ
(9.3)
FE
j
'
is the modified full carbon intensity and
is the diagonal matrix composed by
the domestic products' proportion of intermediate input in each sector.
ρ
ρ
j
¼
1
8
Yan and Yang [
7
].
9
Zhu [
13
].
