June 13, 2018 — A paper we wrote about yesterday, Hilborn et al. 2018, went out with a press release that argued that a selective diet of seafood could have a lower environmental impact than a vegetarian or vegan diet. This claim comes from comparing the results of Hilborn et al with Poore and Nemecek 2018, a paper published just a few weeks before the Hilborn paper that used the same kind of analysis to also evaluate the environmental cost of food.
Both papers used a newer kind of analysis, called life cycle assessment, that can quantify nearly every environmental impact of a food product throughout all stages, from “cradle to grave.” Life cycle assessments are a comprehensive way to measure and compare the environmental impacts of food.
Poore and Nemecek compiled the most complete dataset of life cycle assessments for agricultural food production and reported general findings for several major food types. Hilborn et al. focused only on animal-protein, but went into greater detail. For example, Poore and Nemecek reported the impact of all capture fisheries grouped together, while Hilborn et al, reported the impact of different kinds of capture fisheries, like small pelagics, large pelagics, and white fish.
The results from Hilborn et al’s analysis show that certain kinds of seafood have a lower environmental impact than plants. For example, farmed oysters and small pelagic fish (like sardines) are probably the best food you can eat for the planet. Below is an unpublished figure provided by Ray Hilborn that adds plants to the comparison from Figure 1 in Hilborn et al. The figure, and discussion of plant-based food vs animal-based food, were cut during the review process.