Displacement, Migration, and the ‘Immobility Paradox’: How Climate Change Shapes Relocation
One of the drivers of migration globally is climate change — but, as international policies are discussed and developed, the full picture of how the two are intertwined continues to be studied.
Climate change drives migration when things like extreme weather, including floods, wildfires, and droughts, occur, as well as longer-term shifts, like sea-level rise and desertification.
In response to sudden-onset disasters — like hurricanes, floods, and wildfires — immediate, but often temporary, displacement occurs. In 2022, over 1.1 million people were displaced in Somalia by drought following four consecutive failed rainy seasons, which led to widespread death of livestock and a food crisis, as reported by International Organization for Migration, a United Nations organization. The majority of people who were displaced went to Somali cities and towns, seeking humanitarian assistance.
Typically, sudden-onset disasters lead to short-term displacement, but people may decide to move further or permanently away if events recur repeatedly or cause major damage, according to Migration Policy Institute.
Slower-onset change, like rising sea levels, land degradation, coastal erosion, and extreme temperatures, create long-term migration pressure by making areas unlivable. This type of movement may be more permanent, including across borders.
In a worst-case estimate by World Bank — without “early and concerted climate and development action” — up to 216 million people could move within their own countries by 2050 from areas facing water scarcity and lower crop productivity. World Bank predicted the number could drop by up to 80%, to 44 million, if governments work to mitigate the pace of climate change, as well as its impacts.
There is also the Immobility Paradox, where people from countries most exposed to climate change have had far fewer emigrants than expected. These “trapped populations,” while the “most exposed to the onset of climate change,” are, at the same time, “less able to migrate away from its consequences,” as reported by the Institute of Labor Economics.
Groups with incomes near the average for their region are those most likely to migrate due to climate-related impacts, read a report by Stanford Doerr School of Sustainability, while those with the highest and lowest incomes are less likely to migrate. The lowest income population typically do not have the resources to move, while those with the highest income are able to adapt without moving.
In its 2025 Global Report on Internal Displacement, Internal Displacement Monitoring Centre described disaster displacements — the “forced movement of people within the country they live in” — in 2024 as “exceptionally high” at 45.8 million — double the annual average of the past decade. In 2024, 29 countries and territories reported their “highest disaster displacement figures on record,” including the United States, which accounted for nearly one-quarter of global disaster displacement.
In the U.S. Gulf Coast, a study conducted by nonprofit research organization Urban Institute found that communities that received an influx of climate migrants following hurricanes Katrina and Maria faced challenges related to housing markets, transportation resources, employment opportunities, and emergency services, which, the report suggested, can help be mitigated with pre-planning.
In a 2021 report from World Food Program, Migration Policy Institute, and Massachusetts Institute of Technology, 6% of migrant-sending households from El Salvador, Guatemala, and Honduras cited climate- and environmental-related reasons for emigration.
In a piece published by RAND, Senior Policy Researcher Shelly Culbertson described the relationship between climate change and migration as “not direct or linear.” The author noted that there is a wide spectrum of how climate change will shift where people remain and where they move, in the U.S. and globally.
While the majority of people migrating due to climate change stay within their countries, a study published in Proceedings of the National Academy of Sciences (PNAS) in November 2024 linked undocumented migrants from Mexico and other countries crossing the Mexico-U.S. border due to “weather shocks.” The study found that those who depend on rain-fed agriculture are more likely to migrate to the U.S. without documents after extremely dry seasons. Their decision to stay in the U.S., the study found, was also affected by continued extreme weather.
When it comes to international migration, an article published in PNAS in October 2020 found restrictive border policy can increase exposure and vulnerability, trapping people in areas that are more exposed and vulnerable than where they would migrate otherwise. The researchers also found that a majority of migrants move to areas where they are less exposed and vulnerable, when they have the opportunity to migrate. The report also said decisions regarding migration are usually multicausal, rarely due solely to environmental stress.
The number of disasters per year globally may increase from around 400 in 2015 to 560 per year by 2030 — a projected increase of 40% — according to a 2022 report by United Nations Office for Disaster Reduction, if current trends continue. When it comes to droughts, though there is a “large year-on-year variation,” current trends indicate a likely increase of more than 30% between 2000 (16 drought events per year) by 2030 (21 per year).
In the RAND piece, Culbertson suggested three topics future policy should fall into: helping people stay where they are located, helping people leave, and aiding people who land in communities that may receive a population influx.
The first, and so far only, bilateral agreement on climate mobility, the Falepili Union treaty, was established in 2023 with Australia and the Pacific island nation of Tuvalu, which offers 280 permanent residency spots each year for Tuvaluans affected by climate change. More than one-third of Tuvalu’s population of 11,000 applied for a climate visa to migrate to Australia, with the first arriving in December 2025, according to an article in Reuters.
