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

GROUP 2, SESSION A: CARBON OR WATER FOOTPRINTS, SOIL, BIODIVERSITY 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
44. Carbon footprint and energy use of different options for
greenhouse tomato production
Joana Almeida 1,* , Wouter Achten 1,2 , Bruno Verbist 1 , Bart Muys 1,*
1 Group Forest Ecology and Management, Department of Earth and Environmental Sciences, University of
Leuven, Belgium, 2 Department of Metallurgy and Materials Engineering, University of Leuven, Belgium,
Corresponding authors. E-mail: joana.almeida@ees.kuleuven.be; bart.muys@ees.kuleuven.be
Rising sustainability awareness makes consumers increasingly interested in the environmental performance
of the products on the market, concerning e.g. the emission of greenhouse gases (GHG). For this reason,
there are market-driven environmental impact assessment tools, which can both inform consumers and be
used by producers to highlight their sustainability efforts. The carbon footprint has been suggested as
straightforward and resonant indicator for product environmental performance (Weidema et al., 2008).
In this case-study we report the carbon footprint and energy use of the production of Cuore di bue tomatoes
in a greenhouse in Northern Italy with different energy-provision options. Despite the existence of other
studies of this nature performed in Europe (e.g. Roy et al., 2009; Boulard et al., 2011), none has been performed
in this region nor compares different energy supply configurations.
The conventional system consists of a polyethylene greenhouse supplied with grid electricity and heated
through a natural gas boiler. The CO2 released in the combustion is used to fertilise the plants. There are
future plans to obtain heat through municipal solid waste (MSW) incineration and recover CO2 from industry
exhausts (scenario 1). Alternatively, both can be obtained from a co-generation facility (scenario 2), the latter
providing also electricity. We assessed the life cycle GHG emissions and energy use of the present production
chain and those alternatives. This exercise was performed according to appropriate official standards for
life cycle assessment (ISO 14040-14044) and for carbon footprint (ISO 14067). Allocation was avoided by
system boundary expansion. Assessment was made with software SimaPro ® (PRé, the Netherlands), through
the single-issue methods IPCC GWP 2007 100a and Cumulative Energy Demand (expressed in kg CO2 eq
and MJ eq, respectively). The functional unit is 1 kg of fresh tomatoes packed and delivered at the local market.
The carbon footprint of each kg of tomato produced in the current system is 2.33 kg CO2 eq (Fig. 1-A). Coupled
heating and CO2 enrichment are responsible for 54% of GHG emissions. Construction of the greenhouse
and fertilisation contribute 21% and 13%. The footprint can be decreased by 16% if MSW incineration
supplies heat and CO2 fertilisation (scenario 1). If the co-generation facility were to be installed (scenario 2),
the carbon footprint would be lowered by 7% (2.15 kg CO2 eq kg -1 tomato), owing to the excess electricity
credited to the system. From the energetic point of view, the scenarios imply higher reductions (Fig. 1-B).
While the energy use of the conventional system is 77 MJ eq kg -1 tomato, the co-generation and the waste
valorisation options reduce it by 52 to 55, respectively. Heating and CO2 fertiliser reach 75% of the energy
input to the current system and 50% and 54% in scenarios 1 and 2 respectively. In all cases, construction and
transport, packaging and waste disposal are the second and third energy consumers.
Literature presents wide ranges of GHG emissions and energy use of tomato production, influenced mainly
by location and sophistication level of the system as described by Roy et al. (2009). These results are in line
with averages from literature, even though Cuore di bue variety typically shows lower yields than conventional
varieties.
References
Boulard T., Raeppel C., Brun R., Lecompte F., Hayer F., Carmassi G., et al., 2011. Environmental impact of
greenhouse tomato production in France. Agron. Sust. Devel. 31(4), 757-77.
Roy, P., Nei D., Orikasa T., Xu Q., Okadome H., Nakamura N., Shiina T. 2009. A review of life cycle assessment
(LCA) on some food products. J. Food Eng. 90(1): 1-10.
Weidema B., Thrane M., Christensen P., Schmidt J., Løkke S., 2008. Carbon footprint: a catalyst for Life
Cycle Assessment? J. Ind. Ecol.12(1), 3-6.
719