Climate mobility explained: who is responsible, and when
Can climate change make someone stateless?
The legal risk is generally thought to be lower than often feared, but the practical risks are real.
Rising seas have raised questions about the future of low-lying island states. No state has yet ceased to exist because its territory was submerged. Pacific Islands Forum leaders declared in 2023 that statehood and sovereignty will continue despite sea-level rise, Tuvalu has written this into its constitution, and the International Court of Justice’s 2025 advisory opinion indicated that a state would not necessarily lose its statehood if one of its elements, such as territory, disappeared.
The more immediate risk is practical. People who lose their identity documents in a disaster may be unable to prove their nationality, and regional free movement agreements often do not cover stateless people and non-nationals. Reissuing documents quickly after a disaster is an important protection.
Who is responsible for climate mobility: national governments, local governments or countries of destination?
All of them, in different ways.
- National governments have the primary responsibility to protect and assist people displaced within their own borders, as reflected in the UN Guiding Principles on Internal Displacement.
- Local and city governments are often the first to respond and the places that host newcomers, so they need funding and plans in place.
- Destination countries are bound by obligations they already have, including not returning people to serious harm, and decide on their own admission routes.
- The international community shares responsibility through climate finance, development cooperation and regional agreements.
Within any one government, responsibility is usually spread across many ministries. For that reason, the Institute recommends that the centre of government (the Cabinet Office or equivalent) adopt a working definition of climate mobility and assign responsibilities across departments, so that each is clear about its role. This is best done early, well before a crisis.
When does government protection become inadequate?
When a state is unable or unwilling to protect people from serious and foreseeable harm.
This can happen suddenly, when a disaster overwhelms the state’s ability to respond, or gradually, as slow onset change affects water, food, income or safety. It can also happen selectively, when some groups are left out of protection or adaptation support.
In assessing a person’s situation, decision-makers can ask whether the country of origin has provided protection or adaptation support that is meaningful in that person’s own circumstances. A national plan on paper may not be enough.
Are there metrics to measure whether a place is habitable?
There is no single agreed measure, but there are useful indicators.
Physical indicators include extreme heat and humidity, freshwater availability and salinisation, how often coastal flooding and erosion happen, and changes in crop yields. Social indicators matter just as much: whether people have access to income, services, housing and safety.
Because habitability is a matter of degree rather than a threshold, no single measure will show when a place has become uninhabitable. For deciding who is eligible for support or a pathway, the Institute suggests that governments use a transparent set of criteria, such as a country falling below a set vulnerability score, or a national climate agency designating an area as facing “serious and reasonably foreseeable uninhabitability”. Waiting until a place has become uninhabitable would be too late.
Can the UK develop frameworks in isolation?
It can start alone, but it can achieve more with partners.
Much of what the Institute recommends is within the UK’s own control: guidance for decision-makers, adapting existing visa routes, domestic housing and funding reform, and building climate mobility into intelligence and development planning.
Results are likely to be stronger with partners, for example through bilateral labour agreements, support for regional free movement agreements, multilateral climate finance and the Platform on Disaster Displacement.
About the Institute
The Institute for Law and Policy on Climate Mobility brings together world-leading experts to research, inform, and advise on rights-based responses to climate mobility. We seek to mainstream climate mobility in legal and policy frameworks as the centrepiece to climate resilient governance structures.
How to cite
Iengar, S. (2026) Climate mobility, explained. Explainers. Oxford: Institute for Law and Policy on Climate Mobility, University of Oxford. Available at: https://www.law.ox.ac.uk/border-criminologies/institute-for-law-and-policy-on-climate-mobility