The food system is set to come under growing strain as world populations grow and appetites for meat increase—studies show that to meet demand, we could need 60% to 120% more crops by 2050.
Of course, producing more food isn't the only answer. Society could try to minimize the incredible inefficiency of agriculture today. Not only do we literally waste one-third to one-half of all food we produce, but of the rest, much of it doesn't even go to feed people, a new study finds.
The calorie economy, it turns out, is dominated by livestock. The researchers at the University of Minnesota show that more than a third of all calories we produce goes to feed animals, with only 12% of that actually contributing to calories consumed by humans. Rearing meat isn't a good use of scarce resources (how ever much you might like your steak). An animal needs to eat 30 calories for every one calorie humans get back in edible food.
The study finds that growing food on cropland currently devoted to feeding animals and making biofuels could release an enormous amount of extra calories—in total, feeding as many as 4 billion people. But even more modest shifts, like rearing less beef and more pork and chicken, could be useful. The researchers estimate that replacing feedlot beef production with chicken and pork would feed 357 million additional people, based on a 2,700-calorie daily diet. Ending meat production completely, and substituting in milk and eggs, would feed 815 million people.
"We essentially have uncovered an astoundingly abundant supply of food for a hungry world, hidden in plain sight in the farmlands we already cultivate," says Emily Cassidy, lead author of the paper published in the journal Environmental Research Letters.
She is keen to point out that the research isn't some vegetarian manifesto. At bottom, it is intended to show how shifts within the current system could pay as many dividends as expanding it. That's worth bearing in mind the next time someone says the world is running out of food.