Abstract
Carbon footprint labelling can help foodservice providers guide customers toward more environmentally sustainable menu choices. However, limited empirical research has investigated how different types of carbon labels affect food choices in real-world restaurant settings. This paper presents real-world evidence from two experimental field studies examining the effects of carbon warning and carbon value labels on menu choices. Study 1 shows that, contrary to encouraging pro-social food choices, the combined use of carbon warning (red) and carbon value (green and yellow) labels can negatively affect product category sales across all red, yellow and green labelled products. While red(high) carbon choices decrease as intended, the choice for green(low)- and yellow(medium)-carbon menu options also drops dramatically. We theorise that these results are driven by contagion effects and the use of multiple environmental cues. Study 2 addresses this by using only a carbon value label with local food as a proxy for communicating climate-benign options without triggering aversive responses. The study's findings underscore how carbon value labelling can enhance the influence of carbon labels on environmentally sustainable food choices. These findings offer actionable insights for foodservice providers, helping them to design menu labels that drive positive consumer responses to more environmentally sustainable menu options.