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

PARALLEL SESSION 7C: FOOD CHAIN AND FOOD WASTE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 2. Sensitivity analysis results
Impact Category
GWP100 (kg
CO2 eq)
Water footprint
(WF) (m 3
Virtual water)
Weighted WF
(m 3 Virtual
water)
Agricultural
land occupation
(m 2 .yr)
Pesticide hazard
indicator
E.I.Q.
Abiotic depletion
(kg anti-
mony eq.)
Photochemical
oxidation -
high NOx (kg
ethylene eq.)
Acidification -
(kg SO2 eq.)
Eutrophication
(kg PO4--- eq.)
624
A. Raspberries,
fresh at
UK RDC in
May (base)
A1. Raspberries,
fresh at UK
RDC in
May, fruit
yield +10%
A2. Raspberries
fresh at UK
RDC in
May, cane
yield +30%
Product System
B. Raspberries
fresh at UK
RDC in
July
B1. Raspberries
fresh at UK
RDC in
July, yield
+10%
C. Raspberries
frozen
at UK RDC
in November
C1. Raspberries
frozen at UK
RDC in
November,
maximal
cold-store
occupancy
7.3 5.7 6.0 7.4 6.7 7.7 7.5
2.7
2.7
Not calculated
Not calculated
Not calculated
Not calculated
1.3
0.09
Not calculated
Not calculated
1.3
0.09
Not calculated
Not calculated
1.5 1.3 1.5 1.6 1.5 1.6 1.6
0.3 0.3 0.3 0.3 0.3 0.3 0.3
0.01 0.01 0.01 0.004 0.004 0.006 0.005
0.0004 0.0004 0.0004 0.0001 0.0001 0.0002 0.0002
0.01 0.008 0.009 0.003 0.003 0.004 0.003
0.005 0.004 0.005 0.004 0.003 0.004 0.003
For impact categories other than water, likely (e.g. year-to-year) variations in fruit yield and cane yield
could rise to variations in the results obtained for one particular case greater than the differences between the
different cases shown in Table 1.
N2O emissions from horticulture contribute a large proportion of the GWP: 75% for A and more than
90% for B and C. However, in this project the calculation of N2O emissions from soil following the incorporation
of crop residues both in the UK or overseas was highly problematic. The IPCC 2006 method using the
tier 1 approach is complex and uses many default values for specific crops or crop groups. A large number of
crops are not represented in the IPCC method, therefore default data relevant to several of the products considered
in this project – including raspberries - were not available. Data for another crop product were used
as a proxy, but this introduces a further element of uncertainty.
The production of polyethylene contributes some 25% of the abiotic depletion potential in A. Tunnels account
for the majority of the polyethylene in this case. While there is some uncertainty about the fate and
longevity of the material used for these tunnels in practice, extending the material’s life and recycling it
when it is no longer useable are clearly desirable.
In case C (frozen raspberries supplied in November) no allowance was made for loss or spoilage during
cold storage. Such losses increase the impacts associated with supplied product but no relevant data for loss
rates were available when the work was conducted. Recent work by WRAP (Terry et al., 2011) provides an
estimate of 2-3% losses of fresh raspberries in packing and in retail stores, but provides no estimate for
losses of packed fruit consigned to frozen storage. The loss rates found for packing are similar to those used
in this study.
5. Conclusions
An LCA has been completed of a soft fruit supplied in the UK at three different times of the year. The
impact assessment results are quite similar across all three, perhaps surprisingly so in light of the operational
differences between the supply systems. The influence on environmental impact of the place of production