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“Eating with the seasons” has long been the rallying cry of local growers and their supporters. It is a message that is easy to accept.
The flavor and nutritional value of a year-round supermarket stock greenhouse tomato is no match for that of one sun-ripened in a community garden. You’ll get far more berries for your money picking them yourself at a U-Pick farm than buying them packaged in plastic half-pint containers and airlifted from thousands of miles away. And patronizing our neighborhood farmers’ markets gives us the good feeling of getting to know our sustainably-minded growers and their environmentally friendly practices while investing in the local economy.
But do personal food choices like these do much, if anything, to heal our sick planet?
The answer is complicated and depends on the food in question. A 2021 United Nations-backed study shows that the way we produce, process and package food it accounts for more than a third of global greenhouse gas emissions caused by human activity. A 2019 report by the EAT-Lancet Commission, a team of leading scientists around the world, further warned that without drastically changing our food consumption habits, we will not be able to meet the nutritional needs of a growing world population without irreversible environmental damage. . .
and a new study exploring the carbon footprint (greenhouse gas emissions) of Americans’ changing eating patterns assures us that our efforts to shop and eat better are not in vain. Some foods impact the environment in drastically different ways. Animal products and highly processed and packaged foods, for example, typically require much more energy to produce than homegrown and handmade foods at local farmers markets. Five staples are responsible for more than 75% of the carbon footprint of the American diet, according to one study: beef, milk and dairy products, pork, chicken, and eggs. And more than half of those greenhouse gases can be attributed to beef.
“The good news,” said study co-author Clare Bassi, is that “dietary changes are occurring.” According to their study, over a 15-year period, beef consumption in the US fell 30%, while collective changes in eating habits across all demographic groups led to a 35% decline in greenhouse gas emissions. That’s roughly equivalent to taking all passenger vehicles off the road for nearly two years, she said in an email.
The study calculated greenhouse gas emissions based on the individual daily diets reported by more than 39,000 American adults in the National Health and Nutrition Examination Survey between 2003 and 2018. Bassi looked at how the averages changed over time and examined trends based on demographic factors such as gender, age, family income, and race/ethnicity. The study was published in the Journal of Cleaner Production.
Bassi added that other studies have shown that more than half of Americans are willing to eat more plant-based meat alternatives, and the global market for plant-based protein sources is projected to grow fivefold by 2030.
A common claim among local food advocates is that reducing our “food miles” — the distance our food travels from farm to plate — can also help combat climate change. Some groups have even recommended labeling to indicate the mileage of a product to its destination.
That might make sense intuitively, but in a 2020 report, Hannah Ritchie, Research Director of Our World in DataHe calls it “one of the most ill-advised pieces of advice.”
Land use and emissions from the agricultural stage, including the application of fertilizers and the production of methane in the stomachs of livestock, account for more than 80% of the footprint of most foods.
Transportation is responsible for less than 10% of your final carbon footprint; for beef it is less than 1%. The rest of the emissions from a food occur primarily during processing, packaging, and retail.
“Eating local would only have a significant impact if transportation was responsible for a large part of the final carbon footprint of food,” Ritchie wrote in the report. “For most foods, this is not the case.”
However, he points to one exception where seasonality and geography make a difference: products that travel by air. Most of the food is transported by ship, which generates far fewer emissions. Air freight is generally reserved for highly perishable foods where speed of delivery is essential, such as blueberries or green beans. So it’s probably a safe bet that those fragile fruits and vegetables at the farm stand will be a more climate-friendly option than their out-of-season, mass-produced counterparts.
The same as recyclingtrying to offer one-size-fits-all solutions is tricky and sometimes even counterproductive.
Scientists and activists tell us that no amount of individual action will be enough to stop catastrophic impacts on the climate. Global policies that hold industry accountable for its role in the crisis, they stress, are essential to addressing the magnitude of the problem.
But that doesn’t mean consumers are powerless beyond lobbying their legislators. “Little changes in the home can really have a significant positive impact,” Bassi said.
By far the most important thing we can do at the dinner table to mitigate climate change, he said, is to eat less meat and dairy, and incorporate a variety of healthy plant-based alternatives into our diets: fruits, vegetables, grains, legumes, nuts.
While eating less meat is one of the most measurable actions we can take, other actions add up as well.
“Local sourcing can be a driver for impact reduction,” Bassi said. “But often it’s a small or highly variable lever for change.” She and other experts stress that it’s important for consumers to understand that what we eat, rather than where it originated and how it gets to us, is most important when it comes to reducing our own carbon footprint.
“Most consumers don’t want to spend tons of time untangling these simultaneous equations in their heads when doing their food shopping,” said Roni Neff, assistant professor at the Johns Hopkins Bloomberg School of Public Health and program director at the Johns Hopkins Center for Health. Hopkins. for a Livable Future. Nor should they.
Making these dietary changes doesn’t have to be difficult, Neff said. “If the goal is greenhouse gas reduction, weighing the differences between this apple and that apple is less important than simply knowing what an apple is,” she said. “Think about the bottom of the food chain that you learned about in grade school: plants and plant-eating shellfish.”
Another practical way for people to take control of their carbon footprint is to reduce food waste.
Farmers have to grow far more food than we really need, because 30-40% of what they produce is wasted, according to the United Natural Resources Defense Council. That comes at a huge cost in greenhouse gases, Neff said. Furthermore, it wastes land, water, labor, energy, and other valuable means.
In this sense, he pointed out, controlling the size of our portions is important not only for our waistlines, but also for the planet. “It’s easy to buy more than we can actually eat, especially when we’re shopping at a farmers market when everything is fresh and beautiful and we just want to try everything and buy everything,” she said.
Turning food scraps into nutrient-rich compost can combat food waste while helping your garden grow. Neff also suggested getting creative with leftovers, following guidelines for freezing excess, and placing a special container at the front of the refrigerator for things that need to be used up faster.
“A really useful way to find solutions is to write down everything your household eats for a week,” Neff suggested. “Get in the habit of communicating with family members to coordinate schedules so you know who will be around for meals.”
Scientists tell us that a great diversity of plant and animal life, from microbes in the soil to large predators like bears and wolves, is essential to maintaining a balanced and healthy ecosystem. Monoculture, the practice of growing a single species with identical genes in the same field, is responsible for much of the uniform produce available year-round in supermarkets. While these methods have the advantage of producing large volumes cheaply and consistently, they also destroy biological diversity needed for long-term sustenance.
“We have lost much of our biodiversity in our food supply and have limited ourselves to a few varieties of fruits and vegetables that we like and know and keep coming back to,” Neff said. “A farmers market is a great place to try and try a lot of things you haven’t tried. You could be the first on your block to try a new variety of peach they’ve never heard of, and who knows, that peach might prove more resistant to drought or blight than the common ones on the supermarket shelf. .”
From peaches and tomatoes in the summer to citrus and kale in the winter, nature is our best teacher in helping us add variety to our meals, which is good for our diet and good for the planet.
the Seasonal Food Guide is a comprehensive national database with a downloadable app of seasonal foods (vegetables, herbs, beans, nuts) available in every state year-round, based on data from the National Resources Defense Council and state departments of agriculture and university extension programs throughout the US. The guide offers recipes and tips to maximize its uses in your kitchen. For guidance on how to choose the most sustainable seafood in your area or in the supermarket throughout the year, see Monterey Bay Aquarium Shellfish Viewing app