chapter 3 inventory of local food systems

Project CP/59 - “Instruments and institutions to develop local food systems”
In a similar way, we calculated the carbon dioxide emissions (see table 3) for the
different food items, resulting in comparable trends as seen in the energy results: in local
food systems the highest total values are for cheese (2399 g CO2/kg), the lowest for
apples (77 g CO2/kg) and in-between values for vegetables and beef. In the mainstream
system all figures are lower, but with also the highest value for cheese (1833 g CO2/kg),
the lowest for apples (67 g CO2/kg).
When looking at the total carbon dioxide emission per portion, cheese has the highest
emission rates for both the local and the mainstream system, even though cheese
accounts for a portion of only 15 g, compared to e.g. 200 g for potatoes.
When comparing transport energy uses and CO2 emissions per kilogram on the one side
to processing and storage energy uses and CO2 emissions per kilogram on the other side
(table 2 and table 3), almost all data for processing and storage are lower than for
transport, except apples, both locally sold and through the mainstream system, and
cheese in the mainstream system. Apple storage uses more energy and emits more CO2
both in the local and the mainstream food systems because of the long storage period
(up to 10 months in ULO-refrigeration ). Cheese in the MFS consumes more energy and
emits more carbon dioxide during storage than in LFS, as the production process in this
study is the same for local and mainstream food systems. This is mainly because of the
longer total storage time due to longer storage at each step in the mainstream food
chain.
2.5.3. Discussion
We are aware of the sensitivity of our results to assumptions (see annex), as a lot of the
data are difficult to obtain in exact figures and as this study is based on a small number
of specific case studies. Although by using the same methodology for the local and the
mainstream food systems, this sensitivity to assumptions can be largely reduced by
comparing the relative differences between these two food systems. In addition, there
can be large differences between similar LFS and there are some side effects outside
these system boundaries of the basic simulation (full summer and inland production)
presented in the results that have a non negligible impact on the total energy
consumptions and on the total carbon dioxide emissions of a specific food item. These
side effects are: the transport efficiency of the consumers’ purchase of food, the transport
efficiency of the transport mode for imports from abroad, and production in greenhouses
versus in open air. Finally, it is also complicated to compare the absolute levels of
energy uses and carbon dioxide emissions of this study with other studies because of the
differences in system boundaries, calculating methods etc.
Variation between existing food systems
Even though the selected case studies are representative for the present LFS in Flanders,
there can still be a large variation between LFS of the same kind. For instance there is a
relative difference in energy use for transport of 1 over 9 between two investigated
farmers selling their apples through farmers markets and of 1 over 13 for the energy uses
of storage of two other farmers. Probably these differences are also to be found in other
systems such as box schemes. The main causes for these large differences are
SPSD II - Part I - Sustainable production and consumption patterns - Agro-Food 43