Urban Transformation

Climate change will force millions of us to move, but where will we go?

climate change migration hurricane tornado sea level rise global warming environment nature cities population density citizen urban weather land

'Climate haven' cities are already thinking about Image: Unsplash/Oliver Niblett

Tim McDonnell
Reporter, Quartz
Amanda Shendruk
Visual Journalist, The Things Team, Quartz
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Cities and Urbanization

This article is part of: Sustainable Development Impact Summit
  • From hurricanes to coastal flooding, climate change will force millions of people around the world to reconsider where they live - but where will they go?
  • In the US alone, 13 million people could be forced away from the coasts by 2100.
  • The question is where will these people go? And how will cities prepare?

After Hurricane Maria hit Puerto Rico in September 2017, thousands of people fled the island. The exact headcount, and how many of those moves were temporary or permanent, is hard to nail down. Budget data from cell phone records, federal aid requests, school enrollments, and other indicators tell a story of mass migration. Florida, especially the Orlando area, was by far the top landing spot. New York City and Philadelphia, both with strong existing Puerto Rican communities, were also popular.

But a less obvious metro area also drew in thousands of evacuees: Buffalo, New York.

To George Besch, that was no surprise. Besch is an urban planner who grew up in Buffalo and spent most of his career crossing the globe, helping local governments in Denmark, the UK, France, Australia, and India decide how to make better use of their land and natural resources. Decades ago, he realized that his hometown was naturally endowed with many of the environmental advantages other cities sought: abundant access to water and agricultural land, moderate weather, and at least 16,000 lots of underutilized or unoccupied urban space.

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Besch, who moved back home in 1996 and now runs a sustainable design and advocacy group, also took note of the cultural and economic attributes that helped many post-Maria evacuees decide to stay in Buffalo. The city has jobs in a range of blue- and white-collar fields, affordable housing, good bilingual schools, and tight-knit, diverse communities. To him, these features all suggested an obvious path forward for a city that, like many across the Rust Belt, struggled to find a modern identity after the decline of the US manufacturing industry sapped its economy and population.

So Besch became an early evangelist for the idea that Buffalo should reinvent itself as a haven for people displaced by climate change.

climate change migration hurricane tornado sea level rise global warming environment nature cities population density citizen urban weather land
Buffalo has 16,000 underutilized or vacant lots. Image: Quartz

“We’re not getting hit with hurricanes and droughts and wildfires and sea level rise,” he said. “This could be such an incredible city with the synergy of our natural resources and people moving here.”

The idea didn’t catch on at first. At public meetings with local planning officials, Besch, who is 80, said, “I would mention climate migrants and they would look at me like I was senile.” But recently, the idea is gaining currency: In his 2019 State of the City address, mayor Byron Brown declared Buffalo a “Climate Refuge City,” and has since touted initiatives like installing solar panels on public buildings and making the sewer system more flood-proof.

But for Besch, that’s “a non-response.” To make the city a true climate haven will require a much more sweeping vision of an urban space’s obligation to its current and future residents in a warming world. A vision that leverages vacant lots and antiquated infrastructure as building blocks for a city that is not only more sustainable and climate-proof, but simply better to live in.

“Buffalo has the potential to leapfrog over more built-up cities,” Besch said. “It is a refuge, but it’s also where you can build a wonderful, vibrant life.”

A mass migration of historic proportions

Every year, millions are displaced from their homes by climate change. Some are forced out by sudden catastrophes like Hurricane Maria, which are becoming more frequent and severe. Others are driven away by the inexorable grind of stress and mounting costs brought on by slow-onset disasters: drought-driven food and water shortages, or recurrent flooding made worse by sea level rise.

That climate-related displacement will eventually amount to one of the largest mass migrations in human history.

A 2018 World Bank study projected that by 2050, 143 million people will be displaced within their own countries by climate impacts in sub-Saharan Africa, Latin America, and south Asia alone. A model produced this year by the same researchers and ProPublica estimated that in a dire warming scenario, 30 million migrants could come to the US from Central America by 2050.

Within the US alone, where one of the primary climate risks is flooding exacerbated by sea level rise, 13 million people across a wide spectrum of social and economic backgrounds—but in many cases starting with minority and low-income communities that are at higher risk—could be forced away from the coasts by 2100.

Unless there’s someplace for people to go, there’s a strong danger they might resettle in dangerous places or be pushed further to the margins.

Migration experts believe that most of these journeys will end in cities, the hubs of social networks and economic opportunity. But not all those urban endpoints are equally well-suited to provide a safe haven.

In cities that are highly exposed to extreme weather and sea level rise, a comfortable life will become increasingly expensive and exclusive, thanks to the rising costs of less-exposed real estate, flood protection measures, and insurance. Some less climate-vulnerable metros, including Chicago, Illinois or Seattle, Washington, also have high living costs and are surrounded by unsustainable urban sprawl.

So a growing number of urban development scholars and advocates believe it’s time to start planning climate havens: cities that are insulated from extreme weather and have the room and resources to grow.

Governments are slowly getting on board, encouraged to act as the costs of disaster relief rise. With US costs totaling nearly half a billion dollars since 2005, the US Federal Emergency Management Agency in August rolled out a $500 million fund to support pre-disaster hazard mitigation projects, which can include relocating entire at-risk communities. The approach, known as managed retreat, is already underway in a few highly vulnerable towns in Louisiana, Alaska, and elsewhere.

The hope is that, rather than fleeing helter-skelter from a storm or being forced into retreat by a government mandate or unaffordable insurance premium, residents of vulnerable places will feel empowered to proactively seek a safer home if well-organized climate havens are available.

“We need to provide better safe places to live as a first priority,” said Thaddeus Pawlowski, managing director of Columbia University’s Center for Resilient Cities and Landscapes. “Unless there’s someplace for people to go, there’s a strong danger they might resettle in dangerous places or be pushed further to the margins.”

It will require years of planning and a huge investment to identify potential climate havens and remake their economies and cityscapes to accommodate a population that is larger and more diverse in terms of race, culture, and income. The good news is that urban planning isn’t only a tool for confronting climate risk: What cities must do to become attractive havens for climate migrants are the very things they need to become more equitable, sustainable, and productive.

“Responding to climate change and escalating inequality could provide a unifying national purpose like we haven’t had since World War II,” Pawlowski said. “This gets to the very heart of who we want to be as a people in the 21st century.”

Finding the havens

Just because a city looks like a climate haven on paper doesn’t mean people will move there. Migration decisions are based on a complex web of demographic, geographic, and economic factors.

Most migrations are relatively short—people are more likely to move to the next town over than across the country or over an international border. Faced with a climate threat, wealthier people may be able to wait longer to move, and then go further when they do. And the choice of destination depends strongly on social networks: One family moving from County X to County Y raises the odds of another doing the same.

Researchers are working to understand how climate change fits into this picture, and to produce data cities can use to prepare. Mathew Hauer, a sociologist at Florida State University, first began his work on climate-induced migration in the US in 2011, while working on a sea level rise adaptation plan for Tybee Island, Georgia, in the coastal wetlands east of Savannah.

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Residents of Tybee Island, Georgia face off against flooding on a regular basis. Image: Reuters/Tami Chappell

“The mayor just asked a real simple question about population projections, and where people will go if they’re displaced from the island,” he said. “That kicked off all the work on this question.”

Hauer set about building a model that combined projections—of population growth and sea level rise—with historical data on county-to-county relocation patterns from IRS tax records. The model also accounted for income distribution, on the assumption that wealthier households would be less likely to migrate. In 2017, he published a paper in Nature Climate Change that offered the first national, science-based glimpse of which US counties could see the biggest influx of climate migrants.

Hauer found that by 2100, 56% of US counties would see their populations grow because of migration, assuming that sea levels rise by 1.8 meters, a mid-range estimate. Austin, Dallas, and Atlanta all ranked as likely destinations. New York, New Orleans, and Miami could all see huge losses; Florida could lose 2.5 million residents, the most of any state.

This year, a separate team at the University of Southern California took Hauer’s work a step further by examining migration in counties affected by Hurricanes Katrina and Rita. Using that data to fine-tune the model’s assumptions about extreme weather impacts, they similarly found high rates of migration to Atlanta and other southeastern counties set back from the coast, as well as central Texas and the Great Plains.

Where will American climate migrants go?

As sea levels rise, Americans will leave coastal counties for other areas. This projection suggests which counties will see the greatest impact from incoming migration by 2100.

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Sea level rise will displace millions of citizens. Image: Dilkina et al. (2020)

Of course, coastal flooding isn’t the only risk. Another model, produced in 2019 by students in the lab of Portland State University urban planning professor Vivek Shandas, incorporated data from a representative sample of 82 US counties on heat waves, wildfires, and other disasters, as well as household-level demographic data. Those factors—home values, income, age, household size, and whether a house is owned or rented—all influence whether, where, and when a given household might move.

Shandas’ team identified a number of midsized Midwestern and Rust Belt cities that are projected to see the largest relative gain in population from climate migrants, among them St. Paul, Minnesota; Madison, Wisconsin; and Toledo, Ohio. Number four on the list: Buffalo, New York.

Shandas said he’s happy to see Buffalo and other US cities start to lean into the climate haven identity. But so far, he said, there’s little to show for it.

“There’s a lot of rhetoric, but places are putting the cart in front of the horse,” Shandas said. “It’s pretty frustrating. If you’re not doing the thinking to plan for lots of people moving in, you’re really missing the point.”

How to build a haven

Missy Stults is starting with sewage.

Stults is the sustainability manager for the city of Ann Arbor, Michigan, a vibrant college town of 122,000 just west of Detroit. Like Besch in Buffalo, she saw her city’s potential as a climate haven: abundant natural resources, low climate impacts, room to grow, and the anchor of a major employer, the University of Michigan. In March 2019 she secured a $10,000 grant from the National League of Cities to study how the city should prepare for climate migration—and hired Mathew Hauer to run the numbers.

Hauer projected that, broadly, southeastern Michigan could expect to see at least 50,000 climate migrants by mid-century. Stults said she recognized immediately that the city’s current “social and physical” infrastructure weren’t yet equipped for that kind of influx.

climate change migration hurricane tornado sea level rise global warming environment nature cities population density citizen urban weather land
Anchored by a major employer, the University of Michigan, Ann Arbor is a potential climate haven. Image: Reuters/Emily Elconin

“When you have new people in the economy, they stimulate it. I really do think climate migration is an opportunity to foster new innovation and growth, to make us stronger,” she said. “But if we do it poorly or don’t plan for it, it becomes a vulnerability.”

Her first order of business has been to develop a $100 million proposal to overhaul and expand the city’s water treatment system, to support the city for the next 75 years. That process is just beginning, and will likely be paid for by a municipal bond needing voter approval.

In the meantime, Stults plans to sneak Hauer’s projections into every nook and cranny of the city’s planning process. On the way, she hopes to produce a blueprint that other cities could use to guide their own transformation into climate havens.

It’s forcing this conversation about what we are now and what we could be in the future. That’s scary for some people.

The list of requirements is long. In addition to water and waste, climate havens will need to improve public transit, and beef up electric grids with distributed renewable energy systems. They will need to invest in schools, and in cultural and artistic programs to facilitate community cohesion. They’ll also need to improve food supply chains, with an emphasis on local sources, to ensure both that new residents don’t land in food deserts and that the city is less vulnerable to climate shocks elsewhere.

Vacant lots can compete to host multifamily housing, solar panels, or micro-farms. Havens could provide tax breaks to attract entrepreneurs in growing industries (Google and the digital security firm Duo already have offices in Ann Arbor). They’ll need to spruce up their parks and outdoor spaces.

And perhaps most importantly, they will need to dramatically expand access to affordable housing. On that count, Stults said, “we can’t even meet current demand.”

That’s a common problem for potential climate havens. Affordable housing is in increasingly short supply across America, and especially so in cities that have favored suburban sprawl over centralized density—a description that applies to all the top 10 haven cities identified by Shandas.

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Seattle, Washington looks to be the most affected area for low-income housing. Image: Harvard Joint Center for Housing Studies

It’s a Catch-22: All the attributes that make a city an attractive climate haven will tend to drive up real estate values, making a move there less feasible for displaced family.

On average, affordable housing stock (where rent is below $800) in the Shandas cities has fallen nearly 20% since 2011, according to Harvard’s Joint Center for Housing Studies. The national average is about 12%. Meanwhile, the cost of all single-family homes in these cities is rising faster than the national average, up nearly 90% on average since 2000.

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Home values for single-family homes and condos. Image: Shandas et al., Zillow Home Value Index

Susannah Drake, a landscape architect and professor of environmental design at the University of Colorado, Boulder, said one easy way for cities to address affordable housing shortages is to relax zoning restrictions. Allow individual homeowners to subdivide their properties, and let large developers stick a few extra stories on top of an apartment tower if they dedicate some portion of the income to, say, restoring the local waterfront.

“If a migrant could buy a single lot and subdivide it and use the rent to pay the mortgage, that’s wealth generation,” she said. That strategy was essentially responsible for most of the historical residential development of New York City, she said.

The federal government could also build on its existing buyout program for houses with high flood risk, and offer vouchers for housing in climate havens, said Ryan Nunn, a development researcher at the Federal Reserve Bank of Minneapolis.

Stults said the nuts and bolts of policy in Ann Arbor, while certainly in need of tweaking, don’t keep her up at night. Planning a sewer upgrade or affordable housing are familiar challenges for city planners; with a little forethought and a growing tax base, these upgrades will pay for themselves, she said.

The bigger, more unprecedented challenge is whether Ann Arbor’s residents are ready for this kind of change. “It’s forcing this conversation about what we are now and what we could be in the future,” Stultz said. “That’s scary for some people.”

Setting aside issues of physical infrastructure, Drake said, climate havens will require people to overcome some intellectual barriers. Many people are strongly attached to their landscape of origin—good luck telling a lifelong resident of a Louisiana coastal shrimping community that they’d be better off in an apartment in central Ann Arbor.

At the same time, the last half-century of urban development in America has primed people to instinctively resist urban density. Upward mobility is psychologically sited in the suburbs. That may be especially true after Covid-19, which has fueled a universal craving for breathing room.

“Americans have been taught to fear cities,” Drake said. “A lot of it is rooted in a myth of the merits of the suburb that was created in the post-war period as a sort of massive development scheme. But that layout now controls our economy.”

climate change migration hurricane tornado sea level rise global warming environment nature cities population density citizen urban weather land
Northern cities including Chicago became dramatically more diverse during the Great Migration of the early and mid twentieth century. Image: Library of Congress

Correcting the legacy of mass migration

If planning for the future requires a reckoning with history, Buffalo might start by looking to the last seminal period of mass migration in America, the northward movement of an estimated 6 million Black Americans during the Jim Crow era of the early and mid twentieth century.

Before then, 90% of Black Americans lived in the South. This “Great Migration” dramatically diversified northern cities (including Buffalo, Chicago, and Detroit), fueling the Harlem Renaissance, the birth of modern jazz and blues, the explosion of the automotive and manufacturing industries, and innumerable other cultural and economic achievements.

But it also fueled a surge in northern racism, which was particularly manifest in the housing market. White families decamped to the suburbs and fortified their neighborhoods with highways and discriminatory legislation like the 1934 National Housing Act, which initiated the practice of “redlining” Black neighborhoods to preclude them from federally-insured home loans.

The wave of climate migrants could accelerate patterns of discrimination and conflict—or provide a chance to remedy the mistakes of the past.

Up to today, the guiding principle of many cities has been to maximize property value, said Henry Louis Taylor, a historian of urban planning at the University of Buffalo. In Buffalo as elsewhere, he said, that has usually meant that “the value of white neighborhoods was based on their capacity to exclude people of color and low-income groups.” The decay of dense housing in urban centers was often beneficial for developers, he said, because they could still charge high rents even as the property value declined, increasing their profit margin.

More recently, that process has reversed, as young white people have flocked back into Buffalo in search of space and cheap rent, if not necessarily a climate haven. Gentrification, in addition to driving up property values, accelerates a neighborhood’s rate of 911 calls, Taylor has found, and thereby the rate of potentially violent encounters between the police and people of color.

Depending on how the city prepares, the new wave of climate migrants could accelerate those patterns of discrimination and conflict, he said—or provide the city chance to remedy the mistakes of the past.

“We could easily accommodate another 200,000 or more residents in this city,” Taylor said. “But for Buffalo to do this in an equitable way, we have to completely reimagine the way we’re building this city.”

For Taylor, Buffalo’s most important asset in that struggle isn’t its climate, Lake Erie, or a bunch of vacant lots. It’s the city’s strong network of community organizations, and the willingness of Buffalonians to work together in pursuit of a shared vision.

“When we imagine the new city, we’re talking about dismantling that racist legacy, and creating a new city based on social justice,” Taylor said. “If we do that, then as that population floods into Buffalo, they’re flooding into a city that lets people live their lives to the fullest.”

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