Going the Distance – A Digestible Explanation of Food Miles

By: Kelly D’Amico

Animal agriculture is often criticized for its methods of feeding livestock improper diets which contribute significantly to methane emissions, thus increasing carbon levels in the atmosphere. Other agriculture practices often contribute to the rise in carbon such as fossil fuel powered equipment and manufacturing processes. However, once the produce leaves the farm, another process has the potential to significantly contributes to emissions through the transportation.

Eating local produce is important for a number of reasons including but not limited to: supporting your local economy, eating food at peak freshness, and a reduced carbon footprint in the food distribution. As a life long New Jersey Resident, we only have this luxury for a portion of the year. As we are moving through the winter months, it’s a struggle to find fresh ingredients that come from a local source. Food preservation technology has made significant advances with processes such as Individual Quick Froze (IQF), High Pressure Processing, Retorting, and other processes that provide us with frozen and shelf stable products respectively. Alternatively, fresh produce needs to travel longer distances in the colder months, which further contributes to our carbon emissions.

The phrase food miles is very straight-forward – the distance the food has traveled from harvested to your plate are its food miles; the frequented idiom farm to fork when referring to restaurants or farmers markets highlights its reduced food miles. It is estimated that processed foods travel 1,300 miles, and fresh food travels over 1,500 miles before it is consumed^[1]. It is important to note that emissions from agricultural and cultivation practices are not included in this calculation.

Food distribution is a science in itself, one which use various forms of transportation from semi-truck for ground, rail cars for trains, ships for overseas transport, and air freighting. Our food system is a carefully monitored on a global scale constantly. In addition to preventing damage, food distribution has the added challenge of delivery before expiration and must meet rigorous safety standards in order to be approved upon arrival. With many companies now moving direct to consumer and increased use of e-commerce, the system is becoming increasingly complex.

The Environmental Protection Agency (EPA) closely monitors and regulates emissions among other things from both companies and transportation. The Environmental Defense Fund  developed the method to calculate food miles using a standard calculation with variables for the mode of transportation^[2]. The calculations shown here were conducted according to the EDF method, however, there are several websites tools that can perform the calculations for you.

Food Miles contributes to freight emissions which can be calculated by the distance traveled multiplied by the weight of the product multiplied by the emissions factor. The emissions factor varies based on the mode of transportation used. Air freight emits the most emissions followed by oceans then followed by truck. Produce that is time sensitive or climacteric is often air freighted to combat the shelf life of the food. These metrics are typically calculated to accommodate metric tons, and converting them to consumer levels can be challenging due to the emissions factors. 

Using MyClimate.com emissions calculator, we calculated the amount of emissions of a local produce, such as a tomato and compared it to a tomato imported from Mexico. Local tomatoes may travel 50 miles to your local farmers market driving a pick up truck or a cargo van that’s powered by gasoline. The carbon emissions equal for this particular load are equivalent to 0.034 tons of CO2 ^[3].

In the Northeastern region of the United States, tomatoes are typically sourced from Mexico in the winter time, and depending on the demand, it can be all year long. The distance traveled between these two locations is around 2700 miles. If the tomatoes are transported using a semi-truck to maximize the cargo of the trip, the emissions were estimated to be 1.8 tons of CO2. Given that this is an extensive trip, distributors may even choose to airfreight the produce, which emits 1.1tons of CO2 per flight. 

While airfreighting preserves material and has less carbon emissions, it is still 32 times more emissions than a local tomato. While there are other factors that contribute to this metric which were not factored into the calculation, the amount of emissions from the locations is vastly different. Other components not factored include but are not limited to the weight of the vehicle, the type of fuel used, the size of vehicle, and even road conditions. Regardless of conventional or organic produce, the emissions are the same.

While the rate of emissions from food mileage is alarming, there are a few methods that you can use to help reduce your food miles and thus emissions. To start, purchase more produce from local markets, or farmers markets. Farmers markets provide in season produce that was locally grown. This supports the local economy and provides high quality produce at peak freshness. In the winter months, consider preserved food such as canned or frozen. These are often picked fresh season and preserved for the winter months. There’s also the option to preserve your own food using your freezer or home canning. If fresh is required off season, check the country of origin before purchasing. For example, blueberries which grow locally in New Jersey under great conditions are often imported from countries in South America in the winter months. This is a great place to supplement frozen or wait until blueberries are in season in your area. 

It’s important to know where our food comes from and the implications of our product purchases. If you enjoyed this article, please share with others, and follow Made to Sustain for more content like this.

Sources:

1. Hill, Holly. NCAT.“Food Miles: Background and Marketing” A Publication of ATTRA – National Sustainable Agriculture Information 40 • 2008. http://www.attra.ncat.org 

2. Environmental Defense Fund. “The Green Freight  Handbook” A Practical Guide for Developing a Sustainable Freight Transportation Strategy for Business. 

3. Foundation myclimate https://www.myclimate.org