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

PLENARY SESSION 2: METHODOLOGICAL CHALLENGES FOR ANIMAL PRODUCTION SYSTEMS 8 th Int. Conference on
LCA in the
Agri-Food Sector, 1-4 Oct 2012
such as phosphorus, pesticides, heavy metals, and pathogenic microorganisms. This became the framework
of analysis for an integrated livestock-ecosystems model.
2. Methods
A review of factors driving change in the livestock sector was undertaken, including key agricultural and
environmental policies. The opinions of a range of industry representatives were canvassed regarding views
on the role of livestock in the rural economy and its relationship with the environment. The relationship
between livestock farming systems and society was then explored using an ecosystems framework, namely
the affect on provisioning (e.g. food production), regulating (e.g. GHG emissions) and cultural (e.g. landscape)
services. A variety of scenarios were then developed to reflect actual and potential demands from the
livestock sector, given current and future drivers.
2.1 Scenarios for modelling
Following a review of scenarios used in previous projects and the understanding developed in a review of
science and policy, a set of plausible future scenarios was developed to explore how the UK Government
Department for Environment, Food and Rural Affairs (DEFRA) objectives for the livestock sector could be
met, namely a “profitable and competitive domestic industry which enhances the biodiversity and rural landscape
of England while minimising its impact on climate change, soil, water, and air quality”. These were:
1. Business As Usual (BAU): a baseline business as usual scenario, examining the net balance between the
Provisioning, Regulating, and Cultural impacts of the livestock sector and determining how individual
sub-sectors contribute to this.
And also a series of optimising scenarios to determine the effect of:
2. Maximising employment generation associated with the livestock sector
3. Minimising production costs from the livestock sector
4. Reducing GHG emissions by 25%
5. Shifting from red (beef and lamb) to white meat (pork and poultry) - with red meat assumed to be provided
only from dairy beef, as a by-product of milk production
6. Reducing production of each livestock sector by 25%, balanced as far as possible by plant commodities
2.2 Data inputs and model development
Data for the valuation of Provisioning, Regulating and Cultural services were developed from a variety of
sources and adjusted, where needed, to 2009 values with HM Treasury GDP deflators (2011). Whilst data
on provisioning services were relatively easy to find, data on the impact of livestock systems on the value of
regulating and cultural services were especially difficult to develop. Valuation data were developed from a
variety of sources, including the Report on the Environmental Accounts for Agriculture (Jacobs, 2008).
2.3 Development of an integrated livestock-ecosystems model
An integrated livestock-ecosystems linear programming model was developed to assess the economic and
environmental impacts of the livestock sector, using an ecosystem services framework. For this, the Cranfield
Life Cycle Assessment Model (Williams et al., 2006, 2007) was combined with a grassland productivity
model and a soil erosion model to assess environmental consequences of the livestock sector. A model
was also developed to calculate soil erosion for each 5x5km grid square in England and Wales using the
Morgan-Morgan-Finney model (Morgan et al., 1984). Soil erosion was calculated per unit area for each
slope angle for the different land uses and slope proportions, then allocated between the different systems,
after removing non-productive land. From this, average erosion values (t ha -1 ) were derived for arable, dairy,
beef and sheep, and then split among lowland (