The migration–environment nexus

Environmental phenomena impacting migration are usually grouped into two broad categories, disasters and environmental change.

Disasters

In other words, disasters occur when exposed and often vulnerable populations are impacted by hazards, and local response capacities are overwhelmed.

• While “natural disasters” is an expression that is commonly used, it is in fact a misnomer: disasters are the results of how a society reduces and manages risks.
• Hazards can be natural events. This chapter focuses on natural hazards (such as cyclones and floods) but human-induced hazards, such as industrial accidents, can also affect migration.
• A natural hazard may or may not lead to a disaster, and a disaster may or may not trigger displacement.
• Disasters can be sudden onset or slow onset – triggered by hazards that last seconds (earthquakes), days (cyclones), months or even years (droughts).
• The vulnerability of people, communities and societies to hazards is mainly due to poverty, inequality and lack of preparedness.
• Disasters often result in large-scale displacement, as people flee for survival.
• Disasters may also result in secondary movements, when damage to homes and livelihoods is considerable, as people move first to a safe shelter or site, then to another place looking for work or accommodation.
• People may find themselves in situations of protracted displacement when disruption is long lasting, and finding durable solutions is challenging.

Environmental change

• Environmental change takes place over variable time scales, often decades or longer, although localized processes dependent on intense ecosystem use can be much quicker.
• The impacts of environmental change do not affect all regions or localities in the same way. The most affected regions are drylands, mountain regions and low-elevation coastal zones (LECZs) situated less than ten metres above sea level.
• Environmental change drives migration primarily through its negative impacts on livelihoods, notably rural livelihoods such as farming, livestock herding and fishing. Nonetheless, impacts on livelihoods in urban areas can also be severe.

Vulnerability

In the context of disaster and environmental change, vulnerability is defined as:

These factors shape people’s need to move, capacity to move, available options for moving and conditions in transit and at destination. Relatedly, resilience can be understood in relation to the capacity to cope with environmental shocks and stresses, including related socioeconomic impacts.

Disaster displacement

• In most cases, displacement, whether caused by sudden- or slow-onset disasters, happens over short distances.
  
  For example, displaced agricultural communities in Bangladesh often move only across short distances from their residence following, for instance, loss of homes due to flooding (Shamsuddoha et al., 2011).
• Disaster displacement is most often temporary: where conditions for safe return and sustainable reintegration exist (housing, livelihoods), most people prefer to return. Nonetheless, considerable support for rehabilitation and recovery is often needed, and protracted displacement of disaster-affected populations does occur.
  
  For example, many of the people displaced by the Fukushima disaster in Japan in 2011 are still unable or unwilling to return. People in situations of protracted displacement are often highly vulnerable, particularly in camp and camp-like settings.
• Most disaster displacement occurs at a local level and within countries, but cross-border displacement does occur and poses specific challenges.
• Displaced persons often require both short- and long-term assistance. This ranges from immediate humanitarian assistance to the provision of durable solutions to displacement (further details in Solutions and recovery).

Voluntary migration

• Most voluntary environmental migration takes place within countries (internal migration), often from rural to urban areas or rural to rural areas, as a result of increasing pressure on rural livelihoods linked to environmental change and in conjunction with other (mainly economic) drivers of migration.
• Where movements do involve crossing an international border, the majority are to neighbouring countries. In some cases, rural–urban migration may be a stepping stone to international migration at a later stage.
• “Voluntary” migration also can occur after initial displacement caused by disasters, especially when return is not yet possible (for instance, as a result of limited access to livelihoods).
  However, following disasters, the distinction between migration and secondary displacement may be difficult to make, since there is probably a forced element to migration even when undertaken voluntarily as a coping strategy.

• Voluntary migration in the context of disasters and environmental change can be temporary or permanent:
  • The movement is often of a designated member(s) of the household and more likely to be toward urban centres or employment hubs.
  • Migration is a common response to environmental pressures such as reduced crop yield or failed harvests.
    
    In areas subject to annual dry or rainy seasons (or in the tropics, annual cyclone season) seasonal migration is a common and integral part of livelihood systems. It is usually local, rural–rural migration, and is often essential to food security. Timing of movements is often linked to agricultural cycles, with people migrating away from home during times of low demand for work (often the dry season) to areas with different agricultural cycles, more favourable weather conditions, labour shortage caused by outmigration, or a combination of these.
• Permanent migration is more likely at advanced stages of environmental degradation, as slow processes such as sea-level rise and desertification gradually render livelihoods unsustainable or areas inhabitable.
• Migration can be a significant factor for reducing vulnerability and building household resilience, particularly when planned.

Planned relocation

Planned relocation can be an effective pre-emptive intervention for reducing the exposure of vulnerable populations (and assets) to disasters and severe environmental degradation (further details on Planned relocation in Managing environmental migration below, in this chapter).

• Relocation is typically a collective movement of a community or a part of it, but may take place in successive steps over long timeframes. Relocation can be organized by the community affected or – more commonly – with the support of public authorities. Due to the costly nature of relocation, in terms of acquiring land, housing and re-establishing livelihoods, some form of support is usually needed.
• To date, relocation in the context of disasters and climate change has been primarily within countries. The threat posed by sea-level rise to a number of low-lying island States raises the potential need for international relocation, which would bring additional challenges.
• There is general agreement in research and international policy circles that relocation should be a last resort once other options have been exhausted due to the complex challenges involved.

Immobile populations

There is growing concern for those who are or might become trapped, unable to move away from areas where environmental change impacts on livelihoods.

• It is rarely the poorest who migrate, as they do not have the financial and informational resources to do so. Their inability to move is an expression and a cause of vulnerability as not migrating from high risk areas can jeopardize their well-being.
• In the long term, the existence of trapped populations may lead to increased recourse to (expensive) planned relocation programmes.
• Sometimes, people choose to stay in spite of negative environmental conditions. Though some might stay because they are unable to move away, others will choose to stay – voluntary immobility – despite the challenges, for a variety of reasons (e.g. perceptions of risks and opportunities, or the strength of social or spiritual ties to home). They remain vulnerable to the impacts of environmental change.

Livelihoods also are an important determinant of vulnerability. Rural livelihoods dependent on local natural resources are particularly vulnerable to the impacts of environmental change. At the same time, the ways in which these threats to livelihood relate to mobility are diverse.

• Smallholders who depend on rainfall for their crops are very vulnerable to climate variability. Smallholders may lack the resources to migrate or may be pushed to migrate in conditions which increase their (and their household’s) vulnerability.
• Pastoralists (livestock herders) are often especially vulnerable, as in addition to their shrinking access to pasture and water points, they are often marginalized and/or lack access to public decision-making and support. Although pastoralists’ livelihoods are based on mobility, environmental pressures may push them to move across greater distances. However, once certain thresholds are crossed, environmental pressures may also lead to sedentarization.

Nonetheless, it is important to look beyond this negative picture. Mobility can also be a form of adaptation that builds resilience (see more on how to minimize and address displacement in Managing environmental migration).