Environmental degradation is primarily a result of the dynamic interplay between economic, political and social processes or failures. Some causes of environmental degradation include habitat fragmentation (when urban or rural development breaks up solid stretches of land); water and air pollution (contaminants that damage or kill animal and plant species); and rapid human population growth, which adversely affects natural resources and the environment. There are at least two major components to environmental degradation and its implications - those related to human activities, and those related to natural systems (particularly natural hazards such as cyclones, floods, and earthquakes). A lot is known about environmental degradation as a research field and similarly, a great deal is known about migration. Environmentally-induced migration, however, still needs a commonly accepted definition.

According to the United Nations (UN) Office of Humanitarian Affairs (OCHA) and the Internal Displacement Monitoring Centre, the worldwide population boom and reduced economic opportunity in rural areas are major factors that have brought about the largest worldwide migration in recent history.(2) This paper discusses an emerging phenomenon that has been evidenced across the globe, more particularly on the African continent. It attempts to find a working definition of the concept ‘environmentally-induced migration' while introducing the reader to the occurrence of this phenomenon - based upon selected case studies in Africa. By highlighting human movement as a core component of the human development agenda, it is hoped that the following insights will add value to the ongoing discourse on environmental migration.

Human movement in Africa's ecological context

Migration can be broadly defined as a social process of geographical movements by individuals or groups for the purpose of changing residence. People move in order to improve their ‘quality of life'. They leave their known and trusted environment to relocate to places where they can earn more money or grow more food, and where the social environment is better than in their original place of residence.(3) The reason for migration is therefore intertwined with the economical, ecological or social aspects of people's lives.

For many people in Africa's developing countries, moving away from their hometown or village can be the best - sometimes the only - feasible option for improving their life chances with regard to their physical health and economic well-being. Much conventional analysis of migration centres on the effect of movement on the well-being of people. In other words, the absence of formal restrictions on the movement of people across or within borders does not in itself make people free to move if they lack the economic resources, security and networks necessary to enjoy a comparatively better life in their new home. Neither are they free to move if informal constraints such as discrimination significantly impede the prospects of moving successfully - i.e. improving their living conditions.

Consider the case of people who have to relocate because of the threat of political discrimination or degraded environmental conditions such as drought, lack of arable land, or flooding. In these cases, external circumstances have made it more difficult, perhaps impossible, for them to remain at their former residence. These circumstances restrict the scope of their lifestyle choices, and in the process inhibit their freedom of choosing where to live. This induced movement may very well coincide with a further deterioration in their living conditions, but this does not mean that the movement is the cause of that deterioration. In fact, if they were not able to move, the outcome would probably have been much worse.

The environment can be a key driver of human movement from nomadic pastoralists who follow the favourable grazing conditions that arise after rain, to people displaced by natural disasters such as the Indian Ocean tsunami and Hurricane Katrina. Environmental conditions have been intimately linked to movements of people and communities throughout human history. Some are now expecting that the continuing warming of the earth will generate massive population shifts.

Environmental migration is often referred to as a change of residence due to resource scarcity and/or natural disasters.(4) Environmental adversity acts as the pushing factor that motivates people to relocate. However, the phenomenon is intangible and, as mentioned, there seems to be no agreed international definition of ‘environmental migration.' Attempts to find this definition can be made by asking the following questions: To which kind of migration does environmental degradation lead? Internally displaced persons or international migrants? How big is the problem? Where are the people going to? Are there any regional differences?

Since climate change and environmental factors are closely interlinked with others determinants such as economic, ecological and social factors, environmentally-induced migration is difficult to capture and delimit. Furthermore, the slow deterioration of the environment is often not felt directly, but is manifested by a change of livelihoods and the interaction with other economic and social factors. Due to this slow deterioration, environmentally-induced migration is hardly ever triggered by a single tipping point but rather by a series and combination of ‘push and pull' factors.

Push factors, those factors that influence the decision to migrate, include local economic decline, unequal land distribution, land degradation, and a lack of access to a resource such as water. Pull factors include employment opportunities, access to healthcare, urban convenience, and higher incomes. In general, people are attached to their original place of living and would prefer not to move. Improving the livelihoods in the respective countries of origin could therefore offer a chance and more opportunity (to stay) for those having to migrate and also offer an important strategy of survival for those who cannot afford to move due to poverty.

The urban manifestation of environmental migration in Africa

During a study that was carried out on migration patterns in Nairobi, Kenya, (5) people who moved were classified as ‘environmental migrants' if they mentioned at least one environmentally related issue as a reason for their migration. The main environmental reasons cited were droughts and floods.(6) A spatial pattern was found where droughts were mainly mentioned by people from the south-eastern region and floods by those from the western region in Kenya.(7) Lastly, statistically significant changes in temperature and rainfall levels from 1960 ‐ 1989 and 1990 ‐ 2008 have been associated with an increased number of environmental migrants since 1990.(8) Other environmentally related issues cited by rural-urban migrants in Kenya were crop failures, natural disasters, lack of wood for cooking, land degradation, and inadequate access to safe drinking water.

In Senegal, due to soil salinity as well as the lack and overuse of fertiliser, the soil's fertility in the so-called Peanut Basin is poor. Farmers have to live on one - if any - agricultural season per year.(9) As such, the region experiences strong emigration. In the River Valley region, irrigated agriculture is possible in some zones but farmers face difficulties in accessing land and in paying the fees for the use of irrigation infrastructure.(10) Due to dam construction and the new irrigation system, several problems have occurred. These include inundations, lack of flooding, soil salinisation,(11) and water pollution due to fertiliser and pesticides.(12) Out- as well as in-migration can be noted, the latter mostly by seasonal workers.

In Egypt, current environmental problems that have been linked to migration include land degradation, water shortage, water salinity, and water pollution.(13) Historical problems such as soil scrapping, and the development project at the Aswan High Dam, must also be taken into consideration when gauging the occurrence of environmental migration in the area. In a similar study done in some areas of Egypt, it was concluded that water shortage due to the increasing population, as well as soil degradation in the Nile Valley, is a cause for migration only if the migrants are hired in the land.(14) People who were surveyed said that they would be leaving their home and moving to another place only if there are absolutely no more livelihood possibilities for them. Furthermore, people would move only if they can financially afford migrating to another region/country, and/or if there are other social and economic reasons that would motivate them other than desertification.(15)

Migration has long been part of life in the dry reaches of West Africa, but in recent years, with economic development taking place elsewhere and erratic rains making rural life increasingly difficult, more and more people are taking to the road. The figures are inexact, but about 20% of those born in northern Ghana are now thought to live in the richer, more urbanised south.(16) In Nandom, the administrative centre for more than 50,000 people - chiefly farmers - in one of the poorest corners of Ghana, the human movement numbers are relatively high: half the population has migrated to cities.(17) People from the town offer varying reasons for the exodus - lack of jobs, enticing "greener pastures", deteriorating climate - but they agree that this migration cannot go on indefinitely or Nandom will never prosper.(18)

Existing estimates indicate that several developing areas will be strongly affected by climate change, although the range of estimates is still very wide and predictions are subject to considerable uncertainty. At one extreme, it is expected that by 2020 the yields from rain-fed agriculture in southern Africa could be halved by drought.(19) Regrettably, there is little hard science backing these numbers. For the most part, they represent the number of people exposed to the risk of major climatic events and do not take into account the adaptation measures that individuals, communities and Governments may undertake.(20) It is thus difficult to know whether such inevitably crude estimates facilitate or obstruct reasoned public debate.

According to Britain's 2006 Stern Review, estimates of the number of environmental refugees in 2050 is between 200 and 250 million, or around 10 times the number of refugees and internally displaced persons in the world today.(21) The numbers are enormous, the scenarios abstract. The Stern Review puts the total number of displaced people from small island states like the Maldives at 1 million.(22) The other 249 million (23) will come from places more like Nandom or rural areas such as Kenya's western province: poor, agricultural societies that have existed for a long time in marginal climates, with little room for error, but are now struggling to support themselves. It is here that the real numbers - the tens of millions of potential migrants - lie and yet it is also where the future is hard to read, where there is still hope, and where climate change is often taking place in among other profound transformations, such as economic development, rapid population growth or political upheaval.

Towards an understanding of emerging challenges

Climate change is projected (expected to) to increase environmental stress in already marginal lands and to raise the frequency of natural hazards. Continued greenhouse-gas (GHG) emissions are likely to be associated with changes in rainfall patterns, desertification, more frequent storms, and rises in sea level, all of which have implications for human movement.(24) Changing rainfall patterns, for example, will affect the availability of water and hence the production of food, possibly increasing food prices and the risk of famine. However, not every migration case under adverse climatic conditions should be considered as ‘environmental migration'. For instance, nomads from Kenya's arid northern region migrate as part of their pastoral livelihoods; this behaviour should be understood as part of community tradition.(25)

The effect of climate change on human settlement depends partly on how that change comes about - as discrete events or as a continuous process. Discrete events often come suddenly and dramatically, forcing people to move quickly to more secure places. Continuous processes, on the other hand, are associated with slow-onset changes like sea-level rise, salinisation or erosion of agricultural lands, and growing water scarcity.(26) In many cases, continuous change leads communities to develop their own adaptation strategies, of which migration - whether seasonal or permanent - may be only one component. Under these conditions, movement typically results in income diversification by the household, with some household members leaving and others staying behind.(27) This pattern has been observed, for example, among Ethiopian households hit by severe and recurrent droughts between 1990 and 2001.(28)

Given the uncertainty as to whether climate change will occur through a continuous process or discrete events, the extent and type of the resulting adaptation and movement are difficult to predict. Moreover, environmental factors are not the sole determinants of movement, but interact with livelihood opportunities and public policy responses. It is often the case that natural disasters do not lead to out-migration of the most vulnerable groups, because the poorest usually do not have the means to move and natural disasters further impair their ability to do so. More fundamentally, what will happen in the future is affected by the way we consume and use our natural resources today.

Concluding remarks

A working definition of environmentally-induced migration put forth by the International Organisation for Migration (IOM) states that "environmental migrants are persons or groups of persons who, for compelling reasons of sudden or progressive change in the environment that adversely affects their lives or living conditions, are obliged to leave their habitual homes, or choose to do so, either temporarily or permanently, and who move either within their country or abroad."(29)

Even though there is currently a debate about the formal definition of ‘environmental migration', the phenomenon is by no means negligible. It is thus crucial to reconsider the factors that may lead to environmental migration, which in turn could lead to further environmental problems - thereby creating a vicious cycle of people relocating from one area to another and potentially bringing about further environmental degradation in their new place of residence.

Research on environmental migration should be carried out in a trans- and interdisciplinary way. At the same time, a legal framework needs to be developed, and environmental protection as an international obligation must be addressed in a more effective way. Furthermore, migration should be discussed at the adaptation dialogues of climate-change conventions, since migration may sometimes be a part of the adaptation to environmental change - although it more often is rather the failure to adapt.

The poorest of the poor are almost always unable to migrate and many may not want to leave their current place of residence because of family and social ties. Furthermore, many people lack the migration networks that would support a move away. This suggests that we may be facing different policy questions in the future. Instead of "How many migrants would relocate?", we might well be facing the question of "How do we deal with the increasing number of humanitarian crises as a result of global change?". Further recommendations on how to address the problem of environmentally-induced migration also include: providing training in processing and food-transformation techniques as well as in sustainable agricultural practices, strengthening farmers' self-organisation, providing other income opportunities, promoting equitable access to water and land resources, and supporting regional economic integration.

Written by: Angela Kariuki (1)

NOTES:

(1) Contact Angela Kariuki through Consultancy Africa Intelligence's Eyes on Africa Unit,
(eyesonafrica@consultancyafrica.com).
(2) UN OCHA and IDMC, Mass Migration as a result of Environmental Changes, http://www.internal-displacement.org, 2010.
(3) Cliggett, L., 2001. Social Components of Migration: Experiences from Southern Province, Zambia. Human Organisations, 59(1), p. 283.
(4) Kinuthia-Njenga, C. & Blanco, P.L., 2009, Climate Change and Migration in Nairobi, 5th Urban Research Symposium: Cities and Climate Change: Responding to an Urgent Agenda, Marseille, France, pp. 9-16.
(5) Ibid., p.9.
(6) Ibid., p.11.
(7) Ibid., p.13.
(8) Ibid.
(9) UN OCHA and IDMC, Op. Cit.
(10) Ibid.
(11) Salinisation is generally defined as the build-up of salts in soil - exacerbated by ill-planned irrigation schemes.
(12) UN OCHA and IDMC, Op. Cit.
(13) Agriculture and Industry Survey, "Environmental Migration in Africa", 8 September 2009, http://www.agricultureinformation.com.
(14) Ibid.
(15) Ibid.
(16) Agriculture and Industry Survey, "Mass Migration as a result of Environmental Changes", 8 September 2009, http://www.agricultureinformation.com.
(17) Ibid.
(18) Ibid.
(19) S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Avery, M. Tignor, and H. L. Miller (Eds.), 2007, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press.
(20) Barnett, J. and M. Webber. 2009. "Accommodating Migration to Promote Adaptation to Climate Change". Melbourne:
Commission on Climate Change and Development, University of Melbourne.
(21) Stern, Sir Nicolas, (2006) Stern Review on the Economics of Climate Change, HM Treasury.
(22) Ibid.
(23) Ibid.
(24) Barnett and Webber, 2009. Op. Cit.
(25) Stark, O.,1991. The Migration of Labour. Cambridge: Basil Blackwell.
(26) UNDP, 2007, Human Development Report 2007/2008: Fighting Climate Change: Human Solidarity in a Divided World. New York: Palgrave Macmillan.
(27) Stark, O., Op. Cit.
(28) Ezra, M. and G. E. Kiros. 2001. Rural Out-Migration in the Drought Prone Areas of Ethiopia: A Multilevel Analysis. International Migration Review 35 (3), pp. 749-771.
(29) IOM, 2007. IOM Website: http://www.iom.int.