Food Insecurity in Africa - Scenarios For The 21st Century

David. S. Battisti (Department of Atmospheric Sciences, University of Washington) and Rosamond L. Naylor (Program on Food Security and the Environment, Stanford University) published a very interesting report called "Historical Warnings of Future Food Insecurity with Unprecedented Seasonal Heat" in January 2009 (Link).

In the report they published a figure in which they show the "likelihood (in percent) that future summer average temperatures will exceed the highest summer temperature observed on record (A) for 2050 and (B) for 2090".

Battisti and Naylor state that extreme seasonal heat will have a massive negative impact on regional agricultural productivity. As seen in the figure especially areas in the tropics and subtropics have a chance higher then 90% that future summer average temperatures exceed the highest summer temperature observed on record by 2090. At the moment about 3 billion people live in these areas and many depend primarily on agriculture to sustain their livelihood. Battisti and Naylor claim that higher temperatures will have an immediate impact on the agricultural productivity and lead to a highly insecure situation for the local and world population.
Experiments undertaken in the question how much influence the change will have, lead to results between 2.5 to 16% yield loss for every 1°C increase in seasonal temperature.
They also state that beside the higher summer temperatures also the drying of the subtropical areas (which is seen as likely by the IPCC) might lower the agricultural productivity, as well as the sea level rise and decreased soil moisture.

Battisti and Naylor conclude:
"If growing season temperatures by the end of the 21st century remain chronically high and greatly exceed the hottest temperature on record throughout the much of the world [...] then global food security will be severely jeopardized unless large adaptation investments are made."

Another articles underlining the general views of Battisti and Naylor is "Agriculture and food systems in sub-Saharan Africa in a 4°C+ world" by Philip K. Thornton, Peter G. Jones, Polly J. Ericksen and Andrew J. Challinor. This article was published in 2010 (Link).

This article approaches the problem from a slightly different angle and sees the temperature increase as the "perhaps [...] most significant and most urgent challenge for the adaptation of crops to global change."

An article published in 2011 by Christoph Müller, Wolfgang Cramer, William L. Hare and Hermann Lotze-Campen (Link) with the title: "Climate change risks for African agriculture" is focuses on the same topic, but leaves the reader with a slightly different impression:

"The overall picture may seem diffuse and unsuited for clear conclusions: following the IPCC confidence rating guideline [...], there is very high confidence that climate change will negatively affect
at least parts of African agriculture (14 of 14 studies), while simultaneously, there is also high confidence that African agriculture will be partly affected positively by climate change (12 of 14).
As there are so many climatic and nonclimatic aspects that determine agricultural productivity that are mainly not considered in these studies, there is only low confidence in what the overall impact of climate change on African agriculture will be. Despite all uncertainty in climate change and impact projections and incomplete coverage, there are already robust conclusions for policy makers and research agendas. There is broad consensus among the studies that all African agriculture runs some risk to be negatively affected by climate change, i.e., no one is on the safe side."


In the next weeks I will continue to show different effects of the Global Environmental Change on the human population. So make sure to check back for new posts!