Climate migration will be the defining crisis of the 2030s

What's this about?

People disagree about whether climate migration will become the biggest crisis of the 2030s.

Climate change already makes some people leave home, but this claim makes a much bigger guess.

What supporters say

• Climate disasters already force many people to move, and this problem seems to be growing.
• Climate change can harm farming, jobs, and food supplies, which may push families to move.
• Long-term computer models suggest that millions could move inside their own countries by 2050.

What critics say

• Climate is only one cause of migration, along with war, poverty, jobs, and unsafe politics.
• The claim treats an unsure future guess as if it were a sure fact about the 2030s.
• Most climate-related movement happens inside one country or lasts only a short time.

How to read this

The number of points on each side does not show who is right; the strength of the facts matters more.

The bottom line

Climate migration is already a serious problem, and it may grow much larger.

But the evidence does not show that it will become the defining crisis of the 2030s, so the critics have the stronger case.

The claim that climate migration will be the defining crisis of the 2030s goes beyond saying that climate change will drive serious displacement. It predicts that climate-related movement will become the decade’s most important crisis, a stronger conclusion that the available evidence does not yet establish.

The case for

Climate-related displacement is already occurring on a large scale and appears to be growing. The IPCC says climate change has increased vulnerability through displacement and involuntary migration linked to extreme weather and climate events. The Internal Displacement Monitoring Centre recorded 75.9 million people living in internal displacement at the end of 2023, including a record level of disaster-related displacement. These figures include many hazards that cannot be attributed entirely to human-caused warming, but they show how climate-sensitive disasters can create major humanitarian and government pressures. 1

Long-term projections also point to substantial future movement within countries. The World Bank’s Groundswell assessment estimates that, under an adverse scenario, as many as 216 million internal climate migrants could exist across six regions by 2050. It identifies possible migration hotspots emerging as early as 2030. (see Figure 2) The estimate depends heavily on emissions, economic development and adaptation, so it is not a precise forecast for the 2030s. But it suggests that climate mobility could become large and concentrated enough to reshape cities, infrastructure and public policy. (see Figure 3) 2

Research also supports the main pathways linking climate change to migration. Climate variability can affect international migration through agriculture and other livelihood pressures. Studies have found that changes in climate can influence permanent household migration, while reviews of multiple studies report consistent effects from weather and climate conditions. The impacts differ by region, income, hazard and access to safer destinations, but the overall relationship is real. 3

The case against

The strongest objection is that the claim turns an uncertain projection into a certainty. Climate-migration models are best understood as scenarios, not timetables. Their results depend on assumptions about future emissions, development, adaptation, government capacity, data and how people respond. The World Bank’s 2050 figure therefore describes a plausible high-impact pathway, not proof that climate migration will dominate the 2030s. 4

The form of movement also matters. Most climate-related movement is internal rather than international, and much of it may be temporary or repeated. Disaster-displacement totals record people moving after hazards, including events not caused solely by climate change. Such movement can place severe pressure on communities and governments, but it does not necessarily amount to one worldwide refugee crisis. 5

Climate is also only one cause of migration. Conflict, poverty, inequality, economic disruption, urbanization, governance and health threats can all shape whether people move, stay or are unable to leave. Climate change may sometimes make migration an adaptation strategy, while poor adaptation can increase involuntary displacement. The evidence does not show that climate migration will outrank all these other challenges in the 2030s. 6

The bottom line

The evidence strongly supports the narrower conclusion that climate affects migration and that substantial internal mobility risks require preparation. Climate-related movement is already significant and could become a major regional and policy challenge, especially in vulnerable agricultural areas, exposed coasts and rapidly growing cities.

But the evidence is much weaker for the claim’s global and decade-specific superlative. Existing projections generally extend to 2050, depend on uncertain scenarios and vary sharply by region. Displacement data also combine climate-sensitive disasters with other causes and do not, by themselves, measure permanent migration caused by human-driven warming.

Overall, the claim is not proven. Climate migration may become one of the defining regional challenges of the 2030s, but the evidence does not justify high confidence that it will be the single defining crisis of the decade.