Provision of food is a prerequisite for the functioning of human society. Cropland where food and feed are grown is the central, limiting resource for food production. The amount of cropland needed depends on population numbers, average food consumption patterns, and output per unit of land. Around the globe, these factors show large differences. We use data from the Food and Agriculture Organization to consistently assess subcontinental dynamics of how much land was needed to supply the prevailing diets during a span of 46 y, from 1961 to 2007. We find that, in most regions, diets became richer while the land needed to feed one person decreased. A decomposition approach is used to quantify the contributions of the main drivers of cropland requirements for food: changes in population, agricultural technology, and diet. We compare the impact of these drivers for different subcontinents and find that potential land savings through yield increases were offset by a combination of population growth and dietary change. The dynamics of the three factors were the largest in developing regions and emerging economies. The results indicate an inverse relationship between the two main drivers behind increased land requirements for food: with socioeconomic development, population growth decreases and, at the same time, diets become richer. In many regions, dietary change may override population growth as major driver behind land requirements for food in the near future.global analysis | land use | historical trends | decomposition analysis T hroughout the world, agriculture provides human society with food. Since the emergence of large-scale agriculture, this crucial activity has been responsible for the largest environmental impacts of humans on natural systems: presently, the largest shares of human land and freshwater use (1, 2), biomass appropriation (3), and the alteration of the global nitrogen and phosphorus cycles (4, 5), and a significant contribution to energy use and greenhouse gas emissions (6), are associated with the provision of food. Within agriculture, croplands take a central and often limiting role. These lands are usually of high quality and, by generating food and feed crops, they provide the lion's share of the global food supply: in 2005, more than 90% of all food calories and approximately 80% of all food protein and fats available in the world were derived from croplands [Food and Agriculture Organization (FAO) of the United Nations, http://faostat.fao.org/].The amount of cropland needed to supply a society with food depends on population numbers, the type of diet, and the food output per unit of land. Population, diets, and production techniques change over time and show large spatial variation. With socioeconomic development, population growth rates decrease (7) and diets change: typically, consumption of animal protein, vegetable oils, fruits and vegetables increases, while starchy staples become less important (8). These changes from staples toward richer diets imply that cropland demand of avera...
