The science of sustainable seafood, explained

New database gets us closer to understanding environmental impacts of food

A recent paper in Science introduced a new database for researchers to use to quantify the environmental impacts of food around the world.

Previously, impacts of food were studied using only a few different variables like greenhouse gas (GHG) emissions or fertilizer use. However, a newer kind of analysis, called life cycle assessment can quantify nearly every environmental impact of a food product throughout all stages, from “cradle to grave.”

Life cycle assessments offer a more complete way to measure and compare environmental impacts of food. The new dataset, complied by the authors, consists of 570 life cycle assessment studies that cover ~38,700 commercially viable farms in 119 countries and 40 food products representing ~90% of global protein and calorie consumption. The dataset is available here.

In addition to compiling the dataset, the authors reported some fascinating findings:

  • Food production is the largest emitter of GHGs and climate change and the biggest driver of deforestation. Food production causes ~32% of global terrestrial acidification, a condition that lowers pH of soil, threatening plants and animals dependent on a healthy ground composition, and ~78% of eutrophication, a massive influx of contaminants in a body of water that leads to low amounts of oxygen in the water. This can fundamentally alter species composition of natural ecosystems and reduce biodiversity and ecological resilience. Farms are the most impactful, causing 61% of food’s GHG emissions (81% if you include deforestation) and 79% of acidification & 95% of eutrophication.
  • Agriculture covers 43% of the world’s ice- and desert-free land. 87% is used for food, with the remaining 13% for biofuels & textile crops.
  • Beef is by far the most impactful terrestrial food to produce, both in terms of land-use and GHG emissions.
Estimated global variation in GHG emissions, land use, terrestrial acidification, eutrophication, and scarcity-weighted freshwater withdrawals, within and between 40 major foods. A) Protein-rich products. Grains are also shown here given that they contribute 41% of global protein intake, despite lower protein content. (B) Milks. (C) Starch-rich products. (D) Oils. (E) Vegetables. (F) Fruits. (G) Sugars. (H) Alcoholic beverages (1 unit = 10 ml of alcohol; ABV, alcohol by volume). (I) Stimulants. n = farm or regional inventories. Pc and pctl., percentile; scty., scarcity. From Poore and Nemecek 2018.

As you can see from the figure, the paper mainly focused on terrestrial farms. A more in-depth analysis of life cycle assessments and capture fisheries & aquaculture came out a few weeks after this study and complements it well.

Solutions

The authors offer several suggestions to reduce environmental impacts of food—from both top-down policy change focused on food production, and bottom-up change coming from consumers.

On the producer side, the first step is to monitor impacts. This paper sets a good baseline, but monitoring will contribute to mitigation targets in the future. These mitigation targets could be incentivized through taxes or subsidies. Other changes could come from technological innovation or advances in knowledge & practice.

The consumer side (that means you!) has more potential to make change: “Today, and probably into the future, dietary change can deliver environmental benefits on a scale not achievable by producers.” We have long maintained that the biggest impact an individual can have on the planet is to be mindful of their eating habits. Replacing beef with alternative animal or plant protein is a great way to make a difference. A recent paper we wrote about earlier this week, can help inform Earth-friendly choices. Large-scale improvements and conservation action will come with policy change and political pressure, register to vote here.

Picture of Max Mossler

Max Mossler

Max is the managing editor at Sustainable Fisheries UW.

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