Our Research Assessing climate vulnerability of West African food security using remote sensing observations

Sub-Saharan Africa (SSA) food security is vulnerable due to a number of unique and co-existing factors: 1) food production is mostly rain-fed, 2) the rainy season is only three months long and has large interannual variability in the timing of its onset and intensity, 3) the population growth in the region is among the highest in the world and, unlike other regions, projected to only increase in the coming decades. These factors combine to create one of the most challenging food security problems in the world.

The food security problem in West Africa is sensitive to variability in the seasonal onset, duration and intensity of the rainy season. In this project the research team asks:

1. How do crop yields in West Africa respond to year-to-year variations in rainy season timing and intensity?
2. How will West African crop yields shift in response to climate change?
3. What management interventions can mitigate the impacts of climate change on yields?

In order to address the first question, reliable data on historical crop yields and historical precipitation are required. The climate record for the West Africa Monsoon (WAM) are available (Nicholson, 2013), but crop production records virtually do not exist. The first task is to produce a multidecadal map of crop yields across West Africa using observations from space-borne remote sensing instruments. The new crop maps that span several decades, when juxtaposed against the large year-to-year variations in the WAM, enables the research team to quantify the vulnerability of the Sub-Saharan Africa food production system to climate variability. This addresses the first question.

For the second question, the team is using climate model projections of shifts in the West Africa Monsoon to assess changes to the SSA food security. They are using a robust technique to analyze the reliable and resolved fields in climate models (Whittleston et al., 2017). The multi-model estimates of the shifts in the West Africa Monsoon for the remainder of the 21st Century will be used in conjunction with the quantified climate-vulnerability to assess the future of food security in Sub-Saharan Africa in the coming decades.

For the third question, the team is using the climate model projections developed in 2) to force a crop model. They are varying management practices in the crop model such as irrigation and fertilizer application to assess the extent to which changes in management can offset climate change impacts on yield.