A massive worldwide societal upheaval is underway — the uprooting and displacement of huge numbers of people living in places growing increasingly risky to live in because of climate change. “The Great Displacement: Climate Change and the Next American Migration,” by Jake Bittle, a staff writer for Grist, is a must-read account of this hugely important transformation. The title is a reference to the Great Migration of the 1920s through 1960s — the largest single migration event in American history — when more than 6 million Black people left the South and moved to northern cities.

Focusing on the United States, Bittle traces the stories of a new generation of domestic climate migrants, displaced in an unpredictable, chaotic, and life-changing way: “These people live in every corner of the country, from the waterlogged streets of Miami to the parched cotton fields of Arizona. They run the gamut from minimum-wage workers to millionaires, from liberals in big coastal cities to entrenched small-town conservatives. Their stories range from the tragic to the comic and from the inspiring to the infuriating. Indeed, there is only one thing they all have in common: they are moving.”

What makes this book particularly effective are Bittle’s interviews with people, which brings the human impact of climate change to life and provides a vivid picture of the challenges faced by those who are forced to leave their homes behind. Included are stories of Americans displaced by fires in California, drought in Arizona, sea level rise (in Norfolk, Virginia, and southern Louisiana), and from hurricanes (Hurricane Harvey in Houston, Hurricane Irma in the Florida Keys, and Hurricanes Fran and Floyd in North Carolina). Too often, it is the poor and marginalized who are most affected, with the rich and the privileged receiving the greatest help from the disaster relief system. Bittle advocates for the government to put in place policies to address the lack of affordable housing, ensuring that everyone has access to housing, before and after disasters.

Are people leaving California because of climate change?

The book opens with the story of Greenville, California (population 1,000), which was 75% destroyed by the Dixie Fire of 2021. Bittle documents how the displaced residents of Greenville suffered from an underfunded disaster relief system, a dire shortage of affordable housing, and a broken insurance market. “These same factors are fueling displacement in other parts of the country, after other kinds of disaster: climate change is applying stress to an already brittle social and economic order, widening cracks that have been there the whole time.” According to the U.S. Census Bureau, the county that Greenville is in, Lassen, had the largest decline in population of any U.S. county for 2021-2022 (6%).

In a later chapter, Bittle follows people from Santa Rosa, California, who were displaced by the 2017 Tubbs Fire. Five years after the fire, a lack of nearby affordable housing and an insurance crisis have left portions of the city looking like they are just beginning to recover. An insurance gap — caused by homes that cost in the millions, but fire insurance that can only be purchased to cover a few hundred thousand dollars in damage — was so extreme that “many residents chose to cut their losses and buy somewhere else rather than spend countless thousands of dollars to rebuild homes in an area they knew was dangerous. They sold their empty lots to investors and speculators from out of state, most of whom sat on their holdings and waited for the price of land to rise rather than build new houses.”

U.S. migrations trends, 2010-2020
Figure 1. U.S. migration trends from 2010-2020, from U.S. census data. Migration hot spots, where many more people moved into a region than out, are in shades of red. Migration cold spots, where many more people left than arrived, are in shades of blue. Statistical outliers (in some cases, places with low population where closure of a correctional facility led to spurious population changes) were excluded from the analysis but are shown in the darkest shades of red and blue. (Image credit: Clark et al. 2022, Flocking to fire: How climate and natural hazards shape human migration across the United States, Front. Hum. Dyn., 08 December 2022 Sec. Migration and Society, Volume 4- 2022, https://doi.org/10.3389/fhumd.2022.886545)

Despite climate change, people are still moving to high-risk places

Migration patterns in the U.S. over the past decade would seem to contradict the idea of a climate change-induced Great Displacement. People have been leaving cooler Rust Belt states like Ohio, Illinois, and Michigan, flocking to places with increasing climate-change-induced risk: the ocean coasts and the hot, dry West. Almost 100 million people in the U.S. now live in coastal counties. And the fastest-growing state in 2022 was Florida, which is at high risk from sea level rise, extreme heat, and hurricanes. Five of the 15 fastest-growing cities from 2020 to 2021 were in Arizona, which faces an increasing risk of extreme heat and water availability.

A 2022 study, Flocking to fire: How climate and natural hazards shape human migration across the United States, found that from 2010-2020, people moved away from areas prone to heat waves. But they moved toward areas at risk of river flooding, earthquakes, hurricanes, and wildfires. Not surprisingly, people also move for social and economic reasons — in addition to environmental reasons like the weather — and the study found that after controlling for all of these factors, people moved away from areas most affected by heat waves and hurricanes but toward areas most affected by wildfires; people also moved toward areas with warmer summer and winter temperatures, including metro areas with particularly hot summers. “These trends suggest that migration is increasing the number of people in harm’s way, even as climate change continues to exacerbate summer heat and contribute to more frequent and severe wildfires,” the researchers wrote.

Two major exceptions to this trend of movement toward risky areas over the past few years include California, which has lost population thanks to exorbitant housing costs and a wildfire crisis, and Louisiana, which has been pummeled by multiple hurricanes and is also suffering an insurance crisis (according to the U.S. Census Bureau, four of 10 of the counties suffering the largest percentage decline in population during 2021-2022 were in Louisiana). According to the Internal Displacement Monitoring Center, wildfires in California (population 39 million) displaced 597,000 people in 2020 and 159,000 people in 2021; in Louisiana (population 4.6 million), Hurricane Laura displaced 585,000 people in 2020, and Hurricane Ida displaced 257,000 people in 2021.

Bittle argues, though, that the patterns of displacement that arise because of climate change have already begun in small towns and remote places. Over time, the instability will spread to major cities and entire regions: “As disasters continue to pummel our housing markets, public and private powers will push more people out of vulnerable areas, and escalating fear of danger will spur more to move of their own volition. The result will be a shambling retreat from mountain ranges and flood-prone riverbeds, back from the oceans, and out of the desert. It will take decades for these movements to coalesce, but once they do, they will reshape the demographic geography of the United States.”

He cites a survey of more than 2,000 people in the U.S. conducted by the real estate company Redfin, which found that almost half of those planning to move in the next year were motivated by natural disasters, more than a third were motivated by rising sea levels, and three-quarters of the respondents said they would hesitate to buy a home in an area threatened by climate change, even if it were more affordable. Another study, from Cornell University, found that 57% of the 1,000 respondents in a nationwide sample said that climate change would have at least a “moderate” effect on their decision about whether to move over the next decade. Sea level rise is already lowering coastal property value, according to a 2019 study: “Homes exposed to sea level rise sell for approximately 7% less than observably equivalent unexposed properties equidistant from the beach.” 

Buyouts can help people leave flood-prone areas, but they may not be enough

The book does a great job explaining why so many people live in flood plains and near the coast in regions subject to flooding — ignorance about how floods work, plus an economic dynamic that sociologists call the growth machine: “More construction meant more money for developers, more people living in waterfront towns and cities, and more tax revenue for local governments. A booming tax base allowed more spending on public services, which in turn attracted more people, created more demand for construction, and spread more money around.” This process was encouraged by FEMA and the Army Corps, which endeavored to keep flood-prone communities where they were: “The Corps wrapped levees and sea walls around existing towns to protect them from flooding, and FEMA stepped in after flood disasters to help people rebuild.”

Read: ‘Is it foolish to hold onto my family’s beloved waterfront home?’

Beginning in the 1960s, with growing realization that this model was unsustainable, the National Flood Insurance Program was created. People who wanted to buy a home in a flood plain were required to get flood insurance in order to receive a federally backed mortgage. This approach was supposed to discourage people from moving into flood zones, but the price of the insurance was set too low, resulting in the government subsidizing people living in high-risk areas. It wasn’t until 1989 that FEMA was finally allowed to stop exclusively rebuilding in the same place after a disaster, but instead prevent future flood losses by buying out homes that suffered repeated flooding.

But buyouts currently comprise less than 20% of FEMA’s flood risk reduction budget, and this initiative has been seriously flawed. “The Great Displacement” describes the yearslong, convoluted process experience of residents of Kinston, North Carolina, after flooding from two hurricanes (Fran in 1996 and Floyd in 1999). Among the many issues: FEMA disproportionately funds buyouts of vulnerable properties in White communities compared to communities of color, because money is allocated based on a cost-benefit analysis that prioritizes more expensive properties. In addition, wealthier communities may also have more resources to influence decision-makers who decide who gets a buy-out. It’s clear from Kinston’s experience that FEMA must drastically improve the buyout process to avoid massive chaos in the coming decades when sea level rise and heavier precipitation events will likely force millions of people to abandon risky flood-prone areas. Between 1989 and 2017, just 40,000 buyouts occurred.

The book reviews a few alternatives. The government could buy flood-prone homes, then rent them back to their owners until a flood comes, at which point the owners could leave. In Surfside, Florida, developers and the city contribute equally to a “relocation fund” intended to offer grants to assist people moving from flood-prone areas. Government-brokered land swaps could be arranged between homeowners in flood plains and landowners outside of flood plains who have extra land they want to develop. The Norfolk area nonprofit Wetlands Watch has proposed that the city only allow developers to build on high ground if they first purchase a few homes in flood-threatened areas, allowing those homeowners to make a clean escape. When the occupants move out, the city would clear the land.

With sea level rise, every coastal home is now a stick of dynamite

Long before rising seas inundate coastal cities, the coastal real estate market will fall, and once property values decline, they will not go back up, Bittle writes. He likens owning a coastal home to holding a stick of dynamite with a long fuse.

“When humans began to warm the Earth, we lit the fuse. Ever since then, a series of people have tossed the dynamite among them, each owner holding the stick for a while before passing the risk on to the next. Each of these owners knows that at some point, the dynamite is going to explode, but they can also see that there’s a lot of fuse left. As the fuse keeps burning, each new owner has a harder time finding someone to take the stick off their hands.

“What should we do with the dynamite? For how long should people be allowed to keep passing it around? Who should be responsible for throwing it away? And how can we move everyone out of the blast radius? As of right now there are no answers to these questions, and indeed there are very few people willing to even ask them. For the moment, the coastal housing market is a three-way staring contest, with homeowners, governments, and real estate industry figures all straining to keep their eyes open, to keep up the pretense that everything will be fine.

Sooner or later, though, someone is going to blink.”

Figure 2. Number of people displaced by weather disasters in the U.S., 2008-2021. (Image credit: Internal Displacement Monitoring Center)

The future of climate migration in the U.S.

Bittle argues that “managed retreat” is unlikely to happen on the mass scale needed in coming years because sea level rise will simultaneously affect huge portions of coastal real estate worth many billions. “But just because there won’t be a managed retreat doesn’t mean that there won’t be a retreat,” he says. The combined value of all the coastal real estate in the United States that faces flood risk from sea level rise is somewhere between half a trillion and 2 trillion dollars — about 2-4% of the national economy. Sea level rise will “cause a plunge in coastal property values that will inflict economic harm even on people whose homes have not suffered any damage, sharply reducing the value of the most valuable assets they own. As a city’s housing values decline, so, too, does its tax base, which means less money to pay for basic services like trash collection and street repair. Among the portion of the population that stays, there will be many who want to leave but can’t, who are tethered by their mortgages to homes they can’t sell.” 

Where will the displaced people go? Bittle cites the work of Mathew Hauer of Florida State University, whose research found that the younger and wealthier members of a given community will tend to leave first and that these people will tend to move to the nearest large city that does not face extreme climate risk. In the long run, Bittle foresees that cities in the Midwest will see runaway growth of the same kind that places like Austin and Phoenix are seeing now:

“It is almost a certainty that by the end of the century there will be a substantial flow of people toward relative safe havens and away from the riskiest and least hospitable places. It may take decades for these demographic flows to coalesce, but barring a profound shift in climate trends or government policy, many people will move northward. The driving force behind their migration will be the same force that has stacked up houses on eroding coastlines and bent the water system in Arizona out of shape to accommodate new development. Our profit-driven society relies on economic growth, and the climate crisis will make some areas far more conducive to growth than others.”

It’s not too late to prevent the worst

“The Great Displacement” is a timely and important book on the climate change-induced mass migration that has already begun and that will fundamentally rock society. It is a powerful reminder that we have a responsibility to act now to prevent the worst effects of this crisis. Bittle’s final recommendations include a call to reduce climate-warming pollution, ramp up investment in post-disaster aid and climate adaptation measures, reform the National Flood Insurance Program and the private fire insurance industry, allow increased numbers of international climate migrants to enter the U.S., and address the lack of affordable housing by ensuring that everyone has access to housing — before and after disasters.

For those wanting to learn more about this critical topic, another great book is “Nomad Century,” by Gaia Vince, which argues that migration should be encouraged because it drives economic growth and reduces poverty. The author calls for a safe, fair process for migration, overseen by a global agency with powers to police it. Another recent book, which I did not get a chance to review, is “Planetary Specters.” It argues that to understand the systemic reasons for displacement, it is necessary to reframe climate disaster as interlinked with the history of capitalism and the global politics of race.

“The Great Displacement: Climate Change and the Next American Migration” (Simon and Schuster, 2023) is $14.99 on Kindle at Amazon.com and $28.99 in hardcover.

Related: Disasterology: a book review

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Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...