Food supply and bioenergy production within the global cropland planetary boundary.

R C Henry,K Engström,A Arneth,M D A Rounsevell,S Olin,P Alexander,Paul C Struik

doi:10.1371/journal.pone.0194695

Abstract

Supplying food for the anticipated global population of over 9 billion in 2050 under changing climate conditions is one of the major challenges of the 21st century. Agricultural expansion and intensification contributes to global environmental change and risks the long-term sustainability of the planet. It has been proposed that no more than 15% of the global ice-free land surface should be converted to cropland. Bioenergy production for land-based climate mitigation places additional pressure on limited land resources. Here we test normative targets of food supply and bioenergy production within the cropland planetary boundary using a global land-use model. The results suggest supplying the global population with adequate food is possible without cropland expansion exceeding the planetary boundary. Yet this requires an increase in food production, especially in developing countries, as well as a decrease in global crop yield gaps. However, under current assumptions of future food requirements, it was not possible to also produce significant amounts of first generation bioenergy without cropland expansion. These results suggest that meeting food and bioenergy demands within the planetary boundaries would need a shift away from current trends, for example, requiring major change in the demand-side of the food system or advancing biotechnologies.

Highlights

Projected population growth to over 9 billion people by 2050, the impacts of climate change on agricultural productivity [1,2,3,4], and shifts toward animal-based diets [5,6,7,8] all pose a challenge to ensuring food security in the future
Dietary requirements were estimated from a global population of 9.1 billion in 2050 [42] and a daily dietary energy requirement of 2350 kcal per capita per day
When the cropland planetary boundary target is considered, the number of simulations drops sharply to only 12 (Fig 1, yellow lines). Simulations achieving both the food-supply and cropland planetary boundary target have global average yields that are within the upper third of projected yield increases (Fig 2, yellow lines), with yield growth rates of 0.9 to 1.0% yr-1 over the 2000–2050 period

Summary

Introduction

Projected population growth to over 9 billion people by 2050, the impacts of climate change on agricultural productivity [1,2,3,4], and shifts toward animal-based diets [5,6,7,8] all pose a challenge to ensuring food security in the future. The proportion of globally undernourished people halved between 1990 and 2015; falling from 23.3% in 1990–92 to 12.9% in 2015[9]. There were still around 800 million undernourished people in 2015, mostly in Asia and Africa. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Methods

Results

Conclusion