Global food demand and the sustainable intensification of agriculture cover image

Resource information

Date of publication: 
October 2011
Resource Language: 
ISBN / Resource ID: 
DOI10.1073/pnas.1116437108
Pages: 
5
License of the resource: 

Global food demand is increasing rapidly, as are the environmental impacts of agricultural expansion. Here, we project global demand for crop production in 2050 and evaluate the environmental impacts of alternative ways that this demand might be met. We find that per capita demand for crops, when measured as caloric or protein content of all crops combined, has been a similarly increasing function of per capita real income since 1960. This relationship forecasts a 100–110% increase in global crop demand from 2005 to 2050. Quantitative assessments show that the environmental impacts of meeting this demand depend on how global agriculture expands. If current trends of greater agricultural intensification in richer nations and greater land clearing (extensification) in poorer nations were to continue, ∼1 billion ha of land would be cleared globally by 2050, with CO2-C equivalent greenhouse gas emissions reaching ∼3 Gt y−1 and N use ∼250 Mt y−1 by then. In contrast, if 2050 crop demand was met by moderate intensification focused on existing croplands of underyielding nations, adaptation and transfer of high-yielding technologies to these croplands, and global technological improvements, our analyses forecast land clearing of only ∼0.2 billion ha, greenhouse gas emissions of ∼1 Gt y−1, and global N use of ∼225 Mt y−1. Efficient management practices could substantially lower nitrogen use. Attainment of high yields on existing croplands of underyielding nations is of great importance if global crop demand is to be met with minimal environmental impacts.

Authors and Publishers

Author(s), editor(s), contributor(s): 
David Tilman Christian Balzer Jason Hill Belinda L. Beforta
Publisher(s): 

PNAS is one of the world's most-cited and comprehensive multidisciplinary scientific journals, publishing more than 3,800 research papers annually. Established in 1914, PNAS publishes cutting-edge research, science news, Commentaries, Reviews, Perspectives, Colloquium Papers, and actions of the National Academy of Sciences.

The journal's content spans the biological, physical, and social sciences and is global in scope. Nearly half of all accepted papers come from authors outside the United States.

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