- World Bank warns 143 million could be forced to move by 2050.
Climate change is no longer just an environmental crisis. It is a slow-moving migration shock, a mounting strain on housing supply and an immigration policy reckoning the United States is dangerously unprepared to confront.
In 2018, the World Bank published Groundswell: Preparing for Internal Climate Migration, warning that “climate change has emerged as a potent driver of internal migration, propelling increasing numbers of people to move from vulnerable to more viable areas of their countries to build new lives.”
Without concerted climate and development action, the report projected, “just over 143 million people … could be forced to move within their own countries to escape the slow-onset impacts of climate change” by 2050 across Sub-Saharan Africa, South Asia and Latin America.
“Internal climate migration is a development issue. Unless we act it will become the human face of climate change,” the authors wrote — adding that “internal climate migration may be a reality, but it doesn’t have to be a crisis.”
Most of this movement, the report makes clear, will not take the form of caravans crossing borders but of farmers leaving drought-stricken land for cities, coastal residents relocating inland and families gradually moving toward regions with more stable water and crop conditions.
The report identifies emerging “hotspots” of in- and out-migration and warns that “many urban and peri-urban areas will need to prepare for an influx of people, including through improved housing and transportation infrastructure, social services, and employment opportunities.”
Housing, in other words, is climate policy.
The cascading risks described in The Uninhabitable Earth by David Wallace-Wells underscore the magnitude of what is coming.
Extreme heat erodes human labor capacity, rising seas threaten densely populated deltas, crop failures destabilize food systems and climate stress compounds across economic and political structures — so that in such a world, migration is not aberration but adaptation.
But adaptation is uneven.
Recent research from the Stanford Doerr School of Sustainability complicates the familiar story of inevitable mass exodus.
Hélène Benveniste, an assistant professor of environmental social sciences, has found that climate change tends to intensify pre-existing migration patterns rather than create entirely new ones.
“Basically, climate change influences pre-existing migration flows,” she said.
More strikingly: “Climate change is both increasing the number of people who are forced to move and increasing the number of people who are forced to stay.”
That paradox challenges simplistic narratives.
Benveniste’s research shows that middle-income groups are often the most responsive to climate risk.
They possess just enough resources to move but remain vulnerable enough to be pushed by drought, sea-level rise or crop loss.
The poorest frequently cannot afford to leave; the wealthiest can often adapt in place.
“Climate change often depletes resources, including for very vulnerable communities,” she noted.
This dynamic produces what scholars call involuntary immobility.
In a 2022 study, Benveniste and her co-authors estimated that emigration among low-income populations could actually be about 10 percent lower in 2100 under climate change than in a no-warming scenario — precisely because environmental stress erodes the resources required to migrate.
“The presence or absence of migration does not tell you everything you need to know,” she said. “It might be the case that a decrease in migration is actually a reflection of an increase in vulnerability to environmental stress.”
Climate migration, then, is not just about who crosses borders. It is also about who becomes trapped.
Benveniste’s work further suggests that when people do migrate internationally, they often move to places with lower climate risk. But restrictive border regimes can shrink that flow.
“They end up staying in areas where they’re more exposed,” she said.
A 2025 study published in Nature Communications sharpens this picture.
Using advanced statistical methods to isolate the climate signal in migration data, the researchers concluded: “Climate change can both incentivize people to move away and increase the number of people who don’t have the ability to migrate.”
Severe droughts and heat waves increase migration pressures while simultaneously depleting the financial and social capital required to relocate.
Migration under climate stress becomes more selective.
Pre-existing corridors — rural to urban, lower-income countries to higher-income ones, agriculturally stressed areas to more diversified economies — intensify.
Education, assets and occupational flexibility increasingly determine who can use mobility as a survival strategy.
Governance matters.
When legal migration pathways are limited and borders harden, people exposed to growing environmental risk may remain in high-risk areas longer than they otherwise would. Migration, when managed, can reduce vulnerability.
When constrained, environmental risk accumulates in place — and often spills outward later in more destabilizing ways.
Meanwhile, domestic housing policy in the United States remains largely detached from this reality.
The country is already experiencing internal displacement from wildfires, hurricanes and sea-level rise.
Insurance markets are retreating from high-risk regions. Some communities will gradually become less viable; others — frequently inland metropolitan areas — will become receiving hubs.
The unresolved question is whether those receiving regions will build enough housing to absorb population shifts without triggering spiraling prices and political backlash.
The World Bank’s modeling shows that internal climate migration will intensify through 2050 under every emissions scenario considered.
Climate impacts such as “crop failure, water stress, sea level rise” increase “the probability of migration under distress,” the report warns.
Even under more optimistic pathways, some degree of climate mobility is locked in.
The United States cannot afford to treat housing scarcity and immigration enforcement as separate debates in a warming century.
If climate change shapes both who moves and who becomes stranded, resilience requires two parallel strategies: dramatically expanding housing capacity in lower-risk regions and modernizing immigration frameworks to reflect environmental realities.
Climate migration is not only about arrivals at the border. It is about whether cities are prepared to grow. It is about whether land-use rules, infrastructure investment and social policy recognize that geography itself is shifting.
Migration, the World Bank reminds us, “can be a sensible climate change adaptation strategy if managed carefully and supported by good development policies and targeted investments.”
Without that foresight, climate change will not only flood coastlines and parch farmland. It will strain housing markets, inflame politics and deepen inequality.
As the planet heats, people will move.
The choice before us is whether we build systems ready to receive them — or allow both migrants and communities to absorb the shock unprepared.
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So should Canada start planning and building sprawling developments in order to house the flood of Americans northward. I mean that 50 foot wall of fire is coming, right?
An important goal of US foreign aid since the end of the Cold War has been to help stabilize countries whose governments are at risk of failure, as failed states are risks to their region. A big part of that has been providing assistance to agriculture and land use management to mitigate the impact of climate change. Mass migration due to drought and famine, as happened in Syria and Sudan, can be reduced with help from money from western countries managed through NGO’s and other agencies. Increasingly those dollars have been focused on climate change initiatives. Emergency food assistance as was provided by US foreign aid dollars can prevent famine and reduce population migrations during drought emergencies.
Restoration of foreign aid programs will be an important policy undertaking for the next US administration.
Got it. It’s Davis’ duty to approve two sprawling developments, to accommodate climate change.
Apparently, the Vanguard’s claim that Measure J is otherwise at risk isn’t working as intended. :-)
In any case, shouldn’t the Vanguard be advocating for Trump to acquire Greenland, given this logic? (Seems like he’s given up on Canada.)
Not sure if David himself has noticed, but the Sacramento valley (INCLUDING Davis) already does not seem like a place that people move to in order to avoid hot summers.
Of course, those places don’t need to be owned by the U.S. in order to accommodate immigrants (including those escaping FROM the U.S.).
“We” may be the immigrants in regard to the currently-frozen north.
Given this logic, it might be time to start preparing to vacate the entire valley, and most of California for that matter.
Haha! So if I got this right, we should vote for Village Farms because a flood of immigrants is coming north to escape the heat. Is that about right?