190
8
that this region will become drier, other models suggest that there may be more rain in
the Sahel in the future. However, Biasutti (2013) finds that most models conclude that
the rainy season will be ‘more feeble at its start’ and ‘more abundant at its core’. Hence,
the overall trend seems to be towards wetter conditions, but with rainfall more concentrated in time, with more variability, and with higher average temperatures. Of 20 models investigated by Biasutti (2013), only 4 are coming to other conclusions.
Moreover, Giannini (2016) discusses the causes of drought in the Sahel during
the late twentieth century reviewing the power of two competing explanations that
have been hotly debated. The first posits that human induced land degradation
increases the albedo effect from the land surface that again feeds back into the
regional climate. The second relies on the influence of the oceans and the monsoon
to explain rainfall variation and is therefore more connected to a global climatic
system. Giannini (2016: 281–82) concludes that ‘drought was caused by large-scale,
if subtle, shifts in oceanic temperatures, not by local anthropogenic pressure on the
environment’ thereby undermining the hypothesis about the albedo effect. Given this
conclusion, Giannini also opens up for the possibility that the droughts in the late
twentieth century have been influenced by global warming associated with emissions
of greenhouse gases.
The idea that deserts are spreading, either due to climate aridification or land-use
practices, has, however, existed since early in the colonial period (Davis 2016;
Benjaminsen and Hiernaux 2019). In the late nineteenth century and the first decades
of the twentieth century, desiccation was understood as the main driver of environmental change in the West African Sahel. However, from the 1930s, the desiccation
narrative, or what has been referred to as ‘desiccation theory’ (Davis 2016) was
replaced by a narrative focusing more explicitly on desert advance caused by local
mismanagement (Benjaminsen and Hiernaux 2019). Later, the droughts in the Sahel
of the 1970s and 1980s enhanced this desertification narrative and led to an institutionalization of desertification at different levels from the regional and national levels in the Sahel to the United Nations, which established desertification as a global
environmental problem. This happened despite the greening in the Sahel that has
taken place since the droughts in the 1980s.
Already early analyses of the trends after the drought using remote sensing technology indicated a fast recovery of the vegetation cover (Tucker et al. 1991). Further
research on better corrected data and longer time series confirmed the overall
greening in the Sahel (Olsson et al. 2005; Hutchinson et al. 2005; Herrmann et al.
2005; Fensholt et al. 2006; Dardel et al. 2014; Brandt et al. 2016). There are, however,
some local exceptions to the general greening, related either to continued loss of
vegetation on shallow soils as in parts of northern Mali or to expanding cropland as
in western Niger (Trichon et al. 2017; Tong et al. 2017).
Increased rainfall from the mid-1980s appears to have been the main driver of
the greening. During the period 2000–2014, woody cover in the Sahel in general
Chapter 8 · Climate Change, Scarcity and Conflicts in the Sahel
8
that this region will become drier, other models suggest that there may be more rain in
the Sahel in the future. However, Biasutti (2013) finds that most models conclude that
the rainy season will be ‘more feeble at its start’ and ‘more abundant at its core’. Hence,
the overall trend seems to be towards wetter conditions, but with rainfall more concentrated in time, with more variability, and with higher average temperatures. Of 20 models investigated by Biasutti (2013), only 4 are coming to other conclusions.
Moreover, Giannini (2016) discusses the causes of drought in the Sahel during
the late twentieth century reviewing the power of two competing explanations that
have been hotly debated. The first posits that human induced land degradation
increases the albedo effect from the land surface that again feeds back into the
regional climate. The second relies on the influence of the oceans and the monsoon
to explain rainfall variation and is therefore more connected to a global climatic
system. Giannini (2016: 281–82) concludes that ‘drought was caused by large-scale,
if subtle, shifts in oceanic temperatures, not by local anthropogenic pressure on the
environment’ thereby undermining the hypothesis about the albedo effect. Given this
conclusion, Giannini also opens up for the possibility that the droughts in the late
twentieth century have been influenced by global warming associated with emissions
of greenhouse gases.
The idea that deserts are spreading, either due to climate aridification or land-use
practices, has, however, existed since early in the colonial period (Davis 2016;
Benjaminsen and Hiernaux 2019). In the late nineteenth century and the first decades
of the twentieth century, desiccation was understood as the main driver of environmental change in the West African Sahel. However, from the 1930s, the desiccation
narrative, or what has been referred to as ‘desiccation theory’ (Davis 2016) was
replaced by a narrative focusing more explicitly on desert advance caused by local
mismanagement (Benjaminsen and Hiernaux 2019). Later, the droughts in the Sahel
of the 1970s and 1980s enhanced this desertification narrative and led to an institutionalization of desertification at different levels from the regional and national levels in the Sahel to the United Nations, which established desertification as a global
environmental problem. This happened despite the greening in the Sahel that has
taken place since the droughts in the 1980s.
Already early analyses of the trends after the drought using remote sensing technology indicated a fast recovery of the vegetation cover (Tucker et al. 1991). Further
research on better corrected data and longer time series confirmed the overall
greening in the Sahel (Olsson et al. 2005; Hutchinson et al. 2005; Herrmann et al.
2005; Fensholt et al. 2006; Dardel et al. 2014; Brandt et al. 2016). There are, however,
some local exceptions to the general greening, related either to continued loss of
vegetation on shallow soils as in parts of northern Mali or to expanding cropland as
in western Niger (Trichon et al. 2017; Tong et al. 2017).
Increased rainfall from the mid-1980s appears to have been the main driver of
the greening. During the period 2000–2014, woody cover in the Sahel in general
Chapter 8 · Climate Change, Scarcity and Conflicts in the Sahel