Climate change is new, but the issues it raises are not. Weather variations have always existed; the difference today is the unprecedented speed at which temperatures are rising to heights never seen before, and the human responsibility for it. That is climate science. From a social science perspective, climate change is new to humans in its urgency and the necessity it creates for self-reflection. Climate change challenges us, as humans, because we are both responsible and victims, though a generic ‘we’ makes little sense given the differentiated contributions and impacts across people within and between countries. Climate change thus fascinates scientists across disciplines, perhaps in a disproportionate way compared to the also significant urgency of other planetary boundaries.
When it comes to human migration, climate change also constitutes a new phenomenon that sheds light on old failing (legal) structures. Climate change has not created a new category of migration: often qualified as ‘threat multiplier’, it influences the complex set of interrelated factors motivating movement, in line with the multicausality of movement well-known in the social sciences. Climate change, nonetheless, highlighted problematic conceptualisations that focused on deserving forced cross-border migrants.
While the social sciences have evolved to improve their understanding of human movement, especially with the mobility studies (1), the legal framework still largely reflects these shortcomings, which impede the use of mobility as a tool for adapting to climate change (2). As legal scholars, it is our role to offer another conceptualisation of law to enable it to evolve towards a governance capable of addressing today’s challenges. Policy categories have long influenced (forced) migration studies; now that scientific categories are established, it is our turn as legal scholars to take stock of them and suggest improvements to the legal framework. This paper, therefore, draws on the social sciences to show how law could help make adaptive mobility a tool in the face of climate change (3), while also acknowledging the dangers (4).
Mobility studies in the social sciences
In the social sciences, the field of refugee studies has evolved into forced migration studies, recognising that migration can be forced even when not linked to one of the five grounds of the Refugee Convention, including when driven by climate change. More recently, migration studies have evolved into displacement studies, notably because of the acknowledgement that a large part of forced migration occurs within countries, including when linked to environmental factors. Despite the term evolving to be more encompassing, all three still make a distinction between forced and voluntary movement. Yet, ‘there is no categorical analytical distinction between ‘forced’ and ‘voluntary’ migration, since all migration involves both choices and constraints’.
Mobility is a broad field of study that I limit to human movement, although it usually extends beyond that. It is useful for examining migration, as it reflects the diverse, shifting, and complex nature of movements. People constantly shift from one form of mobility to another, but also from mobility to immobility. And not all movements carry the same value. Mobility studies analyse how structures allow some mobilities and impede others, and include the question of mobility justice. This is illustrated in the context of climate change, to capture the diversity of movements in terms of form, timing, and destination, as well as to refuse simplified assumptions about unidirectional, monocausal, or inherently positive or negative character. The need to focus simultaneously on immobility was also prominent when it comes to climate change, first to include the trapped populations unable to move, then to give voice to affected people willing to stay in place.
The actual legal framework: a palliative approach in the face of foreseeable risks, with a negative understanding of movements limiting potential for positive adaptation
The legal framework is far from incorporating such complexity. International migration law, even in its most comprehensive attempt, the Global Compact for Migration, remains mostly founded on the three steps of departure, admission and sojourn in a segmented and fixed conception of mobility. This also implies a focus on cross-border mobility, with the Guiding Principles on Internal Displacement and their regional and national declinations being the significant exceptions. Some instruments more specifically devoted to mobility in the context of climate change or more specific aspects of it that were suggested, are more comprehensive (Peninsula Principles on Climate Displacement within States, Kaldor Centre Principles on Climate Mobility, ILA Declaration of Principles on the Protection of Persons Displaced in the Context of Sea Level Rise), but their authority is relative.
Moreover, international migration law is still largely trapped in the dichotomy between forced and voluntary migrants, where forced migration is the only way in if one does not benefit from another legal immigration avenue, whose access is highly unequal. The regime therefore seems to value forced – becoming ‘deserving’ – migration. This leads to a paradox where ‘forcibly displaced persons in the context of climate change and disasters may be better protected in some cases — meaning they may qualify for international protection — if their country of origin doesn’t fulfil its human rights obligations’. Contrary to the concept of mobility, which is not in itself attached to any positive or negative symbolic meaning, migration in law is considered an anomaly in a sedentary world, to be avoided. Migration is portrayed as a harmful impact of climate change, undermining its potential as a positive response to it.
Finally, international migration law is mostly concerned with people already on the move, in a palliative way. A typical example is international protection law, where timing is important because the feared harm must be sufficiently serious. Concerning the effects of climate change on the Pacific archipelago of Kiribati, in the Teitiota views, the United Nations Human Rights Committee considered that this was not the case because the State still had time to intervene. In law, an anticipatory movement is therefore often confused with a voluntary movement. Yet, in political philosophy, most, if not all, movements driven by climate change are considered displacements, since they are forced from a moral perspective. The difference between anticipatory and reactive displacement lies in the range of valuable options available. Anticipatory mobility offers space to reduce harm, although it does not always do so. Climate change, therefore, underscores that mobility could be a viable strategy, as deterioration is foreseeable in some places.
A new conceptualisation in law enabling adaptive mobility
The notion of adaptive mobility itself suggests a (promising) interaction between migration law and climate change law. As I already argued elsewhere, adaptive mobility could be divided into two categories for legal purposes: individual and planned. For individual mobility to be adaptive, it should be accessible to individuals in need. This includes a holistic legal framework that allows cross-border movements through new (genuine) legal avenues for migration, while also providing better protection and durable solutions for people on the move and for communities of origin and destination. Climate change only adds to a much broader argument for governing human movements differently, promoting voluntary movements to minimise forced movements. Other legal scholars have begun to use the term ‘mobility’ to call for a rethinking of international law, ‘which pits territorial boundedness as the normal state of affairs, and considers transnational mobility as the aberration rather than the norm’ or to ‘[put] human beings front and center’.
On the other hand, planned mobility relates to the concept of (planned) relocation, which is the preferred term in recent discussions in the context of climate change and disasters, although the development field first studied it under the label resettlement. But what is covered by this notion? The instruments sometimes use the notion without defining it (like the Cancun Adaptation Framework), and sometimes provide definitions, with the most frequently cited being the one used in the Guidance on Protecting People from Disasters and Environmental Change through Planned Relocation. Some authors have also suggested definitions (Cantor, Bower & Weerasinghe). It seems established that this must be a planned process leading to permanent settlement that enables people to rebuild their lives, with a certain degree of coordination, although it is not entirely clear whether the public authorities should be involved.
From a legal perspective, the involvement of an authority is interesting, though. Planned relocations are appealing because States take their responsibility to protect their citizens from known hazards, and particularly the most vulnerable. Indeed, it replies to the call from the ‘migration as adaptation’ literature, which warned against a liberal turn reflecting a ‘move away from inherent rights, towards the idea that risk should be governed through the fostering of individual preparedness, which in this case falls on the shoulders of (potential) migrants’. Moreover, it includes those labelled as trapped populations, i.e. people who lack the capacity to move. Planned relocations, therefore, came back to the forefront in the social sciences with the awareness of climate change, although they have long been studied in the development context, notably.
(Im)mobile adaptation: law as a benchmark in a solution that needs to be contextual
Mobility is only one of the adaptation strategies people can use, notably in a changing environment. Other adaptation measures are in situ, allowing people to stay in place, to stay home. In the field, the notion of choice often underlies community discourses. It was no surprise that the idea of voluntary immobility emerged from empirical scholars. Still, its legal translation may be found in the legal framework helping to stay in place, such as disaster risk reduction, or in the more emerging right to remain. This is also what makes individual mobility attractive, since it means an individual has reached their tipping point, prompting them to move.
There is indeed no uncontested way of designing a land as ‘uninhabitable’. This is linked to the uncertainty of climate science, but also to more human factors. Inhabitants’ risk perception is personal and related to how they deal with their attachment to place. It does not mean that people leaving are not attached to their place, but different people have different attachments and can deal with them differently. People, therefore, have different tipping points in their decision to leave, as migration results from a complex set of factors. The fact that family members are already elsewhere may, for example, play a role. It does not mean either that people choosing one form of mobility (e.g., circular) would accept another (e.g., permanent).
Knowing when to use planned relocations is therefore not easy, especially given that the development literature has already highlighted many cases of instrumentalization, notably speculation on seized land. A body of literature has long existed on how to conduct planned relocation. Yet climate change drives us to question when to use it – to ‘move people out of harm’s way’ – and how to take that decision while avoiding ‘anticipatory ruination’.
The in situ adaptation measures taken by authorities indeed play a role in a territory’s habitability. There are no hard limits to habitability; instead, there is a decision not to choose technical solutions. The refusal to take such adaptation measures can be instrumentalised, but can also result from legitimate considerations, such as the impact of such measures on the ecosystem or equity concerns. On the coast, for example, mobility measures can enable a more respectful relationship with nature on land that humans have profoundly altered and prevent the constant shifting of erosion problems to downstream communities caused by sea wall construction.
Some authors have tried to identify criteria to consider planned relocation or migration more generally as successful adaptation. The criteria are multiple, but what emerged is the need to take into account the needs of relocated people, as well as the well-being and equity of all affected people, including communities of origin and destination, and sustainability considerations.
Planned relocations were grasped by legal scholars in a deeper way than ever before in the context of climate change, as it holds the potential to enable the collective movement of the entire community. The aforementioned Guidance and its accompanying Toolbox were drafted following a lengthy process involving expert meetings and a thorough review of international law and existing operational frameworks relevant to relocation.
The response may only be contextual, but the law can offer benchmarks, for example, through participatory rights to avoid abuses. In general, it is interesting to see how many legal scholars in the field engaged with the empirical social sciences or even entered the field to grasp and understand the human implications of the measures they examined.
Climate change, therefore, brought old questions from the migration field back to the forefront. Most profoundly, it reminds us of what mobility is: a human phenomenon, part of adaptation strategies, and of the role of law in that regard, which cannot be limited to regulating cross-border forced movements but should reverse the paradigm and allow positive mobility when possible to avoid displacement in the future.
Marie Courtoy holds a Bachelor’s degree in Sociology and Anthropology, and Bachelor’s and Master’s degrees in Law. She is a researcher at UCLouvain and KU Leuven, and an associate researcher in the Law & Anthropology Department of the Max Planck Institute for Social Anthropology.
This topical paper is part of the special series on ‘Internal Displacement in a Changing World Order’, led by the Internal Displacement Research Programme at the RLI. The experts contributing to this series assess how rapid shifts in contemporary politics, plummeting levels of humanitarian aid and escalating global crises are impacting displacement-affected communities. The series ties into a recently launched 45-chapter “Handbook of Internal Displacement” (2026) that comprehensively addresses this issue.
KEYWORDS: Internal Displacement, IDPs, climate, adaptation, mobility, law.
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