What would happen if everyone in the United States made a decision to go vegan?

What would happen if all Americans went vegan?

What would happen if all Americans went vegan?

But it's a lot more complicated than advocates for an all-vegan country might hope, a new study found.

The authors wrote: "This assessment suggests that removing animals from U.S. agriculture would reduce agricultural GHG emissions, but would also create a food supply incapable of supporting the United States population's nutritional requirements".

That means animal agriculture is a perennial target for those hoping to cut emissions and tackle global warming. So, what would happen if everyone immediately went vegan? Their study discovered that annual agricultural emissions would fall from 623 million tons to 446 million tons.

"This assessment suggests that removing animals from USA agriculture would reduce agricultural GHG emissions", they said, "but would also create a food supply incapable of supporting the US population's nutritional requirements".

Robin White, of Virginia Institute of Technology, and Mary Beth Hall, of the US Dairy Forage Research Centre, created statistical models showing the effects removing farmed animals from the agricultural system would have on nutrition and GHG emissions.

For better or worse, it's not that simple, scientists told Science Magazine. Eliminating animals altogether would leave behind tons of corn stalks, potato waste and other plant byproducts that right now end up in livestocks' stomachs.

With no more livestock-produced manure, demand for artificial fertilizer would rise as well, Science Magazine reported, driving an additional 23 million tons in carbon emissions each year. The analyst then calculated how the change would decrease greenhouse gas emission based on the scientists' model.

Cutting out animals would hurt Americans' diets, too.

Looking at the nutritional content of crops now produced, the team also found that a plant-only system wouldn't be able to meet the USA population's requirements for calcium, vitamins A and B12, and a few key fatty acids. "With carefully balanced rations, you can meet all of your nutrient requirements with a vegetarian diet", White says.

"Despite the production of a greater quantity of food in the plants-only system, the actual diets produced from the foods result in a greater number of deficient nutrients and an excess of energy", the authors wrote. Yet it's fuel efficiency - not hamburger and chicken nugget bans - that policymakers hoping to tackle greenhouse emissions focus on.

That's not to say that eating a little (or a lot) less meat on an individual level can't have an impact on your carbon footprint, though - especially considering how much of our individual greenhouse emissions come from meat consumption.