Василиса▶ Я жду вашего обращения. Что Вы хотите узнать?
Meat-eaters may speed worldwide species extinction, study warns | Science | AAAS AAAS ScienceMag.org Search Search X Science Menu ShareAround the world, people are converting forest to pasture to raise cattle, a practice that can lead to the loss of biodiversity.

Around the world, people are converting forest to pasture to raise cattle, a practice that can lead to the loss of biodiversity.

Paulo Santos/Reuters/Corbis Meat-eaters may speed worldwide species extinction, study warns

Diets rich in beef and other red meat can be bad for a person’s health. And the practice is equally bad for Earth’s biodiversity, according to a team of scientists who have fingered human carnivory—and its impact on land use—as the single biggest threat to much of the world’s flora and fauna. Already a major cause of extinction, our meat habit will take a growing toll as people clear more land for livestock and crops to feed these animals, a study in the current issue of Science of the Total Environment predicts.

“It’s a colossally important paper,” says Gidon Eshel, a geophysicist at Bard College in Annandale-On-Hudson, New York, who studies how human diets affect the environment, and who was not part of the study. Researchers have struggled to determine the full impacts of meat consumption on biodiversity, Eshel says. “Now we can say, only slightly fancifully: You eat a steak, you kill a lemur in Madagascar. You eat a chicken, you kill an Amazonian parrot.” That’s because species-rich habitats are being converted to pasture and feed crops as the human appetite for meat swells.

But others disagree that livestock production is the leading cause of habitat loss. “They’ve created [a] stickman to be knocked down,” says Clayton Marlow, a grassland ecologist at Montana State University, Bozeman, “without accomplishing anything for either the ecosystem or the poor.”

Previous studies have explored links between modern livestock production and climate change, water pollution, and the loss of some herbivores and top predators such as wolves and lions. “But how is it impacting other species?” asks Brian Machovina, an ecologist at Florida International University in Miami, and the paper’s lead author.

To find out, he and his colleagues looked at studies that identified the world’s biodiversity hotspots—those areas that contain the highest percentage of endemic plant and animal species. Most are located in tropical nations. Then, the researchers picked out countries that are most likely to expand their industrial livestock operations, and determined where and how much land will be lost to grazing and growing crops to feed livestock. Using data from the Food and Agriculture Organization and other studies about the production of cattle, pigs, and chickens in these countries from 1985 to 2013 and the amount of land the livestock required, they extrapolated the likely future expansion of agricultural lands. Finally, they created maps of overlap.

Many of the places expected to see the greatest shift in land use from forest to livestock are in 15 “megadiverse” countries, which harbor the largest number of species, Machovina says. “By 2050, given current trends, these countries will likely increase the lands used for livestock production by 30% to 50%”—some 3,000,000 square kilometers—the researchers estimate.

The habitat loss is so great that it will cause more extinctions than any other factor, the study notes, particularly when coupled with other deleterious effects of livestock production, including climate change and pollution. “These changes will have major, negative impacts on biodiversity,” Machovina says. “Many, many species will be lost.”

The trend toward meat-eating is already having an impact, the scientists say.

Citing other studies, they note that more than three-quarters of the land previously cleared in the Amazon region is now used either as pasture for livestock or to raise feed crops for domestic and international markets. And the rapid deforestation there continues: Another 1898 square kilometers of forest were removed over the last year. Further, more than half of the Amazon’s Cerrado, a woodland savanna ecosystem known for its rare species, has also been cleared for raising cattle and soy. Habitats have also been—and continue to be—lost throughout Central and Latin America for the same reasons, the scientists say, who see a similar future for Africa.  

By revealing where the most flora and fauna will disappear as lands are converted to agriculture for meat production, “the study equips us with a means to quantify the costs of our dietary choices in terms of species loss,” Eshel says.

The study also “suggests potential solutions that merit serious consideration,” notes ecologist David Tilman from the University of Minnesota, Twin Cities, who was not part of the work. To stop the loss of biodiversity, Machovina and his colleagues recommend that people limit meat consumption to 10% of their calories; eat more fruits and vegetables; replace beef—the most land-hungry meat—with pork, chicken, and fish; and change livestock production practices. But Tilman warns this won’t be easily done. “The challenge is to find solutions that meet human needs and simultaneously protect remaining natural habitats.”

Meeting the challenge of “feeding the world’s growing population with a shrinking land base” can’t be done without “intensive animal and crop production,” says Marlow, who argues that the real problem facing biodiversity is the loss of arable land to development such as urban and slum sprawl. He adds that developing countries are adopting industrialized livestock production because it’s efficient and “the only way we can feed the world’s growing population.”

If eating meat means consuming habitat, the world might consider food writer Michael Pollan’s advice: “Eat food. Not too much. Mostly plants.” It could save a lemur and a parrot.

Posted in: Environment Plants & Animals


Virginia Morell Twitter More from News A fisherman casts a net from a boat in the Gulf of Guinea with other boats visible in the background. Modern fishing methods are driving small whales and dolphins to extinction a 40-hectare lake on Baffin Island in Canada DNA recovered from Arctic lakes holds clues for our future world reconstruction of Mesophthirus engeli feeding on dinosaur feathers Even dinosaurs had lice, fossils entombed in amber reveal Got a tip? How to contact the news team ScienceInsider A visible light image of Tropical Storm Harvey moving north over Texas and Louisiana. Microsatellites will capture GPS reflections to sharpen weather forecasts three women sit listening in an audience during a presentation Astronomy funder finds that gender diversity takes more than good intentions conceptual illustration of researchers holding balloons with different countries on them U.S. scientists who hide foreign ties should face research misconduct sanctions, panel says Dome of the U.S. Capitol, with an American flag in front of it. Congress creates two new bodies to tackle foreign influence on U.S. research ScienceInsider logo Political tensions unravel plan to convert Iranian nuclear site to civilian uses More Science Insider Sifter Enterococcus faecalis Scientists hope to fight antibiotic-resistant bacteria by targeting their ‘alarm proteins’ artist's concept shows a hypothetical "rejuvenated" planet Scientists just found a planet circling a dead star  Yellow-bellied flycatcher Rising temperatures are making birds smaller a cat in green grass with flowers How good are you at reading your cat’s facial expressions? blue whale How slow can you go? A blue whale’s heart beats just twice a minute More Sifter

Read the Latest Issue of Science

6 December 2019

Vol 366, Issue 6470

Magazine Cover Table of Contents Scientific Community Ready to retire? Atmospheric Science Nitrogen crisis threatens Dutch environment—and economy Medicine/Diseases Institute that aims to reshape health care seeks renewal European News Italy set to create €300 million research funding agency Epidemiology Beset by neural tube defects, Ethiopia may fortify salt Astronomy Europe to lead in monitoring carbon from space About Us Journals News from Science Leadership Team Members Work at AAAS For Advertisers Advertising Kits Awards and Prizes Custom Publishing Webinars For Authors Submit Information for Authors Editorial Policies For Librarians Manage Your Institutional Subscription Information for Librarians Request a Quote FAQs Related Sites AAAS.org EurekAlert! Science in the Classroom Science Magazine Japanese Help Access and Subscriptions Order a Single Issue Reprints and Permissions Contact Us Accessibility Stay Connected AAAS Terms of Service Privacy Policy Contact AAAS
© 2014-2019 ЯВИКС - все права защищены.
Наши контакты/Карта ссылок