What Is Climate Mobility, and Why Should We Care?

Our world is built on the assumption of climate stability. We expect the land beneath our feet, the climate we experience, and our way of life to remain constant. Today, these assumptions no longer hold. Rising sea levels, coastal erosion, drought, and increasingly frequent extreme weather events are reshaping landscapes, hindering livelihoods, and endangering lives. As the climate continues to change and the habitability of once-stable territories shifts, humans—along with other species—must adapt to the new realities redefining where and how we live.

Climate change and its related disasters are already influencing patterns of human mobility and will continue to impact people’s mobility choices significantly. To empower individuals and communities to make climate-informed decisions about where to live and work in the face of accelerating climate risks, there is a need to develop creative governance arrangements, accessible finance mechanisms, and forward-looking policies that acknowledge the intersection of climate change, human mobility, and various other policy areas. Central to this effort is the need to develop a greater understanding of how the adverse effects of climate change interact with patterns of human mobility. Only then will it be possible to craft the necessary context-specific policies and plans to maximize adaptation benefits, uphold human rights, and minimize further vulnerabilities.

What Is Climate Mobility?

Given the reality of climate change, significant numbers of people are, and increasingly will be, on the move. While this movement will primarily occur within country borders, it will also happen across international boundaries. The Intergovernmental Panel on Climate Change, the body tasked with assessing climate science and its impacts, reports that climate hazards are already driving displacement in all regions globally.¹ Around the world, droughts, wildfires, floods, food crises, and storms are forcing people from their homes. The International Organization for Migration estimates that weather-related disasters have resulted in over 218 million internal displacements over the past ten years.² In 2024 alone, the Internal Displacement Monitoring Centre reported 45.8 million new internal displacements caused by disasters—more than double those caused by conflict.³

Despite the escalating impact of climate hazards on human mobility, there is no universal framework to govern such movements. Existing definitions and international legal protections for refugees, such as the 1951 UN Refugee Convention, do not extend to those displaced by climate or environmental factors. Terms such as “climate refugee” are not recognized under international law.⁴ While there is no consensus on nomenclature for climate-related human movement, the term climate mobility is currently used to encompass the range of population movements that result from climate impacts.⁵  There are three key forms of population movements:

• Migration involves some degree of agency when moving within or across borders. For example, prolonged drought in Central America’s “Dry Corridor” has severely devastated traditional agricultural livelihoods, driving many to migrate to larger cities or, in some cases, to other countries in search of better opportunities.⁶ 
• Displacement refers to the forced movement of people within or across borders, often driven by acute environmental pressures that overlap with existing crises. In the cases of Sudan and the Lake Chad Basin, the loss of livelihoods and scarce water resources exacerbates existing conflicts, forcing people out of their homes.⁷
• Planned relocation refers to the planned process of moving individuals or communities because the land has become—or threatens to become—uninhabitable, usually within a country’s borders and with the government’s support. This was the case for Gardi Sugdub in Panama, Vunidogoloa in Fiji, and Isle de Jean Charles in the U.S. state of Louisiana.⁸

Thus, climate mobility serves as an inclusive term to represent the multiplicity of causes, forms, directions, and dimensions of human movement in the context of climate change.⁹ It encompasses movement that is voluntary or forced, temporary or permanent, within countries or across borders.¹⁰ This complex phenomenon can also span diverse time frames, legal categories, and geographic and climatic contexts. Receiving communities must be equipped to understand and prepare for this phenomenon. If not, climate-displaced individuals risk resettling in vulnerable areas and once again exposing themselves to new and future climate risks.

Decisions about abandoning homelands or staying in the face of climate impacts involve complex social, economic, and political considerations. In many cases, political leaders shy away from these decisions for fear of appearing to abandon places that communities have called home. The challenge, then, is to create a response framework that can make these decisions more manageable to navigate, offering both individuals and governments more options. Ultimately, measures adopted to facilitate climate mobility must accomplish three fundamental goals: (1) enable people to stay at home where adaptation in situ is feasible and desired; (2) empower people and communities who seek or need to move to do so safely, voluntarily, and with dignity, including facilitating evacuations or relocation for those at great imminent risk; and (3) provide support for receiving communities.

The Challenge of Estimating Climate Mobility

Understanding the scale and direction of climate mobility is not a straightforward endeavor. Climate change rarely causes movement on its own.¹¹ Instead, climate mobility is typically the result of the intersection of multiple factors that create emergent harms.¹² The direction, scale, and duration of people’s movements in response to climate risks are influenced by highly complex dynamics that cannot be easily disentangled. For example, individuals who move because of food security or livelihood challenges may not directly attribute their decision to climate change but may be influenced by climatic stressors.  

Best efforts by the World Bank estimate that anywhere between 44 and 216 million people across six regions could be internally displaced by 2050, depending on the severity of future climate scenarios.¹³ However, attempts to estimate climate mobility face significant challenges, such as the issue of attributing causality, the inherent unpredictability of climate hazards, unforeseen shifts in border governance, and the uncertainty of future adaptation plans.¹⁴ These all hinder the ability of stakeholders to make accurate forecasts. Given the current scale of climate mobility, it is essential that modeling, future planning, and projection exercises continue. There is an urgent need to estimate the direction, magnitude, and duration of climate-related mobility more precisely to allow for adequate responses by states and other stakeholders.

A better understanding of the relationship between climate hazards and human mobility is crucial.

While unlikely to fully resolve the causation conundrum, innovative modeling exercises can offer valuable predictions of how climate change will likely affect movement trends. Such predictive tools will allow for effective policies to be crafted, direct public and private investments to the right places, and strengthen the communities likely to receive inflows of new residents. Continued innovation and investment in modeling, future planning, and projection exercises are essential.

New Questions, New Solutions

Climate mobility introduces challenges that traditionally have not been considered in migration policy. One key dimension of that is immobility: Individuals may choose to remain in their homes despite imminent climate risks, guided by a strong attachment to place, cultural traditions, or other factors. Protecting the “right to stay,” where safe and possible, is a relevant policy concern for addressing climate mobility.¹⁵ On the other hand, there are those who need to or prefer to migrate from areas of high climate risk but are unable to do so. This may be because they lack the financial resources to move, face physical limitations, or encounter a restrictive policy environment. Vulnerable communities, such as people with disabilities, unaccompanied minors, and older people, are disproportionately affected by this challenge.¹⁶ Strengthening adaptive capacities by facilitating people's right to either stay safely or migrate with dignity is a key policy priority.

Another set of questions concerns how people move. While cross-border migration garners the most media attention, most climate mobility occurs internally.¹⁷ Given that challenge, policymakers thus need to consider the appropriate domestic responses to prepare for—or mitigate—internal mobility. For some, that might entail a legal approach: In Colombia, disaster-related displacement in 2023 surpassed conflict-related displacement by more than 50,000 individuals.¹⁸ As a result, in 2024, the Constitutional Court ruled that climate change could be legally considered a cause of forced displacement, creating obligations for state protection.¹⁹ Other policymakers may have to contend with a more systemic approach toward preventing large-scale displacement. In the United States, approximately 40 percent of the population lives in coastal areas facing escalating flood risks.²⁰ Despite that, the housing finance system has been slow to adapt to physical climate risk, threatening a coastal property market collapse that may spur large-scale movement. In that case, policymakers might want to consider reforms aimed at creating a more secure and resilient housing market. ²¹

When cross-border mobility does occur, it generally remains within the region—a pattern similar to non-climate-related movement. ²² For example, out of the 7.89 million Venezuelans abroad, 6.7 million remained in the region, with 2.8 million living in Colombia, compared to the 770,000 in the United States.²³

Finally, different climate hazards result in movement with distinctive characteristics. Understanding the underlying factor driving an instance of climate mobility is essential in allowing for adequate legal and policy responses to be crafted. Sudden-onset hazards, like hurricanes, floods, and tropical storms, often cause immediate and evident displacement. This movement is generally temporary, though it may result in permanent migration if return becomes unviable, and usually involves shorter distances. ²⁴ This form of climate mobility is comparably well understood and will often activate government disaster-related responses in the immediate aftermath of a disaster. Greater policy attention should hence be directed toward longer-term post-disaster results.²⁵ 

In contrast, slow-onset events like sea level rise, salinization, and desertification produce adverse effects that are often less understood. These events can also force migration when livelihoods become unsustainable. However, this form of climate mobility is less identifiable, more individualized, and more permanent. It also often involves greater distances traveled.²⁶ As a result, crafting an adequate and supportive policy and programmatic response becomes more challenging. In this context, given a likely greater level of agency for individual migrants, mobility has the potential to serve as an important adaptation and risk management strategy; greater attention should be given to policies and programming that support proactive decisionmaking in migration that will enhance the benefits of migrating and minimize associated risks.²⁷

Complexity Does Not Mean Inaction

No universal framework exists to manage or govern human mobility related to climate change. Thus far, most policy responses focus on either disaster management or reducing displacement; few focus on facilitating human mobility.²⁸ Until recently, no government had committed to offering legally binding remedies based on an individual’s exposure to climate change.²⁹

However, this does not mean that nothing can be—or has been—done to address climate mobility. A nascent, if patchy, international governance framework is emerging that recognizes the importance of addressing the impacts of climate change on human mobility. States are increasingly considering their duties regarding climate mobility. Chile and Colombia, for example, have asked the Inter-American Court of Human Rights for guidance on the obligations and principles that should inform the measures that states—individually and collectively—adopt to deal with involuntary human mobility exacerbated by the climate emergency.³⁰  

Within the existing institutional frameworks supporting the implementation of the UN Framework Convention on Climate Change (UNFCCC), climate mobility has received formal recognition in the form of the 2010 Cancun Adaptation Framework and the decision of the eighteenth session of the Conference of States Parties (COP18) on loss and damage adopted in Doha in 2012.³¹ In 2013, the Warsaw International Mechanism on Loss and Damage was established during COP19 (with a mandate to increase knowledge on how the impacts of climate change affect human mobility) and dedicates a strategic workstream focused on “human mobility, including migration, displacement and planned relocation.”³² In addition, the Task Force on Displacement was created under the Warsaw Mechanism during COP21 to “develop recommendations for integrated approaches to avert, minimize and address displacement related to the adverse impacts of climate change.”³³ In COP27, a loss and damage fund under the Sharm el-Sheikh Implementation Plan was created to address, among other things, “forced displacement . . . [and] human mobility.”³⁴ COP28 confirmed the inclusion of human mobility in the loss and damage fund, and COP29 referenced human mobility in both the funding decision and as part of the indicator recommendation in its Global Goal on Adaptation.³⁵ 

Outside of the UNFCCC, the migration and displacement policy field has also produced a raft of instruments to address climate mobility. For instance, the 1998 Guiding Principles on Internal Displacement included considerations for internal displacement in the context of disasters.³⁶ In March 2015, the Sendai Framework for Disaster Risk Reduction was adopted to “prevent new and reduce existing disaster risks” and “increase preparedness for response and recovery, and thus strengthen resilience,” recognizing disaster displacement as a relevant concern and acknowledging the role of disaster in driving human mobility.³⁷ That same year, the Protection Agenda of the Nansen Initiative provided guidance to enhance protection for people displaced across borders in the context of climate change and disasters.³⁸ Finally, the Global Compact for Safe, Orderly and Regular Migration, adopted in 2018, made specific recommendations aimed at ensuring safe human mobility in the contexts of disasters, environmental degradation, and the adverse impacts of climate change.³⁹ 

A range of international instruments and innovative “soft law” frameworks have been developed in recent years to address the intersection of climate change and human mobility. They provide a foundation for addressing this issue, and a more comprehensive list can be found in Annex I of this article. 

Moving Forward

The key focus of addressing climate mobility is not to “solve” the impacts of climate change. Instead, the challenge is to strengthen the adaptive capacity of vulnerable communities, ensuring that those who wish to stay can do so in safety, while those who need or choose to move can do so voluntarily, safely, and with dignity. Effective responses will have to be context-specific and sensitive to the particular needs of affected communities.⁴⁰ As such, a panoply of measures will be needed to ensure that responses adequately address the varieties of climate mobility, for those who have to or choose to move, those who stay behind, and the transit and receiving communities.

We must draw from the existing toolbox of policies, practices, and initiatives to address this challenge. While many of these tools were not explicitly designed with climate mobility in mind, they offer solutions for people displaced by a deteriorating climate, ensuring access to socioeconomic rights and lawful status for individuals displaced directly or indirectly by climate change. The path forward lies in understanding what tools are already available and what needs to be created to develop the responses that communities require. Successfully doing so will require a better understanding of the phenomenon of climate mobility and a more holistic approach to supporting communities and individuals with heightened climate vulnerabilities, wherever they are.