EATING MEAT CONTRIBUTES TO CLIMATE CHANGE
From the FMS Global News Desk of Jeanne Hambleton
Posted on July 21, 2014 by Stone Hearth News
Eating meat contributes to climate change, due to greenhouse gasses emitted by livestock. New research finds that livestock emissions are on the rise and that beef cattle are responsible for far more greenhouse gas emissions than other types of animals. It is published by Climactic Change.
Carbon dioxide is the most-prevalent gas when it comes to climate change. It is released by vehicles, industry, and forest removal and comprises the greatest portion of greenhouse gas totals. But methane and nitrous oxide are also greenhouse gasses and account for approximately 28 percent of global warming activity.
Methane and nitrous oxide are released, in part, by livestock. Animals release methane as a result of microorganisms that are involved in their digestive processes and nitrous oxide from decomposing manure. These two gasses are responsible for a quarter of these non-carbon dioxide gas emissions and 9 percent of total greenhouse gas emissions overall.
The research team, including Dario Caro, formerly of Carnegie and now at the University of Siena in Italy, and Carnegie’s Ken Caldeira, estimated the greenhouse gas emissions related to livestock in 237 countries over a nearly half a century and found that livestock emissions increased by 51 percent over this period.
They found a stark difference between livestock-related emissions in the developing world, which accounts for most of this increase, and that released by developed countries. This is expected to increase further going forward, as demand for meat, dairy products, and eggs is predicted by some scientists to double by 2050. By contrast, developed countries reached maximum livestock emissions in the 1970s and have been in decline since that time.
“The developing world is getting better at reducing greenhouse emissions caused by each animal, but this improvement is not keeping up with the increasing demand for meat,” said Caro. “As a result, greenhouse gas emissions from livestock keep going up and up in much of the developing world.”
Breaking it down by animal, beef and dairy cattle comprised 74 percent of livestock-related greenhouse gas emissions, 54 percent coming from beef cattle and 17 percent from dairy cattle. Part of this is due to the abundance of cows, but it is also because cattle emit greater quantities of methane and nitrous oxide than other animals. Sheep comprised 9 percent, buffalo 7 percent, pigs 5 percent, and goats 4 percent.
“That tasty hamburger is the real culprit,” Caldeira said. “It might be better for the environment if we all became vegetarians, but a lot of improvement could come from eating pork or chicken instead of beef.”
The Carnegie Institution for Science is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
THE REAL PRICE OF STEAK: NEW RESEARCH REVEALS THE COMPARATIVE ENVIRONMENTAL COSTS OF ANIMAL-BASED FOODS
From the FMS Global News Desk of Jeanne Hambleton
Released: 23-Jul-2014 3:00 PM EDT
Source Newsroom: Weizmann Institute of Science
Citations Proceedings of the National Academy of Sciences, June 2014
Newswise — We have heard that eating beef is bad for the environment, but do we know its real cost? Are other animal or animal-derived foods better or worse? New research at the Weizmann Institute of Science, conducted in collaboration with scientists in the U.S., compared the environmental costs of various foods and came up with some surprisingly clear results.
The findings, which appear in the Proceedings of the National Academy of Sciences (PNAS), will hopefully not only inform individual dietary choices, but those of governmental agencies that set agricultural and marketing policies.
Dr. Ron Milo of the Institute’s Department of Plant Sciences, together with his research student Alon Shepon and in collaboration with Tamar Makov of Yale University and Dr. Gidon Eshel in New York, asked which types of animal-based food one should consume, environmentally speaking. Though many studies have addressed parts of this issue, none have done such a thorough, comparative study that gives a multi-perspective picture of the environmental costs of food derived from animals.
The team looked at the five main sources of protein in the American diet: dairy, beef, poultry, pork, and eggs. Their idea was to calculate the environmental inputs – the costs – per nutritional unit: a calorie or gram of protein. The main challenge the team faced was to devise accurate, faithful input values. For example, cattle grazing on arid land in the western half of the U.S. use enormous amounts of land, but relatively little irrigation water. Cattle in feedlots, on the other hand, eat mostly corn, which requires less land, but much more irrigation and nitrogen fertilizer.
The researchers needed to account for these differences, but determine aggregate figures that reflect current practices and thus approximate the true environmental cost for each food item.
The inputs the researchers employed came from the U.S. Department of Agriculture databases, among other resources. Using the U.S. for this study is ideal, says Dr. Milo, because much of the data 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.