William Yu, UCLA Anderson Forecast

USA - Is the $1 Trillion Coastal Housing Market a Future Financial Crisis?

Homebuyers ignore warnings of rising seas; lenders keep lending. A confluence of natural disasters due to climate change “could lead to a sharp fall in asset prices … This could have a destabilizing effect on the financial system, including in the relatively short term.” —Financial Stability Board

A financial crisis often seems to arrive out of nowhere — dot-com stocks plunging in 2000, the American mortgage meltdown of 2008 — but when we look back, we always find early and substantial signs of trouble to come. What’s more, these crises are often preceded by a very public debate over their likelihood, with the doomsayers initially few and often mocked.

A decade or two from now — perhaps much sooner — we may be parsing the early signs of the Coastal Housing Crisis, brought on by climate change and its rising seas. If present trends continue, that crisis would also involve soaring home prices and mortgage debt in the most flood-vulnerable zones, and regular, if not catastrophic, flooding that makes once-prized areas undesirable, if not unlivable.

That could lead to hundreds of billions of dollars in losses, given the $1 trillion-plus size of the market and even a modest correction.

Rising seas are creeping onto large swaths of today’s expensive coastal markets, and the encroachment is accelerating. Unless trends in carbon emissions change, the higher sea levels will leave millions of U.S. coastal homes underwater or chronically flooded before the year 2100, according to forecasts endorsed by thousands of scientists.

Long before these houses become uninhabitable, buyers will begin to price them as risky assets, rather than the top-dollar luxuries they are today.

When the market correction comes, perhaps due to a particularly devastating hurricane season and resulting change in sentiment about homes near the water, taxpayers and institutional investors stand to lose money alongside coastal homeowners. And, if the country is unlucky, this could trigger broader economic repercussions.

If that scenario seems hyperbolic, take a look at the fresh wave of research on sea level rise. Note that investment banks, financial regulators and municipalities have joined climate scientists and environmental activists in worrying about rising seas:

    In Florida, coastal home prices recently started declining, after sales volume first tailed off, even as the broader housing market continues to gain value. This is a pattern seen in past real estate bubbles, according to a University of Pennsylvania study.
    BlackRock, the G20-backed Financial Stability Board and the U.S. Commodity Futures Trading Commission n are voicing concerns about unflagged flood risks squirreled away in mortgage-backed securities, bond markets and other real estate-backed investments. Common themes: The exact size of exposure is elusive but big; markets don’t currently price for it; these assets pose a threat to the stability of the global financial system.

In the Bloomberg Barclays Aggregate Index, which is a popular investment among pension funds and other conservative investors, about one-fifth of the underpinning properties were in New York, Houston and Miami; cities particularly vulnerable to sea level rise. —BlackRock
    U.S. lenders continue to underwrite sales of homes exposed to sea level rise, even as they are taking steps to insulate themselves from the risks. These moves include selling the exposed loans to Freddie Mac and Fannie Mae faster than their other mortgages. The transactions move the risk of default to Fannie and Freddie, which are ultimately backed by taxpayers.Millions of at-risk homes lack sufficient flood insurance. Homes that have any coverage typically buy it through the National Flood Insurance Program, an insolvent program also guaranteed by taxpayers.
“Alarmingly, more than half of that (at-risk property) exposure is estimated to lie outside FEMA flood zones. That means those properties are at higher risk of being underinsured, and, therefore, the loans attached to them are at higher risk of impairment, with increased risk for the value of the related CMBS (securities).” —CFTC
    Borrowing costs among coastal governments are rising as municipal bond investors demand more from issuers in places where sea level rise will threaten property values.

In the actual housing market, however, evidence of this threat is hard to find. Some 40% of the U.S. population lives along the continental coasts, according to the National Oceanic and Atmospheric Administration. Values on homes exposed to sea level rise usually trend up as fast as prices on less risky properties nearby. Where price trends on coastal properties have broken from broader markets, discounts are typically minimal.

“Coastal real estate is still in high demand in the U.S., whether in California or on any other coast,” UCLA Anderson Forecast’s William Yu writes in a recent report. “An ocean view and proximity to the beach continue to make these properties more expensive and attractive to buyers despite warnings of danger.”

In California’s coastal home market, Yu finds some 66,600 homes housing about 155,600 people likely to drop in value under moderate scenarios for sea level rise. He estimates potential property value losses in the state at about $93 billion, or slightly less than 1% of the total California housing value.

And yet, prices on California homes most at risk from sea level rise climbed faster between 2011 and 2020 than the state’s housing market at large, and faster than coastal homes in less exposed locations nearby, according to Yu’s findings. Building in these zones continues.



The U.S. Global Change Research Program developed three categories of risk projections varying according to future levels of global carbon emissions, a determining factor in ice melt that causes sea level to rise.

*The high scenario assumes increases in carbon emissions continue at recent (pre-pandemic) rates: average sea level rise around the U.S. of about 2 feet by 2045 and about 6.6 feet by 2100.

*The intermediate scenario assumes mitigation efforts turn carbon trends down by midcentury: sea levels rise an average of about 1 foot by 2035 and 4 feet by 2100.

*The low scenario assumes more immediate reductions in carbon emissions, similar to those outlined in the 2016 Paris Agreement: 1.6 feet by 2100.


For homeowners in risky areas now, the slow creep of rising seas and the parallel threat of sudden destruction from increasingly violent storms are more financially dangerous than the end-of-century forecasts. A stunning ocean view might still attract top dollar, even as king tides occasionally sop the lawn. But homebuyers start losing interest when regular tides flood cars five, six, seven times a year. That could occur decades before what’s known as chronic inundation, defined as tidal flooding covering at least 10% of the community 26 times a year or more.

Yu suspects market corrections will play out slowly and locally, varying as effects of sea level rise become apparent. But extreme weather could trigger sharper and more widespread corrections, he says. Potential buyers tend to remember images of major devastation, he says, whether its floodwaters plowing through houses or wildfires consuming them.

The question is no longer if rising seas will erode coastal home values, but who will get stuck with the devalued assets when the markets turn.

Threats to Homes and People

The most respected projections for sea level rise and its effects come from massive, peer-reviewed research projects that involve hundreds of experts across academia, government and the private sector. They include separate reports published by government-backed groups such as the United Nations Intergovernmental Panel on Climate Change and the U.S. Global Change Research Program, as well as nonprofit organizations including the Union of Concerned Scientists and First Street Foundation. A few takeaways:

    By 2100, nearly 490 communities nationwide will experience chronic inundation. These include Huntington Beach and San Mateo, California, as well as roughly 40% of all oceanfront communities on the East and Gulf coasts. That’s an intermediate scenario, not worst case.FEMA designations incorrectly peg millions of properties as having little risk of flooding, according to most experts. By the agency’s own accounts, some 40% of flood insurance claims between 2017 and 2020 were on properties its maps deemed low risk.The rate of sea level rise has generally picked up in recent years and is expected to rapidly accelerate in coming decades. Beyond 2100, sea level will continue to rise for hundreds of years more.

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About the Research

Keys, B. and Mulder, P. (2020) Neglected No More: Housing Markets, Mortgage Lending, and Sea Level Rise.

BlackRock Investment Institute (2019). Getting Physical: Scenario Analysis for Assessing Climate Risks.

Financial Stability Board (2020) The Implications of Climate Change for Financial Stability.

Report of the Climate-Related Market Risk Subcommittee, Market Risk Advisory Committee of the U.S. Commodity Futures Trading Commission (2020) Managing Climate Risk in the U.S. Financial System.

Yu, W. (2020). Sea Level Rise and Its Impact on California Housing Markets, The UCLA Anderson Forecast, December 2020.

U.S. Global Change Research Program (USGCRP) (2018). Impacts, risks, and adaptation in the United States: Fourth National Climate Assessment.

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Union of Concerned Scientists (2017) When Rising Seas Hit Home.

First Street Foundation (2020) The First National Flood Risk Assessment: Defining America’s Growing Risk.

Keenan, J.M. & Bradt, J.T. (2020). Underwaterwriting: From Theory to Empiricism in Regional U.S. Coastal Mortgage Markets. Climatic Change.

Ouazad, A. and Kahn, M.. (2021) Mortgage Finance and Climate Change: Securitization Dynamics in the Aftermath of Natural Disasters.

Goldsmith-Pinkham, P., Gustafson, M.T., Lewis, R.C. and Schwert, M. (2019) Sea Level Rise and Municipal Bond Yields.

Painter, M. (2020) An Inconvenient Cost: The Effects of Climate Change on Municipal Bonds. Journal of Financial Economics.

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