Since the 1980s, the issue of climate-related forced displacement has grown, yet there is still no clear legal definition of “people fleeing their country for climate-related reasons”. Although the Global Compact for Safe, Orderly and Regular Migration (the Marrakech Compact), adopted by the United Nations General Assembly in 2018, acknowledges the impact of environmental changes, the non-binding nature of the agreement limits its effectiveness.

The term “climate refugee” refers to someone who has been forced to move due to a climate-related disaster or, more broadly, due to the effects of global warming on their living environment. This can fall under a broader category: “environmental refugees”. A 1985 report from the United Nations Environment Programme (UNEP) defines environmental refugees as individuals who are forced to leave their habitat, either temporarily or permanently, due to environmental disruption of natural or human origin that threatens their existence or seriously undermines their quality of life.

Most climate-related migration occurs within countries rather than across borders. For example, a 2021 World Bank report projects that around 216 million people will be internally displaced by 2050 due to movements driven by climate-related and environmental degradation. The United Nations High Commissioner for Refugees (UNHCR) therefore prefers to speak of “people displaced by natural disasters and climate change” rather than “climate refugees”.

While migration linked to environmental changes is not a new phenomenon, its scale continues to grow due to the intensification of extreme climate events. High-risk regions include Sub-Saharan Africa, which is facing drought; South and Southeast Asia, which are exposed to typhoons and tsunamis; and small island States, which are confronted with rising sea levels. According to an update published by the Bosch Foundation in 2025, these migrations will primarily affect cities, which will have to absorb the majority of internal mobility on their own.

In its latest report (AR6), the Intergovernmental Panel on Climate Change (IPCC) emphasises that migration can serve as a genuine adaptation tool when it is anticipated, supported and opted for. Conversely, when migration becomes forced, it becomes a source of vulnerability and risk. Since 2015, the International Organization for Migration (IOM) has had a division dedicated to ‘Migration, Environment, and Climate Change’ (MECC), overseeing, supporting and coordinating initiatives related to migration resulting from global warming.

According to an estimate by the World Meteorological Organization (WMO), water stress could displace up to 700 million people in Africa by 2030. The 2020 World Disaster Report projects that, by 2050, around 200 million people per year may require humanitarian assistance due to the combined effects of climate-related disasters and the socio-economic impact of climate change. Climate change exacerbates existing challenges and underlying vulnerabilities, forcing communities to confront growing crises.

According to multiple sources, Small Island Developing States (SIDS) face an existential threat due to rising sea levels, with tropical cyclones resulting in approximately 7.5 million people being displaced last year alone. The Asia-Pacific region bears a heavy burden from the adverse effects of climate change. In 2022 alone, the region experienced over 140 disasters, resulting in more than 7,500 deaths and affecting over 64 million people. The economic damage was estimated at over 57 billion dollars. Around seventy percent of the countries most affected by climate change are among the world’s most vulnerable. Storm Daniel devastated the Mediterranean in early September, causing loss of life and displacing more than 40,000 people in Libya alone. Displaced communities in Pakistan were still recovering from the 2022 monsoon floods when heavy rains struck again in June 2023.

Officially recognising that climate change causes massive human displacement would have several highly sensitive implications.

  • Firstly, it would create a legal status of “climate refugee”, which would grant new rights. Many developed countries are reluctant to assume this due to fear of legal precedent, moral responsibility or a stronger duty of reception.
  • It would also mean acknowledging a heavier climate debt, as it would imply that some States historically responsible for emissions have direct responsibility for these displacements.
  • It would also redefine the boundaries of sovereignty, as migration touches on domestic politics, border control and integration — areas where states want to maintain full control outside the multilateral framework.

The paradox is therefore profound: the climate crisis is also a human crisis, yet it is treated as a technical issue. What is missing from the negotiations is a “human mobility” pillar. If we are to take scientists’ projections seriously, it is essential that future COPs include this pillar, i.e.:

  • Official recognition of climate-displaced people, who currently do not exist legally;
  • Funding to support both regions of departure and host areas, as the cities receiving these populations are often the poorest;
  • An international protection framework, not to force reception, but to organise dignified and humane mobility; 
  • A long-term vision for the habitability of territories is also needed, as some areas of the world will become too hot to live in.

If future COPs truly want to address the climate crisis, they will need to broaden their scope from carbon to the human lives affected by it.