Of the many terms attached to our burgers and steaks, "sustainable" and "grass-fed" often sit next to each other. But a new study finds that raising livestock on grassy pastures is far from sustainable and doesn't have the climate benefits proponents have claimed.
"Can we eat our way out of the climate problem by eating more grass-fed beef?" study author Tara Garnett and her colleagues asked. The answer, they found, is no.
Eating grass-fed beef doesn't get climate-conscious carnivores off the hook.
Cattle and other ruminants have long been considered a major source of greenhouse gases, largely because of the methane they emit through belching and the carbon dioxide released when forests are cleared for grazing or growing feed.
But in recent years, researchers have found that cattle raised on pastures, munching on grasses and treading the ground underneath them, have the potential to sequester carbon in the soil. Some have made the argument that certain kinds of managed grazing practices not only provide the key to feeding calorie-dense beef and dairy products to a growing global population—predicted to hit 9.8 billion by 2050—but are critical to controlling greenhouse gas emissions because of their ability to store carbon in the soil and potentially offset their emissions. Not everyone is convinced.
"This is an area of contestation," Garnett said. "We wanted to look at the evidence."