Efforts to get the world to eat less meat have gained some traction, with meatless meals becoming more common for many of us and whole websites dedicated to vegan and vegetarian recipes. However, getting people to eat less meat fast enough to fix our climate problem is highly unlikely. In fact, as the population grows and the incomes of people in developing countries rise, demand for meat has soared. Reducing the impact of the meat may prove more effective than encouraging curtailment, as it has in other areas like water and energy conservation. To lessen the impact of the world’s meat habit on the climate, scientists are working to find ways to reduce the emissions caused by cattle. And they’ve come up with some interesting discoveries.
Can Cows Make Less Methane?
A recent study from the Royal Botanic Gardens, Kew, Scotland’s Rural College, and the Senckenberg Biodiversity and Climate Research Centre, Frankfurt suggests that changing what animals eat could help cut the emissions associated with raising them. Ruminant animals, primarily cows and sheep, produce methane when grasses and other foraged plants break down in their stomachs.
The Kew study found that a warmer climate makes these plants tougher and less nutritious, which means they require more time in these animals’ digestive tracts, leading to increased methane production. Lead author Mark Lee notes that what their research uncovered is a “vicious cycle.” Cows and other grazing animals “produce methane which warms our planet. This warmer environment alters plants so they are tougher to digest, so each mouthful spends more time in the animals’ stomach, producing more methane, further warming the planet, and the cycle continues.” Less nutritious forage also leads to lower milk yields and less weight gain, requiring more animals to yield the same amount of milk and meat. More animals means more methane, perpetuating the cycle further.
Researchers mapped areas of the world where they expect the greatest increase in cattle methane production caused by changes in plant quality. They believe methane levels will rise everywhere, but they have identified particular regions of North America, Central and Eastern Europe, and Asia where they expect the most significant increases. They also noted that many of the identified areas are seeing sharp increases in livestock farming.
Predictions of climate- and forage-driven increases in cattle methane production (%) under temperatures predicted for 2050 using (a) a low estimate of future temperature changes (RCP 2.6) and (b) a high estimate of future temperature changes (RCP 8.5). Light grey regions are currently unsuitable for ruminant livestock. Dark grey regions have predicted temperatures greater than 30 ◦C.
Lee believes this research points to ways farmers can cut methane production and thus lessen the climate impact of meat. “Our research has shown that cultivating more nutritious plants may help us to combat the challenges of warmer temperatures,” Lee explains. Researchers at Kew are working to “identify the native forage plants that are associated with high meat and milk production and less methane, attempting to increase their presence on the grazing landscape.”
What About Factory Farming?
Other research aimed at reducing the emissions of animal products has focused on efficiency, trying to produce the most meat and milk with the least impact. Some studies have noted that different cattle breeds produce far more milk than others, while other research has looked for ways to minimize the climate impact of feeding cattle by using crop waste rather than more emissions-intensive grain. Several studies have found that industrial cattle farming produces less greenhouse gas than pasturing, in part because the grain fed to such animals produces less methane in the digestive tract, but primarily because animals fed grain reach full weight far faster than those who eat grass.
However, the prevailing industrial model has significant environmental and human health impacts — as well as ethical issues surrounding the animals’ treatment — that can’t be ignored. Ruminants’ digestive tracts are simply not designed to handle grain, so they’re far more prone to disease, part of the reason antibiotic use and resistance has risen so dramatically in recent decades. Additionally, the immense quantity of manure emanating from factory farms has far-reaching ecological implications, and often pollutes air and surrounding waterways.
A 2012 study by the U.K. nonprofit National Trust found that intensively managing pasture-raised cattle could be climate-neutral or even positive when the effect on carbon sequestration is taken into account. Furthermore, many such pasturing operations use marginal land unsuited for other purposes and promote healthier biodiversity. Their manure, rather than posing health problems, provides natural fertilizer for plants, eliminating the need for emissions-intensive synthetic fertilizers.
The Role of the Eater
Global meat production has more than quadrupled since 1961, and is expected to rise further as a growing global middle class adopts the diet of wealthier nations. While research on making beef more climate-friendly continues, educating people where meat consumption is highest — the United States for example — can help slow demand. In fact, beef consumption in the U.S. has been dropping, but at an average of 75 pounds per person annually, consuming less beef in favor of foods with a smaller footprint could make a significant difference.
If you’re looking to make your diet more sustainable, the Environmental Working Group’s Meat Eater’s Guide can point you to foods with smaller climate impacts than beef. Meat eaters choosing chicken, turkey, or fish rather than beef can cut the greenhouse gas emissions of their next meal. Better still, more people eating less meat overall and getting more calories from plant-based sources would reduce the emissions coming from our diets. Vegetarians who consume dairy should also be aware that cheese coming from ruminant animals like cows and sheep has a surprisingly large impact, on par with many meats.
Feeding a population of nine billion on a warming planet will be one of the greatest challenges of the century. All measures to make this daunting task more sustainable — whether through scientific breakthroughs or the daily decisions we make about what’s on our plates — will be needed as we adapt to a changing climate.
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