Pulling out rice seedlings for replanting in a rice field (north-east Thailand).

1The ability of human civilisation to handle the issues of climate change partly depends on the accuracy of the data concerning this change and the power of forecasting models. The IPCC Fifth Assessment Report is both more precise and more alarming than the previous ones in this respect. It also depends on the determination of decision makers to consult each other to set targets aimed at mitigating the effects of climate change, in particular by a drastic reduction of greenhouses gases, and to strengthen our measures for adapting to an inevitable change, even if there is still disagreement on the scale of the latter. But populations in the South have not waited for the decisions of experts to begin to adjust their subsistence strategies in response to changes that they can perceive and anticipate. These adjustments concern as much the maintaining of their sociocultural integrity as that of the natural ecosystems on which they depend on an everyday basis and with which they maintain progressive interactions. Considering local reactiveness is just as important as considering that of the international select few.

Mitigation, adaptation and resilience

2The perception now being confirmed of a break related to climate change has led to a change in the way of qualifying the necessary responses over the past 20 years. Mitigation was the dominant approach used to reduce the effects of warming until the end of the 2000s. Put forward by a community of scientists and experts devoted mainly to risk management and climatic disasters, mitigation consists of reducing the exposure and sensitivity of the system. A central theme of the successive IPCC reports, it is defined there as the human intervention necessary to reduce sources of greenhouse gases or increase carbon sinks, in other words to limit greenhouse gas emissions and store atmospheric carbon. Until recently, researchers and decision makers believed that mitigation would suffice to control the effects of climate change.

Street food vendor in Ho Chi Minh City (Vietnam).

3In the face of warming that seems inevitable today, ‘adaptation’ has become dominant progressively since the end of the 2000s. The taking into consideration of the capacity for systems and populations to adapt has been more the affair of researchers in social sciences. A large amount of literature has been published on the subject in economics, human geography, sociology and anthropology. Numerous studies address the adaptation capacity of rural populations in the South in relation to their environment. Here, pluriactivity and migration clearly show the complexity of the social responses used to handle environmental and social changes (population growth, political crises, rocketing foodstuff prices, drought, etc.).

4More recently, the efforts made by climate change specialists have been focused on synergy between mitigation and adaptation. In particular this means examining the ‘resilience’ of the system with regard to both its biophysical component and that concerning its human population. The popularity of the concept of resilience (defined as the capacity of a system to absorb disturbances or withstand changes without damage to its functions, structure, identity and functioning) thus leads to the perception of risk of failure. But the polysemy that marks this notion still makes operational use difficult. Proof of this is that it is used in very varied disciplines. The word ‘resilience’ comes from the physics of materials where it defines the quality of a body to conserve or return to its original form after deformation. The concept is also used in psychology to describe the capacity of a person to recover after being badly treated and in ecology to define the reconstitution capacity of an ecosystem after partial destruction by a natural or anthropic catastrophe. The term often has a positive connotation when applied to a society. It is not limited to reconstruction after a crisis but implies a capacity to overcome it and adapt to it.

5Applied to public development policies, the notion could begin to provide a response to situations of growing incertitude and vulnerability related to climatic events, economic crises, etc. IRD participates in reflection on the interest of resilience as a new standard to the evaluation of public policies.

Sociocultural adaptation, ecological adaptation: entwined developing processes

6The developing adaptation process is clearly revealed by the analytical framework of the ‘socio-ecological system’ defined by the international network Resilience Alliance as a set of dynamic interactions between biological and social factors, between populations, societies and the environment. These interactions are generic and applicable to all types of societies but are fully relevant for populations in the South whose subsistence mode still depends to a considerable extent on the resources provided by the natural environment.

Survey on the contribution of livestock farming to the resilience of ecosystems and social groups in Djougou, Benin.

7As societies with subsistence economies are fairly self-sufficient, their socio-ecological system can be seen as governed mainly by endogenous dynamics. However, the increasing effect of changes at the scale of the planet—including climate change—is tending to cause the situation to evolve significantly. The attractiveness of markets and consumer goods, public environmental policies, inter-ethnic relations, rural/urban interfaces, external economic stakeholders such as agro-industries, conservation and development agencies and NGOs, etc. are all ‘externalities’ that are weighing increasingly on locally drafted adaptive strategies. Analysis of the ‘box’ formed by these socio-ecological systems obviously assumes that increasing account is taken of what is happening ‘outside the box’.

Ecological resilience and social resilience

8The resilience of the socio-ecological system of a rural population in the South is only justified if it can ensure the sustainability of resources in parallel with that of the social system mobilised in their management. Figure 32 is a synthesis of the way in which the social and ecological components can interact in the face of climate change, independently of the broad range of subsistence strategies—farming, animal husbandry, hunting, fishing, gathering and so on—that is a feature of societies with subsistence economies. The ecological component is exposed to the effects of climate change and its sensitivity to these effects will damage the environmental services and resources that it provides. The social component developed a degree of vulnerability because of the degradation of the services rendered by the ecosystem (in food supply or water resources for example) and will have to adjust by developing adaptive responses to correct the effects of the change. In this context, the adaptive capacity of the population makes it possible to counterbalance the exposure of the ecosystem or adjust its sensitivity to the effects of climate change. This capacity is measured in a way in the potential of the society in question to maintain or possibly restore the services and resources provided by the ecosystem.

9The generally accepted idea about the socio-ecological systems of social groups or communities, especially in the South, whose subsistence and well-being depend mainly on the natural environment, is that ecological resilience and social resilience go together and must be maintained together. However, the work carried out in central Cameroon by IRD for two decades invalidates this idea and shows an interesting case in which forest peoples are obliged to counter-balance the natural dynamics of the ecotone to maintain the integrity of their social system (Box 60).

Figure 32. Exposure of a socio-ecological system to the effects of climate change.

Migration: adaptation or crisis?

10Population migrations are one of the foreseeable consequences of climate change, especially in tropical countries. But migration is not inevitable for these societies. Societies in the North tend to have an opinion of so-called ‘developing countries’ that is somewhat remote from reality. The populations concerned are far from being overdetermined by their environment and frozen in history that they have not understood.

Burning off at the edge of a forest before growing maize in the forest-savannah ecotone in central Cameroon.

11Migration is one of the responses of human societies to changes in their environment, whether these are brutal changes (natural catastrophe) or gradual (decreased resources). Seasonal or definitive and operating at all latitudes, this facility for mobility demonstrates adaptation capacity in case of changes. Except in cases of serious catastrophe, population displacement is the result of long and complex processes in which climate change is just one parameter among others. Conditions of access to resources (including land), farming systems and population growth are all factors, among other variables, to be taken into account in the interpretation of migrations.

Loading a lorry with migrant workers and goods in Niger.

12In addition, studies on regions where climate change has already had an impact on the living conditions of the population show that most migrations are stimulated primarily by socio-economic factors. Finally, migration is often chosen as much as imposed.

Mobility is as old as humanity

13Mobility goes with the type of occupation of the environment used by the last hunter-gatherers in the world and that was a feature of humanity as a whole before the advent of farming. The subsistence economy of hunter-gatherers is still closely linked to the natural resources available in the environment and mobility is essential for access to these resources that is continuous in space and time. While mobility is not a fatality for these nomadic peoples, the obligatory settlement that states try to impose on them is as painful as migration for gregarious societies forced to move by dramatic circumstances.

Climate refugees?

14With land flooded by the rise in sea level, natural catastrophes, wars and conflict for access to resources etc., climate change may cause the departure of millions of people from their regions, creating as many ‘climate refugees’. The term certainly makes sense when the effects of climate change are sudden and extreme, wiping out all local capacity to adjust to the suddenness and scale of the event. As researchers are cautious with regard to the links between certain extreme phenomena and global warming, the term ‘climate refugees’ should be used with caution and the use of ‘environment refugees’ preferred. Then if the areas affected occasionally or definitively by changes may be very varied, it is rare for changes to result in massive, rapid migrations across the frontiers of states. From this point of view, describing these migrants as ‘refugees’ is inappropriate with regard to international law.

A family displaced by drought in Kenya.

A woman in Funafuti (Tuvalu).

Vulnerability factors and adaptation strategies

15The climate risk is far from being expressed in a brutal, violent manner everywhere and it would be a mistake to reduce the consequences to environment refugees alone, however difficult the situation may be for the latter. As in the well-known boiling frog allegory—if a frog is placed in a recipient of very hot water it will jump out immediately. But if it is placed in water at room temperature that is then heated, the frog will not react to the progressive rise in temperature, will become drowsy and let itself be boiled to death—it is because climate change in a humid tropical forest environment is slow, progressive and not always very tangible that climate specialists have difficulty in make the general public and decision makers aware that it is urgent for us to get ready.

16Much research at IRD consists of analysis of vulnerability factors and the adaptation strategies of populations after serious social or environmental changes. These analyses are of crucial importance as they contribute to the setting up of public policies that can accompany the changes.

17Adaptation is thus an essential mechanism for the dynamics of societies. So why should it be a new challenge within the framework of climate change? Doubtless because of the scales involved and especially the speed of global climate change that is unprecedented in human history.