Page 210 - Materials Chemistry, Second Edition

196 R.K. Rosenbaum et al.

• Sorting and clustering midpoint impact categories on a nominal basis (e.g.: by
characteristics such as emission-related and resource-related, or global, regional
or local spatial scales)
• Ranking the impact categories according to a set (subjective—based on ethical
value-choices) hierarchy (e.g.: high, medium or low priority)

10.4 Footprints Versus LCA

“I was exceedingly surprised with the print of a man’s naked foot on the shore,
which was very plain to be seen in the sand.” (Daniel Defoe, Robinson Crusoe,
1719). The meaning of the term “footprint” has largely evolved since Daniel
Defoe’s famous novel and is currently used in several contexts (Safire 2008). Its
appearance in the environmental field can be tracked back to 1992 when William
Rees published the first academic article on the thus-termed “ecological footprint”
(Rees 1992), which was further developed by him and Mathis Wackernagel in the
following years. Its aim is to quantify the mark left by human activities on natural
environment.
Since then, the mental images created by the word have contributed to its use as
an effective way of communicating on different environmental issues and raising
environmental awareness within the scientific community as well as among policy
communities and the general public. Since the early 2000s, several footprints have
thus emerged within the environmental field with different definitions and mean-
ings, ranging from improved ecological footprint methodologies to the represen-
tation of specific impacts of human activities on ecosystems or human health to a
measure of a specific resource use. Prominent examples are:
• Ecological footprint focusing on land use (http://www.footprintnetwork.org)
• Cumulative Energy Demand (CED) focusing on non-renewable energy
• Material Input Per unit of Service (MIPS) focusing on material use
• Water footprint focusing on water use volumetric accounting (http://
waterfootprint.org)
• Water footprint focusing on water use impacts including pollution (ISO 14046)
• Carbon footprint focusing on climate change (ISO 14064, ISO/TS 14067,
WRI/WBCSD GHG protocol, PAS 2050)
Later developments focused on the introduction of new environmental concerns
or enlarging the scope of footprints. Examples for such emerging footprints are:
• Chemical footprint focusing on toxicity impacts
• Phosphorus depletion footprint

As illustrated in Fig. 10.4, all footprints are fundamentally based on the life
cycle perspective and most of them focus on one environmental issue or area of
concern.