Poore and Nemecek 2018

• The inefficiency of animal products

• Grass fed beef is not better for the environment

• Eating local makes only small improvement to your environmental impact

• OWID has visualised the data here

• Or the raw data here

Food’s environmental impacts are created by millions of diverse producers. To identify solutions that are effective under this heterogeneity, we consolidated data covering five environmental indicators; 38,700 farms; and 1600 processors, packaging types, and retailers. Impact can vary 50-fold among producers of the same product, creating substantial mitigation opportunities. However, mitigation is complicated by trade-offs, multiple ways for producers to achieve low impacts, and interactions throughout the supply chain. Producers have limits on how far they can reduce impacts. Most strikingly, impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change. Cumulatively, our findings support an approach where producers monitor their own impacts, flexibly meet environmental targets by choosing from multiple practices, and communicate their impacts to consumers.

570 studies, ~38700 farms in 119 countries and 40 products representing ~90% of global protein and calorie consumption.

On average, transportation of food accounts for less than 10% of carbon emissions in the global food supply

While meat and dairy provide just 18% of calories and 37% of protein, it uses the vast majority – 83% – of farmland and produces 60% of agriculture’s greenhouse gas emissions.

even the very lowest impact meat and dairy products still cause much more environmental harm than the least sustainable vegetable and cereal growing.

The research also found grass-fed beef, thought to be relatively low impact, was still responsible for much higher impacts than plant-based food.

Half of the world’s ice-and-desert-free land is used for agriculture.

Shifting away from animal agriculture completely would free up more than 3 billion hectares of land, equivalent to the size of Africa.  Transport typically accounts for less than 1% of beef’s GHG emissions (less than 10% for most other foods): choosing to eat local food has very minimal effects on its total footprint.