4.4 Discussion
67
of mutual understanding between different scientific communities in the field. The
reality is that non-area-based footprints are now ubiquitous, and that LCA is not the
only way to implement an inventory analysis, in addition to which a footprint is not
necessarily committed to an impact assessment. Moreover, there are certain important types of questions for which footprints are desirable but for which a life cycle
perspective is not or only partially appropriate. Such a methodological limitation has
been demonstrated in Sect. 4.2, with the case of OEF.
The footprint family has been envisaged in such a way that it can be easily extended
to capture a broader scope of sustainability issues. Some emerging footprints, such
as the celestial, employment, and inequality footprints, open the door for footprint
developers to establish and measure human well-being in terms of happiness and
equality, which remains the ultimate goal of sustainable development. These social
and economic dimension–LCA, however, suffer from difficulties in data availability,
societal impact assessment, and result interpretation.
One thing that LCA can learn from environmental footprints is the comparison of
a footprint and indicator of carrying capacity. The ecological footprint has a tradition
of benchmarking human land occupation with available planetary area and thereby
determining whether the situation is sustainable or not. So do the blue water footprint
and chemical footprint—the two can be readily compared with blue water availability
and chemical boundary, respectively. The convergence of footprints and planetary
boundaries makes sense in that it allows for the evolution of environmental impact
assessment (EIA) to environmental sustainability assessment (ESA), which is more
informative for policy purposes but lacking or at least inconspicuous in current LCA
frameworks.
Admittedly, facilitating the calculation of footprints with mature methodological
frameworks is preferred, and because of this, many footprint users have learned and
borrowed much from LCA, IOA, or a hybrid of both. Even so, narrowing footprints
down to an LCA context potentially creates blind spots, where exhaustive inventory
data for compiling and/or consensus models for characterization of impact pathways are not available—and vice versa—some typical impact categories (e.g., ozone
depletion, ionizing radiation) are out of the scope of the footprint family in its current
form.
To sum up, footprints are not to be interpreted as a new name for the good old
impact category indicators defined in LCA and, more importantly, LCA does not
substitute but complements environmental footprints. The nuanced ways that footprints and LCA deal with anthropogenic stressors should not be viewed as merely
a source of controversy but rather as an opportunity for complementary use, and
for development and refinement of these tools. For instance, an initiative has been
launched to investigate the possible synergies between classical water footprint and
water-use LCA (Boulay et al. 2013). More investigations are needed into the relationship of individual footprints and LCA scopes. Examples include the ecological
footprint and land use, chemical footprint and toxicity, as well as nitrogen footprint
67
of mutual understanding between different scientific communities in the field. The
reality is that non-area-based footprints are now ubiquitous, and that LCA is not the
only way to implement an inventory analysis, in addition to which a footprint is not
necessarily committed to an impact assessment. Moreover, there are certain important types of questions for which footprints are desirable but for which a life cycle
perspective is not or only partially appropriate. Such a methodological limitation has
been demonstrated in Sect. 4.2, with the case of OEF.
The footprint family has been envisaged in such a way that it can be easily extended
to capture a broader scope of sustainability issues. Some emerging footprints, such
as the celestial, employment, and inequality footprints, open the door for footprint
developers to establish and measure human well-being in terms of happiness and
equality, which remains the ultimate goal of sustainable development. These social
and economic dimension–LCA, however, suffer from difficulties in data availability,
societal impact assessment, and result interpretation.
One thing that LCA can learn from environmental footprints is the comparison of
a footprint and indicator of carrying capacity. The ecological footprint has a tradition
of benchmarking human land occupation with available planetary area and thereby
determining whether the situation is sustainable or not. So do the blue water footprint
and chemical footprint—the two can be readily compared with blue water availability
and chemical boundary, respectively. The convergence of footprints and planetary
boundaries makes sense in that it allows for the evolution of environmental impact
assessment (EIA) to environmental sustainability assessment (ESA), which is more
informative for policy purposes but lacking or at least inconspicuous in current LCA
frameworks.
Admittedly, facilitating the calculation of footprints with mature methodological
frameworks is preferred, and because of this, many footprint users have learned and
borrowed much from LCA, IOA, or a hybrid of both. Even so, narrowing footprints
down to an LCA context potentially creates blind spots, where exhaustive inventory
data for compiling and/or consensus models for characterization of impact pathways are not available—and vice versa—some typical impact categories (e.g., ozone
depletion, ionizing radiation) are out of the scope of the footprint family in its current
form.
To sum up, footprints are not to be interpreted as a new name for the good old
impact category indicators defined in LCA and, more importantly, LCA does not
substitute but complements environmental footprints. The nuanced ways that footprints and LCA deal with anthropogenic stressors should not be viewed as merely
a source of controversy but rather as an opportunity for complementary use, and
for development and refinement of these tools. For instance, an initiative has been
launched to investigate the possible synergies between classical water footprint and
water-use LCA (Boulay et al. 2013). More investigations are needed into the relationship of individual footprints and LCA scopes. Examples include the ecological
footprint and land use, chemical footprint and toxicity, as well as nitrogen footprint