Major Supermarkets Fail to Tackle Methane in Their Supply Chains

Methane isn’t exactly the sexiest greenhouse gas. It’s often trumped in the climate conversation by carbon dioxide, a heat-trapping gas known for its longevity in the atmosphere. Yet, methane is more potent –– it traps about 80 times more heat over a 20-year period. Human activities are responsible for about 60 percent of methane emissions, with the largest offender being food, such as cows belching out methane during digestion. A new report suggests large supermarket chains, including Walmart, have an important role to play in bringing down methane emissions from food but for now, none of them are taking action.

Supermarkets are the place where we, as consumers, interact with food systems and to a greater extent, those systems emissions. Food-related methane mainly comes from farm animals — their belches and manure — and food waste in landfill sites. A new report from Mighty Earth found that none of the 20 top-grossing retailers in the U.S. and Europe — including household names like Lidl, Kroger and Walmart — are addressing methane emissions within their supply chains.

This leaves a crucial blind spot in reaching 2050 net-zero targets — an emissions reduction goal of the Paris Agreement to tackle climate change — which many of these retailers have committed to. U.S. supermarkets performed especially badly, “displaying a stark lack of climate accountability and ambition from their European counterparts,” the report found.

Retailers Omit Indirect Emissions From Climate Promises

Since none of the 20 food retailers surveyed had set a methane reduction target, Mighty Earth designed a scorecard to assess what action on methane emissions retailers have taken within their food supply chains. Only one UK supermarket, Tesco, scored above 50 points while U.S. retailers Kroger and Walmart lagged behind severely at a mere 9.5 and 7 points, respectively.

Many of the retailers named in the report do have climate plans, and goals to reduce their emissions. Walmart, for example, aims “to achieve zero emissions across global operations by 2040” and reduce their scope 1 and 2 emissions by 2025. Scope 1 and 2 emissions are what’s directly emitted by the company — the energy needed to keep food cold, for instance. Yet there is scant mention of efforts to reduce scope 3 emissions, which are indirect emissions generated from their supply chain, including methane emissions from foods like beef.

Scope 3 emissions aren’t just a drop in the ocean. For grocery stores, they’re the bulk of their climate pollution, estimated to make up 93 percent of European retailers total emissions profile, with meat and dairy accounting for almost half of all scope 3 greenhouse gas emissions, according to the report. In this way, retailers are missing the elephant — or rather the cow — in the room when it comes to creating meaningful climate plans, Gemma Hoskins, global methane lead at Mighty Earth, tells Sentient.

“Supermarkets talk a lot about climate change, but very, very few are acknowledging meat and dairy, given that could be almost 50 percent of their emissions — that is a huge proportion,” Hoskins tells Sentient.

Paul West, senior scientist of Ecosystems and Agriculture at Project Drawdown says most retailers don’t address scope 3 emissions because they can’t directly control them and it requires changing consumers or companies’ behaviors through incentives or penalties. A 2024 decision by the Securities and Exchange Commission (SEC) ruled that retailers aren’t required to disclose their scope 3 emissions.

Despite these challenges, reducing demand for high-emissions foods remains a critical component of climate plans. “Aside from deforestation, supermarkets’ largest source of greenhouse gas emissions in their supply chains come from raising beef and dairy cattle. Changes in manure management, feed additives and other practices can reduce emissions a bit, but the only big way to do it is to reduce demand. Supermarkets, or any business, have little incentive to reduce demand for one of its products unless there is more demand for an alternative,” West tells Sentient.

A Question of Consumer Demand

Mighty Earth’s researchers argue that retailers are in a unique position to initiate the necessary changes in the food environment due to their ability to negotiate with producers, set prices and market directly to consumers.

The U.S. and EU launched the Global Methane Pledge in 2021 committing to reducing methane emissions by 30 percent by 2030. “Since the food sector is the largest source of methane emissions by people, it needs to lead the way to meet this target,” West tells Sentient.

There is a lack of accountability for retailers. Take food waste, for instance — while in the last year of the Biden administration, the USDA and EPA pledged to cut food waste in half by 2030, there are no legally binding targets for retail supermarkets. Companies can play a role by redirecting unsold food to pantries or educating shoppers on how to effectively reduce waste at home.

The report did note that eleven of the supermarkets do call out animal agriculture emissions as a key contributor to climate change, with many suggesting eating more plant-based foods could help, but the researchers also found these companies often fail to implement the kinds of actionable changes that would address their role in fueling emissions.

This is a missed opportunity, according to Project Drawdown scientist Paul West. “Supermarkets are a critical part of the supply chain. The majority of environmental impact happens earlier in the supply chain, mostly driven by what and how food is produced. On the flipside, most of the food waste in the U.S. and Europe is when it reaches people’s households. The big stores are right in the middle. Because they control so much of the market share, larger stores have more influence on what and how food is produced than consumers do,” West tells Sentient.

In Europe, there is more consumer demand for plant-forward foods because of their Green Deal and other initiatives aimed at reducing carbon emissions and promoting sustainable food systems. In some European countries, there are efforts to knock VAT off plant-based milk to reach price parity with cows milk and “protein split” initiatives to expand supermarket sales of plant proteins. In much the same way that retailers helped inform consumers on the downsides of single use plastics, Hoskins says they need to be transparent about sources of their emissions.

“If you said to the average shopper, do you realise that half of the emissions coming from a retailer are meat and dairy, I think people would be really shocked by that … and would make people think very differently about what was in their basket,” she says.