Beyond ingredients, seasonality and even calorie content, some restaurants are now offering information on their food’s carbon emissions – and it may help diners make more sustainable choices.
When you peruse the menu at Wahaca, a popular chain of Mexican restaurants in the UK, you will see two labels alongside each dish: one detailing the number of calories and another telling you about the food’s carbon footprint.
In April, the UK government said that restaurants, cafes and takeaways with more than 250 staff are legally required to print calorie counts on their menus. The policy was introduced to tackle obesity and encourage people to make healthier food choices. But it was criticised by many restaurants who said it would increase costs.
Wahaca was among the critics, with its co-founder Thomasina Miers describing calorie counts as a “blunt tool for assessing goodness in food” at the time.
But the company decided to seize the moment to add another annotation to its menu for diners to consider: information about the climate impact of the food they were eating.
“When the government started telling us that we had to put calories on our menus, we thought it was a nice opportunity to start talking about carbon,” says Miers, who founded the restaurant chain after winning the UK TV cooking talent show Masterchef in 2005. “Calories are not a brilliant way to determine how healthy food is and they’re definitely not a good way to determine whether it’s good for the planet.”
Wahaca introduced carbon labels to give customers clear information about their choices, she says. People feel “completely overwhelmed” by the extreme weather events they are witnessing around the world, such as the devastating floods in Pakistan, says Miers. “[Carbon labels] help them realise that they do actually have quite a lot of power at their fingertips.
“Food choices are political. If we begin to realise this and start voting with our mouths, then we have a lot of power as a consumer.”
Our food choices have a huge impact on the climate. Global food production is responsible for 35% of all human-caused greenhouse gas emissions. Within that figure, emissions from plant-based foods contribute 29%, while emissions from animal-based foods account for 57%. The remaining emissions come from the conversion of land used to grow crops such as cotton into fields for food crops. And while animal products contribute the majority of emissions, they provide only 20% of the world’s calories.
We are used to seeing a lot of information on menus, from dishes’ ingredients to their calories – should we also see food’s carbon emissions? (Credit: Getty Images)
To meet the UK’s climate goals, the country’s Climate Change Committee (CCC) recommends a 20% reduction in meat and dairy consumption by 2030, rising to 35% by 2050 for meat.
“The majority of customers are expecting food businesses to be engaging with this subject because [they know] that what they eat has such a huge impact on the planet, on biodiversity and on soil,” says Miers.
A Carbon Trust survey of 10,000 people in eight European countries found that two-thirds of respondents supported carbon labelling on products.
Wahaca’s carbon labels “really highlight that if you are eating more vegetables and pulses, then it’s better for the planet and generally speaking better for you as well,” says Miers.
The restaurant chain partnered with Swedish startup Klimato, which calculates and communicates the climate impact of food, to develop the labelling system.
Dishes with a CO2e (or “CO2 equivalent”) level of 0.6kg or lower, such as a sweet potato burrito (0.46kg), are labelled “low carbon”. If they have a carbon footprint between 0.6kg and 1.6kg of CO2e, such as a grilled chicken club quesadilla, they are “medium-carbon”. Any dishes with a higher footprint, such as a chargrilled steak burrito (3.04kg CO2e), are tagged “high-carbon”.
The calculations cover the emissions of growing all the ingredients, as well as those generated transporting, storing and cooking them.
What is CO2e?
CO2 equivalent, or CO2e, is the metric used to quantify the emissions from various greenhouse gases on the basis of their capacity to warm the atmosphere – their global warming potential.
A growing body of research suggests that environmental labels on packaging and restaurant menus are a useful tool to incentivise people to make more sustainable choices when it comes to food. One study led by psychologists Ann-Katrin Betz and Benedikt Seger at the Julius-Maximilian University of Würzburg in Germany revealed how clever menu design and carbon labels can reduce the environmental impact of dining out.
The researchers created menus for nine hypothetical restaurants to test how adding carbon labels, which revealed the greenhouse gas emissions (CO2e) per dish, and switching the default options to foods with a lower environmental impact, affected diners’ choices when eating out.
They used a traffic-light system to highlight whether dishes had a high (red), medium (amber) or low (green) carbon footprint, and presented low-emission dishes as the standard option, displaying a bean burger more prominently than a beef patty on the menu, for example.
One way that restaurants can nudge customers towards lower-carbon choices is to present a plant-based meal as the “default” option (Credit: Getty Images)
Study participants were presented with a menu in one of the following four formats: high-emission defaults with or without carbon labels, and low-emission defaults, with or without emissions information. Both these tweaks to the menu led to participants making lower-emission choices.
“The average reduction of CO2e emissions per dish was 500g for the default switches and 200g for the CO2 labels,” says Seger.
When people were given menus with low-emission dishes, such as a coconut curry with tofu instead of beef, as the default, CO2e fell by almost one third. Simply labelling with carbon emissions led to CO2e decreasing by 13.5%.
“The default switches had a greater effect than the carbon labels,” says Seger. “We speculated in the paper that the default switches [led to] more changes between categories (from red to yellow or green), while the information labels may have [resulted in] more changes within categories.” For example, people would stick to the red-labelled dishes, but opt for a 1.8 kg CO2e dish instead of a 2.4 kg CO2e one, he explains.
Although default switches led to greater reductions, Seger says carbon labels have an important role to play as they help educate people and provide “an incentive and opportunity to act”.
“The results are quite encouraging because they show us that people are ready to [incorporate] the climate crisis into their everyday decisions if they are reminded to do so,” he says.
There can be several times fewer greenhouse gas emissions from a plant-based dish than a meat-based one (Credit: Getty Images)
According to research by the World Resources Institute (WRI), sustainability-focused language on menus incentivises consumers to choose more environmentally-friendly dishes.
WRI tested 10 different sustainability messages on 6,000 study participants in the US. The messages ranged from highlighting the taste benefits of plant-based dishes to revealing their environmental impacts and focusing on people’s sense of generosity and altruism.
Messages which emphasised that small behavioural changes can have a big climate impact and encouraged diners to “join a growing movement” of Americans who are swapping meat for plant-based dishes were found to be the most effective.
These two messages roughly doubled the percentage of vegetarian dishes that consumers ordered and made them more likely to order a plant-based dish next time they ate out. Anne Bordier, director of sustainable diets at the WRI, says it is important to pair carbon labels with motivating sustainability messages.
Standalone figures on carbon emissions are difficult for the average consumer to understand, she says. “They’re quite meaningless…because people don’t really know whether it’s good or bad.”
Most people know their recommended calorie intake per day, says Bordier, but when it comes to our individual environmental footprint, “we just don’t know how much we should consume”.
When it comes to effective language, using terms such as “vegan” and “vegetarian” on menus can actually be off-putting, says Bordier. “It’s much more effective to talk to people about flavour.”
To date, no countries have introduced mandatory environmental food labelling, but France is working on a unified scheme, called Eco-Score, for all food providers to adopt. The scheme is modelled on Nutriscore, which calculates the nutritional value of a food item on a scale from A to E, using colour-coding (high-scoring products receive a green label, while unhealthy foods are labelled red).
Bordier says that when it comes to environmental labels there is a strong parallel with nutrition, though at the moment there is a real risk of confusion among consumers because sustainability messaging is still rare, and when it is present it can be inconsistent between products. Many companies and industries have developed their own certificates and benchmarks, making it difficult for consumers to tell whether the product has been inspected by an independent regulator and verified. (Read more: Why some climate claims are unprovable).
“We need to think about how we make those labels and ensure that the data behind them is robust,” she says, adding that regulation and clear guidelines would help achieve this.
Michael Clark, a postdoctoral researcher on the Livestock, Environment and People programme at the University of Oxford, agrees. “Regulation is needed to ensure eco-labels are consistent across food retailers within a country, and possibly also across countries,” says Clark.
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“There are around 120 ‘eco-labels’ on the market, from Fair Trade to organic and Rainforest Alliance Certified,” he says. “Until we have a single, unified metric, it is really difficult for consumers to make those food judgments themselves.”
Clark says it is important that carbon doesn’t become the only measure used to determine food’s environmental impact. “We need to take a holistic perspective,” he says. Besides carbon, we should consider how the food we eat impacts water, land and biodiversity, he says, noting that foods with a high carbon footprint often require a large amount of land for production.
This isn’t always the case, he adds. Wild-caught fisheries, for example, don’t use large amounts of land or freshwater, but can release a lot of CO2 when they drag weighted nets across the ocean floor, and have devastating impacts on ocean ecosystems through overfishing and seafloor destruction. (Read more: Can eating fish ever be sustainable?)
Miers agrees that carbon labels only tell us a fraction of the story, but says it’s a useful tool that gets people to start thinking about food’s climate impact. “But if we just focus on carbon, we are really at risk of oversimplifying a complex subject which is nature and shooting ourselves in the foot,” she says, adding that Wahaca is also focusing on other environmental issues beyond greenhouse gas emissions, including sourcing ingredients from regenerative farmers who do not use any herbicides or fertilisers to boost soil health (which further enables it to trap more carbon).
“We’re not here to bash people over the head,” says Miers. “It’s just about giving people information. It’s not about telling people what they can or can’t eat.”
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