Page 94 - Materials Chemistry, Second Edition

8 Scope Definition 79

Ecosphere
Technosphere

Legend

Process Product or Elementary
waste flow flow

Fig. 8.2 Division between ecosphere and technosphere for a generic product system. Elementary
flows are represented by blue arrows, while flows within the technosphere are in black

Elementary flows are per definition the only flows that go across the boundary
between the technosphere and the ecosphere (see Sect. 8.2.1) and it is because of
these flows that the Areas of Protections are potentially impacted by the product
systems assessed in LCA. Note that there is no clear-cut large-scale spatial sepa-
ration between the technosphere and the ecosphere. The two spheres are in fact
largely intermingled and therefore quite abstract. Surely, natural reserves and
undeveloped land largely belong to the ecosphere, but the transportation and
tourism infrastructure (roads, trash bins, etc.) going through them belong to the
technosphere. In addition, though cities may appear like they belong 100% to the
technosphere, the outdoor or indoor air that the population inhales belongs to the
ecosphere, because human health can be impacted through air pollution. Note also
that the exact location of the boundary between the technosphere and the ecosphere
is often debated in the LCA community, for example, with regards to agricultural
systems (see Chaps. 29 and 30).

8.2.3 Foreground and Background System

Often hundreds of unit processes are required to deliver the product studied in an
LCA. It is useful to distinguish between unit processes belonging to the foreground