Want a side of CO₂ with that? Better food labels help us choose more climate-friendly foods
- Written by Yi Li, Senior Lecturer in Marketing, Macquarie University
When you’re deciding what to eat for lunch or dinner, do you consider the meal’s greenhouse gas emissions? How do you compare the carbon footprint of a beef sandwich with that of a falafel wrap?
Most people can’t tell what’s better for the climate. Even those who care deeply about making sustainable food choices can struggle.
In Australia, meat products are responsible for almost half (49%) the greenhouse gas emissions of products consumed at home. Switching from these high-emission foods to lower-emission foods, such as plant-based meals, can significantly reduce household emissions. But a lack of knowledge may be stopping people doing the right thing.
The good news is my colleagues and I have a simple solution. Highlighting the source of the food as animal- or plant-based on carbon labels makes a big difference to consumer choices. In our latest research, we show this new carbon label encourages switching from animal-based to plant-based foods.
Closing the knowledge gap
Previous research has shown consumers consistently underestimate the vast difference in greenhouse gas emissions between animal- and plant-based foods. For instance, producing one kilogram of beef emits 60kg of greenhouse gases, whereas producing the same quantity of peas emits just 1kg of greenhouse gases. However, most people think the gap between the two is much smaller.
This matters because collectively, our food choices have a big impact on climate change. Agriculture generates almost a third of global greenhouse gas emissions, with animal products the biggest contributors.
Making carbon labels more informative
A “carbon footprint” refers to the greenhouse gas emissions associated with a product.
Globally, there is increasing interest in carbon food labelling, given its potential to nudge consumers towards more sustainable food choices. In Australia, such labelling is voluntary and not yet widespread.
Most carbon labels follow a similar approach. They typically display a number representing greenhouse gas emissions, and a traffic-light system indicating the level of environmental impact from green (low) to red (high). But such labels do not indicate whether the food is animal- or plant-based. So a high carbon score does not help people identify the source of the emissions.
We designed a new type of label. It clearly displays whether the food is sourced mainly from animals or plants, along with the standard emissions score and traffic-light colour code. This approach is especially useful for the growing segment of pre-prepared and packaged foods such as soups and other ready-to-eat meals, which often contain a mix of meat and plant-based food.
Our label creates a mental link between a food source and its carbon impact. When a consumer sees high carbon scores and red traffic lights appearing more frequently on meat and other animal products, they begin to make the connection between those products and higher emissions. This is key to addressing a lack of knowledge around food carbon emissions.
We tested our label against the existing labels in a series of experiments with 1,817 everyday consumers from Australia, the United States and the Netherlands.
One experiment involved soup. Compared with the group exposed to the standard carbon label, the group exposed to our label learned to associate animal-based soups with higher greenhouse gas emissions more effectively. They were more accurate at estimating the greenhouse gas emissions of a second batch of soups without labels.
This improved knowledge also translates to more climate-friendly food choices. In another experiment with Australian consumers, we encouraged participants to choose five meals from ten options. Five were animal-based and five were plant-based.
Half the participants saw the meal options with our carbon labels, and the other half did not see the carbon labels. The group exposed to our carbon labels chose fewer animal-based options in their weekly meal plan. In this case, we don’t know whether a third group exposed to the standard label would also make more climate-friendly choices, but our earlier experiments suggested our label was more effective.
In the final experiment conducted in the Netherlands, displaying our carbon label made university students more likely to choose the plant-based snack option rather than the animal-based option.
When knowledge isn’t enough
While people who care most about sustainable eating may think they know better than others, we found that is not the case. These people were not better able than other participants to tell the difference in greenhouse gas emissions between animal- and plant-based foods without seeing our carbon label.
But they were better learners. When confronted with the facts about the differences between animal and plant-based foods on our labels, they were more likely to change their choices and switch to plant-based foods.
What this means for consumers and businesses
A simple change to food labels could help consumers make more informed environmental choices. For businesses and policymakers, it shows displaying only carbon numbers isn’t enough – the food source is crucial.
Some forward-thinking restaurants and food companies are already experimenting with adding carbon labels to the menu to encourage diners to choose climate-friendly dishes. Our research suggests this approach could be more effective when combined with the new carbon labels we designed.
Meat products make a significant contribution to climate change.
Valmedia, Shutterstock
Implications for climate action
As Australia grapples with meeting its climate commitments, helping consumers understand the environmental impact of their food choices will become increasingly important.
The challenge for businesses, policymakers and researchers isn’t convincing people to care about sustainability – they already do. Almost half of Australian shoppers (46%) say sustainability is important to them and influences their purchases, despite cost-of-living pressures.
But most sustainable actions in retail involve recyclable packaging, products and materials, and local produce. The carbon emission implications of these actions, sadly, are far less than reducing animal-based food consumption.
Instead, we need to focus on giving people the tools to make their environmental concerns count. Our carbon labels could be the key to helping consumers turn their sustainable intentions into meaningful climate action.
Authors: Yi Li, Senior Lecturer in Marketing, Macquarie University
