Food marketers may claim that plant-based beverages are a more sustainable choice than real dairy. In reality, dairy cows play an important role in nature’s carbon cycle.

Cattle are the original “upcyclers,” explains Stephanie Clark, a dairy scientist from Iowa State University.

Cattle can consume plant materials — such as grasses, corn stalks, ethanol byproducts and more — that humans can’t eat. That’s because of cattle’s unique ruminant digestive system. About 75% of what cattle consume is inedible to humans, Clark notes.

Even vegetarians benefit from cattle. Cattle often eat inedible food waste, such as fruit and vegetable trimmings, oat hulls and corn stalks, keeping these byproducts out of landfills.

Food waste is a major source of greenhouse gas emissions in the United States, according to the U.S. Environmental Protection Agency.

The EPA recommends that food companies find a way to feed food waste to people first, and then livestock — and to only use landfills as a last resort.

U.S. dairy farmers and processors are continuing to work to reduce their environmental impact and provide sustainable, nutrient-rich dairy foods, Clark notes.

For example, since 2007, the dairy industry uses 30% less water and 21% less land, produces 20% less manure and has reduced its carbon footprint by 19% for each 1 gallon of milk produced, according to the Dairy Sustainability Alliance.

“The dairy industry has been working for quite a few years; they’re diligently working on sustainability and recycling of nutrients,” Clark says.

The Dairy Sustainability Alliance is a coalition of dairy farmers and processors working to achieve net zero carbon emissions in the U.S. dairy industry by 2050. Alliance members account for three-fourths of U.S. milk production. For more information about dairy farmers’ sustainability achievements, visit