Environment

Global warming study raises the steaks

Damian Carrington

Latest research shows that eating less red meat would have a greater impact in cutting carbon emissions than giving up cars.

Beef has a significant impact on global warming because, as ruminants, cattle make far less efficient use of their feed. (Joel Thungren)

Beef’s environmental impact dwarfs that of other meat, including chicken and pork, new research reveals, with one expert saying that eating less red meat would be a better way for ­people to cut carbon emissions than giving up their cars.

The heavy impact on the environment of meat production was known but the research shows a new scale and scope of damage, particularly for beef. The popular red meat requires 28 times more land to produce than pork or chicken, 11 times more water and results in five times more climate-warming emissions. When compared with staples such as potatoes, wheat and rice, the impact of beef per calorie is even more extreme, requiring 160 times more land and producing 11 times more greenhouse gases.

Agriculture is a significant driver of global warming and causes 15% of all emissions, half of which are from livestock. Furthermore, the huge amounts of grain and water needed to raise cattle is a concern to experts worried about feeding another two billion people by 2050. But previous calls for people to eat less meat in order to help the environment, or preserve grain stocks, have been highly controversial.

“The big story is just how dramatically impactful beef is compared to all the others,” said Professor Gidon Eshel, at Bard College in New York State, who led the research on beef’s impact. He said cutting subsidies for meat production would be the least controversial way to reduce its consumption.

“I would strongly hope that governments stay out of people’s diet but, at the same time, there are many government policies that favour the current diet in which animals feature too prominently,” he said. “Remove the artificial support given to the livestock industry and rising prices will do the rest. In that way you are having less government intervention in people’s diet and not more.”

Less efficient use of feed 
Eshel’s team analysed how much land, water and nitrogen fertiliser was needed to raise beef and compared this with poultry, pork, eggs and dairy produce.

Beef had a far greater impact than all the others because, as ruminants, cattle make far less efficient use of their feed. “Only a minute fraction of the food consumed by cattle goes into the bloodstream, so the bulk of the energy is lost,” Eshel said.

Feeding cattle on grain rather than grass exacerbates this inefficiency, although Eshel noted that even grass-fed cattle still have greater environmental footprints than other animal produce.

The footprint of lamb, relatively rarely eaten in the United States, was not considered in the study, published in the journal Proceedings of the National Academy of Sciences.

Professor Tim Benton, at the University of Leeds, said the new work is based on national US data, rather than farm-level studies, and provides a useful overview. “It captures the big picture,” he said, adding that livestock is the key to the sustainability of global agriculture.

“The biggest intervention people could make towards reducing their carbon footprints would not be to abandon cars but to eat significantly less red meat,” Benton said. “Another recent study implies the single biggest intervention to free up calories that could be used to feed people would be not to use grains for beef production in the US.”

But the subject was always controversial, he said. “This opens a real can of worms.” – © Guardian News & Media 2014

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