Re-Greening of the Sahel

Leader: Alessandra Giannini
Thursday, October 26

About the Readings

Changing Land Management Practices and Vegetation on the Central Plateau of Burkina Faso (1968-2002)
Reij, Tappan, and Belemvire, 2005, Journal of Arid Environments

Farmers, governments and NGOs started to experiment with improving soil and water conservation (SWC) techniques in the early 1980s in the northern part of the central plateau of Burkina Faso, following a series of drought years. This study looked at the impact of SWC investments in nine villages between 1968 and 2002 and identified a number of impacts, including: increased yields in millet and sorghum which means improved household food security; greater availability of forage for livestock; more cash available to invest in livestock; rising ground water tables; population growth; and decrease in rural poverty. Areas not treated with SWC techniques continue to degrade. In sum, the technological change in SWC in the early 1980s helped trigger a process of agricultural intensification.

Recent Trends in Vegetation Dynamics in the African Sahel and Their Relationship to Climate
Herrmann, Anyamba, and Tucker, 2005, Global Environmental Change

This paper looks at the pattern of and relationship between vegetation greenness and rainfall variability in the African Sahel. This study uses the Normalized Difference Vegetation Index (NDVI) as a proxy for vegetation greenness and gridded satellite precipitation estimates as a proxy for rainfall, and looks at data between 1982 and 2003. Overall, positive trends in NDVI indicate a net increase in biomass production between 1983-2003, challenging the notion of irreversible desertification in the Sahel. While rainfall is the dominant reason for the increase in vegetation greenness, the authors state there is evidence of another, human-caused change, though field studies are required in order to show causes at the local level. Human-induced factors include changes in land use, exploitation of natural resources, production strategies and conservation efforts.

Discussion Summary

The Droughts of the Sahel
The droughts in the Sahelian region in the late 1960s through the 1980s were unprecedented in their length and impact. Scientists hypothesized that the Sahelian droughts were caused by mismanagement of land resources (cutting trees, etc. that persisted drought and reduced precipitation). The correct explanation is that the droughts were caused by large-scale changes in sea surface temperatures. But to what extent can we attribute these effects to global climate changes, specifically to anthropogenic emissions?

Since the 1980s, there has been an increase in greenness over large areas of the Sahel, though not uniformly. It took a long time to recover from the droughts, so it is difficult to know what to attribute this greenness to – the global system or the local adaptation measures.

Climate projections are happening at the regional or global scale, while adaptation is at the local scale, rooted in immediate experiences. Climate needs to be part of the thinking within adaptation, but it is only one piece of the puzzle. Adaptation is a multi-disciplinary problem. For example, most projections for the southwest US talk about enduring drought, and communities are worried about water scarcity. Then this year, there were floods, and we were completely unprepared.

Adaptation is really up to local municipalities. Sometimes there is not local capacity because there is no legacy planning. Cities are cash strapped and don’t have money for everything. In polls, people care more about things like education and health than climate change.

There is also a question of how the communities themselves play a role in adaptation or how they understand it. Adaptation is an overwhelming concept for the general public. We don’t necessarily make it easy for them, nor are the communities included in planning and conversation. Climate services is one piece that tries to address this.

The Application of Science in Policy
What is the role of climate science? We have to understand the nature of the variability and trends in different locations and also have some sense of attribution. At the local scale, local variability doesn’t always mean something for adaptation in practice. There is then a question of how to reconcile local experiences and narratives with large scale trends. There are nuances in policy and law, and you don’t always have all the expertise that you need around the table.

By studying the climate, we can improve on our resilience. The information delivered to non-scientists should be slightly different. Policy makers often want to know what exactly is the technical adaptation. But there is enough uncertainty that we cannot prescribe something specific, though we keep telling people that we will someday know.

We need more dynamic policies and frameworks that can build resilience to the point that makes sense and allow people to better prepare.

Policy prescriptions are largely not changed by the nuances of the natural sciences predictions. Sometimes it is too overwhelming for policy makers to be given and asked to respond to so much data. But there are also two different policy streams: reactive policy and resiliency planning. We need more dynamic policies and frameworks that can allow people to better prepare and build resilience to the point that makes sense. There is also a question of who uses the science, and how it gets institutionally into the system, trickled to the local level responses.

Then we have structural policy – things like early warning and early action systems, that are based on vulnerable populations. These types of structural approaches to providing more security in a climate insecure future don’t necessarily need narrow projections. Donors are willing to give money for climate related actions and projects. How do you convince them that early warning systems are actually adaptation to climate change?

We don’t recognize some of the adaptation strategies that people have, including migration. There is a signal between drought and out-migration. Was out migration an issue in the 70s and 80s in the Sahel region? And are people going back?

In the case of Senegal, there was a lot of out-migration to Europe in the 70s and 80s. People in the northern Sahelian region of Senegal are less vulnerable to climate; they rely heavily on remittances. In the wetter southeast of Senegal, there was no intervention because they didn’t reach points of famine and migration. Adaptive capacity indicators are very low there; there are no roads, health centers, low education levels. People tend to not out-migrate because they are not used to it; as a result, vulnerability to climate is much higher.

Are climate change migrants treated differently from other migrants, and can we meaningfully separate them? The factors that affect refugees are all intertwined, and it is difficult to say with accuracy that someone is a climate refugee versus a political refugee, for example.

Click here for a full summary of the discussion.