Page 29 - Materials Chemistry, Second Edition

2 Main Characteristics of LCA 11

Raw materials Biorefinery Distribution Car driving
Fig. 2.1 Graphic representation of the biofuels life cycle from feedstock to end user (Icons made
by Flaticon from www.flaticon.com)

When taking a life cycle perspective it is clear that no biofuel is “climate
neutral”, because of the inputs of fossil fuels needed in industrial processes prior to
the use stage. In addition, a consequence of the increased demand for biofuel crops
may be the conversion of natural land (such as forest) to cultivated land and this
releases the carbon bound in the natural biomass (e.g. wood) and the soil as CO 2 .
Sometimes the conversion of natural land happens as an indirect consequence, i.e.
forest is being cleared to make room for the crops that used to be cultivated at the
piece of land now used for biofuel crops. This means that a country that increases
its production of biofuel crops, at the expense of a decrease in food crops may
indirectly contribute to a loss of natural land (e.g. forest) somewhere else, possibly
on a different continent, due to the mechanisms of international trade.
Regarding the second point, LCA considers multiple environmental issues (and
sometimes social issues, see Chap. 16) when evaluating a product or a system. This
is an important attribute in the case of biofuels because the release of nutrients from
fertilizer use and synthetic chemicals from pesticide use, lead to eutrophication and
toxic effects on freshwater ecosystems and elsewhere, and because the cultivation
requires large amounts of land and water for irrigation, which can lead to biodi-
versity loss and water scarcity. Social impacts from an increased production of
biofuels have also been reported in the form of increasing food prices.
The insights provided by LCA were a key reason for the rapid change in per-
spective on biofuels by policy-makers and media that began around 2008. For
example, in 2010 the European Commission amended its legislation on biofuels by
introducing a set of sustainability criteria, which relates to life cycle emissions of
greenhouse gases and prohibits the conversion of land with previously “high carbon
stock” and “high biodiversity” for the production of biofuels (EC 2010).
With the above text, we are not arguing that the transportation sector should
abandon biofuels as a strategy to reduce its use of fossil fuels and climate impacts.
We are merely trying to show that the world is not black and white and that a more
holistic perspective is required when evaluating and guiding technological changes.

2.2 Main Characteristics

Having made a case for LCA with the topic of biofuels, we now turn to describing
its main characteristics in slightly more technical terms and end the chapter by
listing its strengths and limitations.