72
5 Understanding the Complementarities of Environmental …
In a similar case to that of the ecological footprint, the blue and gray water footprints were envisaged as a way of comparing with the blue and gray water boundaries,
respectively, where the results are expressed in the form of a quotient (Hoekstra et al.
2012; Liu et al. 2012). The footprint-to-boundary ratios depict the relative severity
of water scarcity and pollution as a consequence of the mismatch between water
withdrawal and renewable supply. The ecological and water footprints are, in this
sense, able to inform policy makers on to which degree the biophysical limits of the
biosphere and hydrosphere are being approached or exceeded, respectively (Costanza
2000; Galli et al. 2012).
Table 5.1 summarizes existing practices that aim at incorporating the boundary
concept into footprint analysis. As seen, so far not all of the footprints include a
comparison to quantified capacity thresholds. In fact, many do not, although this is
being perceived as increasingly useful. Even for those which have been linked to a
threshold value already, there remain limitations that have been a notable source of
controversy in footprint analysis; thus, we believe that recent developments regarding
planetary boundaries will inspire and facilitate the ongoing process of benchmarking
environmental footprints against capacity thresholds.
5.3 Why Environmental Footprints Are Important
for Making the PBF Scientifically Robust?
Contrary to popular belief, Rockström et al.’s framework is not only about planetary
boundaries, but also about current state estimates—a neglected field of research into
the planetary boundary issues. In other words, its ultimate goal is not to quantify a
boundary but to quantify the transgression or reserve of a boundary, determined by
the comparison of planetary boundaries and current human pressure. As a whole,
Rockström et al.’s estimates are reliant on literature review reflecting expert knowledge that inevitably contains uncertainty, subjectivity, and arbitrariness (De Vries
et al. 2013; Lewis 2012). Nevertheless, currently, this is perhaps the best way to
quantify planetary boundaries in view of the difficulties of prediction. Furthermore,
by using the best available knowledge and the precautionary principle, planetary
boundaries are claimed to be more science-based than a common policy framework
(Nykvist et al. 2013).
However, the problem is that Rockström et al. do so to measure the current status of
investigated environmental issues, which could have been more rigorous and robust
if appropriate environmental models are used instead. As environmental footprints
are derived from a great number of quantitative models, of which the majority have
a broad base of acceptance with respect to documentation, transparency, and reproducibility (Fang et al. 2014; Hoekstra and Wiedmann 2014), it is natural to expect that
the methodological maturity of footprints would be able to enhance the expression
and quantification of current estimates involved in the PBF.
5 Understanding the Complementarities of Environmental …
In a similar case to that of the ecological footprint, the blue and gray water footprints were envisaged as a way of comparing with the blue and gray water boundaries,
respectively, where the results are expressed in the form of a quotient (Hoekstra et al.
2012; Liu et al. 2012). The footprint-to-boundary ratios depict the relative severity
of water scarcity and pollution as a consequence of the mismatch between water
withdrawal and renewable supply. The ecological and water footprints are, in this
sense, able to inform policy makers on to which degree the biophysical limits of the
biosphere and hydrosphere are being approached or exceeded, respectively (Costanza
2000; Galli et al. 2012).
Table 5.1 summarizes existing practices that aim at incorporating the boundary
concept into footprint analysis. As seen, so far not all of the footprints include a
comparison to quantified capacity thresholds. In fact, many do not, although this is
being perceived as increasingly useful. Even for those which have been linked to a
threshold value already, there remain limitations that have been a notable source of
controversy in footprint analysis; thus, we believe that recent developments regarding
planetary boundaries will inspire and facilitate the ongoing process of benchmarking
environmental footprints against capacity thresholds.
5.3 Why Environmental Footprints Are Important
for Making the PBF Scientifically Robust?
Contrary to popular belief, Rockström et al.’s framework is not only about planetary
boundaries, but also about current state estimates—a neglected field of research into
the planetary boundary issues. In other words, its ultimate goal is not to quantify a
boundary but to quantify the transgression or reserve of a boundary, determined by
the comparison of planetary boundaries and current human pressure. As a whole,
Rockström et al.’s estimates are reliant on literature review reflecting expert knowledge that inevitably contains uncertainty, subjectivity, and arbitrariness (De Vries
et al. 2013; Lewis 2012). Nevertheless, currently, this is perhaps the best way to
quantify planetary boundaries in view of the difficulties of prediction. Furthermore,
by using the best available knowledge and the precautionary principle, planetary
boundaries are claimed to be more science-based than a common policy framework
(Nykvist et al. 2013).
However, the problem is that Rockström et al. do so to measure the current status of
investigated environmental issues, which could have been more rigorous and robust
if appropriate environmental models are used instead. As environmental footprints
are derived from a great number of quantitative models, of which the majority have
a broad base of acceptance with respect to documentation, transparency, and reproducibility (Fang et al. 2014; Hoekstra and Wiedmann 2014), it is natural to expect that
the methodological maturity of footprints would be able to enhance the expression
and quantification of current estimates involved in the PBF.