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Rural societies in the face of climatic and environmental changes in West Africa

 | 
Benjamin Sultan
, 
Richard Lalou
, 
Mouftaou Amadou Sanni
, 
et al.

Conclusion

Benjamin Sultan, Richard Lalou, Mouftaou Amadou Sanni, Amadou Oumarou et Mame Arame Soumaré

Texte intégral

New environmental opportunities

1After 30 years of drought in the whole of the Sahel, rains returned in the first decade of the 21st century. This is a particularly strong trend in the central part of the Sahel, although the humid conditions of 1950-1969 have not been reached, and less marked in the western Sahel where drought lasted longer until the end of the 2000s.

2In response to this return of rainfall, a regreening trend was observed in practically the whole of the Sahelian strip during the period 1981-2011. The resilience of vegetation concerns the herbaceous stratum in particular; this seems to have considerable recovery capacity, even after the droughts in the 1970s and 1980s. These field observations were made in particular in the agropastoral systems in the Gourma in Mali. Although their reappearance is less spectacular, the population of ligneous plants also seems to be in the process of regeneration after the recent increase in precipitation and the recharging of groundwater. These observations were made on the Faidherbia albida acacia population in Senegal.

Perceptions that tend to correspond to the ongoing changes

3Even if rural societies who very often know nothing about the notion of climate change do not perceive or interpret current climate change in the same terms as those of scientists, they see—in Senegal, Benin and Niger—the recent change in the average climate and its annual variations, as observed by climatologists. This matching of local social perception and scientific observations of the climate is particularly good when climate changes are rapid, can be seen by everybody and they have an impact on ways of life and production volumes. Rural people in Senegal make a clear distinction between the environmental situation of some 20 years ago when drought was a stress factor and the present conditions in which farmers no longer perceive the climate as a major constraint, thanks to the return of rain and in spite of its interannual variation. In contrast, in northern Benin where the scientific reality of climatic changes is much less marked farmers’ perception differs markedly from observations—in one direction or the other.

Cultural and adaptive innovations

4While crop and livestock farmers clearly perceive changes in the climate they also adapt very rapidly, displaying considerable capacity for reaction and spontaneous adaptation. Particularly clear examples have been found in Senegal. In both the Niakhar observation zone (in the centre of the Senegalese groundnut production zone) where long cycle (110-120 days) Sanio millet has been reintroduced and spread throughout the Sine after disappearing nearly 30 years ago, and in the Senegal River Valley where sowing periods have been adjusted, changes in farming practices have been observed that have direct links with recent changes in the climate and with no intervention by researchers or development stakeholders. The Escape project has thus shown that a shortage of economic and technical resources did not mean that family farming was incapable of adapting. Even without investment, this category of farming innovates according to its resources and for cropping performances that enable farmers at least to live and stay on their land.

5The innovations currently used in West African farming types and that give them dynamism are not either only or mainly responses to the variability of climates and natural resources. On a more overall and deeper basis, small family agriculture adapts to the major economic, demographic and political evolutions that change the features of its territory. Whether focused on crop farming or animal husbandry, whether they are near the coast, in the Sahel or in forest, rural societies and then their socioeconomic organisation and farming system adapt and change continuously. Among other things, innovations include the emergence or generalisation of new commercial crops and production, such as cashew nuts and soya in Benin, watermelons, cattle fattening and horticulture in Senegal and potatoes in Niger. These changes are also accompanied by new agricultural practices, with modified farming calendars (sowing date and crop rotations) and ever-broader diversification of extra-agricultural activities: crafts, trade and handling work according to the increasing needs of towns. It is true that not all these innovations are direct responses to climate change but they are certainly sources of income that help to reduce the vulnerability of farms, especially in the face of the climate. Here, they help to strengthen the capacity of small family farming to withstand climatic disturbances.

Migration: one component of a self-adaptive system

6Seasonal long-term migration of rural people in Sahelian Africa is often considered to be a response to worsening features of the environment and the climate. All the studies focused on this question after the major droughts of the 1970s and 1980s have shown that these ecological crises have caused an increase in domestic (rather than international), circular and short-term migration, especially in the poorest families and for women and children. We have found the same migratory pattern in Niger and above all Senegal in the recent climatic context marked by alternating extreme contrary events (droughts and then floods), with the drought years being marked by an increase in seasonal migration, especially of young people and women. Here, widespread migration is an adaptive, reactive response which takes shape from a threshold defined by strongly degraded farming conditions. However, even in this situation migration cannot be considered as the failure of self-adaptation. At all the sites that we studied, migrants maintain an economic link with their families that remain in the village; they participate directly or indirectly in food security and sometimes facilitate the development of new activities on the original farm (transfers of financial, material and technological resources).

7Although migration is linked with climatic conditions, it does not stop during years of rain and good harvests. On the contrary, the source villages maintain a continuous flow of migrants to ensure the cash requirements of families and individuals who usually consume a large proportion of their farm production. Large numbers of adult men migrate during the dry season to accumulate money for the survival of their households or for productive investments. But young people (girls and boys) attending schools also migrate during the rainy season to fund their education or to make up a dowry. Finally, migration—even disconnected from the climate factor—contributes to keeping rural households on the land as they are less strongly dependent on farming. This is the case in the groundnut zone where, among other factors, the crisis in the groundnut sector and advanced soil degradation have resulted in comparative regression in agriculture to the benefit of the non-agricultural sector—driven by trade, crafts, transport, migration, etc. These also favour the reduction of poverty (and especially food poverty) on farms in the process of decapitalisation. Finally, they make it possible—with no credit available—to earn the extra-farm income required for farms in the capitalisation phase. In short, when migration is strongest it responds to climatic and environmental shocks, but in return also tends to reduce the vulnerability of the people who stayed in the villages and to enhance agricultural innovation. Here, like a retroaction loop, migration thus increases to varying degrees according to the context the capacity of farms to adapt to climate change.

New climate risks

8After experiencing the historical droughts of the 1970s and 1980s, the Sahel is now wetter and greener and ecosystems and the populations know how to benefit from the new situation. But although this book rightly shows the rapid resilience of natural and anthropic systems and the great adaptaion capacity of the population, the overall picture cannot be edited. The Sahel is not to become accustomed to a new climate but must face up to an extremely changing one.

9Indeed, although the recovery of rainfall has been observed clearly in the Sahel, detailed analysis of the hydrological cycle in the region shows that the increase in annual annual rainfall depth is accompanied by a continued decrease in the number of days of rain and hence an increase in violent events (very strong storms). The situation is typical of a strongly variable climate with an intensitifaction of the precipitation regime with alternating hydrological extremes such as droughts and floods rather than being an indication of a return to the former humid conditions that prevailed in the 1950s. As has been noted, dry years are not a thing of the past. The Sahel has experienced at least four major food crises at the beginning of the 21st century—in 2003, 2005, 2010 and 2012. Except for the 2007-2008 crisis caused mainly by the excessive volatility of world foodstuff prices, food crisis periods result from problems of availability caused by droughts. At the same time, floods with strong socioeconomic impacts are much more frequent that in previous decades. Local situations featuring the flooding of fields, strong winds that lodge crops, rapid rises in water levels in low-lying land that submerge crops and decimate flocks and herds, soil eroded and/or runoff have become in addition to droughts regular catastrophes that crop and livestock farmers have to face.

10Although the recent increase in rainfall that allows somewhat more abundant vegetation and the recurrence of violent rainfall events are the most visible signs of climate change, West African farmers consider that they are accompanied by the warming of the surface of Africa since the 1950s, a phenomenon that is much less clearly perceived but nonetheless undoubted. The hottest periods of the year are those most affected, and especially the spring when steadily increasing temperatures are 2°C higher than they were 60 years ago. The amplification of the annual temperature cycle consists mainly of an increase in night temperatures, with daytime temperatures remaining stable. The causes of this have not yet been established. In spite of the fact that temperature is central to the study of water and energy balances and that warming is found in all climate change scenarios, reaching + 2 °C to + 4 °C at the end of the century, it has been the subject of many fewer studies than precipitation.

11But it is nonetheless a new constraint that African farmers may face in the future, with a negative effect on crop yields, livestock and cultivable areas as soon as the + 2°C threshold has been reached. A joint study by IIASA and FAO considers that the area that can be used for cereal crops in West Africa will decrease by 7 to 15%, depending on the temperature rise scenario considered (+ 1 to + 3oC) (Fischer et al., 2002). The temperature increase in the mid-21st century—of more than 3°C in certain places—is so great that there will soon be no equivalent in the African climate in recent history. Although this warming is already visible in climate observations, it is nonetheless less well perceived by the rural populations questioned as heat is omnipresent in rural zones and the harmful effects on agricultural production and health has not yet been felt clearly. Without perception of the changes, it thus seems difficult to develop adaptation strategies, especially as the climate in Africa in the decades to come will be totally new in human memory in terms of temperature, with warming whose speed and intensity could exceed the adaptation capacity of African populations.

Lasting constraints and vulnerabilities

12Demographic data is of prime importance in development and the environment. Strong population growth exerts strong pressure on the natural resources of the continent and weighs heavily on economic growth, in particular because of the very high rate of dependence. A study by Ndulu (2006) thus shows that three-quarters of the overall negative gap between the per capita growth rate in sub-Saharan Africa and that in other developing countries from 1960 to 2004 is accounted for by demographic factors.

13Demographic growth in Africa is the greatest of all the continents and the gap with the rest of the world is still becoming wider. As the groups of childbearing age will continue to form a large fraction of the population and because of the inertia of demographic phenomena, population growth will remain high and the age pyramid will remain young for several decades to come. According to the mean hypothesis of the United Nations, the population of Africa will have doubled by 2050, reaching 2 thousand million, that is to say 22% of the world population, and 27% will be less than 15 years old (United Nations, 2009). Although the rural African population is in a downward phase, the numbers will continue to grow until 2050, increasing from 592 million in 2007 to 764 million en 2050. Africa will account for 27% of the world’s rural population in the mid-21st century (United Nations, 2008).

14This original demographic movement obviously has effects on African economic development and in particular the development of agriculture. Today, farmers in the southern Sahara use about 200 million hectares of land (Roudart, 2010). However, the continuous degradation of cultivated land and the growth of the agricultural population can only cause a rapid extension of farmland. For reasons of poverty, the great majority of West African farmers are unable to acquire farming techniques likely to increase soil productivity and their only choice is often that of using the land until it is no longer suitable for farming or to gain new farmland in forest and prairie areas (as in Niger and Benin). When land reserves have been exhausted, as is the case in the part of Senegal studied, the natural growth of the number of farming households results in the rapid division of fields and a considerable decrease in the area of agricultural land owned. Overall, in many parts of West Africa, landholding pressure, excessive or unsuitable agricultural activities, intensification—often poorly managed—to meet the food requirements of a growing population and repeated droughts (or violent precipitations) trigger soil degradation and erosion processes, surface crust and runoff, loss of fertility and a decrease in crop productivity. African farmers rarely have the capacity to make an effective, sustainable response to these challenges and constraints.

Environmental changes and adaptation strategies analysed at the local scale

15Characterising the evolution under the effect of human activities, the climate and the environment in the coming decades and envisaging effective adaptation options for the rural world are made all the more difficult by the great regional disparity in environmental changes. Although a tendency for regreening after the return of precipitations has been shown, especially in the agropastoral ecosystems of the Malian part of the Gourma, there is also proof of the degradation of ecosystems in the Sahel. This is the case in the Fakara region in Niger where fallows are less productive than they were 20 years ago and where surface soil erosion, a decrease in plant cover and an increase in runoff coefficients are markers of a degraded environment. In addition, the clear contrasts in climate evolution in the Sahel make analysis of trends and projections at large scales complex overall. For example, the warming observed in West Africa for 60 years is not homogeneous; it is stronger in the Sahel than in the Sudanian and Guinean regions. The return of rainfall is more visible in the central Sahel but seems to be later in the western part where the drought has lasted longer. Furthermore, the climate scenarios maintain this contrast between the western Sahel, where precipitation is considered to be decreasing, in particular with the lateness of the monsoon season in comparison with the current period, and the central Sahel that is considered to be receiving more rainfall at the end of the winter season. The contrast in rainfall trends between the western and central Sahel is not seen in temperatures. On the contrary, these show warming on a latitudinal gradient between the northern regions of the Sahel, with more warming, and those of the south. These regional disparities create different degrees of vulnerability in West Africa, where it would seem that the western part could be more affected by droughts, the northern part threatened by strong warming and the central part exposed to increased risk of violent rainfall and flooding. All this increases the complexity of what scientists say about the evolution of the climate and the environment in the region and about the ways to adapt.

16Likewise, adaptations are often only designed at local or territorial scales giving the responses contributed by societies a very variable or even heterogeneous character. Both adaptation and adaptation capacity depend on the context in which they take shape. They vary not only according to the level of economic and technological development of the territory but also according to social norms and cultural values. However, adaptation scales are not totally independent either. The capacity of a household to face climate risks results to a certain extent from a favourable community environment, and the community’s adaptation capacity is a reflection of the resources and processes used by the region or country. Adaptations thus vary from one country to another, from one community to another, between individuals and social groups and according to the passing of time. Adaptation is neither easily reproducible in all socio-spatial contexts nor necessarily constant in time, making it more difficult to plan on a large scale.

The advantage of the interdisciplinary approach and observations over long periods

17Through the interdisciplinary mobilisation that it triggered, the Escape project has been an ideal framework for starting true dialogue between the scientific communities. This is focused on a common aim defined by the climate and environmental changes in West Africa. Indeed, the relations between humans and their environment are set in complex economic, social and political configurations that must be examined and related to climate and environmental phenomena using an interdisciplinary approach. The latter is crucial for addressing the question of adaptation to environmental changes where the response of societies is set in global social changes. There is a real need for a diversity of viewpoints, for sharing and comparing approaches centred on the question of environmental changes. Bridging gaps between different communities often takes longer than applying a single scientific discipline; joint subjects for study, a shared language and fields in which the different disciplines involved must be defined. The first step has been taken with the implementation of this interdisciplinary study centred on the same investigation. This investigation must now be continued and the sustainability of the approaches maintained beyond the Escape project. But these are actions to be conducted over a long period, that is to say under conditions that are often not very compatible with the logic of projects and publications that is a feature of the way in which research operates.

18Furthermore, the results described here show that the challenges resulting from the complexity of relations between humans and their environment in a context of climate change cannot be gathered without long-term observations of the climate-society system. The continuity of meteorological and sociological observations is very important for detecting changes in progress, understanding the causes and anticipating the consequences in order to develop strategies for reducing the possibly harmful effects of these changes.

19The monitoring facilities focused on populations in Niakhar, on the environment (Amma-Catch) in Niger and Benin and on agro-ecosystems in the Fakara in Niger are a very good example of this. Finally, the great disparities observed not only in the evolution of the climate and also in ongoing societal changes in West Africa underline the importance of conducting multi-site and multi-scale comparative approaches, placing in parallel the regions with contrasted environmental and socioeconomic constraints.

Research to be carried out on anticipatory adaptation

20A few lines on future research are needed before concluding. Our work has strongly addressed spontaneous, reactive adaptation. Reflection remains to be conducted in anticipatory adaptation—frequently promoted by politicians and scientists for its ability to reduce the social, economic and ecological costs of change. In agriculture, possessing effective tools for the management of climate risks can bring true value-added to the adaptation strategies of African populations faced with the issues of food security, population growth and climate change and that can directly affect political balance. But these tools are still used little or not at all by farmers in spite of the proofs assembled by research programmes on their acute awareness of the climate risk, on the potential of climate information in planning and decision making and on recent progress in forecasting climate fluctuations (beginning of the rains, dry sequences) days or even months ahead. The many reasons for this contradiction include lack of knowledge about matching the procedures for the use of the information generated and farmers’ requirements (scales of space and time, forecasting period, degree of confidence), about the most effective technical or organisational responses to climate fluctuations (changing farming calendars, making use of water, diversification of work, financial instruments such as loans and insurance for example) and about the way farmers can incorporate and appropriate these risk management tools developed by research in their own practices. In addition, this planned adaptation takes place at public authority level and at territorial scale; decision makers who can have access to the climate information produced by scientists are thus involved. Although the approach must take into account the uncertainty inherent in climate forecasts, it assumes nonetheless a clear perception of the uncertainty, the risk and the conditions that will change. In addition, this adaptation must be detailed and reflection carried out on its limits according to different farming systems and climate evolution scenarios in the west, centre and north of the Sahel in order to avoid any maladaptation and to integrate it in an overall agricultural development strategy for the region.

Bibliographie

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