Millions of people migrate each year because of the impacts of climate change and other extreme environmental events. While people can and do cross international borders, typically this movement is within their own country, a report by Migration Policy Institute, MPI said. In 2022 alone, it said disasters drove some 32.6 million recorded internal displacements—the highest figure in more than a decade. This includes people forced to flee floods, monsoons, and other shock events; an additional unknown number moved in response to gradually deteriorating environmental conditions such as sea-level rise, coastal erosion, extreme heat, and climatic variability.

Yet, as worrying as these statistics are, the vast majority of people living in places highly vulnerable to climate change do not migrate. If migration or displacement was the inevitable response to environmental change, the world would be in the midst of a much more dramatic upheaval. The fact that it is not could be interpreted as a good thing, since being settled is often seen as normal and even desirable and, therefore, unproblematic.

However, the reality is both more complicated and more concerning. Catastrophic predictions that climate change will create huge numbers of desperate migrants ignores that the relationship between migration and climate change is non-linear. Its impacts are not distributed evenly nor responded to equally. Some individuals can adapt in place, while many people do not have the capability to move, and others might be able to but are reluctant to leave homelands to which they feel irrevocably bound. When migration is not a viable option, people who are unable or unwilling to move may be the ones most negatively affected by climate change, as they become trapped in increasingly uninhabitable locations.

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Immobility: As Complicated as Migration

Climate-linked migration is often portrayed in alarmist media reports as negative or abnormal, but more recent thinking has positioned it differently. Especially when done voluntarily and pre-emptively, movement can positively affect people and communities by bringing them to safety or offering them opportunities to improve their well-being. These benefits can be shared: labor migration to the city or abroad may be the best way to fund improvements that allow loved ones to withstand more extreme climate events back in their places of origin. Historically, many societies have engaged in some sort of mobility to respond to changing environmental and economic conditions. Pastoralist groups such as Fulani herders in West Africa have done so for centuries. For these communities, staying in place is the exception. Abundant research on the climate-migration nexus thus emphasizes the actual or potential power of migration—and mobility more broadly—to act as an adaptation strategy. This shifts away from predominately negative portrayals of climate migrants, for whom migration is considered an act of last resort and desperation.

If human mobility can be a relatively rational and even lifesaving response to damaging environmental events, one might expect many more people to move than currently do. Only a small share of all people affected by climate impacts relocate. Why do people stay in places where their homes, livelihoods, and their very lives are threatened? This article examines the range of reasons why some people do not migrate away from climate impacts, whether by choice or because they are forced to remain.

Human mobility is spurred by any number of reasons and is almost always multicausal. It stands to reason that a range of motivations drive non-migration, too. Just as there is no singular cause of migration, there is no one explanation for why people, households, or communities remain in place. Evidence shows a variety of micro-, meso-, and macro-level factors influence these decisions, including personal wealth, social connections abroad, cultural norms, and government policy.

One reason why so many people stay in regions affected by environmental change (including but not limited to changing climate) is because not everyone is equally affected. Extreme estimates that billions of people will become “climate refugees” (a fraught and legally meaningless term) often rely on deterministic and linear assumptions rather than empirical evidence, supposing that everyone living in a vulnerable area will be forced to move. This overlooks the differential vulnerabilities across and within regions, communities, and even households. In a sudden-onset event such as a hurricane or wildfire, some households are less exposed or more resilient than others. For instance, people living directly on coastlines are more threatened by coastal erosion than their neighbors even a few streets back. Nonagricultural households may not feel the economic strain of erratic rainfall in the same way as farmers.

Other people may be exposed to environmental change but manage to adapt in situ, limiting the pressure to migrate. Wealthier households may be able to install irrigation systems, invest in drought-resistant crops, purchase better fishing equipment, or build stronger homes that can withstand increasingly intense and frequent storms. Some also migrate so that others can stay; migration-generated social and financial remittances can increase the adaptive capacity and resilience of those who remain and decrease their reliance on local natural resources.

Trapped in Place

Then there are people who are sufficiently exposed to climate impacts but who lack the wealth or other resources needed to adapt, including by moving. While migration can offer one solution, it is not available to all those suffering the effects of climate change, whether they lack the means or the opportunity. Even in its precarious forms, migration takes varying degrees of financial, human, and social capital, which not everyone has. In other words, some people in climate-vulnerable regions simply cannot “afford” to migrate. Thus, in contradiction to the widely circulated and highly politicized image of the impoverished climate refugee, it is not always the poorest and most vulnerable who move.

Such groups have come to be called “trapped populations”: people who need to move and want to move but cannot. The label can equally be applied in other crisis contexts such as conflict, health pandemics, or extreme poverty. Indeed, various crises often overlap and can exacerbate the forces keeping someone in place, but the term trapped populations has gained a particular foothold in research focused on climate and other forms of environmental change. Acknowledging these populations opens up a relatively new area of discussion on the climate-mobility nexus. An increasing number of studies seek to identify and understand trapped populations. As an alternative to the more prevalent focus on people who move at least in part because of negative impacts of climate change, researchers are now also asking who, when facing these same impacts, does not move and why.

A Vicious Cycle

Special Issue: Climate Change and Migration

This article is part of a special series about climate change and migration.

EXPLORE THE ISSUE

Climate change can both increase a person’s need to migrate and simultaneously inhibit their capability to do so. Demonstrating the non-linear relationship between climate and mobility, or what has been termed the immobility paradox, the world may actually be facing a future in which fewer people are able to move as a result of climate change because environmental changes can decrease the very resources needed to migrate. People’s normal mobility patterns can be disrupted by shifting climatic conditions or a sudden-onset event. For example, a farming household that regularly engages in seasonal migration to cities for off-season employment may no longer be able to do so because diminishing crop yields force them to redirect assets to meet their basic needs. In the case of severe drought, evidence from West Africa shows that households tend to allocate dwindling resources to basics such as food, water, and shelter rather than investing in migration.

Trapping Factors

By far, poverty is the most cited constraint on out-migration in studies of trapped populations. Accordingly, it is typically the poor who are left behind when environmental disasters and slow-onset change compel their neighbors to move. This holds true for individuals but also for places. In Zambia, for example, one study found that while wealthy districts showed a positive climate-migration relationship, poor districts were characterized by climate-related immobility.

People are not trapped, however, only by a lack of money or assets. Limited social networks outside one’s place of origin, for instance, can have a strong influence on the ability to migrate or evacuate. In the author’s work in the Mekong Delta of Vietnam, the absence of social contacts who might provide advice, accommodation, or job prospects in a potential destination had more of a trapping effect than the financial costs of the move itself. For others, physical barriers block mobility. In remote areas such as the Bartang Valley of Tajikistan, road closures caused by avalanches, snowfall, and river flooding can cut off rural residents and threaten food security.

In sudden disasters, people with disabilities and older people are more likely to become trapped because they often face greater issues accessing early warnings and emergency information, as well as reaching shelters. During the 2011 tsunami in Japan, many were unable to evacuate because the tsunami struck during the daytime, when most family members and neighbors were at work. As a consequence, the elderly and people with disabilities suffer disproportionately high mortality rates during disasters.

Gender, too, plays a role. In coastal Senegal, active, young male fishers often embark on international migration to fish in Mauritania, whereas land-based women who process and sell fish are more vulnerable to dwindling local fish stocks, plummeting biodiversity, and coastal erosion. One study in Bangladesh found that women were more likely to stay in place during cyclones because they feared for their safety in evacuation shelters and believed their role was to stay behind and look after cattle, furniture, and the household.

It is almost always an intersection of social inequities that contributes to involuntary immobility. This includes structural barriers such as legal or administrative rules, lack of transportation networks, and the absence of migration infrastructure, as well as household-level characteristics such as financial resources, social networks, and human capital; personal attributes such as age, education, and skills also are factors. After all, microlevel conditions such as household poverty are often produced—or at least reinforced—by macrolevel inequalities, structural opportunities, and constraints. During Hurricane Katrina in 2005, for instance, those left behind in New Orleans as waters rose were disproportionately Black, low-income, and lacked a car or social networks to secure shelter elsewhere. Many had no way to evacuate and no place to flee to, exposing systemic racial and socioeconomic disparities and blind spots in U.S. government emergency planning.

The Choice to Stay

While trapped populations are defined as people who want to move but cannot do so, there are people and communities who do not want to leave their home despite the risks. Many choose to stay in climate-vulnerable areas even when severe and irreversible environmental events occur. While it is impossible to know precisely how many non-migrants fall into this category, the phenomenon is being studied intensively.

Documentation of voluntary immobility in places such as the Pacific and West Africa highlights the importance of investigating people’s desires and willingness to move, rather than assuming them. The decision may be especially influenced by environmental changes, or it may be more profoundly shaped by other factors, such as attachment to a particular place, cultural ties, social status, gender roles, and kinship obligations. In the author’s work in Saint-Louis, Senegal, some people (especially those who were older), denied being trapped and explained that their poverty had nothing to do with their immobility. “This is the land of my grandparents,” said a 61-year-old fisherman. “Even if I had billions,” he said he would not leave.

In the face of extreme and irreversible climate change, many communities are actively resisting migration and relocation across the Pacific Islands, where rising seas have threatened to subsume entire countries. Community leaders in places such as Kiribati and Tuvalu have voiced their intentions to stay in their lands for cultural, spiritual, and political reasons, fully aware of the negative health and livelihood impacts they face as the waters rise. In these islands, as in other climate-impacted regions, there are those who prefer to die rather than leave.

However, immobility does not necessarily mean stasis. Some people who do not migrate may still engage in everyday mobilities in response to climate change, including commuting for their job or engaging in circular migration. Thus, it is important to recognize that non-migration does not necessarily mean the absence of movement. This perspective also underscores that non-migrating populations are not necessarily victims of circumstance, but rather people engaging in complex behaviors based on an array of factors.

Policy Decisions: The Option to Stay or Go

The people who do not move—or who get stuck in place after an initial migration—may be equally or even more vulnerable than their migrant counterparts. Those who are unable to pre-emptively migrate in a safe, orderly, and regular fashion may end up displaced as environmental impacts worsen. Or they may pay the ultimate price. In Sri Lanka, a study conducted in 13 evacuation camps showed that women and children died at disproportionate rates because they were located indoors and at home on the morning of the 2004 Indian Ocean tsunami. In 2021, 12 people with disabilities living in a group home drowned in floods in Sinzig, Germany because they did not evacuate in time. From a policy perspective, therefore, identifying the existence of trapped populations and addressing the root causes of immobility is critical for targeted interventions designed to anticipate and prevent large-scale humanitarian crises.

While there are discussions at the international level around ways governments can avert, minimize, and address forced migration under climate change, policies directly targeting immobility are rare. Often policymakers assume that, if given a choice, most people confronted with climate change will choose to stay in place. This thinking normalizes immobility and, in turn, crafts climate-related migration as a problem to be solved, rather than a possibly beneficial phenomenon. Policy messages seem intent on stopping or at least inhibiting migration through mitigation efforts (such as by lowering greenhouse gas emissions) and adaptation measures (which seek to minimize adverse impacts of climate change). Largely through these two policy options, policymakers seem to think the immobile ideal can be achieved.

Migration policy arguably always has an immobility component, with the power to halt movement just as much as to facilitate it. For trapped populations, policies and programs that enable people to leave climate-vulnerable regions offer pathways forward. These include existing migration mechanisms, such as bilateral circular migration schemes, or vocational and educational training that helps people access opportunities and services in their destinations. An oft-cited example of the latter is the previous Migration with Dignity program in Kiribati, a small Pacific Island facing sea-level rise, which sought to prepare migrants to prosper abroad through educational and vocational support.

Regional mechanisms allowing for free movement protocols that acknowledge the environment-migration relationship can also help facilitate mobility by diminishing legal and political barriers to international migration. The Intergovernmental Authority on Development (IGAD) in Eastern Africa, a region highly vulnerable to climate change, has developed the IGAD Protocol on Transhumance which allows for the free, safe, and orderly cross-border mobility of livestock and herders as an adaptation mechanism to climate change. Its Protocol on Free Movement of Persons also recognizes that climate change and environmental degradation are important drivers of displacement and that the free movement of persons in the region can mitigate these impacts.

Planned relocation schemes moving people away from vulnerable areas also potentially provide solutions for those wanting to leave, although they tend to be internal rather than international and vary in terms of successful outcomes. As part of its Migration with Dignity program, Kiribati purchased land in Fiji with the expectation of gradual voluntary relocation, though this plan has since been abandoned. Fiji, for its part, has spent several years trying to relocate particularly at-risk villages on some of its more than 300 islands.

People who choose to stay in areas where habitability is eroding and that have been hit by repeated disasters or progressively worsening conditions may be more elusive policy targets. These people are unlikely to spontaneously take advantage of free movement protocols, bilateral agreements, or other internal facilitative actions such as planned relocation. Regarding the latter, planned relocation is complex, costly, and time-consuming, and if people do not consider themselves trapped or are unaware of the risks, they may be unwilling to engage in programs designed to help them leave. If their concerns are not thoroughly appreciated and addressed, planned relocation programs are likely to stall or fail. In Isle de Jean Charles in Louisiana, diverging visions between Indigenous residents and state officials delayed the efforts to relocate residents away from the island’s coastal erosion for several years. Elsewhere, plagued by poor communication, planning, and implementation, as many as 30 percent of relocated households returned to the floodplains of the Zambezi River Valley in Mozambique.

Other policies might not include convincing populations to resettle elsewhere, but rather target adaptation in situ and therefore help people to remain in more sustainable conditions. Climate adaptation programs already exist that can develop smart agriculture and fishing techniques locally, for example, and can be paired with broader development initiatives such as infrastructure, education, and diversifying local livelihoods.

Promoting the right to stay and the right to move should ultimately be seen as complementary rather than competing policy objectives. Initiatives that focus on fostering connectivity between destinations and areas of origin can also make it easier for people to circulate, return, and generally stay connected to their loved ones, which may make both staying and going more appealing and more tenable. Ultimately, policy will succeed insofar as it gives the people most affected by climate change the power and choice over when and how they migrate—if they migrate at all.