12
2 A Conceptual Framework for Constituting a Footprint Family
of appropriate indicators is needed (Giljum et al. 2011). The indicators of environmental footprints have the potential to constitute a series of integrated systems with
the purpose of providing a complete picture of environmental complexity (Ridoutt
and Pfister 2013).
The concept of “footprint” originates from the idea of ecological footprint which
was formally introduced to the scientific community in the 1990s (Rees 1992, 1996;
Wackernagel and Rees 1996, 1997; Wackernagel et al. 1999a, b). Since then, many
different footprint-style indicators have been created and became complementary to
the ecological footprint during the last two decades including the energy footprint
(Wackernagel and Rees 1996), the water footprint (Hoekstra and Hung 2002), the
emergy footprint (Zhao et al. 2005), the exergy footprint (Chen and Chen 2007), the
carbon footprint (Wiedmann and Minx 2008), the biodiversity footprint (Yaap et al.
2010), the chemical footprint (Panko and Hitchcock 2011), the phosphorus footprint
(Wang et al. 2011), the nitrogen footprint (Leach et al. 2012), and so on.
Nowadays, environmental footprints have become colloquial and ubiquitous for
researchers, consultants and policy makers, and the implications for sustainability
and human well-being have been investigated from different perspectives with an
increasing interest in similarities, differences, and interactions between some selected
footprints. Nevertheless, there is not yet a completely satisfactory and generally
accepted footprint that can solely represent the overall impacts of human activities
as the “golden standard” indicator (Huijbregts et al. 2010; Rees 2002). Therefore, it
seems to be a natural step to move toward an integrated system of footprint indicators.
Following Galli et al. (2012), we refer to this as, namely, the “footprint family”. The
concept of a footprint family has only been preliminarily applied in a very limited
number of papers that have dealt with it. Further research is thus required to improve
transparency, consistency, and scientific robustness of this topic.
The aim of this chapter is to further operationalize the footprint family concept.
To that end, it starts from a review of the existing literature on the combination of
different environmental footprints. We then elaborate on a specific footprint family
with the most important, potential members and present a brief survey of those
footprints with reference to their definitions, developments, and applications. The
main characteristics of each footprint are summarized through a comparison of key
issues with particular emphasis on methodological options at different scales. This is
followed by a performance evaluation of the footprint family in different respects. The
remainder of this chapter proposes suggestions for improving the footprint family
and draws conclusions.
2.2 Review of the Literature on Combining Environmental
Footprints
This section is intended to provide background on the criterion for selecting footprints, not as a complete review. The term “footprint family” was first advocated
2 A Conceptual Framework for Constituting a Footprint Family
of appropriate indicators is needed (Giljum et al. 2011). The indicators of environmental footprints have the potential to constitute a series of integrated systems with
the purpose of providing a complete picture of environmental complexity (Ridoutt
and Pfister 2013).
The concept of “footprint” originates from the idea of ecological footprint which
was formally introduced to the scientific community in the 1990s (Rees 1992, 1996;
Wackernagel and Rees 1996, 1997; Wackernagel et al. 1999a, b). Since then, many
different footprint-style indicators have been created and became complementary to
the ecological footprint during the last two decades including the energy footprint
(Wackernagel and Rees 1996), the water footprint (Hoekstra and Hung 2002), the
emergy footprint (Zhao et al. 2005), the exergy footprint (Chen and Chen 2007), the
carbon footprint (Wiedmann and Minx 2008), the biodiversity footprint (Yaap et al.
2010), the chemical footprint (Panko and Hitchcock 2011), the phosphorus footprint
(Wang et al. 2011), the nitrogen footprint (Leach et al. 2012), and so on.
Nowadays, environmental footprints have become colloquial and ubiquitous for
researchers, consultants and policy makers, and the implications for sustainability
and human well-being have been investigated from different perspectives with an
increasing interest in similarities, differences, and interactions between some selected
footprints. Nevertheless, there is not yet a completely satisfactory and generally
accepted footprint that can solely represent the overall impacts of human activities
as the “golden standard” indicator (Huijbregts et al. 2010; Rees 2002). Therefore, it
seems to be a natural step to move toward an integrated system of footprint indicators.
Following Galli et al. (2012), we refer to this as, namely, the “footprint family”. The
concept of a footprint family has only been preliminarily applied in a very limited
number of papers that have dealt with it. Further research is thus required to improve
transparency, consistency, and scientific robustness of this topic.
The aim of this chapter is to further operationalize the footprint family concept.
To that end, it starts from a review of the existing literature on the combination of
different environmental footprints. We then elaborate on a specific footprint family
with the most important, potential members and present a brief survey of those
footprints with reference to their definitions, developments, and applications. The
main characteristics of each footprint are summarized through a comparison of key
issues with particular emphasis on methodological options at different scales. This is
followed by a performance evaluation of the footprint family in different respects. The
remainder of this chapter proposes suggestions for improving the footprint family
and draws conclusions.
2.2 Review of the Literature on Combining Environmental
Footprints
This section is intended to provide background on the criterion for selecting footprints, not as a complete review. The term “footprint family” was first advocated