Predicting climate hotspots to alleviate hunger

Laxenburg, Austria – 3 February 2009. A new study on the impact of climate change on crop yield and undernutrition in Sub-Saharan Africa (SSA), has identified regional ‘hotspots’ where early intervention using adaptive measures may avert future hunger and improve food security.

The study indicates that while some regions may be able to withstand the most severe impacts of climate change, most SSA countries will continue to experience a decline in per capita food availability. Thus it is critically important that adaptation strategies be developed and implemented soon, particularly in the area of improved crop selection, extending crop area and increasing yield through improved water and fertilizer management. 

The hotspots of future food insecurity are identified in the context of global social (population), economic (GDP) and bio-physical (precipitation, temperature, CO₂ concentration, and crop production) changes, by comparing two periods: the 1990s and 2030s. The study provides a more detailed regional assessment than previous studies and paints a clearer picture of potential changes at a finer scale, potentially helping to identify priority areas to combat hunger.  

“To date, most research has focused on undernutrition in SSA at a national level,” says Dr. Junguo Liu from the Swiss Federal Institute of Aquatic Science and Technology, Switzerland.

“We evaluate it with a spatial resolution of 30 arc-minutes (about 50 x 50 km in each grid cell nearby the equator). This means we can ‘zoom-in’ to a local area and pinpoint ‘hotspots’ where the greatest challenges are likely to exist. We’ve checked over 3,500 non-urban districts to improve the accuracy of undernutrition assessment across SSA.”

While wheat yields in traditional wheat growing regions in SSA are projected to decrease by 16-18% by the 2030s, this loss may be offset by higher yields from crops like millet, rice or cassava, which may benefit from the climatic conditions in 2030. The study suggests that countries such as Mauritania, Congo, Gabon, Botswana, Swaziland, Zimbabwe, Angola, Mozambique and Sudan may suffer from lower crop yields, while countries such as Uganda, South Africa and Ghana may experience increased yields.  

“The study also suggests that regions located in southwestern Niger, Nigeria and Sudan will be able to import more food and might therefore reduce food insecurity,” says Dr Liu. “While countries such as Tanzania, Mozambique and the Democratic Republic of Congo are predicted to face more serious undernutrition in the future, as both the capacity to import food and the per capita calorie availability are predicted to decline.”

In contrast to previous studies, this study does not suggest an overall decrease in crop yields in SSA. This is largely accounted for by the incorporation of atmospheric CO₂ in the analysis, which can have a fertilization effect on crops. Furthermore, climate change may benefit crop production in SSA in the short-term, but may not in the long-term. Ongoing research is considering potential impacts to 2100.

“The most important conclusion from this study is that, although overall crop yields may not decline, due to the projected increase in population and stagnating purchasing power, hunger will remain or even worsen if no drastic adaptation measures are taken,” says Dr. Steffen Fritz, Forestry Program, from the International Institute for Applied Systems Analysis, Austria.

“Hunger knows no boundaries or borders, and global change is likely to exacerbate food insecurity in what is already a vulnerable region. It is important that adaptation strategies be developed and implemented soon to avert future hunger. This type of research may assist in the targeting of support for countries as they develop strategies to adapt to climate change and improve global food security,” concludes Dr. Fritz.

The research, published in the recent Special Issue of Global and Planetary Change, is co-authored by researchers at:

• Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland;
• International Institute for Applied Systems Analysis, Austria;
• Centre for World Food Studies, University Amsterdam, The Netherlands;
• Bundesanstalt für Geowissenschaften und Rohstoffe, Germany;
• International Food Policy Research Institute, USA.

The study was supported by the European Commission within the GEO-BENE project framework.

Changes of per capita calorie availability from the 1990s to the 2030s in relation to population density of the 2030s and low degree of subsistence agriculture. For change of per capita calorie availability,  the legend 0-0.25 means a reduction of 100 -75 percent, 0.25-0.5 means a reduction of 75-50 percent, 0.75 -1 means a reduction between 25 and 0 percent, and more than one means that per capita calorie availability will increase between the 1990s and the 2030s. [high resolution]

Changes in per capita GDP from the 1990s to the 2030s in relation to projected population density in the 2030s. A positive percentage in the legend indicates a higher growth rate of GDP than the world average growth rate between the 1990s and the 2030s. For instance, the value of 50% means the growth rate of GDP is 50% higher than the world average growth rate (i.e. 3.6%), or it means the growth rate of GDP is 5.4%. A negative percentage in the legend indicates a lower growth rate of GDP than the world average growth rate between the 1990s and the 2030s. For instance, the value of -30% means the growth rate of GDP is 30% lower than the world average growth rate, or it means the growth rate of GDP is 2.52%. [high resolution]

Number of people with current undernutrition problems in relation to future potential hotspots of food insecurity in the 2030s. [high resolution]

Further reading:

Global and Planetary Change
Volume 64, Issue 3-4, December 2008, Pages 222-235

A spatially explicit assessment of current and future hotspots of hunger in Sub-Saharan Africa in the context of global change
J. Liu, S. Fritz, C.F.A. van Wesenbeeck, M. Fuchs, L. You, M. Obersteiner, H. Yang

Read about IIASA's research on food security and climate change challenges for Sub-Saharan Africa:

• Climate change and agriculture in Africa
• The Challenges of Climate Change in Sub-Saharan Africa

For interviews contact:
Leane Regan, IIASA
Tel: +43 2236 807 316 or +43 664 443 0368

Steffen Fritz , IIASA
Tel: +43-2236 807 353

Junguo Liu Eawag, Switzerland
Tel: +41 4482 350 12

About IIASA:
IIASA is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policy makers to shape the future of our changing world.

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Last updated: 06 Aug 2009