Africa and water; disorder in the form of food insecurity

 Precipitation changes due to Climate change

Fig 2 Source: 

Fig 1 Source: IPCCAR4 2007 Fig 11.1 

(2080-2099 relative to 1980-1990)

The IPCC 2007 report suggested that climate change will lead warming of between 3-4C over this this century. However, the effects of climate change in terms of precipitation are predicted to differ across Africa as shown in Fig 2, which suggest there will be wetter futures in the humid tropics and drier futures in semiarid regions. It must be noted that significant variability exist in the modelling and is displayed more so for the Sahel region where the observation of rainfall in the past few decades doesn't correlate with the results from the modelling for the present and future level of rainfall (Hulme et al 2001)

 Intensification of precipitation

Fig 3 Allen et al (2010) 

Allan and Soden (2008) suggest that there will be fewer low and medium intensity precipitation events and more extreme events of very heavy precipitation. They point out that the effect of atmospheric warming on the increases of extreme rainfall is underpredicted when models are compared to observation.  In order words, they predict there will be larger variability in precipitation in the future.

Allen et al (2010) (fig 3) showed that current changes in the tropical precipitation regime are inline with future projections – there have been more heavy precipitation (shown by >70 percentile) and  less light precipitation (shown by <60 percentile) (fig 3). This is a course for concern as below will demonstrate.  

Effects of change in precipitation on crop yield

Fig 5: Top A, Bottom B Source(Challinor et al 2006).

Drawing from examples in India figure 5A and 5B. It shows explicitly show how increase variability in rainfall reduces crop yield. In both figures, the total rainfall is around 390mm, with 5A at 394mm and 5B at 389mm. However, the level of rainfall in 5A is more spread out with less variability and in 5B the contrary is true. There yield is 1369kg/Ha and 901 kg/ha respectively (Challinor et al 2006). Cooper et al (2008) found similar results in Kenya, where maize productivity deceased due to higher within season variability of rainfall. Additionally, very intense rainfall, hail and drought would also damage crops and reduces yields, which could become more common as our climate changes with more variability and more extreme weather events (Requejo et al 2011).

Effects of changes in precipitation on water scarcity

Fig 4 source: Showing the number of people living in watershed with an increasing water stress by region in 2055, with different amounts of global temperature change relative to 1961-1990. Changes in temperature and rainfall derived from HadCM3 

What would this mean in terms of water stress/scarcity under a background of projected population growth in Africa (and around the world) and in some cases falling precipitation? Currently, 62.1% of Africa’s population still live in rural area and with an urban growth rate of nearly 4% per year (UNEP). Since urban population consume more water it is really a concern for the future, and perhaps a source of conflict.  

Fig 4 shows the projected number of people under water stress using different climate scenario. These are worrying projections, showing the number affected could reach from just 40 to 350 million. They also show varying degrees of impact between regions. Interestingly, the increase in the number of people under water stress in Central Africa only starts to increase steeply after a 1 degree increase (Arnell 2006)

Rise of disorder: Case study of 2007-08 riots 

Map 1 Source: Source Berazneva and Lee 2011

90% of staple food production will continue to come from rain-fed farming systems, the effects of a more variable rainfall regime will be a major concern for the future Cooper et al (2008). The 5th IPCC plenary session in Geneva to “[b]y 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%, as a consequence of climate variability and change”. A report by World Food Programme places emphasized on the role of price hikes as a contributor to societal disorder within countries. Although the linkages between food insecurity and interstate conflict are thought with uncertainties  (Brinkman and Hendrix 2011). . Drawing from the 2007-2008 riots, we could understand how future increases in food prices (via decreased food yield due to climate change) could lead to wide spread societal disorder in Africa.

During the 2007-2008 food protest and riots occurred in 48 countries  (Brinkman and Hendrix 2011, BBC 2008,Berazneva and Lee 2011). In Africa, riots occurred in at least 14 countries. As Map 1 shows, not all places incurred societal disorder which highlights the complexity of the contributing factors of food riots and I only explained the environmental factor in detail in the context of Africa (there are many other factors but the topic is too large to cover in my blog).As Nelson et al (2009) points out, climate change will lead to increasing food prices and price volatility for staple crops like rice, wheat, maize and soybeans. So which countries will be most vulnerable to societal disorder in the future? Looking at the 2007-08 riots, Berazneva and Lee (2011) findings showed those countries with higher levels of human poverty and less political freedom are more prone to rioting. Additionally, countries with cities over 1 million people are estimated to be 24-25x greater to experience riots. This was the case for 11/13 countries that experienced rioting. This is a worrying statistic since urbanization is increasing dramatically in Africa, coupled with increasing water stress in most places in Africa, this would certainly contribute to the ‘risk factors’ of food rioting/revolution.  

The future of crop yield and potential for rise of disorder  

Fig 6 Source

Could more rioting occur in Africa in the future?  Calzadilla et al (2013) results showed that under climate change, production of agriculture products in the Sub-Saharan Africa increase (Wheat, Oil seeds) and all the other decreases (fig4). More importantly, it indicates increases in domestic food price, from 3% to more than 7% (fig4).This could recreate the food rioting episode from 2007-08. However, it is important to note that the effects of price increase will not be homogeneous across Sub-Saharan Africa (Brinkman and Hendrix 2011).  Exploring the effects of future agriculture yield from a world perspective, we could see that from Wheeler and Braun (2013)(Map 2) their projections for 2050’s decrease in crop productivity coincides with regions that have problems with hunger as shown in map 3, measured by the global hunger index. Their study also showed that yields of major crops grown in Africa and South Asia will decline by 8% by 2050. Wheat and Maize are expected to decline by 17% and 5% respective in Africa. While in Asia maize and sorghum is expected to decline by 16% and 11% respectively.  Although there are limitations with modelling, Knox et al (2012) have high confidence that the data for the above crop productivity are significant and robust! These crop yield decreases coupled with rising prices could lead to more episode of food rioting seen in 2007-08 and even

Map 3 Source

Map 2 Source 

One of the main limitation of Wheeler and Braun (2013) paper is that there modelling doesn't account for changes in the productivity of grazing land and hence the effects of cattle. Since meat is vital for both food supply and some economies, it could further reveal how increase meat prices could affect for both LDC and more importantly MDC. Would increases in meat prices cause similar effects as seen with increases in stable crops? Could it fuel more rioting and contribute to revolutionary riots?

More importantly, looking at Map 2 the Middle East is also vulnerable to decreased crop yields. Currently, they are using their wealth from natural resources to import  and subsidies many of their staple food productions. This could be a future source of societal disorder when their resources run out and they couldn't support their subsidization of their agricultural economy (Brinkman and Hendrix 2011). Much similar to Japan’s scraping of their agricultural subsidies for their rice farming (FT 2013). In the future more dire consequences would occur in the Middle East.

My opinion 

What I presented above is the mechanism between decreased crop yield (via climate change) and the rise of food rioting in the future. Drawing from current riots I showed the factors that contributed to the vulnerability of rioting.Coupled with model simulation of future crop yield decrease, and hence the rise of prices (via the mechanism of supple and demand). I believe I presented a strong case that some countries in Africa WILL be vulnerable in the next 50 years, whiles other countries in Africa and Middle East with natural resource wealth are likely to be able to combat higher food prices via welfare benefits, keeping their citizen happy. This won't be sustainable and it is only a short term method of prevention. Coupled with the overwheling fact that Africa still heavily relys on rain-fed agricultural systems, the picture for Africa is even more bleak.