Environmental Migration at the International Level: What’s There, What’s Not, and What’s Needed?

Chiara Scissa
PhD Student in Law at Sant’Anna School of Advanced Studies; Visiting Researcher at the Division of Migration, Environment and Climate Change at IOM Regional Office in Vienna.



From 2008 to 2020, 24.5 million new displacements per year have been registered, 88.9% of which are weather-related. This equals to 67,000 displacements each day. In 2020 alone, 98% of new internal displacements worldwide stemmed from weather events. The 2021 World Bank’s Groundswell report suggests that climate change and environmental degradation may result in the displacement of 216 million people by 2050 due to slow-onset events. Although the majority of people affected by environmental threats are projected to be internally displaced, the exposure to slow-onset events, such as sea-level rise or desertification, may significantly trigger cross-border environmental migration in the future. Currently, approximately 80% of the world’s poorest populations live in degraded rural areas affected by drought and desertification, which have been recognized by the international community as drivers of forced migration. Data suggest therefore that environmental factors have constantly shaped migration movements in the past, and will continue to do so even more strongly, in the future.

What’s There

The impacts of climate change on human mobility have been explored by scientists and academics since the ‘80s, primarily from a security perspective. The investigation led numerous scholars and civil society organizations to advance a wide range of proposals to recognize and protect from the environmental causes of migration, including climate change. None of them, however, met the agreement of the international community. In 2007, the International Organisation for Migration (IOM) defined environmental migrants as those “[…] persons or groups of persons who, predominantly for reasons of sudden or progressive change in the environment that adversely affects their lives or living conditions, are obliged to leave their habitual homes, or choose to do so, either temporarily or permanently, and who move either within their country or abroad”. In opposition to other suggested working definition, IOM’s recognizes a relevant link between environmental threats and migration, while highlighting the complexity of the phenomenon. The climate change-migration nexus has regained momentum only recently, when climate change began assuming the shape of a humanitarian crisis.

Indeed, the 2015 Paris Agreement acknowledges that climate change is a common concern of humankind, and therefore that “[…] parties should, when taking action to address climate change, respect, promote and consider their respective obligations on human rights, the right to health, the rights of indigenous peoples, local communities, migrants, children, persons with disabilities and people in vulnerable situations and the right to development, as well as gender equality, empowerment of women and intergenerational equity”.

Moreover, numerous international soft-law instruments adopted in 2015 contained relevant provisions in the field of environmental migration. For instance, the 2015 Agenda for the Protection of Cross-Border Displaced Persons in the Context of Disasters and Climate Change encouraged States to identify and integrate existing practices at national and sub-regional levels into their own normative frameworks in accordance with their specific situations and challenges in order to protect migrants affected by disasters.

The 2030 Agenda on Sustainable Development, adopted in December 2015, and the 2016 New York Declaration for Refugees and Migrants recognize that the adverse impacts of climate change, environmental degradation and disasters serve as a cause of forced migration. They therefore call on States to provide adequate solutions to climate change and to protect people affected by it both within and across their territory, in order to leave no one behind.  

The 2018 Global Compact for Safe, Orderly, and Regular Migration (GCM) represents a landmark and major breakthrough, as it is the first ever inter-governmentally negotiated agreement to recognize environmental disasters as drivers of forced migration, as well as the urgency to provide protection to their survivors. Most importantly, Objective 5 calls on participating States to use protection mechanisms “[…] based on compassionate, humanitarian, or other considerations for migrants compelled to leave their countries of origin owing to sudden-onset natural disasters”, as well as to devise planned relocation. In doing so, the GCM acknowledges the climate change-migration nexus. For its part, the 2018 UN Global Compact on Refugees confirms that environmental threats may exacerbate forced migration.

In 2019, five UN human rights treaty bodies issued a Joint Statement on Human Rights and Climate Change, where they acknowledged that climate change poses significant risks to the enjoyment of the human rights protected under their related conventions, and encouraged States to offer complementary protection mechanisms for migrant workers “[…] displaced across international borders in the context of climate change and disasters”.

Finally, in its 2020 key legal considerations, UNHCR recalled to carefully consider all intertwined drivers of migration. This included the socio-economic and political impacts of climate change on vulnerable, discriminated or marginalized populations, as well as short and long-term risk of human rights violations related to environmental harm that may bolster claims for refugee status within the definition of the 1951 Refugee Convention.

What’s Not There and What’s Needed

Despite these policy developments, the climate change-migration nexus still needs to be fully recognized and explored. The lack of a common definition of environmental migration is correlated, from a legal viewpoint, to the lack of a specific legal framework that could provide environmental migrants with protection, assistance and rights. Law and application many times do not go hand in hand. What’s feasible from a legal viewpoint might sound unrealistic. Widening protection to environmental causes of migration seems feasible under international law, but it sounds unlikely, given States’ reluctance to assume additional protection responsibilities coupled with the cumbersome process of negotiating or amending international instruments. What is needed (for now) is to make adequately make use of already-existing instruments. As climate changes, migration law needs to change as well to effectively protect from environmental drivers of migration and related violations of human rights. For the international efforts on climate and migration to be truly comprehensive and effective, the international community should address the nexus between the two by: (1) promoting an extensive application of existing protection instruments and human rights law; and (2) extensively interpreting asylum and migration provisions in light of potential environmental threats to migrants’ rights.