Your Biggest Climate Decision Isn't What You Cook—It's What You Don't

So how do we make sustainable food choices from start to finish? Author Paul Greenberg has some ideas.

April 13, 2021
Photo by Rocky Luten

With The Climate Diet, award-winning food and environmental writer Paul Greenberg offers us the practical, accessible guide we all need. This new release contains fifty achievable steps we can take to live our daily lives in a way that’s friendlier to the planet—from what we eat, how we live at home, how we travel, and how we lobby businesses and elected officials to do the right thing. Here, Paul shares on the the role of food waste in our overall climate decision making—and how it's a much bigger deal than we think.

We spend a lot of time climate-agonizing over what to buy and what to cook. By now, most of us know that beef can have 25 times the carbon footprint of legumes, that out-of-season air-freighted things like winter berries and fish from distant shores burden the planet, and that water from the tap is a vastly better choice than bottled. But if we’re really looking to trim our carbon footprints consistently throughout the year—what I call going on a climate diet—addressing what we do after our meals are cooked and eaten can be a real game changer. By doing that, every American could easily cut their carbon footprint from food in half.

The culprit here of course is waste, but not necessarily in the way you think of it. So, let’s take a moment to look at the way discarded food can come back to bite you, and then make a plan to lessen that bite.

To begin with, Americans throw out a lot of food. Somewhere around 40 percent of what we buy goes into landfills. But the hidden problem for climate change isn’t just that we have to grow 40 percent more food than we’d have to in a more frugal society. No, the problem with our wasted food happens in the landfill itself. Food waste in landfills, starved of oxygen, releases methane, which has a warming consequence dozens of times that of carbon dioxide. Because of decomposing food waste, the United States has larger landfill emissions than any other country on Earth, the equivalent of 37 million cars on the road each year.

Join The Conversation

Top Comment:
“whoa there nelly: "There is no such thing as food waste. Food, all of it, is by definition, edible.". Let's bear in mind the poisonous leaves of rhubarb, poisonous roots, stems, leaves of tomaoes, raw cashews, asparagus berries, raw fiddleheads... all poisonous. Some important caveats to your argument.”
— Bri L.

To keep food out of landfills, we can start by changing how we plan for the full lifecycle of our food. We can and should look at the available space in our refrigerators and freezers before going to the grocery store or hitting the buy button. We can plan weekly meals with an eye toward moving perishables from fridge to freezer as they approach their expiration dates.

But perhaps the most significant change we can make with respect to our food is to change our perspective on the very concept of waste. As I’ve slowly begun modifying the way I cook, I’ve come to a shocking realization. There is no such thing as food waste. Food, all of it, is by definition, edible.

Take for example a head of cauliflower. In nearly every recipe I’ve ever read, the cook is instructed to trim the leaves and stem and discard. But why? The stem and leaves of that same head of cauliflower are perfectly acceptable substitutes for celery in a Bolognese or zucchini in a Moroccan vegetable stew. Similarly, the cook is always told to peel carrots and potatoes, trim any fat, and discard chicken skin. Each of these thrown-away items add flavor, texture, and nutrients to your food.

Next, we’ll want to be prepared to take on some post-processing tasks to further stretch what we can do with the food we’ve bought. To this end, I direct you to the vinegar barrel and the stockpot. Because of their sugar content, fruit peels and cores are great agents to promote fermentation. A leftover yogurt container half-filled with water and gradually filled with your cores and peels makes a fine receptacle to start a vinegar culture. Let fruit discards steep for several weeks, strain and boil, and you’ve just saved yourself a trip to the store to buy vinegar. You can take some of that vinegar production and use it to pickle vegetable peels, which make for excellent side slaws and sandwich accompaniments.

But as many of us know (but don’t always heed), the best place for vegetable discards is soup stock. Start a bag in your freezer and put in everything from broccoli stalks to potato peels to onion ends. When you’ve got a full bag, boil the discards with water and salt, and you’ve just saved yourself the cost and the waste of a container of soup stock. For the particularly parsimonious, the tailings from the stock can be chopped in a food processor and later worked into dishes like meatballs, fish cakes, and vegetable patties.

Once everything has been used to its fullest extent, compost what’s left. The U.S. Environmental Protection Agency has compiled a list of Wasted Food Programs and Resources across the United States, which provides information about state and community efforts for recycling, pollution prevention, food rescue, food donation, and composting. You can also start your own composting program even if you don’t have outdoor space, and need something dirt-free and odorless for indoors. A Japanese DIY home-composting method requires just a cardboard box and a few additives that you can order online.

Compost of course is the black gold that turbocharges outdoor home gardens, but you can also use it as a cost-free medium for starting spring seedlings indoors. You might want to even consider getting a little political about this. If you don’t have access to composting space, see if your town or city has a composting program. If it doesn’t, encourage your elected officials to start one. New York City sadly halted its composting program during the pandemic—a major systemic error in my opinion. But this is only one of many broken gears in a system that we need to fix.

Which brings me to my final point. The mechanics that bring American food to our plates are themselves inherently wasteful. Yes, let’s fix the way we cook and amend the way we deal with what’s left over. But let’s also not forget that we do need to think bigger than our own kitchens. More than 10 percent of the nutrients in wheat gets thrown away when food companies mill whole wheat kernels down into white flour. 120 million acres of American land that could grow grains, legumes, fruits and vegetables for humans instead grows corn and soy to be fed to cows. “zeroing in on the hidden (and absolutely massive) waste inherent in our everyday diets is really the problem,” Dan Barber, the renowned chef and launcher of the food waste recovery project wastED food, told me recently. “The Westernized conception of a plate of food—a 6 or 7 ounce piece of meat—that is the most wasteful diet ever imagined.”

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See what other Food52 readers are saying.

  • j7n
  • atelcs
  • Joecs
  • jpriddy
  • Wendy
Paul Greenberg

Written by: Paul Greenberg

Author of The Climate Diet and the NYT bestseller Four Fish


j7n August 7, 2021
Many people religiously observe expiration dates, and trust internet resources to determine what is safe even if they can't detect a problem with their senses. This site also describes many product recalls. Slightly expired food is still good in cooked form where it gets sterilized, and mixed with other flavors. The organism has defense systems; animals don't care about any of this and eat from the ground.

I don't think I want rotting vegetable peels anywhere in sight, and definitely not use the fermented juice in food. That is much worse than eating soured or slightly moldy food. Acetic acid is dirt cheap. Carrot and potato have a muddy skin and a cucumber's skin is thick and rough. Vegetables should be peeled. You can't put peel in mashed potatoes or mild salad. One could buy larger caliber veggies with relatively less peel, according to the square/cube law. In any case, plant matter makes up a small proportion of trash and degrades quickly, unlike plastics. We communal have biowaste trashbins that smell incredibly foul.

Discarding fatty tissue is different and caused by dubious health claims.
atelcs July 13, 2021
Excellent points, from purchase point to compost bin. Thanks for this!
Joecs April 22, 2021
Another serious problem is the waste created from packaging. Plastic bags and hard plastic food containers are recyclable but in many areas they don’t get recycled. Same for glass and metal jars and cans. Much of this ends up in landfills. I think we need to go back to reusable and refillable containers or composable containers.
jpriddy April 22, 2021
I have had the habit of collecting vegetable scraps in my freezer for years. About twice a month I make stock. I never peel vegetables. I bake ww sourdough weekly. My husband and I are vegetarian. It seems I am doing a few things right. Making vinegar? That would be something else. Thank you.
Wendy April 13, 2021
I live in a smallish (population of approximately 40,000) Canadian city with weekly curb side compost pickup.
Since implementation of this program, our garbage to landfill has reduced by over 50%, and curb side garbage pickup has been reduced to once every two weeks.
I always thought that because Canada’s population is 10% of the US, the US would be way ahead of Canada in implementation of waste reduction methods, but maybe I am mistaken. How widespread is compost pickup in the states?
Also here it is illegal to put compostable or recyclable materials in your garbage.
We have done away with plastic straws and styrofoam or plastic take out containers, all take out containers and straws must be compostable.
If you live in an urban or semi urban area, anywhere on Earth without compost pick up, demand it! If you live in a rural region demand a commercial composter (one with higher heat that can digest compostable containers as well as food waste) that you can drop your compost to. These are fairly inexpensive and every neighbourhood should have one.
Raye A. April 15, 2021
Yes, I would LOVE it if we had a curbside compost pickup. That sounds amazing! I've often wondered if cities or countries even did that. We only have a trash pickup and recycling pickup here in Houston. I think they would be concerned that people would put inappropriate things into the compost pickup... maybe that's why they haven't done it. Or like you said, we citizens must demand it. I have two personal composters at home, it makes amazing mulch for our plants. Funny, my mom doesn't own a composter, she just buries her fruit/veggie scraps and coffee grinds in her garden, oh well. Americans can be very indifferent or lazy when it comes to conservation. Even though we have curbside recycling pickup, many of my neighbors don't even bother. They throw everything in their trash. So sad.
M April 13, 2021
I wonder how much waste would decrease if shoppers had more control over fresh amounts. Make a recipe w/ many fresh ingredients, and you have enough produce to make more dinners than you can eat. Esp in 1-3 ppl households.

I'm sure I've said this before here, but I hope this article is followed by actual ways to put this advice into practice. How to work with regularly imperfect/old/mediocre produce, what blemishes are okay, which should be pruned, how to work remnant recipes into a meal plan, what the hell to do when you cook for 1 or 2 and can't give away food... I'm sure more people would follow suit if actionable steps and practices followed.

If nothing else, I hope people embrace stock and schmaltz. Two very easy things to do with leftovers that keep in fridges and freezers indefinitely.
Bri L. April 13, 2021
whoa there nelly: "There is no such thing as food waste. Food, all of it, is by definition, edible.". Let's bear in mind the poisonous leaves of rhubarb, poisonous roots, stems, leaves of tomaoes, raw cashews, asparagus berries, raw fiddleheads... all poisonous. Some important caveats to your argument.
jpriddy April 22, 2021
The "raw cashews" sold in the US have been cooked (roasted or steamed) and are not toxic. Though still labeled as "raw," they are not.
AntoniaJames April 13, 2021
Excellent article! I'm constantly looking for ways to reduce the environmental impact of all of my shopping and cooking practices. There is so much interesting and helpful information here - especially the suggestion to use peels and cores to create a vinegar culture. I'm looking forward to reading the book, to implement more changes. Thank you for another great work. ;o)