In 1798, Thomas Malthus wrote a treatise on population growth, in which he stoked fear that unfettered growth among the working class would lead to widespread food shortages in the future. The Malthusian premise has been repeated over and over again: population growth will eventually overwhelm our ability to feed everyone on the planet. (You can read an excellent description of how Malthus came to his opinions and how the debate manifests in our present on the Fieldquestions blog.)
Malthusian ideas circulate in debates over food and agricultural policy on a regular basis and the debate over GMOs and their role in "feeding the world" is no exception. In his article about changing the global food narrative, Jonathan Foley states the current food narrative this way:
"The world’s population will grow to 9 billion by mid-century, putting substantial demands on the planet’s food supply. To meet these growing demands, we will need to grow almost twice as much food by 2050 as we do today. And that means we’ll need to use genetically modified crops and other advanced technologies to produce this additional food. It’s a race to feed the world, and we had better get started."
But, he argues, this is not a realistic view.
There are currently 7 billion people on the planet, so how can adding two billion to that number require twice as much food? The math doesn't add up unless you also factor in changing diets. As people around the world move into a middle class, they are often adopting the "standard Western diet", heavy on meat and dairy products. This is what will create the need for twice the production, as land is used to grow food for cattle instead of people.
Emily Cassidy makes this point as well, calculating the number of additional people who could be fed if US cropland currently devoted to raising animal feed instead was used to grow plant foods for direct human consumption. Though some of her assumptions may be flawed, it is clear that the shape of the human diet around the world matters as much or more than the number of people on the planet.
Does this mean that everyone should become an instant vegetarian? No. But it does mean that cutting back on meat consumption, even in small ways, can help.