48
3 Exploring Some Fundamentals of Environmental Footprints
3.3.2.3 Comparison of the Two Footprint Categories
An overall comparison between the IVOFs and IPOFs in terms of some inherent
properties is presented in Table 3.1. As shown, the two categories of footprints
differ mostly in the ways they address the inventory results. The IVOFs apply
value-based weighting to the aggregation of inventory results, whereas the IPOFs
are more concerned with the consequences for environmental quality by processing
the inventory results with science-based characterization factors.
To further delineate the difference of interpretation between the two footprint
categories, we briefly present an illustrative comparison of the WF class and WF scarc
Table 3.1 Comparison of the inventory-oriented and impact-oriented footprints
Item
Inventory-oriented footprints
(IVOFs)
Impact-oriented footprints
(IPOFs)
Examples
CF class , WF class , LF class , MF class CF clim , WF scarc , LF disturb , MF scarc
Factors for inventory
aggregation
Weighting factors: reflecting the
relative importance based on
value-based judgments. Easily
obtainable but subjective and not
reflecting the latest scientific
knowledge
Characterization factors:
representing the relative
contributions of substances to a
specific impact category.
Primarily science-based although
including some subjective choices
Rationale
Inventory analysis of
contributing substances enables a
physical interpretation of human
pressure and this may disappear
if translating into an impact
result through characterization
modeling
Different substances per physical
unit vary so notably within any
single impact category that they
cannot be directly compared and
aggregated at the inventory level
Strengths
Compiling different emissions
and extractions with
understandable physical units
and laying an inventory basis for
communicational purposes
Linking quantitative inventory
results to a specific environmental
impact and assessing the impact
on a scientific characterization
basis
Weaknesses
Not revealing the environmental
relevance of different emissions
and extractions with respect to
their relative contributions to
environmental impacts
Not revealing the physical
meaning of emissions and
extractions exerted by human
activities
Applicability
Typically oriented towards the
macro-level of economy (global,
nation-wide, etc.)
Typically oriented towards the
micro- or meso-level of individual
products or processes
Policy relevance
Instrumental for policies aimed
at measuring the pressure of
resource use on the environment
and at identifying the driving
forces that are causing
environmental problems
Instrumental for policies aimed at
assessing potential environmental
impacts of emissions and
extractions and at finding
alternatives for the reduction of
impacts
3 Exploring Some Fundamentals of Environmental Footprints
3.3.2.3 Comparison of the Two Footprint Categories
An overall comparison between the IVOFs and IPOFs in terms of some inherent
properties is presented in Table 3.1. As shown, the two categories of footprints
differ mostly in the ways they address the inventory results. The IVOFs apply
value-based weighting to the aggregation of inventory results, whereas the IPOFs
are more concerned with the consequences for environmental quality by processing
the inventory results with science-based characterization factors.
To further delineate the difference of interpretation between the two footprint
categories, we briefly present an illustrative comparison of the WF class and WF scarc
Table 3.1 Comparison of the inventory-oriented and impact-oriented footprints
Item
Inventory-oriented footprints
(IVOFs)
Impact-oriented footprints
(IPOFs)
Examples
CF class , WF class , LF class , MF class CF clim , WF scarc , LF disturb , MF scarc
Factors for inventory
aggregation
Weighting factors: reflecting the
relative importance based on
value-based judgments. Easily
obtainable but subjective and not
reflecting the latest scientific
knowledge
Characterization factors:
representing the relative
contributions of substances to a
specific impact category.
Primarily science-based although
including some subjective choices
Rationale
Inventory analysis of
contributing substances enables a
physical interpretation of human
pressure and this may disappear
if translating into an impact
result through characterization
modeling
Different substances per physical
unit vary so notably within any
single impact category that they
cannot be directly compared and
aggregated at the inventory level
Strengths
Compiling different emissions
and extractions with
understandable physical units
and laying an inventory basis for
communicational purposes
Linking quantitative inventory
results to a specific environmental
impact and assessing the impact
on a scientific characterization
basis
Weaknesses
Not revealing the environmental
relevance of different emissions
and extractions with respect to
their relative contributions to
environmental impacts
Not revealing the physical
meaning of emissions and
extractions exerted by human
activities
Applicability
Typically oriented towards the
macro-level of economy (global,
nation-wide, etc.)
Typically oriented towards the
micro- or meso-level of individual
products or processes
Policy relevance
Instrumental for policies aimed
at measuring the pressure of
resource use on the environment
and at identifying the driving
forces that are causing
environmental problems
Instrumental for policies aimed at
assessing potential environmental
impacts of emissions and
extractions and at finding
alternatives for the reduction of
impacts