ta quality is high, enabling them to include, for example, figures on import-export imbalances that add to the cost. The environmental inputs the team considered included land use, irrigation water, greenhouse gas emissions, and nitrogen fertilizer use. Each of these costs is a complex environmental system. For example, land use, in addition to tying up this valuable resource in agriculture, is the main cause of biodiversity loss. And nitrogen fertilizer creates pollution in natural waters.
When the numbers were in, including those for the environmental costs of different kinds of feed (pasture, roughage such as hay, and concentrates such as corn), the team developed equations that yielded values for the environmental cost – per calorie, and then per unit of protein – for each food.
The calculations showed that the biggest culprit is beef. That was no surprise, say Dr. Milo and Mr. Shepon. The surprise was in the size of the gap: In total, eating beef is more costly by an order of magnitude – about 10 times, on average – to the environment than other animal-derived foods, including pork and poultry. Cattle require on average 28 times more land and 11 times more irrigation water, are responsible for releasing 5 times more greenhouse gases, and consume 6 times as much nitrogen as egg production or poultry. Poultry, pork, eggs, and dairy all came out fairly similarly, which was also surprising, because dairy production is often thought to be relatively environmentally benign. But the research shows that the price of irrigating and fertilizing the crops fed to milk cows – as well as the relative inefficiency of cows in comparison to other livestock – jacks up the cost significantly.
Dr. Milo believes that this study could have a number of implications. In addition to helping individuals make better choices about their diet, it should also hopefully help inform agricultural policy. And the tool the team has created for analyzing the environmental costs of agriculture can be expanded and refined for application to other areas such as, for example, understanding the relative cost of plant-based diets, or those of other nations. In addition to calculating comparisons, it can point to areas that might be improved. Models based on this study can help policy makers decide how to better ensure food security through sustainable practices.
Dr. Ron Milo’s research is supported by the Mary and Tom Beck – Canadian Center for Alternative Energy Research; the Lerner Family Plant Science Research Endowment Fund; the European Research Council; the Leona M. and Harry B. Helmsley Charitable Trust; Dana and Yossie Hollander, Israel; the Jacob and Charlotte Lehrman Foundation; the Larson Charitable Foundation; the Wolfson Family Charitable Trust; Charles Rothschild, Brazil; Selmo Nissenbaum, Brazil; and the estate of David Arthur Barton. Dr. Milo is the incumbent of the Anna and Maurice Boukstein Career Development Chair in Perpetuity.
The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. The Institute’s 2,700-strong scientific community engages in research addressing crucial problems in medicine and health, energy, technology, agriculture, and the environment. Outstanding young scientists from around the world pursue advanced degrees at the Weizmann Institute’s Feinberg Graduate School. The discoveries and theories of Weizmann Institute scientists have had a major impact on the wider scientific community, as well as on the quality of life of millions of people worldwide.
A new study conducted by the Weizmann Institute of Science looked at the five main sources of protein in the American diet: dairy, beef, poultry, pork and eggs. They calculated the environmental inputs, or costs, per nutritional unit. Find out the real price of steak.