Carbon Footprint of Canned Vegetables Vs Fresh: Measuring Vegetable Emissions

Vegetables are loaded with vitamins and nutrients and are a much more sustainable food choice than meat products; however, most people don’t stop and think about the carbon footprint of canned vegetables.

The truth is everything we consume has a carbon footprint, even veggies.

While the environmental damage is far less than other food products, it’s still worth diving into to understand the impact canned veggies have on the world around us.

Figuring out how to calculate carbon footprint manually can be difficult because most food manufacturers don’t publish reports about carbon emissions or solid waste; however, we can still outline the environmental impact.

So what’s better, frozen or canned vegetables? Are you better off buying chilled vegetables?

The answers depend on a lot of factors, but the carbon footprint of canned vegetables can be calculated, and the results may surprise you.

Assessing the Carbon Footprint of Canned Vegetables Throughout the Product Lifecycle

Assessing the carbon footprint of canned vegetables throughout the product lifecycle can be difficult as most major manufacturers don’t release this information.

However, agriculture makes up about 10% of the total U.S. Greenhouse emissions.²

Plant-based products are better for the environment than meat and dairy products. Canned vegetable production produces 0.7 kilograms of greenhouse gas emissions per kilogram compared to beef, which produces 70.6 kilograms of greenhouse gas emissions per kilogram.³

However, vegetables, especially canned ones, still have an environmental impact and a negative carbon footprint.

The Carbon Footprint of Canned Vegetables: The Process of Canning Vegetables

Many of us don’t think twice about the environmental impacts of canned vegetables, but the canning process of veggies is fairly resource-intensive.

Since there are many actions associated with mass-producing any product we consume, you can imagine that the carbon footprint of canned vegetables has the potential to run very deep, as a lot of energy and resources go into canning, preserving, and distributing food.

If you walk down the grocery store aisle, you’ll notice an abundance of canned vegetables on the shelf. Beans, carrots, corn, peas, and tomatoes are some of the most commonly canned products.

While it might seem simple, the process of producing these products is quite involved, but can be broken down into these categories:¹

• Growing Vegetables: Growing and harvesting vegetables before canning.
• Processing & Cooking Vegetables: Sorting and washing vegetables, adding salt, sugar, or sauces, and cooking them.
• Containerizing: Cleaning the cans with hot water or steam, placing the prepared vegetables into the cans, acidifying the product, removing air pressure (exhausting), and sealing the lid.
• Heat Sterilization: Heating the cans to 212° F (via steam or hot water) and then quickly cooling them preserves vegetables and kills microorganisms.
• Labeling & Distribution: Label designs are created, printed, and applied to cans via glue in a high-speed operation. Packing products in boxes and shipping to grocery stores.
• Disposal: Once purchased, when you use the product, the disposal of the can, even if it’s recycled, generates emissions.

Processing Canned Vegetables

Processing canned vegetables takes place after they’re harvested. Canned vegetables are washed and cooked and seasonings and sauces are applied.

Below are categories of canned vegetable processing that have a negative environmental impact:

1. Shipping: Transporting harvested vegetables to processing facilities around the world.
2. Washing: Mechanically harvested vegetables are thoroughly washed with high-pressure sprays at the processing facility. This requires significant energy and an abundance of water.
3. Sorting: Some vegetables are sorted for size and maturity, which requires machines/moving screens.
4. Sourcing Ingredients: Sourcing salts, seasonings, sauces, and other additives that are used in preparing vegetables before canning.

Canning Vegetables

Containerizing or canning vegetables is a significant stage of the product lifecycle, and the carbon footprint of packaging is meaningful.

Cans are manufactured from steel and tin, shipped to the processing facility, thoroughly cleaned, and filled with vegetables and some additional ingredients, exhausted, and sealed.

1. Can Manufacturing: Sourcing tin and steel and using energy to construct cans in bulk.
2. Shipping: Transporting large quantities of cans to processing facilities, usually by air or diesel truck.
3. Cleaning: Before vegetables are placed in the cans, the cans are sanitized with hot water and/or steam, which requires a significant amount of energy.
4. Exhausting & Sealing: A highly important part of containerizing, the cans receive a heat treatment followed by an immediate cooling to eliminate microorganisms before air is removed and the lid is applied. This process requires significant energy and machinery.

While there is a lack of data on emissions related to shipping, exhausting, and cleaning cans, producing 1 tinplate, which is equal to about 46 cans, emits 2.33 kg of CO₂ and the average cradle-to-grave carbon footprint of a single aluminum can is 77.1g of CO₂ 8.^8,9

Americans consume hundreds of millions of cans of vegetables every year, and producing cans creates a massive amount of greenhouse gases. Because manufacturing cans can have such an environmental impact, the carbon footprint of canned vegetables tends to be higher than the carbon footprint of potatoes or fresh vegetables.