Carbon Footprints and Food Systems
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study including land use change was more than 5 times greater than the case study where no land conversion has occurred for many decades. British Sugar has determined the carbon footprint of sugar produced in the United Kingdom from sugar beet using the PAS 2050 methodology as 0.6 kg CO2e/kg sugar up to the delivery of the product to food and drink manufacturers (www.britishsugar.co.uk). A German modeling study, looking at all life-cycle stages from cultivation to retailing, estimates the carbon footprint of beet sugar at 1.46 kg CO2e/kg sugar (Stratmann et al., 2008). The results of our case studies and other calculations described above highlight the fact that commodities produced at large distances from their markets can have a lower climate change impact than alternatives produced in Europe. Pineapples: Fresh vs. Processed Products
At the farm gate, emissions from the cultivation of pineapples are very low and compare well with other fruit; for example, GHG emissions from oranges produced in Spain have been estimated at 0.25 kg CO2e/kg at the farm gate (Sanjuån et al., 2005, cited in Garne 2006). However, because pineapples in this case study are air-freighted to their European destination due to their short shelf life, their final carbon footprint increases to 11 kg CO2e/ kg. Fruit that can be shipped, in contrast, can have a much lower carbon footprint, such as kiwi from New Zealand (0.75 kg CO2e/kg up to European retail stores) or oranges and grapefruit from South Africa (0.92 kg CO2e/kg up to European retail stores) (Soil & More, 2008a, b). The carbon footprint of fresh pineapples is similar to that of other fresh produce that is air-freighted from Africa, for example, green beans (11 CO2e/kg up to consumption) (Milà i Canals et al., 2008). The production of highly perishable fruit and vegetables in heated and lighted glasshouses in European countries can have similar carbon footprints to tropical produce that is air-freighted to Europe—for example, conventional and organic U.K. glasshouse tomatoes have a carbon footprint of 9.1 and 17.5 kg CO2e/kg, respectively, at the farm gate (Williams et al., 2006), although other authors have calculated lower figures. Other produce with large energy consumption during protected cultivation, leading to a high carbon footprint, include peppers and cucumbers (Jones, 2006). If the shelf life of a product can be extended through processing, making it possible to transport that product to its final market by ship instead by air, then GHG emissions can be reduced by large amounts. This was shown in the pineapple jam case study, where processing of fresh pineapples into jam, which then is transported by ship, resulted in a much lower carbon footprint of 1.3 kg CO2e/kg jam. Because of this, it may be advantageous to encourage processing in the country of production, which would also add value, increase revenue, and thus lead to other socioeconomic benefits for the producing country. Problems in Applying PAS 2050 Data gaps and assumptions made
Despite extensive data collection during site visits, discussions with industry representatives, and further follow-up discussions with farmers, processors, and other contacts made during the data collection visits, some data gaps still remained; and assumptions had to be made to calculate the carbon footprints. In general, the sugar industry on Mauritius is in a good position to calculate carbon footprints because it is highly organized and a lot of data is collected annually by the various sugar organizations, whereas less detailed and reliably documented information was readily available in Zambia, and the data collected on inputs used was very likely incomplete. This kind of problem can have an impact on the final result because, generally speaking, the more information on processes and inputs is available, the more emissions can be included and the higher the carbon footprint will be. This means that the more time is spent on collecting and analyzing data, the more accurate the result