If food waste were a country, it would be the world's third-largest emitter of CO2, after China and the United States. In our nation alone, we throw away some 63 million tons of food a year, even as 40 million Americans are considered food insecure.

Advocates of the "ugly produce" movement say they have a way to radically reduce this waste: cutting the price of fruits and vegetables that normally go uneaten because they look too weird.

"We're not talking about rotten stuff, we're not talking about stuff that's beyond the pale. We're talking about good, fresh food that is being wasted on a colossal scale," says Tristram Stuart, author of "Waste: Uncovering the Global Food Scandal," recounting how, as a teen, he discovered a local farmer throwing away edible potatoes too misshapen for supermarkets. Food & Wine magazine launched #LoveUglyFood, with then-editor in chief Dana Cowin urging readers to "embrace all that is edible, not just what is beautiful." Activist Jordan Figueiredo has championed the "Ugly" Fruit & Veg Campaign by sharing cute photos of knobby eggplants on social media and petitioning Walmart, Whole Foods and other retailers to stock imperfect produce.

Over the past several years, start-ups that bring ugly produce to consumers have proliferated. “Shark Tank” alumnus Hungry Harvest, which delivers boxes of “rescued” fruits and veggies to subscribers’ doorsteps, claims that “demand for aesthetic perfection & homogeneity” drives us to squander food: “100 years ago, farmers could sell their entire harvest regardless of the size, shape or superficial beauty of their produce. People understood that a small apple was as delicious as a large one, a misshapen carrot as nutrient-rich as any other.” The website for rival service, Imperfect Produce, recently valued at $180 million, says: “Approximately 20 percent of organic and conventional produce in the U.S. never leaves the farm just because it looks a little different. . . . We think that’s crazy.”

Yet while the trend may have upsides for some farms and consumers, it’s nowhere near fixing food waste. That’s because advocates are getting the problem exactly backward. Less than 20 percent of total food waste happens at farms and packinghouses, where the ugly-produce movement works its magic, according to ReFED, a nonprofit dedicated to researching food waste policies. The vast majority, more than 80 percent, is generated by homes and consumer-facing businesses like grocery stores and restaurants. “Rescuing” ugly produce is just one of the few, small slices of the food waste problem that are easily monetized by private entrepreneurs. The hype surrounding this movement is inflated by the public’s ignorance of the food supply chain.

Farms run on tight margins; they don't casually waste their crops. When produce doesn't make it off the farm, there's a reason. Despite the dramatic anecdotes about truckloads of landfilled crops, little of farm waste is due to merely "cosmetic" blemishes. Much of it is bruised or weeping goods that can quickly break down and rot the entire crate. With many crops, misshapen produce knocks against its neighbors during transit, poking holes and jeopardizing entire bins. "Drops" (produce that's fallen on the ground) are left behind because otherwise they tend to cause food-poisoning outbreaks. Farms till excessively damaged produce back into the soil along with the crop's stems and leaves, recycling their nutrients. This approach keeps produce from being landfilled and doesn't waste fossil fuels zooming product around in search of a buyer while it continues to deteriorate.

As for packinghouses — the other major culprit, according to ugly-produce proponents — they’re actually the smallest source of food waste in the entire supply chain. North America’s packinghouses discard about 1 percent of the produce that enters their doors, according to the United Nations Food and Agriculture Organization — usually because it’s straight-up rotten.

That number is consistent with my experiences working with packinghouses across the United States. The industry sorts produce into grades. Top-quality product goes to high-end grocery stores and pays the bills for the entire crop. Second-grade produce goes to food service, lower-end groceries, food banks — and, now, ugly-produce vendors. Severely misshapen and discolored product goes to processing to become juice, jam, baked goods, salsa, soups, guacamole or other foods. Packinghouses send culls (rotten goods that cannot be recovered by any means) to be tilled into nearby fields as fertilizer or, as a last resort, landfill them (though they avoid that whenever possible, because it costs money). In most packinghouses, the cull bins are small and few.

For the most part, ugly-produce initiatives are simply gentrifying second-grade produce that was already being eaten - just not, perhaps, by upscale shoppers. It's the food equivalent of Lyft "inventing" a bus.

In truth, four times as much food is wasted at the fork - that is, at homes and consumer-facing businesses — than at the farm or packinghouse. The most effective ways to tackle that waste aren’t as marketable as a shiny new start-up, and they don’t get nearly as much publicity. They boil down to the old mantra to reduce, reuse and recycle.

The single biggest source of U.S. food waste, accounting for 43 percent of the problem, is our own homes. Reducing consumption will look different in every household; personally, I find that once produce goes in my crisper drawer, it might as well be in a black hole. For me, replacing some fresh veggies with frozen, and leaving fresh produce on the table as an easy snack, cut down my family’s food budget and trash volume. Others find meal prepping, and odds-and-ends recipes like stews and smoothies, to be helpful.

Most of all, we should sync our shopping habits with our eating habits. Affluent shoppers waste the most produce because of how much of it they buy and then trash, according to a 2018 U.S. Agriculture Department analysis. We throw out so much food at home that "saving" ugly produce from food service or processing could actually cause more waste. The most important behavioral change consumers can make to address food waste isn't to buy certain kinds of produce. It's to actually eat what we bring home.

Grocery stores, meanwhile, can get a lot of mileage out of reuse: donating food that’s past its “sell by” date but still has a few good days left to food banks. Many retailers already do this for the tax write-offs. But the infrastructure — donation matching software, cold storage and refrigerated trucks — to handle large donations of eggs, dairy, meat, bread and produce is still being built. Funding more food bank infrastructure, educating potential donors about liability laws, creating more donation tax incentives and standardizing food safety regulations would recover up to 996,000 tons of food, or 1.7 billion meals, per year, according to ReFED. Ugly produce maxes out around 266,000 tons of potential recovery per year — much of it just diverted away from processing, food service and food banks.

Homes, food service and grocery stores generate 7.8 million tons of food waste per year that can’t be salvaged, accounting for 12 percentof the problem. This waste needs to be recycled. The Environmental Protection Agency says that the United Statescomposts only 5 percent of its food waste. (Compare that with 15 percent in the European Union.) That’s a lot of room for growth. Biochar - made by heating inedible food and other organic waste until it becomes inert, odorless, nutrient-rich charcoal — could be a very effective way to recycle food waste, but it’s underutilized, because the equipment to do it at municipal scale is so new. Like composting, biochar can be used as a fertilizer, returning food waste’s nutrients back to the soil. Unlike composting, it can handle food waste that’s mixed with general nonhazardous trash — no need for costly separate collection and handling. Biochar also sequesters carbon for centuries.

Some farms do profit from the ugly-produce movement: For now, at least, it helps them fetch higher prices for their seconds than they'd get from the processing market. But there are lots of other, better ways to attain higher returns on crops. Farms can form co-ops to increase volume and market power, as California's citrus and avocado industries have, or process their own seconds. For certain crops like berries, tomatoes, leafy greens and cucumbers, farms can take advantage of state and federal funds that would help them switch from open-field to hoophouse or greenhouse methods. Already common in East Asia and Europe, these methods boost yields and dramatically reduce how much of the crop is too damaged to leave the farm. These active improvements are challenging and capital-intensive, but they'd do more to strengthen farms' financial position than passively riding the ugly-food trend. Even if the movement grows, eventually the market will saturate or investors' money could run out. Then, ugly-produce companies will be just more buyers racing to the bottom on price.

To be clear, ugly produce isn't bad. If it works for your budget and routine, use it: Our distribution systems should make food affordable and accessible. But the movement's narrative, built around tales of dented squash rotting in fields, distracts us from the data about the real sources of waste and how to address them. As long as we eat fresh food instead of shelf-stable nutrient bars, perishability is part of the bargain. The only way to completely eliminate food waste is to abolish fresh food. Beyond that, all we can do is manage the waste.

Consumers are forever being bombarded with claims that our individual buying choices can put a meaningful dent in some big problem. Food waste is one of the few areas where that’s true. But we won’t make much of a difference by acquiring a taste for hideous, gnarly cucumbers. We should just be sure that our shopping carts and grocery budgets aren’t bigger than our stomachs.

Sarah Taber, a crop scientist and former farmworker, runs a farm operations and food safety consulting business from Fayetteville, N.C.