Feeding nine billion people sustainably: Conserving land and water through shifting diets and changes in technologies

In the early 21st century the extensive clearing of forestland, fresh water scarcity, and sharp rises in the price of food have become causes for concern. These concerns may be substantially exacerbated over the next few decades by the need to provide improved diets for a growing global population. This study applies an inter-regional input-output model of the world economy, the World Trade Model, for analysis of alternative scenarios about satisfying future food requirements by midcentury. The scenario analysis indicates that relying only on more extensive use of arable land and fresh water would require clearing forests and exacerbating regional water scarcities. However, a combination of less resource-intensive diets and improved agricultural productivity, the latter especially in Africa, could make it possible to use these resources sustainably while also constraining increases in food prices. Unlike the scenario outcomes from other kinds of economic models, our framework reveals the potential for a decisive shift of production and export of agricultural products away from developed countries toward Africa and Latin America. Although the assumed changes in diets and technologies may not be realizable without incentives, our results suggest that these regions exhibit comparative advantages in agricultural production due to their large remaining resource endowments and their potential for higher yields.