Input-Output LCA

Question 1

What kind of method is Input-Output-Method?

Answer 1

A quantitative economic technique that represents the interdependencies between different sectors of a national economy or different regional economies.

–> purely economic analysis

Question 2

Could you explain the Leontief inverse?

Answer 2

x=(I-A)^-1 *y => (I-A)^-1 is the leontief inverse

I: Identity matrix -> a sector produces 1 unit of its output
A: Input-Output Matrix -> a sector needs these amounts of input

=> describes interrerlations of economic sectors in economy -> in LCA it describes the upstream chain

Question 3

Input-Output Table

Answer 3

Show in monetary units how production and consumption activities are interrelated in an economy

Question 4

Input-Output Matrix

Answer 4

What is needed to produce what?

Question 5

Production level

Answer 5

𝑋=(𝐼−𝐴)^−1∙𝑌

```
I: Identity Matrix
A: Input Output Matrix
Efficiency Matrix
X: Production level
Y: Demand
~~~

Question 6

What is the output level x of industry sectors for a given final demand y?

Answer 6

x=(I-A)^->*y

I: Identity matrix: a sector produces 1 unit of its output
A: Input-Output matrix: a sector needs these amounts of input

(I-A)^-1= Leontief inverse

Question 7

Leontief inverse

Answer 7

describes the interrelations of economics sectors in the economy

in LCA language: it describes the upstream chain

Question 8

IO Tables - examples

Answer 8

•Multiregional Input Output table (MRIO) covering a number of nations or
regions with a certain geographic resolution

Question 9

What is the pollution level m for a given output level x of industry sectors?

Answer 9

m = B*x

m: total emissions
B: IO-Emission-Matrix

Question 10

What is the pollution level m for a given final demand y?

Answer 10

m = B*(I − A)^-1 *y

Question 11

Environmentally

extended IO Tables

Answer 11

•Databases using a country as a system boundary: e.g. simapro, which includes IO LCA based data, in addition to process based databases such as
Ecoinvent

•Databases using multiple countries as system boundary (MRIO): e.g. Global Trade Analysis Project (GTAP) and Externality Data and Input Output Tools for Policy Analysis (EXIOPOL, EXIOBASE)

Question 12

Global Trade Analysis Project (GTAP)

Answer 12

• Developed by the Center for Global Trade Analysis, Purdue University
• Containing tables for 2004, 2007 and 2011 with complete bilateral trade
information, transport and protection linkages
• Comprising 140 countries and regions, including the ROW, each of which
consists of 57 endogenous sectors
•nThese tables are supplemented by satellite data on such issues as
– Energy consumption
– CO 2 emissions
– Land use

Question 13

EXIOPOL ( Externality Data and Input Output Tools for Policy Analysis)

Answer 13

– EU research project during 2007 2011
– Consisting of 44 countries including the “rest of the world (ROW)“
– Sample data are provided free of charge, while the entire database is available on
purchase of a license.
– Extensive satellite data on environmental loads and resource use were used to
estimate
• 30 types of environmental load and
• 80 types of resource use for each sector

Question 14

Limitations of IO-Tables

Answer 14

• Resolution of IO Tables:
– Environmentally Extended Input Output Tables show environmental impact per € in
a particular sector
• Problem:
– If e.g. sand and cement are mixed in the sector “construction materials” they will
have the same impact/€ –> difference in impact/kg only reflected via price

Question 15

Hybrid LCA

Answer 15

• Combination of “normal” process LCA and IO LCA
• Start with process LCA; whenever no upstream data is available, use IO LCA to
fill the data gap

Question 16

Differences between EE-IOA and LCA - time horizon

Answer 16

EE-IOA: one year of consumption and production

LCA: Life cycle of a product with possible inputs produced in former years and services needed in the future

Question 17

Differences between EE-IOA and LCA - reference units

Answer 17

EE-IOA: Monetary value of products

LCA: phsysical flows

Question 18

Differences between EE-IOA and LCA - investment goods

Answer 18

EE-IOA: Production only covered for reference year and not for past provision or future use. Provision of investment goods kept separately and not assigned to the production pattems.

LCA: Investment goods are depreciated over their full life cycle to the production volume in this time.

Question 19

Differences between EE-IOA and LCA - disposal services

Answer 19

EE-IOA: Only included in the reference years. Thus, falsification if stocks of goods are built up.

LCA: Included as far as possible, but future or past disposal assumed to be the same as today and thus possible developments are not considered.

Question 20

Differences between EE-IOA and LCA - system boundaries

Answer 20

EE-IOA: In principle all inputs and outputs are considered.

LCA: Cut-off criteria allow truncaton of inputs or outputs, wich are considered to have a minor contribution in the life cycle.

Question 21

Differences between EE-IOA and LCA - allocation principle

Answer 21

EE-IOA: Environmental impacts are allocated by the value of products provided by a certain sector. No subdivision giong deepeer than the sectors distinguished. –> economic allocation!

LCA: Different principles might be applied. Where possible, joint production processes are subdivided in order to allocate environmental impacts to single products.

Question 22

Differences between EE-IOA and LCA - sectors and products covered

Answer 22

EE-IOA: All economic sectors and thus all products are in principle investigated. …

LCA: Focus on products and services with environmental relevance and large production volumes. …

Question 23

Differences between EE-IOA and LCA - stock of goods

Answer 23

EE-IOA: Production of stocks of goods not sold in the particular time horizon is considered separately.

LCA: Change of stocks is not included in the assessment. It is assumed that products produced by a company enter the market immediately.