2.4 Discussion
29
Meanwhile, the discrepancy between the ecological footprint and the other three
footprints becomes apparent when looking at their underlying hypotheses. From an
ecological footprint perspective, any emissions of GHGs or use of water resources
would be compulsively labeled with “unsustainability” (Fiala 2008) as a clear recognition of sustainability limits relative to the energy, carbon, and water footprints are
lacking in scientific advice for policy makers. In other words, the energy, carbon, and
water footprints suffer from the critique that no distinction is made between sustainable and unsustainable activities, while the ecological footprint is criticized for its
arbitrariness of assuming zero environmental capacity for carbon accumulation in
the atmosphere and for pollutant concentration in the hydrosphere. This illustrates
a very important point: without the reference to sustainability limits, the footprint
family cannot be used to determine whether or not natural capital is being consumed
in a sustainable way; it is only appropriate to measure the environmental impacts
derived from natural capital appropriation by consumption of biological resources
and water, GHG emissions, and discharge of the resulting waste (Fang et al. 2013).
A further extension of the footprint family to relating to planetary boundaries will
be delineated in Sect. 2.4.2.2.
2.4.2 Needs for Further Development
2.4.2.1 Monitoring Stock Depletion
The environmental implications of energy use not only affect the atmosphere where
anthropogenic warming impacts have been sufficiently denoted using the carbon
footprint or the alternatives—the GHG footprint (Hertwich and Peters 2009) or
the climate footprint (Huijbregts et al. 2010), but also affect the lithosphere where
fossil fuel is an essential natural resource for humanity and contributes most to
the stocks of natural capital maintained throughout the world. Unlike the renewable
natural resources such as cropland or grassland, the consumption of fossil energy will
undoubtedly result in a diminished stock of natural capital. From a strong sustainability perspective, all renewable flows of resources and ecosystem services could
be sparingly consumed, but finite stocks should remain constant (e.g., Costanza and
Daly 1992; Niccolucci et al. 2009; Wackernagel and Rees 1997). If stock depletion
continues to grow a tipping point beyond which a tremendously huge accumulation
of debt will never be paid back by natural capital flows, the Earth system would ultimately collapse with disastrous consequences for human beings (Rockström et al.
2009; Wackernagel and Rees 1997). Given this concern, it is desirable to find a
way of reshaping the energy footprint to monitor the depletion of stocks associated
with energy consumption within a given year. We argue that the footprint family
will benefit from such a remodeling because it allows for simultaneous tracking of
human pressure on four life-supporting compartments of the Earth: the biosphere,
lithosphere, atmosphere, and hydrosphere. The major challenges are to calculate the
29
Meanwhile, the discrepancy between the ecological footprint and the other three
footprints becomes apparent when looking at their underlying hypotheses. From an
ecological footprint perspective, any emissions of GHGs or use of water resources
would be compulsively labeled with “unsustainability” (Fiala 2008) as a clear recognition of sustainability limits relative to the energy, carbon, and water footprints are
lacking in scientific advice for policy makers. In other words, the energy, carbon, and
water footprints suffer from the critique that no distinction is made between sustainable and unsustainable activities, while the ecological footprint is criticized for its
arbitrariness of assuming zero environmental capacity for carbon accumulation in
the atmosphere and for pollutant concentration in the hydrosphere. This illustrates
a very important point: without the reference to sustainability limits, the footprint
family cannot be used to determine whether or not natural capital is being consumed
in a sustainable way; it is only appropriate to measure the environmental impacts
derived from natural capital appropriation by consumption of biological resources
and water, GHG emissions, and discharge of the resulting waste (Fang et al. 2013).
A further extension of the footprint family to relating to planetary boundaries will
be delineated in Sect. 2.4.2.2.
2.4.2 Needs for Further Development
2.4.2.1 Monitoring Stock Depletion
The environmental implications of energy use not only affect the atmosphere where
anthropogenic warming impacts have been sufficiently denoted using the carbon
footprint or the alternatives—the GHG footprint (Hertwich and Peters 2009) or
the climate footprint (Huijbregts et al. 2010), but also affect the lithosphere where
fossil fuel is an essential natural resource for humanity and contributes most to
the stocks of natural capital maintained throughout the world. Unlike the renewable
natural resources such as cropland or grassland, the consumption of fossil energy will
undoubtedly result in a diminished stock of natural capital. From a strong sustainability perspective, all renewable flows of resources and ecosystem services could
be sparingly consumed, but finite stocks should remain constant (e.g., Costanza and
Daly 1992; Niccolucci et al. 2009; Wackernagel and Rees 1997). If stock depletion
continues to grow a tipping point beyond which a tremendously huge accumulation
of debt will never be paid back by natural capital flows, the Earth system would ultimately collapse with disastrous consequences for human beings (Rockström et al.
2009; Wackernagel and Rees 1997). Given this concern, it is desirable to find a
way of reshaping the energy footprint to monitor the depletion of stocks associated
with energy consumption within a given year. We argue that the footprint family
will benefit from such a remodeling because it allows for simultaneous tracking of
human pressure on four life-supporting compartments of the Earth: the biosphere,
lithosphere, atmosphere, and hydrosphere. The major challenges are to calculate the