**6. Temporal variations in adaptation actions and drivers of adaptation in the Sahel**

The decade 2008–2016 recorded a total of 270 or 65.2% adaptation actions which represent the highest number of adaptation actions in the Sahel. The subsequent decades witnessed adaptation actions as follows: 1997–2007: (n = 58, 14%); 1986–1996: (n = 29, 7%); 1975–1985: (n = 57, 13.7%). In summary, we end up having a total of 414 adaptation actions which is like the total number of adaptation actions (**Figure 7a**). It can be observed that there has been an increase in the number of adaptation actions over the decades. A review of the drivers shows that most of the adaptation actions are anchored on climatic factors. The climatic drivers recorded 406, or 98% while the non-climatic drivers recorded 395 or 95% (**Figure 7b**). Though the climatic drivers are dominant, an interesting observation is the increase prominence of non-climatic drivers. Some potential climatic drivers include increase precipitation, decreasing precipitation, temperature increase, temperature decline, sea surface temperature changes, trade winds, El Niño, increase solar radiation, atmospheric circulation, and the prevalence of winds/sandstorms like the equatorial westerlies. Non-climatic drivers of adaptation cited in the literature encompass agriculture, population growth, settlements, poor urban planning, pastoralism, and cattle rearing, over exploitation of resources, grazing of animals, deforestation and land degradation, wildfires, insects, economic fluctuations and socio-political.

In the Sahel, some adaptation actions have gained prominence over time. Income diversification which is the highest used adaptation action recorded a frequency of 21 during the decade 1985–1996. Th decade 2008–2016; also recorded 18 adaptation actions. Here also, water harnessing actions were dominant during the decade 1985– 1996 in which they recorded a frequency of 27. The decade 2008–2016, witnessed 15 adaptation actions. On the other hand, soil conservation related actions recorded their highest frequency during the decade 1985–1996. Migration had a frequency of

#### **Figure 7.**

*(a) Variations in adaptation action in various decades in the Sahel. (b) Climatic and non-climatic drivers of adaptation actions in the Sahel.*

8 and this was during the decade 2008–2016. High yielding varieties also recorded a frequency of 13 adaptation actions during the decade 2008–2016. Generally, during the decade1975–1985, two adaptation actions were most frequently used. These included *income diversification* and *migrations*. Help from *kin* and *network* such as friends and family options were second (**Figure 8**). The decade 1985–1996 also had as the most important adaptation option *water harnessing* related options with a frequency of 27; soil conservation recorded the second with a frequency of 19 while income diversification was third with a frequency of 18 (**Figure 8**). During the decade 1997–2007, *income diversification* led with the highest frequency of 8 while more *farm inputs* came second with a frequency of 6 and migration recorded a frequency of 3 (**Figure 8**). During the decade 2008–2016, *income diversification* was still the most used adaptation option with a frequency of 21; water harnessing came second with a frequency of 15 while high yielding varieties were third with a frequency of 13 (**Figure 8**).

*Recent Climate Change Adaptation Strategies in the Sahel: A Critical Review DOI: http://dx.doi.org/10.5772/intechopen.100110*

#### **Figure 8.**

*Composite distribution of variations in different adaptation options reported in the peer review literature published over time for various countries of the Sahel.*

### **7. Discussion**

Climate change adaptation is currently receiving a lot of global attention as governments, NGOs, International organizations, civil society groups inter alia are now placing climate change adaptation as a priority on their political and environmental agenda [94, 95]. Even though we have agreed that climate change adaptation is vital in establishing resilience in the Sahel, stakeholders are still in disagreement with

respect to what approach climate change adaptation actions represent [96, 97]. This chapter attempts at improving our understanding of the regional and country level adaptation actions in the Sahel as well as their drivers and evolution through several decades. The approach used in this study is similar to those used by Ford et al. [30, 98]. Systematic reviews enhance the ability to compare how adaptation is taking place across the Sahel [30, 98, 99]. The results from this study should therefore be considered as proxies for the level of adaptation in the Sahel as they are based on what exist in the scientific literature and therefore provide a baseline.

These findings can be weakened by the fact that several adaptation actions in the Sahel might be beyond the scope covered by this current study. For example, this work does not consider the gray literature and studies beyond 2020. However, the fact that this study covers a time frame that goes beyond 40 years makes these results valid. The decade 1975–1985 recorded the highest number of adaptation actions while the decade 1985–1996 recorded fewer adaptation actions. The surge in adaptation actions recorded during the decade 1975–1985 can be attributed to the surge in climate change shocks in the form of droughts that dominated this decade [43, 48]. These shocks triggered a lot of actions from governments, international and non-governmental organizations to enhance adaptations [7, 46]. From 1985, the droughts that affected the Sahel had reduced and so did the number of adaptation actions due to 'adaptation fatigue' of the previous decade. The adaptation actions of the 1970s and 1980s have already produced positive results in the Sahel. Recent studies show that the Sahel has become greener with a parallel increase in precipitation. Normalized difference vegetation index (NDVI) and precipitation across the Sahel show a strong correlation between NDVI and greening [3, 53, 100, 101]. Prince et al. [23] has argued that the increase precipitation and greening recorded in the Sahel can be attributed to rising aerial fertilization effect of carbon dioxide. The decades 1997–2007 and 2008–2016 recorded 14% and 65.2% adaptations, respectively. These decades are consistent with an increase in the number of adaptation initiatives over time. It is difficult to argue that the climate change adaptations reported in this study are mainly driven by the adaptation initiatives presented in the peer review literature. In addition, with a total of 414 discrete adaptation actions reported in this study, it remains clear that the level of adaptation is still relatively low in the Sahel. Regionally, West African Sahel dominates in terms of adaptation actions. However, in term of countries, Kenya in East Africa records the highest frequency of 18.1%. According to Ford et al. [95], during the period 2006–2012, Kenya recorded a total of 34 adaptation actions and thus was the highest in terms of adaptation actions from a set of African and Asian countries. The fact that West African Sahel has a higher adaptation rate from a regional perspective can be linked to the "Great Green Wall of the Sahara and the Sahel initiative" (GGWSSI) [102].

The finding that income diversification is the most used adaptation action in the Sahel is consistent with other previous studies that report that to better reduce the effects of climate shocks in the Sahel, it is important to resort to a diversification of livelihoods [103, 104]. Water management actions on the other hand which are second in terms of use are vital as the regions keeps facing recurrent droughts and therefore there is an urgent need for adaptation actions to remedy the situation. With respect to the broad categories of adaptation, technically based adaptations are dominant. This in other words shows that adaptation actions anchored on science and technology are those that are mostly reported in the scientific literature. This is without doubts as the response of technical field experts in the Sahel is often in the form of technically based solutions at the expense of indigenous knowledge, economic based and socially based actions. Examples of these technically based actions are drought resistant species, rainwater harvesting and high yielding varieties.

#### *Recent Climate Change Adaptation Strategies in the Sahel: A Critical Review DOI: http://dx.doi.org/10.5772/intechopen.100110*

In terms of policy, it has become evident that income diversification and water harnessing actions have gained prominence over time. This provides an opportunity to further leverage these actions and to investigate how other actions can be further enhanced to improve adaptations. The fact that technically based adaptation actions are more frequently reported shows that policies that enhance both technically based adaptations and others that are less cited should be leveraged in other to enhance the level of adaptation actions in the Sahel. It is important to emphasize the fact that no single adaptation action can single handedly revamp the adaptation landscape in the Sahel because several actions indeed work together better. Those that have been ignored this far need to be researched into to verify what the indigenous people think about them before concrete suggestions are made.

Most of the studies presented here showed that most of the adaptations are driven by climatic variables. However, we also observe an increase attribution of the drivers to non-climatic drivers. Non-climatic drivers are becoming increasingly vital as there are many cases when adaptations are not just taken to adapt to climate change but also in response to other issues such as health, poverty, literacy, and socio-cultural disparities that affect adaptive capacities [95, 96]. The evidence across Africa and the Sahel shows that the problems that Africa and the Sahel are facing ranging from food crisis, deforestation, water scarcity, pandemics and epidemics are mainly caused by non-climatic variables such as deforestation, population movements, wars, and land degradation inter alia with climate change only playing a reinforcing role [1, 3–5].

These results tend to be similar and different from some previous studies based on results and methodology. A study by Ford et al. [95] researched into the status of climate change adaptation in Africa and Asia based on a systematic approach and showed that Kenya had the highest number of adaptation actions. When compared with other vulnerable regions, as the Arctic, there are more reports of adaptation actions in the Sahel. Also, another study by, Ford et al. [30], reported about 157 adaptation actions between 2003 and 2013 while this current study reports 414 adaptation actions for the Sahel for the period 1975–2020. The major areas of differences are that the Ford et al. [95] study focused on both peer review and gray literature while this chapter is based on peer review literature. The Ford et al. study is based on Africa and Asia and covers studies published from 2006 while this current study is based on the Sahel and covers studies from 1975 to 2020. Also, Berrang-Ford et al. [97] used the systematic approach and focused on the peer review literature only, an approach like that adopted by this current study. The results from the latter are also consistent with this in that they report that considerable research has been done with a greater focus on intentions than groundwork. Also, non-climatic drivers are increasingly being presented as the drivers of climate change adaptation [38].
