Environmental Engineering Reference
In-Depth Information
Fig. 3.4
Ecological Ruck-
sack. (Based on production in
1983; Weitzsaecker
1998
)
the implications of current growth on limits and sustainability. I will briefly de-
scribe some of these;
•
Ecological rucksack
describes the total quantity of materials removed from na-
ture to create a product or service, minus the actual weight of the product; in
other words, the amount of waste thrown away in order to obtain a product.
•
Ecological footprint
indicates the amount of biologically productive land and
sea area necessary to supply the resources a human population consumes and to
mitigate associated waste.
•
Factor X
indicates the reduction rate of mass-throughput required in order to
achieve a sustainable society; this corresponds to the environmental efficiency
that is the ratio of service to matter.
•
LCA, life cycle assessment,
is a method for measuring the entire environmental
load of an industrial product throughout its production, use and disposal.
The Ecological Rucksack
is a way of measuring the hidden material flows asso-
ciated with producing raw materials. As can be seen in Fig.
3.4
, the eco-rucksack
of various natural resources supplied to society are shown by grey circles which
indicate the amount of materials removed from nature and discarded back into the
environment and nature after extracting the target material (Weitzsaecker
1998
).
The black circles convey the amounts of materials extracted (in 1983). It is easily
