Environmental Engineering Reference
In-Depth Information
On the other hand is the issue of sustainability, the meaning and implications of
which are intellectually and physically contested. Eco-efficiency and mitigation are
relatively straightforward to observe with respect to an aspect of the environmental
quality of a site (eg ambient noise near an airport), a single input (eg fuel) or a unit of
business output (eg passengers entering a terminal). Moreover, pursuit of eco-efficiency
does not imply a constraint on growth in the scale of an activity. Eco-efficiency is a
win-win activity for corporate growth and 'the environment' if that environment is
defined in only a few terms or with a narrow geographic focus.
Strictly defined, however, indicating environmental sustainability requires assess-
ment of product and service life cycles, linked to protocols for allocating consump-
tion and emission quotas (Upham, 2001). Only if such protocols exist for relating
discrete activity to environmental systems can one reliably assess the sustainability of
a sector, industry, business or other organization. In the absence of these, all that can
be said is that an organization is increasing or reducing its environmental sustain-
ability (Upham, 2001).
Drawing on ecological economic ideas (Georgescu-Roegen, 1971; Daly, 1977,
1992), early work on life-cycle analysis (Schmidt-Bleek, 1993) and an understand-
ing of the Natural Step approach to sustainability (Upham, 2000a), a precautious
approach to assessing environmental sustainability via measuring the flows of masses
mobilized by the human economy through the biosphere implies that growth in the
physical scale of aviation will generally entail movement
away
from conditions of
environmental sustainability.
The adverse environmental impacts implicit in this general rule can be post-
poned to the extent that there are conventional materials and fuel efficiency savings
through the entire life cycles of production and service processes supportive of avia-
tion. At some point, however, the additional material (including fuel) needed to
support growth would literally outweigh that saved by material efficiency, such that
adverse impact would, in general, begin to rise again. Alternatively, the impact of
growth could be reduced if it involved the replacement of mined and subsequently
synthesized materials and fuels with use of biomass and renewable energy in such a
way as to maintain or enhance vegetative soil cover and, preferably, biodiversity.
Again, this replacement would need to be through the life cycles of production and
service processes supportive of aviation (Upham, 2001).
Either way, it is the sheer scale of aviation growth - outlined in Chapter 2 by Ian
Humphreys - that justifies special attention to its environmental impacts. In wider
terms, the European Environment Agency (EEA) has drawn attention to the way in
which the persistence of key environmental problems are a consequence of the over-
all scale of resource use (EEA, 2001a,b). These problems include global warming as
discussed by David Lee and David Raper in Chapter 5. The EEA is of the view that
if environmental and sustainability aims and targets, such as those proposed in the
European Union's Sixth Environment Action Programme, are to be reached, higher
efficiencies in the use of materials and energy will be necessary (EEA, 2001a,b). The
precautious approach to environmental sustainability discussed above requires that
those efficiencies must be achieved through the life cycles of a wide range of prod-
ucts and services, and that growth in material usage necessary for growth in the
physical economy should not exceed efficiency gains.
