ILCD Handbook: Framework and requirements for LCIA models and ...

ILCD Handbook: Framework and requirements for LCIA models and indicators First edition
4.11 Resource depletion
4.11.1 Framework and scope
The earth contains a finite amount of non-renewable resources, such as metals and fuels.
Van Oers et al. (2002) describe the depletion of resources as follows: ―abiotic resource
depletion is the decrease of availability of the total reserve of potential functions of resources,
due to the use beyond their rate of replacement‖. This impact category considers the effect
on both renewable and non-renewable resources. Depletion of minerals and fossil fuels falls
within the category non-renewable resources, while extraction of water, wind (abiotic) and
wood (biotic) falls within renewable resources.
Despite Resource depletion often being considered a single impact category in LCA, this
does not reflect the wide range of issues related to resource depletion. In fact, many
methods combine several issues and use several mechanisms within a single impact
category. This has resulted in a relatively unclear situation. The following pragmatic
approach is recommended:
Focus on the impacts of direct exploitation of resources (renewable or non-renewable).
Indirect damages to resources, especially damages on crops (for instance due to
climate, ozone etc.), are often found in other endpoint impact categories, but these are
not considered in the resource depletion category.
Harvesting crops or wood can be seen as a land-use issue, although the extraction of
―funds‖, like the decrease of the available amount of standing trees, would be a
resource issue. It is not always easy to distinguish which impact category this impact
should be characterized as. The depletion of biotic resources is considered in the
impact category ‗Resource Depletion‘.
Water is treated as a separate issue, as it has many unique properties that make the
problem of water availability very different from such factors as, for example, mineral
resources.
For the impact of renewable resource use, such as wood and fish, two main approaches
are used:
One based only on the amount of renewable resource used (expressed as weight,
volume or exergy), and
another based on the amount of renewable resource used, considering the regeneration
rate.
The methods used to assess the impact of non-renewable resource use can be
categorised into four main approaches (Lindeijer et al., 2002, Stewart and Weidema, 2005).
The effects of the extraction of a certain amount of a resource can be modelled, based on:
energy or mass,
exergy or entropy,
future consequences of resource extraction (scarcity or extra need for energy for
extraction), and
use of stock.
The endpoint characterisation factor for Resource Depletion is assessed as the future
consequences of resource extraction. The basic idea behind it is that extracting a high
concentration of resources today will force future generations to extract lower concentration
4 Requirements for specific impact categories 77