Exploring hotspots in the carbon footprint and energy use profiles of fresh tomatoes. Girija Page
1. Exploring hotspots in the
carbon footprint and energy use
profiles of fresh tomatoes
Girija Page; Brad Ridoutt; Bill Bellotti
2. Why CF and EF of tomatoes for
Sydney consumer?
Carbon Footprint (CF)
Energy footprint (EF)
Background
Agri-food products - environmental impacts
Food labelling for environmental burdens may become
necessary
3. Systems studied
Field
production
Greenhouse
production
Sydney
4. Field Low- Med-
production tech GH tech GH
Location Bundaberg Sydney Sydney
Growing season Mostly year Warmer Year-
round months round
Cropping cycle 3-5 months 5-6 11
months months
Yield t/ha 60 160 340
Artificial heating never minimal mostly
Distance to 1400 25 25
market km
5. System boundary
•GHG (kg CO2)
Raw material extraction, production
•Energy (MJ)
and delivery
Transport to the
Sydney market
Cultivation on farm
7. Hotspots- Field production
MJ kg CO2
Mineral/fertilisers 6.5 7.7
Pesticides 1.2 0.9
Diesel 8.3 8.3
Packaging 8.7 3.7
Electricity 9.6 12.8
Transport 65.7 66.5
8. Hotspots-Low-tech Sydney
MJ kg CO2
Minerals/fertilisers 25.00 44.97
Pesticides 0.49 0.36
Diesel 4.29 4.09
Artificial heating 25.16 29.22
Packaging 11.93 31.82
Electricity 11.65 8.17
Transport 1.63 1.53
9. Hotspots-Med-tech Sydney
MJ kg CO2
Fertilisers 2.9 3.2
Pesticides 0.1 0.1
Diesel 1.9 1.6
Artificial heating 89.2 92.4
Packaging 4.6 1.5
Electricity 0.6 0.8
Transport 0.5 0.4
10. Key results
Best to eat locally grown tomatoes in season
Energy use and associated emissions
OR
Sydney
Heated Sydney greenhouses
Supply from Queensland
11. Further considerations
Trade-offs Different modes of as a out of season?
Eat more processed tomatoes fuel source?
Use with otherbiomass transport?
non-yield environmental considerations?
In this paper we explore the hotspots in the carbon and energy use profiles of fresh tomatoes produced for the sydney market. I am presenting this paper along with Brad Ridoutt from CSIRO and Bill Bellotti from the University of Western Sydney.
Carbon emissions and energy use are amongst the key indicators of environmental sustainability. Tomatoes are an important vegetable in australia in terms of production and trade and given the greater sophistication of vegetable production due to intensive practices it is thought that there are greater opportunities to reduce environmental impacts. Sydney is a major population hub in australia and has a huge demand for agri-food products. Most of the tomatoes consumed in sydney are produced from many other regions in australia. The agri-food sector is responsible for a large proportion of environmental impacts. There is a general consensus that food production and consumption activities which have large enviornmental impact should change to become more sustainable. Towards this end demand for food labelling of environmental burdens is high. Many businesses view food labelling as a way to demonstrate the environmental credential and gain shelf-access to the agri-food products. The most common example of product food labelling for impacts is the carbon footprint. These are some of the many carbon footprint labels which are being developed and already in use. Water land and energy footprints are under development on similar lines. This will enable the consumers to take greater responsibility of their purchasing decisions to reduce the environmental burdens.
In this paper we study three tomato production systems which supply for the sydney market. The first of the studied systems is that from Bundaberg region of Queensland. Queensland produces the majority of fresh market tomatoes grown in Australia. The other two systems are the greenhouse tomato production systems located in the Sydney region. These are classified as low-tech and med-tech depending upon the level of automation used and the variation in yields.
This figure shows the components which are included in the analysis. A life cycle perspective is taken to estimate the carbon and energy footprints of fresh tomatoes. Two life cycle stages are considered 1) cultivation at the farm/greenhouse and 2) transport of tomatoes from farm gate to the sydney market.There are several variables farm inputs used during a typical cropping season such as fuel sources namely L diesel, kg coal, LPG, kWh electricity is used for pumping water and in the packhouse, type and amount of minerals and fertilisers pesticides for growing tomatoes and packaging material. The embodied energy consumed in the raw material extraction, production and delivery of these farm inputs is considered and so also the associated embodied GHG emissions are included for every kg of tomato reaching sydney market. These are expressed as kg CO2 e and MJ.The Australian database in the LCA Simapro software was used for getting various coefficients which are used to convert primary data energy matter coefficients.
The results suggest that the energy footprint for a kg of tomato supplied to the Sydney market ranges from 5 to 19 MJ and the carbon footprint varies from 400gm to 2 kg of CO2 e emissions depending upon the time of the year.
In this table the break-down of carbon and energy footprint is presented. The most important hotspot in the field tomato production is that of transportation to the Sydney market. Tomatoes are transported in a refrigerated truck using road transport
For the low-tech system the minerals and fertilisers had a high carbon footprint and they are quite energy intensive followed by the use of LPG in colder times. Packaging and electricity
Clearly the most important hotspot in the med-tech system is the artificial heating used in the greenhouses. compared to this inputs other inputs appear small in terms of energy use and greenhouse gas emissions.
The results indicated that the CF and the EF of fresh tomatoes consumed in sydney varies depending upon the season. Although the low tech systems fared well in terms of having lower energy use and GHG emissions amongst the studied systems, realistically it would not be possible to grow tomatoes year-round in sydney without artificial climate control. This implies that the luxury of eating fresh tomatoes out of local season means that CF and EF will be higher due to long distance transport from queensland or heating if grown in climate control greenhouse in sydney. The results therefore reinforce the understanding that consideration to seasonality is important along with other things such as food miles type of operation and the type of transport used.