Status: this preprint was under review for the journal ESD. A revision for further review has not been submitted.
Optimizing cropland cover for stable food production in Sub-Saharan Africa using simulated yield and Modern Portfolio Theory
P. Bodin,S. Olin,T. A. M. Pugh,and A. Arneth
Abstract. Food security can be defined as stable access to food of good nutritional quality. In Sub Saharan Africa access to food is strongly linked to local food production and the capacity to generate enough calories to sustain the local population. Therefore it is important in these regions to generate not only sufficiently high yields but also to reduce interannual variability in food production. Traditionally, climate impact simulation studies have focused on factors that underlie maximum productivity ignoring the variability in yield. By using Modern Portfolio Theory, a method stemming from economics, we here calculate optimum current and future crop selection that maintain current yield while minimizing variance, vs. maintaining variance while maximizing yield. Based on simulated yield using the LPJ-GUESS dynamic vegetation model, the results show that current cropland distribution for many crops is close to these optimum distributions. Even so, the optimizations displayed substantial potential to either increase food production and/or to decrease its variance regionally. Our approach can also be seen as a method to create future scenarios for the sown areas of crops in regions where local food production is important for food security.
Received: 14 Oct 2014 – Discussion started: 05 Dec 2014
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Food security is defined as stable access to food of good nutritional quality. In regions where food security is highly dependent on local production it is thus of importance to produce not only enough calories but also to minimize variation in yield. This trade-off is investigated here using simulated crop yield and by selecting relative distributions of crops. The results show a large potential to either increase food production or to decrease its variance by applying optimized crop selection.
Food security is defined as stable access to food of good nutritional quality. In regions where...