Willits-Smith et al., 2020
Willits-Smith, A., Aranda, R., Heller, M. C., & Rose, D. (2020). Addressing the carbon footprint, healthfulness, and costs of self-selected diets in the USA: a population-based cross-sectional study. The Lancet Planetary Health, 4(3), e98-e106.
https://www.thelancet.com/action/showPdf?pii=S2542-5196%2820%2930055-3
identified people open to changing their diet (16% of the sample, 1026 respondents) and then measured what would happen if they changed their diets.
complete substitution of beef for poultry resulted in a decreased GHGE of 35·7% for potential changers, whereas shifting away from all meats to vegetarian protein foods resulted in a 49·6% drop.