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THE BANANA CARBON FOOTPRINT CASE STUDY BY ANTHONY J. CRAIG AND DR. EDGAR E. BLANCO MIT CENTER FOR TRANSPORTATION & LOGISTICS SEPTEMBER, 2009
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THE BANANA CARBON FOOTPRINT CASE STUDY BY ANTHONY J. CRAIG AND DR. EDGAR E. BLANCO MIT CENTER FOR TRANSPORTATION & LOGISTICS, CAMBRIDGE MA, USA SUMMARY: This document describes in detail the process of estimating the carbon footprint of a banana. The case study estimated a total footprint of 121g of CO2equivalents, with transportation and farming being the largest share of emissions (36% and 29% respectively). A description of the breadth, depth and precision of the estimation is included in the document, as well as an illustrative assessment on the level of uncertainty of the carbon footprint calculation.
Introduction
This case study involves the cooperation of Chiquita Brands International (CBI), a leading international distributor of fruits, and Shaw’s, a New England based grocery store chain, to measure the carbon footprint of bananas. The initial phase of this research has involved interviews with key personnel, mapping of the supply chain, visits to a distribution center and retail store, and collection of relevant data. Working with the partner companies the activities associated with the supply chain were examined for any greenhouse gas emissions that might be produced (measured in CO2 equivalents or CO2e). For each emissions generating activity data was collected regarding the amount of emissions generated and the quantity of bananas involved in the activity. In this manner the emissions can be allocated to the product in order to determine the carbon footprint of a pound of bananas sold at a retail outlet. For data that is not available from the partner companies estimates have been made from secondary data sources. The current work has focused on materials that are consumed and used during the handling process, and capital goods have been excluded.
The Banana Supply Chain
Bananas sold in the United States are typically grown in Central America. CBI works with a network of owned plantations, independent growers, and wholesalers at more than 200 locations, primarily in Guatemala, Nicaragua, and Costa Rica. Though practices may vary from farm to farm banana cultivation often involves the application of fertilizers, pesticides, and fungicides. Once the bananas approach ripeness they are picked at the plantation and packaged for transportation. The bananas are shipped from the packing locations by truck in refrigerated containers to one of three outbound ports. Once they arrive at port the bananas remain in the refrigerated containers and are loaded on ocean vessels for shipment to one of five ports in the US. After arriving in the US the containers are unloaded from the ship and the bananas are moved from the containers to refrigerated warehouses located near the port. From the warehouse bananas are shipped either to CBI distribution centers or taken to customers DCs. This transportation can be arranged by CBI or by the customer. Upon reaching the DC the bananas undergo a chemical ripening process using ethylene gas that lasts 3‐4 days. At the end of this process the bananas are
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ready for sale and are immediately shipped to retail outlets. At the retail outlet bananas require no special handling or care such as refrigeration. Bananas are a fast moving product, with most bananas typically being sold within a day of arriving at the store. In addition to the bananas themselves a number of additional materials are used to package the bananas for transport and sale. From the packing station to the DC bananas are normally shipped in container quantities. Each container holds 20 pallets of 48 banana boxes, for a total of 960 boxes per container. Each box contains approximately 40 pounds (18 kgs) of bananas wrapped in a plastic liner and placed in a cardboard banana box. The banana boxes and liners are procured by CBI and sent from the US to Central America during the backhaul portion of the ocean voyage. The materials are sent to the packing stations in the trucks that will be used to transport the bananas from the packing station to the port. Additional packing materials include reusable wooden pallets, cardboard pieces used to help secure boxes of bananas on pallets, and plastic shrink wrap used when transporting pallets of bananas from the DC to the store. Though Chiquita supplies the cardboard and plastic used in packing bananas these materials are eventually disposed of by retailers who purchase bananas from CBI. At Shaw’s grocery stores the cardboard used in packing is saved and sent to a recycler, while the
plastic lining and shrink wrap are thrown out as waste. Beyond the bananas and the packaging materials the only other product consumed during the banana supply chain is the ethylene fluid used in the ripening process. This fluid is purchased from the producer and shipped to the DC through a parcel delivery service. The fluid is packaged inside a plastic bottle. One 32 oz. bottle of ethylene fluid is used to ripen one truckload of bananas. After use in the ripening process the empty bottles are discarded as waste. A map of the supply chain is shown in Figure 1.
Emissions and Data Sources
The emissions considered in this analysis can generally be placed in one of three categories: emissions from mobile combustion, emissions from energy use and electricity consumed in facilities, and emissions related to production and disposal of materials used throughout the supply chain. The materials include not only packaging materials such as cardboard and plastic, but also emissions related to the chemicals used in the growing of bananas and production of ethylene fluid. In theory each of these materials can themselves be traced back through the supply chain to quantify their emissions, however, this requires information not available to the partner companies. In this case these emissions can be quantified using available Life‐cycle Assessment (LCA) data.
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Figure 1. Banana Supply Chain Map
Mobile Combustion The primary emissions contributions for mobile combustion come from ground transportation of the bananas by truck and ocean transportation of the bananas from Central America to the U.S. Secondary contributions include ocean transportation of cardboard boxes from the U.S. to Central America, ground transportation of ethylene fluid and packing materials to the DC, and transportation of chemicals to the banana farms.
Ground Transportation
Ground transportation of the bananas includes shipping from the grower to the outbound Central American port; inbound from the U.S. port to the DC; and outbound from the DC to the retail store. Shipping distance from the grower to port can vary based on where the grower is located and which shipping