Environmental impact of 20 foods
When it comes to the food we eat, the world is rapidly approaching a moment of reckoning. A major study released in August 2019 by the UN Intergovernmental Panel on Climate Change (IPCC) found that human reliance on agriculture is accelerating global warming. Food production—coupled with forestry and other land use—account for almost a quarter of all global greenhouse gas emissions.
Much of that is due to livestock. Cows, in particular, are heavy producers of the potent gas methane, which can trap heat 86 times more effectively than carbon dioxide and stands as a significant contributor to climate change. Experts involved with the project emphasized the planetary benefits of cutting back on meat, although IPCC's authors stopped short of advising a mass shift to vegetarian and vegan diets. But what about the environmental impact of other foods?
That answer varies, according to a 2011 study from the Environmental Working Group (EWG), a non-profit, non-partisan environmental health research organization. For the report, "A Meat Eater's Guide to Climate Change and Health," researchers modeled the greenhouse gas emissions created during the life cycle of common American foods, from production and transport to retail, cooking, and waste disposal. With that data, Stacker created the following gallery to illustrate the environmental impact of 20 common foods, ranked according to the carbon dioxide emitted in the full life cycle of 2.2 pounds of said dish.
Some of the results may be surprising. 2019's IPCC report singled out livestock for a reason—but EWG's findings show that not all greenhouse-gas-intensive foods involve meat or dairy. Those parts of the cycle add up, making some popular foods more detrimental to the environment than many people think.
While EWG's report has implications for most diets, the organization's findings also indicate that cutting out meat alone won't solve serious global problems (even if some culinary choices might help more than others). Read on to discover the impacts of 20 common foods—including several with carbon footprints that can be easily diminished by buying local.
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#20. Lentils
- CO2 emitted during the life cycle of 2.2 lbs of this food: 2.0 lbs
Unlike meat byproduct emissions, plant protein emissions typically occur after crops leave the farms where they are grown. For lentils, post-farmgate emissions represent 59% of total emissions, much of which stems from the energy required to cook them, along with transport and waste disposal.
#19. Tomatoes
- CO2 emitted during the life cycle of 2.2 lbs of this food: 2.4 lbs
Tomatoes are a dietary staple for many people, but that doesn’t mean they come guilt-free. One major source of emissions for tomatoes is transportation. Buying locally makes a major difference: Purchasing at your neighborhood farmer’s market can reduce a tomato’s carbon footprint up to 25%.
#18. Milk (2%)
- CO2 emitted during the life cycle of 2.2 lbs of this food: 4.2 lbs
Meat isn’t the only source of animal-linked emissions; dairy is also a culprit. Production and post-farmgate consumption contribute to milk’s overall emissions, as does waste disposal. While vegan alternatives to milk range in terms of their carbon footprints, milk is typically associated with more greenhouse gases.
#15. Broccoli (tie)
- CO2 emitted during the life cycle of 2.2 lbs of this food: 4.4 lbs
Emissions stemming from broccoli come from various sources, including transportation and waste, especially given the extent to which people tend to throw out stems. But as with tomatoes, buying broccoli locally can help, bringing down the vegetable’s carbon footprint by as much as 20%.
#15. Tofu (tie)
- CO2 emitted during the life cycle of 2.2 lbs of this food: 4.4 lbs
Tofu—or bean curd—is sourced from soy milk, and the EWG report assesses tofu's carbon footprint based on conventional soybean processing. Soybeans already require a lot of moisture and production, driving up emissions and stretching resources thin. Growing soybeans can also lead to mass deforestation, which is environmentally taxing on areas like the Amazon.
#15. Dry beans (tie)
- CO2 emitted during the life cycle of 2.2 lbs of this food: 4.4 lbs
Dry beans closely mirror lentils in their emissions. While dry beans are typically considered climate-smart due to their biodiversity and ability to return nutrients to the soil, they are still associated with greenhouse gases. Post-farmgate emissions represent 65% of the total associated with dry beans, which inherently require energy use during cooking before consumption.
#14. Yogurt
- CO2 emitted during the life cycle of 2.2 lbs of this food: 4.9 lbs
Like other dairy products, yogurt has a notable carbon footprint. Derived from milk, yogurt requires a significant amount of processing. Bacterial starter cultures were not included in the EWG study due to a lack of data, but the electricity cost necessary to make yogurt is already high. That’s in addition to refrigeration and transport, which play a big role in making yogurt moderately emissions-intensive.
#13. Nuts
- CO2 emitted during the life cycle of 2.2 lbs of this food: 5.1 lbs
Nuts range considerably in terms of their carbon footprints. EWG included almonds, pecans, peanuts, and walnuts in its study, ultimately finding them somewhat emissions-intensive overall.
For those seeking to keep their dietary choices environmentally-friendly, peanuts are a reasonable option, especially if purchased locally. Almonds, by contrast, are more controversial: The popular nut requires an extraordinary amount of water and is also associated with widespread pesticide use.
#12. Peanut butter
- CO2 emitted during the life cycle of 2.2 lbs of this food: 5.5 lbs
Peanut butter is derived from one major ingredient—peanuts—with salt sometimes included. The primary emissions associated with peanut butter are related to production and transportation, which can be high. Those interested in making their own peanut butter can do so with relative ease, reducing emissions in the process.
#11. Rice
- CO2 emitted during the life cycle of 2.2 lbs of this food: 6.0 lbs
While rice may be a lower source of carbon emissions than meat products, the staple is contributing to global warming in a big way. Rice farming is responsible for around 12% of all methane emissions, generating a greenhouse gas significantly more potent than carbon dioxide.
Many organizations have been working to make rice more sustainable, and for a clear reason: The food is a leading source of sustenance for people around the world.
#10. Potatoes
- CO2 emitted during the life cycle of 2.2 lbs of this food: 6.4 lbs
Of all protein-rich plants, potatoes have the biggest carbon footprint, albeit with some major caveats. Around 90% of the emissions associated with potatoes are thanks to cooking. That means a baked potato can be worse for the environment than, say, French fries, which the EWG report notes require only a few minutes of deep-frying rather than an hour or longer for baking.
#9. Eggs
- CO2 emitted during the life cycle of 2.2 lbs of this food: 10.6 lbs
Eggs are a major source of protein and contribute fewer emissions than meat. But producing eggs generates greenhouse gases, as does transporting and cooking them. This is another food with a carbon footprint lessened when it is bought and consumed locally.
#8. Canned tuna
- CO2 emitted during the life cycle of 2.2 lbs of this food: 13.4 lbs
The primary source of tuna’s greenhouse gas emissions (68%) is the diesel gas used to power fishing vessels. Canning the tuna requires cooking and processing with further energy costs. Waste disposal is also a factor in canned tuna’s relatively high carbon intensity. That isn’t the only thing to watch out for when purchasing tuna: The fish also carries a high risk of mercury exposure for consumers.
#7. Chicken
- CO2 emitted during the life cycle of 2.2 lbs of this food: 15.2 lbs
A big advantage of chicken is that it has a smaller carbon footprint than other meat options. Feed—mostly corn—represents 53% of chicken’s pre-farmgate emissions, but only 18% of the meat’s total footprint. Other major factors include processing and cooking, both of which contribute to greenhouse gases.
#6. Turkey
- CO2 emitted during the life cycle of 2.2 lbs of this food: 24.0 lbs
This popular Thanksgiving staple is more emissions-intensive than chicken but otherwise very similar. The meat is more sustainable than, say, beef or lamb, but still generates significant greenhouse gases thanks to energy-intensive practices of feeding, processing, and cooking.
#5. Farmed salmon
- CO2 emitted during the life cycle of 2.2 lbs of this food: 26.2 lbs
Unlike free-swimming fish, farmed salmon require feed, electricity, and significant transportation, often between countries. EWG did not look at the carbon footprint of wild-caught salmon, but farmed salmon was found to be emissions-intensive. That’s largely due to processing and transportation distance, but cooking and waste disposal are also important factors.
#4. Pork
- CO2 emitted during the life cycle of 2.2 lbs of this food: 26.7 lbs
Pork’s carbon footprint is indisputably high. Raising pigs is emissions-intensive work, as is overall processing. Transport, refrigeration, and waste disposal add to the total energy cost, but another major factor is cooking. Like most meats, pork takes a significant amount of energy to be rendered safe for human consumption.
#3. Cheese
- CO2 emitted during the life cycle of 2.2 lbs of this food: 29.8 lbs
Cheese proves that meats aren’t alone in shouldering the emissions burden. Less than 10% of cheese is imported, but that small amount goes far in the EWG report, increasing cheese’s overall emissions by around 50%. For domestic cheese, the processing is the driving factor behind the food’s large carbon footprint.
#2. Beef
- CO2 emitted during the life cycle of 2.2 lbs of this food: 59.5 lbs
As efforts to protect the planet ramp up, beef is directly in the line of fire. Post-farmgate emissions from beef are a factor, including processing, transport, and cooking. But the largest source of emissions from beef is in the form of the methane excreted by cows themselves. Cattle and rice fields combined are responsible for almost half of all global methane emissions.
#1. Lamb
- CO2 emitted during the life cycle of 2.2 lbs of this food: 86.4 lbs
Beef may be under scrutiny, but lamb has the largest carbon footprint, according to EWG's report. Eating a little over two pounds of lamb is the equivalent of driving around 90 miles in terms of the environmental cost, according to Business Insider. Some of those emissions are due to shipping, with around 50% of lamb imported at the time of the report. But the combination of animal digestion byproducts, feed production, and cooking makes lamb the worst offender on the list.
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