By now, it’s well known that curbing your meat consumption — or even just switching from beef to poultry — can help to lessen your carbon footprint.
First, some good news
Changes in the American diet from 2005 to 2014 have resulted in some positive changes in our carbon footprint. How big of a difference? According to a recent report from the Natural Resources Defense Council, the reduction in climate pollution was equivalent to the emissions created by 57 million cars in one year.
This change was mostly due to a 19 percent reduction in beef consumption, but Americans have also stopped reaching for other foods with larger carbon footprints like orange juice, pork, milk, and high fructose corn sweetener.
The carbon footprint of produce
So, now that we’re cutting out meat, we’re good to go right? Well...it turns out that not all produce is created equally when it comes to the environmental impact of its production. So, which produce should you cut back on?
When it comes to the carbon footprint of produce, different factors come into play. Instead of looking at just carbon emissions, you have to look at other factors like energy and water use.
In terms of carbon emissions, a study from The National Resource Defense Council and The Environmental Working Group showed that potatoes, rice, and nuts were among the agricultural products that produced the highest carbon emissions. The vegetable that produces the most carbon emissions may surprise you though: Asparagus produces 8.9 kg of CO2 per kg of food. For reference, the average car emits .41 kg of CO2 for every mile driven. So producing one kg of asparagus has a carbon footprint equal to driving 21.7 miles.
Pesticide is another major contributing factor to the carbon footprint of produce. The higher the amount of pesticides used, the more pollutants are put into the surrounding environment. The USDA’s National Agricultural Statistics Service worked in conjunction with the Economic Research Service to track the use of pesticides in 21 agricultural products from 1960-2008.
Over that period of time, the three food items responsible for the majority of pesticide use were: corn, soy, and potatoes. It’s worth noting that this data was cumulative and not measured per pound. Since these are three of the most commonly used ingredients in the American diet, the high amount of pesticides used during that period may be due to the prevalence of corn, soy, and potatoes, rather than the crops requiring an excessive amount of pesticides per pound.
Water usage must also be considered in determining the carbon footprint of produce. The Congressional Research Service published a report on California Agricultural Production and Irrigated Water Use that ranked the fruits, vegetables, legumes, and nuts that required the most water to grow.
The number one offender when it came to water consumption was Alfalfa. After that came almonds and pistachios. Fruit trees were also high up on the list (sorry, that includes avocados). The food grown that required the least water was safflower, which may be a good argument for making safflower oil your go-to cooking oil. Potatoes had the second and tomato had the third lowest water requirements.
It’s still complicated to measure
These rankings serve to illustrate the complications when it comes to measuring the carbon footprint of produce. Because both potatoes and tomatoes ranked high when it came to carbon emissions, but they ranked low when it comes to water usage.
The carbon footprint of produce is not as easily measured as the carbon footprint of meat, and the studies that have been done can offer conflicting information. A 2015 study conducted by Carnegie Mellon, for example, found that lettuce has a larger carbon footprint than bacon per calorie. That means we should all ditch lettuce and load up on the bacon, right? Not quite! As Martin Heller, a research specialist at the Center for Sustainable Systems at the University of Michigan noted to Scientific American in response to the Carnegie Mellon study, “We don’t eat lettuce for its calories.”
The Carnegie Mellon study was meant, in large part, to illustrate that a vegetarian diet was not inherently more virtuous than an omnivore diet when it comes to sustainability. Reducing meat is a great step, but replacing it with leafy greens, corn, and a ton of alfalfa isn’t necessarily going to have a better impact. Still, there are a few things you can do if you’re looking for more ways to reduce your carbon footprint when it comes to your food.
Tips for reducing your carbon footprint
Aside from the consideration of products you’re choosing, there are two major steps you can do to reduce your foods carbon footprint. First, shop local.
The carbon footprint of your produce doesn’t end after it’s picked– so the less your food has to travel, in turn, the smaller its carbon footprint will be.
Second, a concerted effort to reduce your food waste can do wonders. If you throw away half the produce you buy, you’re doubling its carbon footprint. So, try to buy conservatively and use what you have.
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