Do carbon footprint labels promote climatarian diets? Evidence from a large-scale field experiment

In a recent study published in the Journal of Environmental Economics & Management, researchers from the United Kingdom (UK) assessed the causal effect of carbon footprint labelling on individual meal choices in a university cafeteria setting using a large-scale field experiment. The study allowed the scientists explicitly explore whether carbon footprint labels can induce more climatarian food choices and simultaneously quantify potential emissions reductions that can be attained from such changes in food consumption patterns.

The experiment was conducted in partnership with five college cafeterias catering to students and staff at the University of Cambridge between October 2019 and March 2020. Carbon footprint labels were introduced at three of the five cafeterias on all cafeteria main meals served during an intervention period, while two cafeterias served as our control. The researchers collected baseline (pre-treatment) meal choice data as well as a post-intervention follow-up exit survey data. The final dataset consisted of over 80,000 individual dining decisions made by 2228 individuals.

Results from this large-scale field experiment indicate that carbon footprint labels led to a decrease in the probability of selecting a high-carbon footprint meal by approximately 2.7 percentage points with consumers substituting to mid-carbon impact meals. The researchers found no change in the market share of low-carbon meals, on average. The reduction in high-carbon footprint meals was driven by decreases in sales of meat meals while sales of mid-ranged vegan, vegetarian and fish meals all increased. The authors estimated that the introduction of carbon footprint labels was associated with a 4.3% reduction in average carbon emissions per meal.

Carbon Label: University Cafeteria

Based on these results, Lohmann et al. 2022 conclude that labels are an effective tool to leverage pro-environmental preferences in a cafeteria setting and promise considerable greenhouse (GHG) emission reductions at the individual level. And while this study is limited to the cafeteria setting, the authors assert that carbon labels will have a much larger role to play in a broader set of food consumer choices, in particular supermarket purchase decisions (because the volume is much larger than cafeteria choices). These authors point out that additional experiments in these food choice settings with non-student samples will be important to solidify our understanding of how carbon footprint labels affect consumer choices.

Moreover, the authors noted that, “labels allow for product differentiation on sustainability grounds and hence provide clear signals to consumers who hold environmental preferences. Product differentiation aids consumer choices and in turn may bring about significant changes on the producer side if market dynamics continue their current trend in favor of low-carbon alternatives and increasing climatarian dietary preferences. “

“For instance, labels may incentivize suppliers to substitute high-carbon alternatives in favor of lower-carbon alternatives, which could result in substantial decreases in food production emissions. If future carbon footprint labels are based on full life-cycle assessments capturing emissions from ‘farm to fork’, this could further encourage innovations along the entire supply chain.” The researchers observed that the “results are particularly relevant under the current policy climate in the UK, the EU and elsewhere where pilot voluntary carbon food labelling schemes are emerging (e.g. the UK’s Carbon Trust label) and advanced discussions are underway for introducing carbon food labels as part of many countries’  decarbonisation agendas.

This momentum is partly a reaction to an increasing consumer shift towards climatarian diets (i.e. diets aimed at reducing the carbon footprint). Yet, the reality remains that rolling out carbon food labels across the entire food industry is an immensely challenging and complex endeavour, while at the same time, causal hard evidence-based studies on the impact of these labels on actual behavior are lacking (Rondoni and Grasso, 2021).”

The paper by Lohmann et al. (2022) provides one of the first large-scale field experiments that specifically assessed impacts of carbon labeling on behavioral change within a university cafeteria setting in a causal manner. The authors found that carbon footprint labels on food could induce carbon reducing behavioral changes. However, as stated by these authors, “The challenges that remain are how to scale up the use of such labels in a manner that is unambiguous to consumers and also cost-effective.” Furthermore, Faccioli et al. (2022) noted that while information on the carbon characteristics of a food is relevant for consumers in making food choices, use of a combined carbon and health tax policy may be necessary to significantly reduce greenhouse gas emissions.

References:

https://www.sciencedirect.com/science/article/pii/S0095069622000596#b15

Lohmann PM, Gsottbauer E, Doherty A, et al. Do carbon footprint labels promote climatarian diets? Evidence from a large-scale field experiment. Journal of Environmental Economics and Management. 114,102693 (2022). https://www.sciencedirect.com/science/article/pii/S0095069622000596?via%3Dihub

Faccioli, M., Law, C., Caine, C.A. et al. Combined carbon and health taxes outperform single-purpose information or fiscal measures in designing sustainable food policies. Nat Food 3, 331–340 (2022). https://doi.org/10.1038/s43016-022-00482-2

Published by greengrass50

My name is Christine McCullum-Gomez, PhD, RDN. I am a registered dietitian nutritionist with expertise in environmental nutrition, food and nutrition policy, food and nutrition security, food justice, chronic disease prevention, regenerative & organic agriculture, and sustainable healthy dietary patterns. Currently, I serve on the Editorial Review Board and as a Column Editor for the Journal of Hunger & Environmental Nutrition. I live in Bogota, Colombia with my husband, two teenagers (boy-girl twins), and our dog Honey. My website is: www.sustainablerdn.com. You can follow me on Instagram at: https://www.instagram.com/cmccullumgomez/

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