LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 2A: LAND USE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
for conversion to low density housing, or do other housing decisions possess better environmental impact
trade-offs? Specifically, in this paper, the benefits and challenges of applying CLCA to generate decision
making evidence to support peri-urban land-use decisions are evaluated. In agriculture, CLCA has been used
to assess land use decisions (Brandao, 2010). LCA is also used in the built environment, typically as attributional
studies investigating different building forms and building materials (Rossi et al., 2012). In Australia,
recent studies have compared embodied, operational and transportation energy and greenhouse gas emissions
of alternative housing types, supporting the opportunity for energy consumption and emissions to be significantly
reduced by shifting to inner-suburban apartment type dwellings over outer suburban detached homes
(Crawford, 2011). Environmental impacts are typically assessed in isolation within each of the two disciplines
of agriculture or urban planning. Using CLCA, the system boundaries can be defined to include the
activities contributing to the environmental consequence of the change, meaning that impacts associated with
both the urban and agricultural systems affected by this change can be included. The benefit of CLCA at the
urban-agricultural intersection is to provide a new perspective on peri-urban land-use change. Scenarios for
producing vegetables versus producing housing can be ranked according to their environmental impacts and
consequential displacements associated with land use decisions assessed. Environmental impacts were assessed
for both a certain amount of product to be produced for the Sydney market, and for a certain number
of people to be housed. The method implemented in this paper permits for environmental impacts to be calculated
for scenarios that include two distinct types of urban housing systems whilst accounting for agricultural
diversity at the farm scale.
2. Methods
2.1 Scenarios
In applying CLCA to assess the combined environmental impacts involving both horticulture and urban
land use at the peri-urban intersection, hypothetical scenarios were established as illustrated in Fig. 1. The
use of CLCA allowed alternative means of increasing marginal production to be evaluated. Marginal production
refers to the system that would be affected due to changes in demand. The system could be a technology
(such as greenhousing versus field production) or a location (one growing region may expand in preference
to another).
Scenario 1. Scenario 2.
Figure 1. Scenarios to be analysed for land-use change from 1 ha of lettuce to greenfield housing (scenario 1)
or to equivalent infill housing (scenario 2).
In Fig. 1, scenario 1 illustrates how fresh food production is met via production in a marginal region, due
to displacement from the Sydney region by housing. Scenario 2 illustrates how the housing burden is fulfilled
by adoption of a predominantly infill housing system with no displacement of Sydney horticulture. A
third scenario, scenario 3, analyses the trade-offs provided by a high technology greenhouse combined with
increased parkland and infill urban housing compared to the scenarios 1 and 2. Modelling of scenario 3 will
be completed in the next phase of this project and will not be discussed further in this paper.
2.2 Functional units and impact categories
SimaPro 7.3.3 software was used for modelling, selecting data from Australian Unit Process LCI or
Ecoinvent unit processes. Two functional units were used for each scenario: one functional unit to represent
a certain number of people being housed (in units of per hectare); the second functional unit to represent a
certain amount of lettuce being produced for the Sydney market (in units of per kilogram). Having two functional
units facilitates improved understanding of environmental burdens. Environmental impacts were esti-
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