With the global population set to hit 9 billion by 2050, we're in danger of running out of food. The United Nations forecasts the world needs to double production if we're going to meet demand.
A big reason for that is a shift in diets. As countries become richer, they tend to drift towards eating more meat and processed food. That means the planet not only has to produce more beef and chicken, it also has to produce more food to feed the beef and chicken—a double whammy. Livestock animals need 30 calories of feed for every one calorie they return in edible food—an inefficient form of calorie provision.
To get a sense of what changing diets could mean for the planet, take a look at this interactive graphic. It shows what happens when one country adopts the eating habits of another.
Click on Tanzania, then choose the United States as a comparison country. You can see how much extra food, land (more than 13 million acres), and water (19,473,215,575,000 liters per year) is needed, how much additional carbon dioxide would be released (19 million metric tons a year), and the effect on nutrition. By adopting a American diet, Tanzanians would eat 114 more grams of fat per day, 58 grams more protein, and 1,551 more calories overall.
The graphic was created by Michelle Minkoff, Georgia Sambunaris, John Templon, Emily Cassidy, and David Putney during a recent "Future of Food" hack organized by National Geographic. The event generated several other good ideas, which you can see here.
The graphic doesn't all point towards greater demand. If the United States were to take on a Japanese diet, for example, the effect would be a lowered need for cows (though greater need for fish), 61,537,400 fewer acres for production, and 308 million metric tons less CO2 in the atmosphere per year. We'd also consume 69 fewer grams of fat every day, and 965 fewer calories.
If the graphic shows one thing, it's that diets high in meat come with additional costs for the environment and natural resources. It's scary to think of a world living on a diet like our own.