PNAS – Proceedings of the National Academy of Sciences of the United States of America
http://www.pnas.org/content/early/
(Accessed 2 January 2016)
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Biological Sciences – Sustainability Science:
Drivers of household food availability in sub-Saharan Africa based on big data from small farms
Romain Frelat, Santiago Lopez-Ridaura, Ken E. Giller, Mario Herrero, Sabine Douxchamps, Agnes Andersson Djurfeldt, Olaf Erenstein, Ben Henderson, Menale Kassie, Birthe K. Paul, Cyrille Rigolot,
Randall S. Ritzema, Daniel Rodriguez, Piet J. A. van Asten, and Mark T. van Wijk
PNAS 2015 ; published ahead of print December 28, 2015, doi:10.1073/pnas.1518384112
Significance
We collated a unique dataset covering land use and production data of more than 13,000 smallholder farm households in 93 sites in 17 countries across sub-Saharan Africa. The study quantifies the importance of off-farm income and market conditions across sites differing strongly in agroecology and derives generally applicable threshold values that determine whether farm households have enough food available to feed their families. These results show there is a strong need for multisectoral policy harmonization and incentives and improved interconnectedness of people to urban centers and diversification of employment sources, rather than a singular focus on agricultural development of smallholder farmers in sub-Saharan Africa.
Abstract
We calculated a simple indicator of food availability using data from 93 sites in 17 countries across contrasted agroecologies in sub-Saharan Africa (>13,000 farm households) and analyzed the drivers of variations in food availability. Crop production was the major source of energy, contributing 60% of food availability. The off-farm income contribution to food availability ranged from 12% for households without enough food available (18% of the total sample) to 27% for the 58% of households with sufficient food available. Using only three explanatory variables (household size, number of livestock, and land area), we were able to predict correctly the agricultural determined status of food availability for 72% of the households, but the relationships were strongly influenced by the degree of market access. Our analyses suggest that targeting poverty through improving market access and off-farm opportunities is a better strategy to increase food security than focusing on agricultural production and closing yield gaps. This calls for multisectoral policy harmonization, incentives, and diversification of employment sources rather than a singular focus on agricultural development. Recognizing and understanding diversity among smallholder farm households in sub-Saharan Africa is key for the design of policies that aim to improve food security.
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Social Sciences – Anthropology:
Climate challenges, vulnerabilities, and food security
Margaret C. Nelson, Scott E. Ingram, Andrew J. Dugmore, Richard Streeter, Matthew A. Peeples, Thomas H. McGovern, Michelle Hegmon, Jette Arneborg, Keith W. Kintigh, Seth Brewington, Katherine A. Spielmann, Ian A. Simpson, Colleen Strawhacker, Laura E. L. Comeau,
Andrea Torvinen, Christian K. Madsen, George Hambrecht, and Konrad Smiarowski
PNAS 2015 ; published ahead of print December 28, 2015, doi:10.1073/pnas.1506494113
Significance
Climate-induced disasters are impacting human well-being in ever-increasing ways. Disaster research and management recognize and emphasize the need to reduce vulnerabilities, although extant policy is not in line with this realization. This paper assesses the extent to which vulnerability to food shortage, as a result of social, demographic, and resource conditions at times of climatic challenge, correlates with subsequent declines in social and food security. Extreme climate challenges are identified in the prehispanic US Southwest and historic Norse occupations of the North Atlantic Islands. Cases with such different environmental, climatic, demographic, and cultural and social traditions allow us to demonstrate a consistent relationship between vulnerability and consequent social and food security conditions, applicable in multiple contexts.
Abstract
This paper identifies rare climate challenges in the long-term history of seven areas, three in the subpolar North Atlantic Islands and four in the arid-to-semiarid deserts of the US Southwest. For each case, the vulnerability to food shortage before the climate challenge is quantified based on eight variables encompassing both environmental and social domains. These data are used to evaluate the relationship between the “weight” of vulnerability before a climate challenge and the nature of social change and food security following a challenge. The outcome of this work is directly applicable to debates about disaster management policy.