Page 152 - Materials Chemistry, Second Edition

9 Life Cycle Inventory Analysis 137

The table shows that, depending on the combination of the three aspects, the
marginal technology can either be the least cost effective technology available on
the existing market (6 of the combinations) or the future production technology to
be implemented (2 of the combinations). In practice, the marginal technology,
especially long term, can be difficult to identify, and this is a potential source of
considerable uncertainty in the inventory analysis. The importance of this uncer-
tainty may be investigated by sensitivity scenarios for the different potential mar-
ginal technologies. Furthermore, it is possible to create a mix of potential marginal
processes, which means that the inventory data becomes a mix of data from the
different potential marginal processes, as demonstrated in Sect. 9.5. This approach
is used in the ecoinvent database in its version 3 (and higher).
Note that in the discussions above, we have mentioned ‘the market’ as one
entity. However, in reality, there may be many markets for one product, e.g. when
the product has high transportation costs compared to the value of the product. In
cases where there are many small markets for the same product, the market trend
has to be identified in the affected local market. For other products where the
transportation costs are lower, there may be only one global market. The spatial
nature of a market has to be established as a first task when identifying changes in
supply.

Secondary consequences and concluding remarks
In the presented 4-step guidance we have only addressed the rather ‘direct
consequences’ of increased or decreased demands and supplies. However, several
derived effects or secondary consequences of these direct consequences may be
found. Depending on the size of these consequences and the scope of the assess-
ment, these may be relevant to consider. Common for each of them is that they are
difficult to foresee and even more difficult to quantify. We therefore cannot
establish a general procedure for identifying and quantifying these, more than
stating that in-depth knowledge on the topic of concern in most cases will be
necessary. A few examples of the types of secondary consequences are given
below.
Additional or reduced production of a product may affect market prices for the
product hereby affecting the broader demand for the product. For example, if the
assessed decision will lead to the increase in the cost of, say, wheat, the behaviour
of other consumers may be to consume less wheat due to this increase. It may also
be that due to the increase in price, some consumers will begin to use, e.g. corn
instead of wheat, hereby increasing the demand for corn.
Changes in market prices may not only affect the consumers but also the producers.
In the example above, increases in wheat prices may cause producers to increase the
intensity of their production, typically done through increasing the fertiliser use, or
through increasing the agricultural area (for more discussions about secondary con-
sequences specifically related to biomaterial production, see Chap. 30). However, it
may also be imagined that the increase in price of wheat may cause producers to