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CO2 Emissions Produced in the Food Industry

written by: •edited by: Laurie Patsalides•updated: 1/21/2011

The food industry uses large quantities of liquid CO2 for freezing and preserving of food. They are also a major emitter of CO2, which is produced during the stages of food processing and transportation. This is where the emissions can be decreased, reducing CO2 emissions in the food industry.

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    Introduction to CO2 Emissions from the Food Industry

    CO2 is produced by the food industry during processing, storage and transportation operations. During processing stages, liquid CO2 is used to preserve fresh produce or cooked items by freezing. Freezing is usually efficiently carried out in a cryogenic freezing unit which uses liquid CO2 to carry out the operation. These processes inevitably emit CO2 gas to the atmosphere adding to the CO2 produced during food processing.

    The CO2 produced during processing is difficult to measure, but they all add up to a substantial amount of CO2 emittance into the atmosphere.

    Here we examine the different stages of food processing. We shall then and endeavor to estimate the overall amount of CO2 emitted, and have a look at measures to mitigate these emissions.

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    CO2 Emitted by Food Industry Processes

    To obtain a carbon footprint for the food industry we have to start at the initial farming stages and continue through to the storage and transport of the produced food as outlined below.

    1) CO2 produced during the agricultural and animal rearing for food:

    Agriculture

    Includes the machinery used in cultivation and fertilization of the land.

    Animal Husbandry

    All the processes involved in the rearing and supply of fresh meat to the industry.

    2) CO2 produced during the cooking of food:

    Baking

    Baking powder is an ingredient used in bread and cake cooking. As it helps these products to rise, making them light and airy, it also emits CO2.

    Food Cooking

    The cooking of food requires thermal energy, which can be supplied by natural gas or electricity.

    3) CO2 produced in the preservation of food:

    CO2 Emitters

    The quality and shelf life of food can be improved by using preservatives, CO2 emitters, (which are inserted into vacuum packed food) or by freezing, which is the most popular method. The most efficient method of freezing the food is by spraying liquid CO2 onto the food in a cryogenic unit.

    Packaging

    Packaging is one area in need of decreasing CO2 production. These days everything we buy seems to come with excessive packaging and the food industry is no exception.

    Tesco has taken the initiative by reducing their packaging of food and making cash reductions for the return of carrier bags for recycling.

    4) CO2 emitted due to food transportation:

    By Road

    Transport from the original source to processing unit, then to storage and finally to the supermarket.

    By Air

    Transport by air, which adds up and is known as Food Air Miles.

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    Overall CO2 Emissions Produced by the Food Industry

    Recent statistics and data regarding CO2 emissions during the various stages of food processing are not only difficult to decipher but seem to be non-existent. However I have listed the latest emissions below,

    • UK CO2 Emissions = 16,000000 T/year based on a DEFRA report from 2005
    • USA CO2 Emissions = 24,000000 T/year based on a DOE report from 1994

    As these reports go back a number of years, the figures shown are only for information. The relevant Government Departments should be contacted for the current CO2 emissions by the food industry.

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    Reducing CO2 in the Food Industry

    Energy Efficiency

    Renewable energy which produces minimal amounts of CO2 should be the first choice of fuel used by the food industry. The use of natural gas for optimum energy efficiency is well documented, so renewable energy should be supplemented by using natural gas.

    Agriculture and Farming Techniques

    Examination of current techniques employed in the initial supply of food to the industry, for example use of natural fertilizers, such as clover in manure and plowing, use of organic matter such as straw and the use of biodiesel in farm machinery.

    Packaging

    Using less packaging or packaging from recycled paper, Styrofoam and card stock.

    Labeling – the labeling of products giving the CO2 produced in their processing. This allows the customer to compare the carbon footprint of food products, and hopefully select the one with the lowest footprint.

    Transport - road transport causes CO2 emissions from burning fossil fuels. This could be reduced by the transporting of food in container by rail.

    Food Air Miles – this is the biggest CO2 producing culprit of all the transporting of food methods. The only way to reduce this is for consumers to buy local produce.

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    Summary

    Reducing CO2 emissions in the food industry is not an easy task.

    CO2 is produced from the growing of crops, fruit and vegetables right through all of the food processing stages until it arrives on the supermarket shelf.

    It is also produced from the farming of dairy cattle, and the rearing of various animals, fowl, and fish for the food industry. This is added to butchering, through all the processes to the packaging and transportation of the meat to the supermarket shelves, with air transport being one of the greatest emitters of CO2.

    Some leading supermarkets are making inroads to reducing these greenhouse gas emissions during food processing, by using energy efficient equipment, reducing packaging, using more efficient means of transport and cutting down air transport of fresh exotic fruit.

    However it may be up to the general public to help reducing CO2 emissions in the food industry. This can be achieved by avoiding food transported by air, selecting of fresh, lightly packaged, locally produced food and, ordering online for home delivery.

    Reference Webs:

    1. Tesco's Response

    2. Food Contribution to CO2

    3. DOE