Depending on how you count it, it's definitely within a small constant multiple. A ton of global land goes toward food production. In somewhat more detail: It'

Depending on how you count it, it's definitely within a small constant multiple. A ton of global land goes toward food production. In somewhat more detail: It's about 27% of the way there (assuming europe == EU). Multiply by 7.8B people and you get 2.1B acres, compared with the 2.3B acres actually used worldwide. Those numbers might look a little fishy (2.1B should be a hard lower bound, and the upper bounds were >2 acres per person), but the low figure of 2.3B acres in actual use is roughly explained by: - 9% of the world is malnourished - Meat and other high-land-use foods make up well under 20% of the global diet (on average more concentrated in wealthier, lower population nations). - Not all of that meat comes from the land, skewing the exact metrics being used a bit. I'm sure the 0.3+ acre estimate isn't perfect (back of the envelope calculations suggest soybeans can supply the requisite calories in 0.15 acres, and your other nutrients can be furnished in 0.05 acres), but it definitely appears to be in the right ballpark.