Natural Hazards

, Volume 55, Issue 3, pp 689–715 | Cite as

Climate change, environmental degradation and migration

  • K. Warner
  • M. Hamza
  • A. Oliver-Smith
  • F. Renaud
  • A. Julca


Climate change will have a progressively increasing impact on environmental degradation and environmentally dependent socio-economic systems with potential to cause substantial population displacement. The key concerns in Less Developed Countries (LDCs) will include serious threats to food security and health, considerable economic decline, inundation of coastal areas, and degradation of land and fresh water resources (Reuveny in Polit Geogr, 2007). The relationship between environmental change and potential humanitarian crises has been captured by: McGregor (Geography and refugees: patterns and processes of change, Belhaven Press, London, pp 159–70, 1993), Kibreab (Environment and Population Change, International Union for the Scientific Study of Population, Liège, 1994), Kibreab (Disasters 21(1):20–38, 1997), Myers (Bioscience 43:752–761, 1993), Myers and Kent (Environmental exodus: an emergent crisis in the global arena, Climate Institute, Washington, DC, 1995), Black (New Issues in Refugee Research, Working Paper no. 34, 2001), Lee (Environmental matters: conflict, refugees and international relations, World Human Development Institute Press, Seoul and Tokyo, 2001), Castles (Environmental Change and Induced Migration: Making Sense of the Debate Working Paper No. 70, 2002), Christian Aid (Human tide: the real migration crisis, Christian Aid, London, 2007), and Massey et al. (, 2007). However, we know little about the interplay between environmental change and stresses on ecological systems, resulting socio-economic vulnerability and potential outcomes in terms of population displacement or induced migration. So far these relationships are poorly conceptualized, lack systematic investigation, and are reduced to simplistic causal explanations. This leads to misleading conclusions that deny the complex multivariate processes—environmental, political, social, and economic— which are the root causes of environmentally induced migration and/or conflict. When people are faced with severe environmental degradation they have one of three options: (1) stay and adapt to mitigate the effects; (2) stay, do nothing and accept a lower quality of life; or (3) leave the affected area. The process of movement and migration is usually subject to a complex set of push and pull forces, where push forces relate to the source area while pull factors relate to the destination. These forces are in constant flux, as much as environmental change, and interact with socio-economic and political conditions including state or government decision making powers, which can tip the balance at any point by either denying movement or the right to settle elsewhere. The paper focuses on how environmental change and environmental hazards contribute to the migration by exploring the mechanisms through which vulnerability and migration are linked—via livelihoods, relocation policies, and other factors. The paper begins by outlining important definitions of what is environmentally induced migration. The paper also considers the question of whether migration is a process that reduces or increases vulnerability. The paper draws on multidisciplinary literature including ecology, environment, and climate change; sociology of migration; anthropology of displacement; and economics; but also on preliminary from various case studies in Egypt, Vietnam, and Mozambique.


Forced migration Environmental degradation Adaptation Displacement Remittances Resettlement Egypt Mozambique Vietnam 


  1. Adams RH Jr (2006) International remittances and the household: analysis and review of global evidence. J Afr Econ 15(Supplement 2):396–425. doi: 10.1093/jafeco/ejl028 CrossRefGoogle Scholar
  2. Adger WN, Kelly PM, Nguyen HN (2001) Environment, society and precipitous change. In: Adger WN, Kelly PM, Nguyen HN (eds) Living with environmental change: social vulnerability, adaptation and resilience in Vietnam. Routledge, LondonGoogle Scholar
  3. Adger WN, Paavola J, Huq S, Mace MJ (2006) Fairness in adaptation to climate change. The MIT Press, CambridgeGoogle Scholar
  4. Adger WN, Agrawala S, Mirza MMQ, Conde C, O’Brien K, Pulhin J, Pulwarty R, Smit B, Takahashi K (2007) Assessment of adaptation practices, options, constraints and capacity. In: Parry ML, Canziani F, Palutikof JP, van der Linden PJ, Hanson CE (eds) Climate change 2007: impacts, adaptation and vulnerability. Contribution of working group II to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge, UK, pp 717–743Google Scholar
  5. Afifi T (2009) Egyptian water and soil: a cause for migration and security threats? URL:, water scarcity, land degradation and desertification in the Mediterranean Region. URL:, NATO science for peace and security series C: environmental security. Springer Netherlands, pp 131–141. doi: 10.1007/978-90-481-2526-5
  6. Almeria Statement (1994) The Almeria statement on desertification and migration. Statement following the international symposium on desertification and migrations, Almeria, 8–11 FebruaryGoogle Scholar
  7. Arab Center for the Studies of Arid Zones and Dry Lands (ACSAD) (2000) Regional report on desertification in the Arab world. ASCAD technical report. ASCAD, DamascusGoogle Scholar
  8. Bates DC (2002) Environmental refugees? Classifying human migrations caused by environmental change. Popul Environ 23(5):465–477. doi: 10.1023/A:1015186001919 CrossRefGoogle Scholar
  9. Black R (1998) Refugees, environment and development. Addison Wesley Longman Limited, New YorkGoogle Scholar
  10. Black R (2001) Environmental refugees: myth or reality? In: new issues in refugee research, working paper no. 34 Geneva: United Nations High Commissioner for RefugeesGoogle Scholar
  11. Castles S (2002) Environmental change and induced migration: making sense of the debate working paper no. 70 Geneva: United Nations High Commissioner for RefugeesGoogle Scholar
  12. Cernea MM, McDowell C (2000) Risk and reconstruction: experiences of settlers and refugees. The World Bank, Washington DCGoogle Scholar
  13. Christian Aid (2007) Human tide: the real migration crisis. Christian Aid, LondonGoogle Scholar
  14. Conisbee M, Simms A (2003) Environmental refugees. The case for recognition. New Economics Foundation, LondonGoogle Scholar
  15. CRED (2008) EM-DAT: emergency events database. Available at
  16. Dasgupta S, Laplante B, Meisner C, Wheeler D, and Yan J (2007) The impact of sea level rise on developing countries: a comparative analysis. World Bank policy research working paper 4136 (WPS4136), World Bank, WashingtonGoogle Scholar
  17. Desert Research Center (2002) Egyptian ministry of agriculture and land reclamation, United Nations convention to combat desertification. 2002. Egyptian national action program to combat desertification, April 2002, CairoGoogle Scholar
  18. Dun O (2009) Linkages between flooding, migration and resettlement. Case study report on Vietnam for the environmental change and forced migration scenarios project, Available at
  19. de Wet C (2005) Risk, complexity and local initiative in involuntary resettlement outcomes. In: Wet De (ed) Towards improving outcomes in development induced involuntary resettlement projects. Oxford and New York, Berghahn BooksGoogle Scholar
  20. Egyptian National Action Program to Combat Desertification (2002) Arab republic of Egypt, ministry of agriculture and land reclamation. Desert Research Centre (DRC), CairoGoogle Scholar
  21. Egyptian National Action Program to Combat Desertification (2005) Arab republic of Egypt, ministry of agriculture and land reclamation. Desert Research Centre (DRC), CairoGoogle Scholar
  22. El-Hinnawi E (1985) Environmental refugees. United Nations Environmental Programme, NairobiGoogle Scholar
  23. Flintan F (2001) Environmental refugees—a misnomer or a reality? A contribution to the Wilton park conference report on environmental security and conflict prevention, March 1–3, 2001. <>, 10 October 2006
  24. GermanWatch (2004) Sea level rise in Bangladesh and The Netherlands: one phenomenon, many consequences.
  25. Grier P (2005) The great Katrina migration. The Christian Science monitor. September 12, 2005. Access date: December 24, 2006;
  26. Intergovernmental Panel on Climate Change (IPCC) (2007a) Climate change 2007—The physical science basis. Contribution of working group I to the fourth assessment report of the IPCC. GenevaGoogle Scholar
  27. Intergovernmental Panel on Climate Change (IPCC) (2007b) Climate change 2007—Impacts, adaptation and vulnerability. Contribution of working group II to the fourth assessment report of the IPCC. GenevaGoogle Scholar
  28. International Organisation for Migration (IOM) (2007) Facts and figures: global estimates and trends. International Organization for migration, Geneva <>, 28 February 2007
  29. ISDR-International Recovery Platform (IRP) (2007) Learning from Disaster Recovery. Guidance for decision makers. A publication from the international recovery platform. Supported by the Asian Disaster Reduction Center (ADRC), International Strategy for Disaster Reduction (ISDR) secretariat, and the United Nations Development Programme. Preliminary Version for Consultation. MayGoogle Scholar
  30. Jacobson JL (1988) Environmental refugees: a yardstick of habitability. Worldwatch Paper 86. Worldwatch Institute, Washington DCGoogle Scholar
  31. Jäger J (2009) Scenarios. Environmental change and forced migration scenarios project synthesis of results, pp 60–66. Available online at:
  32. Jambor P (1992) Indochinese refugees in South East Asia: mass exodus and the politics of aid. Bangkok, Thailand. UNHCR, GenevaGoogle Scholar
  33. Kenny ML (2002) Drought, clientelism, fatalism and fear in Northeast Brazil. Ethics Place Environ 5(2):123–134. doi: 10.1080/1366879022000020194 CrossRefGoogle Scholar
  34. Kibreab G (1994) Migration, environment and refugeehood. In: Zaba B, Clarke J (eds) Environment and population change. International Union for the Scientific Study of Population, Derouaux Ordina Editions, LiègeGoogle Scholar
  35. Kibreab G (1997) Environmental causes and impact of refugee movements: a critique of the current debate. Disasters 21(1):20–38. doi: 10.1111/1467-7717.00042 CrossRefGoogle Scholar
  36. Kline DS (2003) Push and pull factors in international nurse migration. J Nurs Sch 35(2):107–111CrossRefGoogle Scholar
  37. Lambert J (2002) Refugees and the Environment: the forgotten element of sustainability. The Greens/European Free Alliance in the European Parliament, BrusselsGoogle Scholar
  38. Lee S (2001) Environmental matters: conflict, refugees and international relations. World Human Development Institute Press, Seoul and TokyoGoogle Scholar
  39. Leighton M (2006) Desertification and migration. In: Johnson PM, Mayrand K, Paquin M (eds) Governing global desertification. Ashgate, UK, pp 43–58Google Scholar
  40. Massey D, Axinn W, Ghimire D (2007) Environmental change and out-migration: evidence from Nepal. Report 07-715. Population Study Center. University of Michigan. Institute for social research. Available at:
  41. McGregor JA (1993) Refugees and the environment. In: Black R, Robinson V (eds) Geography and refugees: patterns and processes of change. Belhaven Press, London, pp 159–170Google Scholar
  42. Millenium Ecosystem Assessment (2005a) Ecosystems and human well-being: synthesis. Island Press, Washington, DCGoogle Scholar
  43. Millenium Ecosystem Assessment (2005b) Ecosystems and human well-being: desertification synthesis. World Resources Institute, Washington, DCGoogle Scholar
  44. Myers N (1993) Environmental refugees in a globally warmed world. Bioscience 43:752–761. doi: 10.2307/1312319 CrossRefGoogle Scholar
  45. Myers N (2002) Environmental refugees: a growing phenomenon of the 21st century. In: Philosophical Transactions of the Royal Society B. London. Vol 357, No 1, pp 609–613Google Scholar
  46. Myers N (2005) Environmental refugees: an emergent security issue. 13th Economic Forum, Prague, 23–27 MayGoogle Scholar
  47. Myers N, Kent J (1995) Environmental exodus: an emergent crisis in the global arena. Climate Institute, Washington, DCGoogle Scholar
  48. OECD (2005) Trends in international migration. Annual report 2004 edition. OECD publishing. ISBN 92-64-00792-XGoogle Scholar
  49. Oliver-Smith A (1977) Traditional agriculture, central places, and postdisaster urban relocation in Peru. Am Ethnol 4(1):102–116CrossRefGoogle Scholar
  50. Oliver-Smith A (2006) Reflections on nature, environment and society in vulnerability research. Draft of a forthcoming publication of UNU-EHSGoogle Scholar
  51. Ratha D, Zhimei Xu (2008) Migration and Remittances Factbook 2008. The World Bank. February. ISBN-13: 978-0-8213-7413-9Google Scholar
  52. Renaud FG, Bogardi JJ (2007) Forced migrations due to degradation of arid lands: concepts, debate and policy requirements. In: King C, Bigas H, Adeel Z (eds): desertification and the international policy imperative, proceedings of a joint international conference, Algiers, Algeria, 17–19 December 2006. UNU Desertification Series No. 7, United Nation University, Tokyo, Japan, pp 24–34Google Scholar
  53. Renaud F, Bogardi JJ, Dun O, Warner K (2007) Control, Adapt or Flee How to Face Environmental Migration? InterSecTions. Interdisciplinary security connections publication series of UNU-EHS No. 5/2007. Available at:
  54. Renaud F, Dun O, Warner K, Bogardi J (2009) Deciphering the importance of environmental factors in human migration. J Int Migr (submitted)Google Scholar
  55. Reuveny R (2007) Climate change-induced migration and violent conflict. Polit Geogr 26(6):656–673. doi: 10.1016/j.polgeo.2007.05.001 Google Scholar
  56. Stal M (2009) Case study report on Mozambique for the environmental change and forced migration scenarios project. Available at
  57. Stilwell B, Khassoum D, Pascal Z, Vujicic P, Adams O, Dal Poz M (2004) Migration of health-care workers from developing countries: strategic approaches to its management. Bull World Health Organ 82:595–600Google Scholar
  58. Taylor EJ (1992) Remittances and inequality reconsidered: direct, indirect and intertemporal effects. J Policy Model 14(2):187–208. doi: 10.1016/0161-8938(92)90008-Z CrossRefGoogle Scholar
  59. United Nations Environment Programme (UNEP) (2007) Global environment outlook GEO4. Environment for development. UNEP, NairobiGoogle Scholar
  60. United Nations High Commissioner for Refugees (UNHCR) (2002) A critical time for the environment. In: refugees. no.127, p 2Google Scholar
  61. United Nations High Commissioner for Refugees (UNHCR) (2006) Convention and protocol relating to the status of refugees: text of the 1951 convention relating to the status of refugees, text of the 1967 protocol relating to the status of refugees, and resolution 2198 (XXI) adopted by the United Nations General Assembly, UNHCR, Geneva. <>, 22 February 2007
  62. United Nations High Commissioner for Refugees (UNHCR) (2007) Global trends: refugees, asylum-seekers, returnees, internally displaced and stateless personsGoogle Scholar
  63. United Nations High Commissioner for Refugees (UNHCR) (2008) Climate change, natural disasters and human displacement: a UNHCR perspective. Final version 23 October 2008. Geneva.
  64. Warner K, Erhart C, de Sherbinin A, Adamo SB, Onn TC (2009) In search of shelter: mapping the effects of climate change on human migration and displacement. A policy paper prepared for the 2009 Climate Negotiations. Bonn, Germany, United Nations University, CARE, and CIESIN-Columbia University and in close collaboration with the European Commission "Environmental Change and Forced Migration Scenarios Project", the UNHCR, and the World BankGoogle Scholar
  65. Wilbanks TJ, Romero P, Lankao M, Berkhout F, Cairncross S, Ceron J-P, Kapshe M, Muir-Wood R, Zapata-Marti R (2007) Industry, settlement and society. Climate Change 2007: Impacts, Adaptation and vulnerability. contribution of working group II to the fourth assessment report of the intergovernmental panel on climate change, Parry ML, Canziani OF, Palutikof JP, van der Linden PJ and Hanson CE (eds), Cambridge University Press, Cambridge, UK, 357–390Google Scholar
  66. Wolf AT (1998) Conflict and cooperation along international waterways. In: water policy, Vol. 1, issue 1Google Scholar
  67. World Health Organization (WHO) (2007) Mozambique flood. Preliminary report. February. Available at Accessed on 31 July 2007
  68. Yang D (2007) Risk, migration and rural financial markets: evidence from earthquakes in El Salvador. Paper presented at the new school conference on disasters: recipes and solutions, Nov. 1–2Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • K. Warner
    • 1
  • M. Hamza
    • 2
  • A. Oliver-Smith
    • 3
  • F. Renaud
    • 1
  • A. Julca
    • 4
  1. 1.United Nations University Institute for Environment and Human Security (UNU-EHS)BonnGermany
  2. 2.Stockholm Environment Institute (SEI), Oxford CentreOxfordUK
  3. 3.University of Florida and Munich-Re Foundation Chair on Social Vulnerability at the United Nations University Institute for Environment and Human Security (UNU-EHS)GainesvilleUSA
  4. 4.United Nations Department of Economic and Social Affairs (UN/DESA)New York CityUSA

Personalised recommendations