CO2 labeling on food encourages people to eat more sustainably. An international research team found this out. What matters is how the information is presented. The effect was greatest when CO2 data were visualized in traffic light colors or presented as environmental costs.
Field experience in the canteen
The ten-day field experiment was carried out in one of the largest canteens of the Munich Students’ Union, Mensa Leopoldstrasse. During the testing period, the menu displays not only showed the more than 8,000 visitors to the canteen the usual information, such as the prices of the respective dishes or their main ingredients, but also the high CO2 footprint.
The presentation of the CO2 information was changed once a day during the experiment to test which presentations had the greatest impact on consumer behavior. For example, some visitors were told about the environmental costs in euros that their lunch entails. Others, on the other hand, have learned from the screenings how much of their daily CO2 budget is consumed by their chosen dish. Still others were told about the CO2 emissions in grams caused by the dish.
When the traffic light is red
The information was also complemented by coding in the colors of the traffic lights (green, yellow, red). Ultimately, it had the biggest effect when visitors found out how many euros in environmental damage their lunch did. In this way, up to ten percent less CO2 was caused by the meals than without the information on CO2 emissions.
Starting points for politics and business
“Our experiment makes it clear that information about the carbon footprint can lead to a change in consumer behavior. This insight can help policy and business to take appropriate action for a more sustainable future,” says Thorsten Sellhorn, professor of accounting and auditing at LMU. “Companies can, for example, voluntarily choose to disclose CO2 claims for food or other products and services”.
You can learn more about research on this page.