Who Counts as a Climate Migrant?

As climate change threatens to upend societies around the world, concerns about mass climate migration are becoming widespread. As far back as 1992, the Intergovernmental Panel on Climate Change (IPCC) warned “the gravest effects of climate change may be those on human migration as millions are displaced by shoreline erosion, coastal flooding, and severe drought.” In recent years, tens of millions of people have been displaced annually by natural disasters (which can be, but are not always, related to climate change), and disasters often prompt more internal displacement than do conflicts, according to the Internal Displacement Monitoring Centre. Increasingly unpredictable patterns of rainfall and drought are straining the livelihoods of smallholder farmers around the world. Some governments have embarked on planned relocation of communities threatened by rising seas and natural disasters. As climate change becomes more extreme, the consequences will continue unfolding. Researchers and analysts have repeatedly tried to quantify how many people will be uprooted by climate change, with estimates ranging from the hundreds of millions to well more than 1 billion. In the process, they have created a new category of migrants sometimes referred to as environmental migrants, climate refugees, and increasingly, climate migrants.

However, these terms are nebulous and, crucially, carry no legal meaning. No government currently offers a legal migration pathway based solely on an individual’s exposure to climate change, and the UN High Commissioner for Refugees (UNHCR) has made clear that fleeing the impacts of climate change is not sufficient grounds for receiving refugee status, which is limited to people escaping persecution. The use of these terms, particularly “climate refugee,” has prompted contentious debates among academics, activists, and others.

Nevertheless, the concept of climate migration remains influential in policy-oriented research, most notably in forecasting future scenarios. The World Bank’s influential Groundswell reports estimate that without serious efforts to limit greenhouse gas emissions, 216 million people could become climate migrants within their own countries by 2050. The African Climate Mobility Initiative projects that in Africa alone, the number of internal climate migrants could reach up to 113 million by 2050. These numbers are worrisome—partly by design. Reports often highlight the worst-case scenarios to galvanize international action on climate change. More sensational analysis tends to conflate the number of people living in areas seriously threatened by rising sea levels and other environmental threats with the number of future climate migrants. This neglects the potential for adaptation measures—like building sea walls, creating new food systems, or using air conditioning—that can help keep people in place. It also neglects the reality that societies are already remarkably mobile. Even in the countries that are most vulnerable to climate change, people are already on the move internally and internationally for work, housing, education, family reunification, security, adventure, and other reasons. Rather than forecasting how many people will be uprooted by climate change, analysts might instead ask how climate change will reshape existing patterns of migration and immobility.

Recent research suggests that in a worst-case scenario, as much as 39 percent of the global population, currently at 8 billion, could live in environments outside the “human climate niche,” which provides the most appropriate conditions for human life, by the end of the century. Yet, how people move—or do not move—in response to climate hazards promises to be as mixed and messy as migration has always been. Climate change will leave its mark on all kinds of human mobility, including refugee and survival migration, labor migration, migration for education, and family reunification. This raises the question: Which migrants should count as climate migrants?

This article reviews definitions of climate migration and questions the value of such a definition. It explores the difficulties of distinguishing climate migrants from other kinds of economic or humanitarian migrants, particularly in low- and lower-middle income countries, and it highlights that the populations most vulnerable to climate change are often those who cannot migrate. Rather than attempt to identify and create legal pathways for a new category of climate migrants, analysts might consider how existing policy tools such as humanitarian visas and labor pathways can be leveraged to address the opportunities and challenges of mixed migration from climate-stressed contexts.

Defining Climate Migration

The International Organization for Migration (IOM) defines climate migration as “the movement of a person or groups of persons who, predominantly for reasons of sudden or progressive change in the environment due to climate change, are obliged to leave their habitual place of residence, or choose to do so, either temporarily or permanently, within a State or across an international border.” This is a broad definition that encompasses virtually all forms of migration so long as it is predominantly in response to climate change. 

When is environmental change—or more specifically climate change—the predominant reason for moving? To answer this question, it is important to distinguish between sudden-onset climate events that occur within days or even hours, such as hurricanes, wildfires, or floods, and slow-onset changes that occur over many years, including patterns of erratic and unpredictable rainfall, shifting and more extreme temperatures, changes in soil salinity, or sea-level rise. In the case of sudden-onset events, there is a more direct link between extreme weather and the displacement that follows. Yet even in these cases, where, how, and whether people move is shaped by households’ resources and networks as well as by government preparations and humanitarian-led interventions. This helps explain why, for example, displacement trajectories following Hurricane Katrina showed major discrepancies based on race and class. Those with the least resources, networks, and government support were trapped in the city and disproportionately perished.

In the context of slow-onset climate impacts, the link between environmental factors and migration is more indirect and nonlinear. Research in climate-stressed areas finds that many people do not want to migrate, even if their livelihoods are significantly at risk, and those who do move rarely cite environmental factors as the primary motivations for leaving. For instance, a 2021 report by the World Food Programme, Migration Policy Institute, and Massachusetts Institute of Technology’s Civic Data Design Lab found that only 6 percent of respondents surveyed in northern Central America—a region plagued by severe drought and food insecurity—said they were motivated to move because of climate and environmental reasons; the vast majority cited economic drivers. When climate change occurs gradually, environmental stresses are interwoven with other drivers of migration and immobility so that it becomes very difficult to say who is a climate migrant per se and who is migrating for other reasons.

What may seem like a quibble over semantics has very important real-world consequences. If policymakers cannot say who counts as a climate migrant, they will not be able to design policies or legal pathways to support them. A core challenge to defining climate migration is the reality that climate impacts almost always intersect with other drivers of migration and immobility. This means climate-related migration can take many forms: labor migration, asylum seeking, family reunification, student migration, or even human trafficking. These different forms of climate-related movement require very different policy responses.

Thinking Beyond Climate Migration

To better track, forecast, and prepare for migration in an era of climate change, there are several reasons why policymakers and development organizations might benefit from thinking outside the climate migration box. First, it will be especially difficult to distinguish climate migrants from other kinds of migrants in low- and lower-middle-income countries, where national and international development strategies are also driving migration. In many of the countries that are the most vulnerable to climate change, large segments of the population live in rural areas and subsist on small-scale agriculture. In these contexts, governments and nongovernmental actors are striving to make basic gains in access to education, employment, and health care, as well as to invest in infrastructure, security, and climate adaptation. It is precisely in these contexts where rising levels of human and economic development tend to go hand-in-hand with increasing migration. As countries move from low- to middle-income status, and as countries experience gains in schooling, life expectancy, and other indicators of human development, research finds more people move from rural to urban areas and internationally.

Targeted development assistance can enhance individuals' capability to stay in specific climate-stressed locales, but the deep structural changes associated with development—such as expanding infrastructure and education, economic diversification and industrialization, changing life aspirations, and expectations for consumption—have historically led large segments of a country’s population to abandon rural places. As climate change adds additional stress to rural livelihoods, it can be extremely difficult to distinguish who is leaving rural areas because of climate change and who is following in the footsteps of every other industrializing society.

Climate-Related Immobility

Second, some of the most adverse consequences of climate change may come in the form of reduced mobility and what some researchers call “trapped populations." As Richard Black and colleagues noted in the 2011 Foresight report on migration and global environmental change, there tends to be an inverse relationship between vulnerability to climate threats and the ability to migrate away from them. Migration requires significant resources, including money, networks, and know-how. The most vulnerable groups—those with low levels of income and education, the elderly, or those with disabilities—are more likely to be left exposed to the continued impacts of climate change and descend deeper into poverty. Analysts’ focus solely on climate migration risks overshadowing climate-related immobility as an urgent humanitarian and development concern.

However, many people do not see themselves as trapped and do not want to migrate. Even when governments and organizations explicitly design policies to relocate people away from threatened areas, such as on some of the hundreds of islands that make up Fiji, communities have resisted the push, choosing instead to stay in the place where they were raised and where their ancestors are buried. As the researcher Carol Farbotko has argued, there are many sociocultural, political, and psychological reasons for voluntary immobility, and these may over-ride technical assessments of the benefits of relocation. Perhaps more puzzling is a burgeoning literature that finds many vulnerable populations never meaningfully consider migration or do not perceive climate change as an existential threat. A recent survey from the African Climate Mobility Initiative finds that, despite suffering from climate disruptions, over half of respondents did not consider moving. These different forms of climate-related immobility raise concerns for policymakers that go far beyond the management of climate-related migration.

The Perils of an Overly Broad Definition

Finally, defining climate migration too broadly could undermine efforts to support people who have been obviously forcibly displaced by climate-related disasters. Consider the devastating floods in Pakistan that displaced nearly 8 million people last year, or the 2011 drought in Somalia that led to famine, the internal displacement of tens of thousands, and the death of an estimated 130,000 children. Displacement following natural disasters has distinct features and patterns, more in common with other forms of displacement, such as those following conflict. It requires different responses than migration from places where climate stress has not yet reached these disaster-level proportions. An overly broad approach to climate migration may risk conflating these situations, preventing analysts and advocates from targeting their resources on the most severe humanitarian cases. 

A Multifaceted Approach

Study after study from around the world fails to find a consistent migration response to climate change. Even for seemingly straightforward impacts such as sea-level rise, where it is assumed direct inundation forces displacement, research finds that whether and how people migrate depends significantly on a diversity of socioeconomic, demographic, and cultural factors. Migration responses will vary depending on the nature of the environmental threat, the development context, and a household or community’s knowledge, networks, resources, and values.

Consider the varied impacts of recurrent drought in rural Ethiopia. One study by Clark Gray and Valerie Mueller found that prolonged droughts led to an increase in seasonal labor migration among men, who used migration as an adaptation strategy, and a decrease in marriage migration among women, as fewer families could afford the costs of a wedding. The author’s own research in the country found that in the short term, drought can trap smallholder farming families in ever more precarious positions, unable to afford a move to town and reliant on food assistance to subsist. In the long term, however, recurring droughts undermine the prospects of farming and incentivize rural families to invest in their children’s internal migration for education, hoping they will find better work in an urban area, or international labor migration to the Middle East. Climate impacts can have multiple and even countervailing effects on migration over time.

Addressing the opportunities and challenges of mixed migration and mixed immobility in an era of climate change will demand a multifaceted approach. At the national level, it will require mainstreaming internal migration into climate adaptation efforts alongside those to support in-situ adaptation and sustainable urbanization. At the international level, it will require an increase in humanitarian assistance and an expansion in humanitarian pathways and legal statuses to support those affected by natural disasters. Some examples of these kinds of protections are Argentina’s new humanitarian visa for people displaced by sudden-onset disasters and the United States’ Temporary Protected Status (TPS), which provides temporary legal status to some nationals of some countries that have experienced crises (including severe natural disasters) so long as they are already in the United States.

It will also require an increase in legal pathways to facilitate international labor migration as an adaptation and income-diversification strategy for households suffering from more slow-onset climate impacts. Indeed, emigrants and other members of diasporas can be powerful forces in encouraging investment in their homelands, such as through the sending of financial remittances, which can help build defenses against new impacts of climate change. Beyond humanitarian and economic pathways, expanding access to student migration is another way to support young populations to increase their skills, move into professions less vulnerable to climate stress, and contribute to their country’s sustainable development.

It is impossible to capture all forms of climate-related migration within a single category. The 2022 IPCC report found that between 3.3 billion and 3.6 billion people were living in countries with a high vulnerability to climate change. Migration within and from these places promises to be as mixed and messy as migration has always been. Throughout history, humans have used migration to adapt to environmental, economic, social, and political change. Climate change will demand new kinds of adaptation, but it will not create a new kind of migrant.

Sources

Africa Climate Mobility Initiative. N.d. A Mobile Future: Climate Mobility Is on the Rise. Accessed June 15, 2023. Available online.

---. N.d. Deep Roots: Connected to Land, Culture, Community. Accessed June 15, 2023. Available online.

Ahsan, Md Nasif et al. 2022. Promise, Premise, and Reality: The Case of Voluntary Environmental Non-Migration Despite Climate Risks in Coastal Bangladesh. Regional Environmental Change 22 (1): 1. Available online.

Argentina National Directorate for Migration. 2022. Disposición 891/2022. Buenos Aires: Argentina National Directorate for Migration. Available online.

Benveniste, Hélène, Michael Oppenheimer, and Marc Fleurbaey. 2022. Climate Change Increases Resource-Constrained International Immobility. Nature Climate Change 12 (7): 634-41. Available online.

Black, Richard et al. 2011. Foresight: Migration and Global Environmental Change. London: UK Government Office for Science. Available online.

Black, Richard and Michael Collyer. 2014. Populations ‘Trapped’ at Times of Crisis. Forced Migration Review 45. Available online.

Cattaneo, Cristina et al. 2019. Human Migration in the Era of Climate Change. Review of Environmental Economics and Policy 13 (2).

Chen Chen et al. 2015. University of Notre Dame Global Adaptation Index: Country Index Technical Report. Notre Dame, IN: Notre Dame Global Adaptation Initiative. Available online.

Clemens, Michael. 2020. The Emigration Life Cycle: How Development Shapes Emigration from Poor Countries. Center for Global Development Working Paper No. 540, Washington, DC, August 2020. Available online.

Clement, Viviane et al. 2021. Groundswell Part 2: Acting on Internal Climate Migration. Washington, DC: World Bank. Available online.

de Haas, Hein. 2010. Migration Transitions: A Theoretical and Empirical Inquiry into the Developmental Drivers of International Migration. Determinants of International Migration. Working Paper No. 24, International Migration Institute, May 2010. Available online.

de Haas, Hein, Sonja Fransen, Katharina Natter, Kerilyn Schewel, and Simona Vezzoli. 2020. Social Transformation. Working Paper No. 166, International Migration Institute, July 2020. Available online.

Divers. 2011. Tens of Thousands of Drought-Displaced Somalis Head to Mogadishu. United Nations High Commissioner for Refugees (UNHCR), July 26, 2011. Available online.

Farbotko, Carol. 2018. No Retreat: Climate Change and Voluntary Immobility in the Pacific Islands. Migration Information Source, June 13, 2018. Available online.

Farbotko, Carol, Olivia Dun, Fanny Thornton, Karen E. McNamara, and Celia McMichael. 2020. Relocation Planning Must Address Voluntary Immobility. Nature Climate Change 10 (8): 702-4.

Fussell, Elizabeth. 2015. The Long-Term Recovery of New Orleans’ Population after Hurricane Katrina. American Behavioral Scientist 59 (10): 1231-45. Available online.

Gray, Clark and Valerie Mueller. 2012. Drought and Population Mobility in Rural Ethiopia. World Development 40 (1): 134-45. Available online.

Gray, Clark and Erika Wise. 2016. Country-Specific Effects of Climate Variability on Human Migration. Climatic Change 135: 555-68. Available online.

Hauer, Mathew E. et al. 2020. Sea-Level Rise and Human Migration. Nature Reviews Earth & Environment 1 (1): 28-39. Available online.

Henley, Jon. 2020. Climate Crisis Could Displace 1.2bn People by 2050, Report Warns. The Guardian, September 9, 2020. Available online.

Intergovernmental Panel on Climate Change (IPCC). 1992. Climate Change: The IPCC 1990 and 1992 Assessments. Geneva: IPCC. Available online.

---. 2022. Climate Change 2022: Impacts, Adaptation and Vulnerability. Geneva: IPCC. Available online.

Internal Displacement Monitoring Centre (IDMC). 2023. Global Report on Internal Displacement 2023. Geneva: IDMC. Available online.

Lenton, Timothy M. et al. 2023. Quantifying the Human Cost of Global Warming. Nature Sustainability: 1-11. Available online.

Migration Data Portal. 2022. Mixed Migration. Updated February 21, 2022. Available online.

Ruiz Soto, Ariel G. et al. 2021. Charting a New Regional Course of Action: The Complex Motivations and Costs of Central American Migration. Rome, Washington, DC, and Cambridge, MA: World Food Programme, Migration Policy Institute (MPI), and Civic Data Design Lab at Massachusetts Institute of Technology. Available online.

Schewel, Kerilyn. 2019. Moved by Modernity: How Development Shapes Migration in Rural Ethiopia. Doctoral thesis, University of Amsterdam. Available online.

---. 2022. Aspiring for Change: Ethiopian Women’s Labor Migration to the Middle East. Social Forces 100 (4): 1619-41. Available online.

Shahzad, Asif. 2022. Pakistan Out of Money for Flood Recovery, UN Boosts Aid Request- Minister. Reuters, October 4, 2022. Available online.

Sironi, Alice, Céline Bauloz, and Milen Emmanuel, eds. 2019. Glossary on Migration. Geneva: International Organization for Migration. Available online.

United Nations Children's Fund (UNICEF). 2017. As Famine Looms, Malnutrition and Disease Rise Sharply Among Children in Somalia. Press release, March 30, 2017. Available online.

United Nations Development Programme. N.d. Human Development Index (HDI). Accessed June 15, 2023. Available online.

Wiegel, Hanne, Jeroen Warner, Ingrid Boas, and Machiel Lamers. 2021. Safe from What? Understanding Environmental Non-Migration in Chilean Patagonia through Ontological Security and Risk Perceptions. Regional Environmental Change 21 (2): 43. Available online.

World Bank. 2021. Climate Change Could Force 216 Million People to Migrate within Their Own Countries by 2050. Press release, September 13, 2021. Available online.