Page 67 - Materials Chemistry, Second Edition

The Application of Life Cycle Assessment on Agricultural 53

allocation methods for coproducts and foreground and background data sources-
data quality and assessment; and (5) environmental impact assessment (EIA) and
impact categories.

Goal and Scope Definition

The goal and scope definition phase of an LCA in agriculture includes several
decisions that are of relevance for all subsequent steps, i.e., LCI, Life cycle impact
assessment (LCIA), and interpretation (Frischknecht and Jungbluth 2007). As
Svoboda (1995) stated that the goal of LCA is not to arrive at the answer but,
rather, to provide important inputs to a broader strategic planning process. Use of
LCA assists to focus attention on ‘‘hot spots’’ for optimizing the environmental
performance of systems and broadens the debate to include the wider environ-
mental impacts of alternatives (Cowell 1999). A wide variety and goals were
found to exist in the literature of agricultural LCAs although as Harris and Na-
rayanaswamy (2009) mentioned that agricultural LCAs generally compare the
environmental impact of farming practices or types of animal feed. As such, some
LCA practitioners in fiber production and textile industry used the technique to
examine the energy difference between various types of textiles (Woolridge et al.
2006) or to examine methodological problems and solutions for textile products
(Dahllof 2005) or to determine the energy required to produce one metric tonne
(1,000 kg) of raw cotton (including both seed and lint, in the field) across a range
of global production practices (Matlock et al. 2008). Comparison of production
practices is also illustrated by a study on bread-making wheat production where
the relative environmental impacts of conventional versus less intensive agricul-
tural production systems are compared (Cowell 1999). In LCA of grassland-based
production systems, mainly in dairy production systems, the goal and scope of the
study concerns mainly the eco-friendliness of the system under examination.
Casey and Holden (2006) examined Irish suckler beef units, comparing GHG
emissions of conventional Irish agri-environmental scheme versus organic farms.
The same authors (Casey and Holden 2005), in another study, focussed on GHG
emissions from an Irish dairy unit and assessed various scenarios to be considered
toward GHG emissions reduction. LCA studies in Australia and New Zealand on
dairy industry concerned the environmental impacts of the dairy supply chain and
the implications of intensification on their eco-efficiency, respectively, so that
dairy companies could improve environmental performance of their business
(Nicol and Sage 2003; Basset-Mens et al. 2009).

Functional Unit

The functional unit (FU) is dependent on the goal of the study and the system
boundary and is generally chosen to reflect the way each commodity is traded. The
reference unit, that denotes the useful output, is known as the FU and has a defined