Investors bet on municipal bonds despite accelerating climate concerns

When it comes to the dangers triggered by climate change, the city of Miami isn’t so much in the eye of the storm as at its bullseye.

Rising temperatures routinely broil Miami during the summer. Last year, the local heat index was over 100 degrees for a record-shattering 46 straight days. Sea levels have jumped by about six inches since 2000 and should rise another 10 to 17 inches by 2040; 55% of Miami properties are at risk of flooding over the next 30 years, according to a model developed by the First Street Foundation. And, of course, Miami sits on the Atlantic Ocean at an elevation of barely 40 feet, making it famously prone to tropical storms — so much so that the city has major sports teams named the Heat and the Hurricanes. 

Last April, the city’s own chief resilience officer said Miami is “ground zero for climate change,” and that people there “get to enjoy year-round, beautiful weather — unless there’s a disaster.”

But the Magic City has no trouble borrowing against the revenues its properties generate. Miami issued $271 million in bonds for a new administrative building last December, almost all tax-exempt, at yields ranging from 3.35% to 4.65%. It just negotiated the sale of $251 million more debt, for infrastructure projects. A year ago, S&P Global Ratings increased its long-term and underlying ratings on Miami’s bonds to AA from AA-minus. Among their reasons for the upgrades, one of the world’s leading providers of credit ratings cited “turnovers in the chief financial officer/assistant city manager position in 2022 and the city manager position in 2020.”

Welcome to the world of municipal bond creditworthiness, where a new assistant manager can have more impact on the assessment of a city’s financial health than the fact that it’s the most vulnerable metropolitan area in America to hurricanes. 

The costs of climate-related problems are spiking across the United States, pressuring almost every kind of stakeholder involved in the building and maintenance of houses and businesses or the provision of public services: homeowners, insurance companies, issuers of corporate debt, state and local governments. Not, however, players in the municipal bond market. 

While municipal bonds finance nearly three-fourths of American infrastructure, the muni bond industry has shielded and shifted the costs of climate-related hazards. Experts are hard-pressed to name even one municipal debt issuer that had its credit rating downgraded because of climate dangers. “It’s 1,000 percent accurate to say that climate risk is not being priced into the market,” said Ruth Ducret, senior municipal research analyst at Breckinridge Capital Advisors.

Yet carbon emissions are still rising. Temperatures, sea levels and hurricane intensity are, too. And so are the concerns of regulators, who worry the storms that are literally roiling other sectors of the national economy will finally slam muni bonds. “We’ve heard warnings about a coastal property values crash, a similar collapse in wildfire-adjacent areas, a bursting of the ‘carbon bubble,’ of turmoil in insurance markets, climate inflation, and now danger to a pillar of American investment,” Sen. Sheldon Whitehouse, D-R.I., chair of the U.S. Senate Budget Committee, said at a January hearing on municipal bonds and climate risk.

If that seems apocalyptic, the latest data makes clear that, as George Will once wrote, the future has a way of arriving unannounced. Climate change is already threatening livability and property values in communities around the country — and municipal finance cannot stay disconnected from those foundations of revenue for long. There’s a correction coming, and it could be severe.

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Hurricanes are surely the most visible form of climate-related disasters, and they have become more frequent and more intense over at least the past four decades. Twenty-one tropical cyclones or severe storms hit the U.S. in 2023, incurring $63.5 billion in damages, according to the National Centers for Environmental Information. Each of those numbers is greater than the cumulative totals for the years 1980 to 1989, even after adjusting the costs of the storms for inflation. Most scientists, including leading researchers at the National Oceanic and Atmospheric Administration, expect greenhouse gases and global warming to considerably worsen the future impact of tropical storms. Rising sea levels will keep making tides higher. Hurricanes will probably pour out more rain, simply because warmer air can carry more moisture. And the combination of warmer oceans and a wetter atmosphere is likely to cause a greater proportion of storms to become very intense.

As gloomy as those scenarios might seem, they’re just part of the overall climate forecast. Increasing rainfall and higher tides also combine to produce broader and deeper floods, as stormwaters pour into communities faster than it can drain away. A Washington Post analysis published in April found that 28 million people in the southeastern United States, essentially those living in the region from Cape Hatteras, North Carolina to Brownsville, Texas, are at risk of flooding. The number of rain-driven and flash floods within 10 miles of the coast in that stretch grew 42% from 2007 to 2022, for a total of 2,800 events.

Meanwhile, recent studies found that human-induced climate change doubled the area vulnerable to forest fires in the western U.S. from 1984 to 2016 (mostly by drying out burnable material) and is now the major cause of the country’s dramatic increase in wildfires. Massive, lethal fires now torch about 8.8 million acres of land a year in the West, up from 1.7 million acres a generation ago.

The trend in epic catastrophes has shifted from intriguing to dangerous to terrifying during the lifetime of most American adults. Combining droughts, floods, freezes, hurricanes, storms and wildfires, the number of events in the U.S. causing at least $1 billion in damage (in today’s dollars) has rocketed from 5.7 per year in the 1990s to 13.1 in the 2010s to 22 over the past three years, according to the NCEI. The average annual death toll of those disasters is up from 308 Americans to 523 to 563 over the same spans, and the total annual cost has zoomed from $33.1 billion a year to $98.6 billion to $145.9 billion.

With nearly two dozen disasters now causing almost $150 billion a year in damage — and with many Americans still moving into and developing areas on the Atlantic coast and in the West — climate effects are spreading geographically and overlapping more frequently. In April, an S&P analysis found that 64% of U.S. counties generate at least 5% of their economic output from locations facing an acute climate hazard, such as hurricanes, flooding or wildfires. It further estimated that 21% of counties will have that level of exposure to two or more hazards by the year 2050. In other words, the frontiers where the suburbs meet the coasts or the wilderness may soon become whole new danger zones.

That’s an extraordinary amping of risk, and the corporate bond issuers contributing to it are feeling heat. As opposed to being responsible for infrastructure maintenance, private companies are primarily vulnerable to the costs of needing to transition away from depending on fossil fuels as climate change makes carbon addiction unsustainable. 

And rating agencies have been clanging alarm bells about those dangers for nearly two years. In October 2022, for example, Moody’s Ratings found that high-carbon sectors of the U.S. economy comprised 10% of outstanding debt, and said environmental concerns were increasing their credit risks. 

A January 2023 report by S&P Global Market Intelligence studied various carbon-intensive industries. It projected a 54% chance for airlines to suffer credit downgrades by 2050, equivalent odds for metals and mining companies, and a 48% probability for oil and gas firms — with all of those numbers rising if the global transition to net-zero carbon emissions is “disordered.” Two months later, Fitch Ratings warned that 20% of all corporate bonds could face ratings downgrades by 2035 because of climate vulnerabilities. 

“A financial time bomb is ticking,” an August 2023 report by the Institute for Energy Economics and Financial Analysis said about these announcements. Taken together, IEEFA opined, they indicated that growing climate risks “will likely lead to rating volatility and instability, a costly affair for investors and issuers,”

But at least there are canaries singing in the taxable coal mine. An August 2023 study by researchers from Duke University, Northeastern University and Breckinridge looked at 712,000 municipal bonds representing nearly $2 trillion in outstanding debt, and concluded: “Physical climate risk is not meaningful for municipal bond prices or evaluations in the secondary market.”

Specifically, the paper estimated that all else being equal, increasing a municipal issuer’s climate risk by 32 times would increase the yield it pays by just 4.2 basis points. That’s the equivalent of switching its surroundings from Liberty County in northern Montana to the Florida Keys, with just a negligible outcome.
 
A year earlier, Intercontinental Exchange examined about 800,000 muni bonds representing more than $2.5 trillion in outstanding debt. It found that “physical climate risk is not priced into the cost for issuers to borrow capital.” ICE analysts reviewed one subset of bonds issued between 2017 and 2021, when financial markets generally were becoming more aware of climate threats, and another of bonds with maturities of 20 years or more, to see whether investors focused on long-term issues demanded premiums. The results were the same.

“Muni issues with physical assets exposed to rising sea levels or greater storm frequency should command an additional risk premium from investors, all else equal,” said David Hammer, head of municipal bond portfolio management at PIMCO. “Issuers that need to harden infrastructure are likely to borrow more in future years and could see leverage increase. The majority do not have the luxury of relocating operations.”

So why aren’t investors responding more strongly to climate threats?

For one thing, credit ratings from the biggest rating agencies aren’t signaling that there’s much to worry about. Consider: HIP Investor has developed resilience ratings to measure exposure to climate threats for nearly 127,000 bonds issued by 3,859 municipalities. The correlation between the issuers’ Moody’s credit ratings and their resilience scores is 0.02 (on a scale from -1 to 1) — essentially zero, or no relationship at all. Indeed, some metro areas, including the three with the lowest climate-vulnerability grades among large counties — Galveston County, Texas; Charleston County, South Carolina; and Palm Beach County, Florida — have earned the highest possible credit rating from at least one of the nation’s largest rating agencies.
 
It’s not exactly breaking news that rating agencies typically use at most a few years of economic and demographic data to assess a municipality’s creditworthiness. They look at statistics like population growth, revenue stability and the ratio of a city or county’s fund balance to its spending. And the overall metric that agencies boil their work down to is an estimate of the likelihood of issuer default. In other words, agencies and their analysts are ultimately focused on what short-term trends tell them about the chances that a municipality will completely collapse. 

“The big rating agencies have great climate analytics,” said Andrew Poreda, senior research analyst at Sage Advisory. “They do look at climate risk. However, it’s like an indicator within an indicator; it doesn’t necessarily have too much teeth. They do a great job of analyzing it and showcasing it, but in the end, you can see that it’s a very minor part of the overall methodology in the municipal bond space.”

But in munis, where households hold a plurality of 41% of assets (compared with 2% of corporate and foreign bonds), there are plenty of retail investors who take credit ratings as a stamp of overall financial health and safety. “Individual investors, many of whom are buy and hold, need a long-term view of risk,” said Paul Herman, founder and CEO of HIP Investor. “Many credit ratings appear to be connected more to historical factors, and not easily by future risk.”

Of course, buyers and sellers respond to a far wider array of signals than the letter grades assigned by rating agencies. Thing is, climate change is the kind of non-linear threat that’s hard to get a handle on. It’s an accelerating problem. Rising temperatures are igniting and bringing together multiple intensifying changes. The next half-degree of increase in average heat will be much worse than the last, as storms, fires and floods hit harder and wider and overwhelm more areas around the country. And J-curves are hard to project.

“I would not say this issue is being completely ignored by the market; there are more episodic examples where investors are attempting to incorporate it,” said John Miller, chief investment officer of high-yield municipal credit at First Eagle Investments. “It is one of the most unpredictable factors, and therefore might not be applied consistently in all areas or across all credits. It is difficult to break it out distinctly and isolate it.” 

That’s true whether you’re a bond analyst or investor or homeowner. For instance, 77% of Miami-Dade County residents — a higher proportion than the national average — believe global warming is happening, according to a 2023 survey by the Yale School of the Environment. But 66% told a separate survey last year by the journal Climate Risk Management that they want to live there the rest of their lives. Until very recently, the impacts of climate change have been so huge and so different from what most Americans have ever experienced yet seemingly so far off that they have messed with what psychologists call our “number sense” — our instinct for comprehending large quantities in their proper proportions. They seem outside the course of normal business.

Another factor: U.S. residents have grown accustomed to the federal government conducting massive rescue and rebuilding efforts after major disasters. The federal government has in fact played a key role in bringing people to lands now threatened by climate change and helping them stay there. The Army Corps of Engineers, which is as old as the Revolutionary War, has a storied history of clearing canals, rivers and harbors, building levees and controlling floodways. This encouraged Americans to move to and develop coastal floodlands. And Washington has largely taken over flood insurance through the National Flood Insurance Program, while the Federal Emergency Management Agency has long favored rebuilding in place rather than relocating displaced homeowners and businesses. 

Nowadays, it’s the arrival of FEMA teams that often indicates a disastrous event has moved from crisis to recovery. This federalization has been a major help to distressed municipalities. After Hurricane Sandy in 2012, for example, assistance from Washington temporarily zoomed from an average of 2% to between 30% and 70% of the GDP of counties in New Jersey. And Americans expect its shifting of costs and risks to continue. “One of the main reasons the market is still ignoring climate risk is that most participants believe federal disaster aid will continue for the foreseeable future,” said Triet Nguyen, vice president for strategic data operations at DPC Data.

Prices for municipal bonds, as with any assets, are also driven by fundamental rules of supply and demand. “Over the past 15 years, the muni market hasn’t grown at all,” said Ducret. “It’s still about $4 trillion in size. It hasn’t moved, and there are way more buyers. That reality is a big reason why some will buy regardless of climate risk at this point.”

Volume has stayed flat despite hopes by some Biden administration officials that states and cities would use municipal bonds more heavily to leverage its signature initiatives. The Infrastructure Investment and Jobs Act, enacted in 2021, is sending about $360 billion to state agencies and programs, including funding for roads, broadband, water systems and public transit. The Inflation Reduction Act, passed two years ago, made more than $600 billion in climate-related investments, largely by extending and creating tax credits for everything from installing solar panels to sequestering carbon dioxide in underground crevasses. These investments are not only building projects directly and tinting federal priorities greener, they have helped spur considerable additional municipal appropriations: Capital spending as a percentage of all state and local expenditures grew faster from 2021 to 2023 than at any time since the Carter administration. But they haven’t yet created a new overall investment baseline by spurring state and local issuers to augment that funding with large tranches of new debt.

Broadly speaking, issuers have the capacity to issue more bonds, but have proven unwilling to do so in recent years. Perhaps conditions are due to loosen. “State and local governments have issued less debt, relative to corporate bonds or Treasuries, in recent years,” said Hammer. “They are now in the best financial shape in decades, and federal infrastructure dollars are beginning to flow. We expect this to be a tailwind to higher new-issue supply.”

But the rising prominence of politicians who see debt financing as just another tax also has something to do with that. When it comes to dealing with climate change specifically, the muni bond market has also become one more arena in the battle over “wokeness.” Since 2021, nearly 20 states have enacted laws or regulations prohibiting or restricting the application of environmental, social and governance policies in the investment of public funds. For example, Texas, which together with its various subdivisions issues more debt than any state in the country, now bans municipalities from working with banks that restrict their business with oil or gas companies.

Last year, Florida took even sharper aim at ESG bonds — and explicitly included rating agencies in its sights. The state banned municipalities from issuing “bonds marketed as promoting a generalized or global environmental objective.” It also flatly prohibited issuers from dealing with “any rating agency whose ESG scores for such issuer will have a direct, negative impact on the issuer’s bond rating.” By the plain language of state law, it’s fair — and for rating agencies, it’s crucial — to wonder what climate-related credit risks are necessary to consider and disclose and which would actually be illegal.

Florida officials point out their state has a long record of funding efforts to resist and adapt to climate change, from coastal mapping to hardening infrastructure. “We’ve had a statewide building code since Hurricane Andrew, which was in 1993,” Ben Watkins, director of the Florida Division of Bond Finance, told The Bond Buyer’s National Outlook conference in February. “That requires elevation, coastal setbacks, holding ponds for inland flooding and stormwater management. We’ve been buying conservation land at $300 million a year since before it was cool. We invented emergency management. We’re fine talking about resiliency, but we don’t feel the need to be marketing something that’s not substantive.”

But that’s an exception. Municipal Market Analytics recently studied the partisan orientation of all 50 states. Of the 17 that enacted anti-ESG laws in 2023, all 17 were classified as red (or Republican). And only four of those had finalized state plans for adapting to climate change by the third quarter of last year. In contrast, 15 of 22 blue (or Democratic) states had adaptation plans. “If you look at a map of where the climate risks are, and then you look at where the potential actions are to mitigate those risks, they’re missing in Oklahoma, in many parts of Texas, in the Dakotas,” said HIP’s Herman. “It’s unfortunate that it’s political, but it is.”

All of these variables — the business models of rating agencies, difficulties of making and understanding long-term projections, federal backstop to disaster recovery, political opposition to mobilizing against climate change — have helped block investors from acting on or even perceiving the dangers ahead. Now, some may be starting to weaken. Recent studies have found, for example, that exposure to rising sea levels does affect the price of some municipal bonds, an indication that investors may react to particular types of risk. 

Scientists have also developed the term “heat stress” to measure the everyday, grinding ways in which extreme temperatures affect us. Relentless heat saps productivity, pushes up air conditioning costs, and ultimately increases death rates. And a 2023 study concluded that an increase of one standard deviation in heat-stress exposure leads counties to pay, on average, five basis points more in borrowing costs. This suggests the market might actually be more sensitive to persistent problems caused by ever-increasing warming than to headline-generating disasters. 

Further, it’s not clear for how long or how heavily either property owners or investors can continue to rely on FEMA, which is chronically underfunded and forced to rely on supplemental emergency appropriations almost every year. The Biden administration asked Congress for an extra $9 billion just last month to prevent federal disaster funds from running out. 

“Increasing pressure on federal debt will make it more difficult, economically and politically, for the federal government to help state and local governments with key aspects of climate change,” said George Friedlander, former chief municipal strategist at Citigroup, “including the capacity for the federal government to deal with the aftermath of highly destructive weather-related events.”

For the moment, though, in this era of mounting disasters, most participants in this market are talking and acting the way they have for a long time: they believe “headline risks” may widen spreads from time to time, but unforeseen developments generally get swallowed and digested without having a systemic impact. Municipal bonds, even when backed by residents and revenues from vulnerable communities, are still being widely bought and sold as the safest of investments. “Our market typically doesn’t react to slow-moving credit developments, like climate change, until there’s a catalyst event of some sort,” said Nguyen. “The same thing happened with the public pension crisis, which was building up for years but did not get priced in until the financial crisis of 2008.”

But there’s an adjacent marketplace that also assesses, absorbs and shares risk that’s already getting clobbered by the climate: the insurance industry.

Homeowners insurance costs vary widely around the U.S., but on average, premiums jumped 23% in 2023 after climbing 11% the year before. Even those boosts didn’t come close to offsetting the mounting impact of natural catastrophes. 

American property and casualty insurance companies suffered $24.9 billion in underwriting losses in 2022 and lost $21.2 billion more last year, according to AM Best. Insurers are not only facing rising claims and regulatory limits on just how much they can raise their rates, but on spiking bills in their own mailboxes: Property and casualty reinsurance companies, which help share the risk of disasters, raised their prices 37% last year. As a result, many insurers are simply deciding to exit high-risk areas.

In Florida, the effects of climate change have been exacerbated by a legal environment that rewards litigation. (According to the Insurance Information Institute, 79% of all U.S. lawsuits related to homeowners insurance took place in Florida in 2020.) And insurers have been leaving in droves: Farmers, Nationwide and Progressive all announced significant cutbacks in their homeowners offerings in 2023. Scarcer availability of policies has driven more residents into Florida’s state-backed insurer of last resort, Citizens Property Insurance. Citizens offers spottier coverage than most private companies, but its enrollment bulged 111% to 1.1 million policyholders from 2021 to 2023.

To mix climate-related metaphors, Florida is the tip of the iceberg for a phenomenon that’s spreading like wildfire. In May 2023, State Farm, the country’s largest insurance company, announced it would no longer sell homeowners policies in California. The following month, Allstate followed suit: no more initiating commercial or homeowners insurance in the biggest state in the nation. “The cost to insure new home customers in California is far higher than the price they would pay for policies,” Allstate said, “due to wildfires, higher costs for repairing homes and higher reinsurance premiums.” 

Around the same time, the Wall Street Journal reported that American International Group would limit homeowners policies in about 200 ZIP codes across the country, including locations in Colorado, Delaware, Idaho, Montana, New York and Wyoming. The culprit: high risks of fires or floods. 

The retreat of the insurers, in other words, is now a national phenomenon. And as their products get both harder to find and more expensive to purchase, more Americans are skimping on coverage or taking the giant chance of doing without it altogether (or “going bare,” as the industry calls it). Two-thirds of American homes are now underinsured, according to Nationwide. And a recent survey by III found that 88% of U.S. homeowners had property insurance, down from 95% in just the past five years.

Meanwhile, premiums for federally backed flood insurance went up 272% last year in West Virginia, 249% in Mississippi, 220% in South Dakota. High-risk areas are likely to see even steeper increases in coming years, as the NFIP attempts to price in growing risks — and that program is still more than $20 billion in the red. 

Insurance costs are the connection between climate risk that cannot be ignored and the soundness of municipal bonds. Think about any property, such as a home. Its value depends on how much of a return a potential buyer or investor can get from it, which in turn depends on its net operating income — essentially the revenues it generates minus the expenses it incurs. Insurance is the way we shift away the cost of protecting an asset from disaster; we pay companies to distribute our risk. But insurance also reduces the asset’s bottom line (as do the costs of fixing whatever insurance doesn’t cover). Which is why Miller said: “Annual insurance costs for buildings and homes and other facilities can affect affordability and current debt-service coverage, and are increasingly heavily weighted by our team.”

Higher expenses mean lower income, which in the case of real estate means reduced property values. That’s just basic accounting, but in an environment where insurance rates are trying to catch up with more frequent and expensive climate-related disasters, it has enormous implications. To take an extreme but ominous example, last year, the First Street Foundation used an NOI model to re-price the cost of properties in locations around the U.S. after adjusting for estimated future insurance costs. It found an average rental in West Palm Beach, Florida would drop in value by a whopping 41%. 

From South Florida to the Gulf Coast of Texas to the wildfire-attacked foothills of Sacramento to storm-surged cities in the Northeast, insurance markets are veritably screaming that properties across the U.S. are overvalued because their prices don’t yet reflect the already imminent costs of insuring against or repairing climate damage. A 2023 study published in the journal Nature Climate Change found that residences exposed to flood risk are inflated in worth by $121 billion to $237 billion. Research in 2022 by the consulting firm Milliman put the national total at $520 billion, with 3.5 million homeowners vulnerable to property-value declines of more than 10%. That huge bubble has financed building and development in high-risk areas — and is supporting the bonds issued by their municipalities. “Issuers that are able to take advantage of high ratings win until that cycle reverses, and the data suggest it’s going to reverse quickly because of the nature of the impending climate changes,” said Friedlander. “The typical resort-area buyer is slow to change, for example, but then all of a sudden they do change.”

In the early 2000s, Terrebonne Parish in southern Louisiana was struck by multiple tropical storms, including Hurricane Isidore in 2002. A full decade later, the region was still struggling. Its population declined. It found itself spending 75% of its capital budget on projects like relocating its government buildings and improving drainage systems. Between 2015 and 2019, its per capita debt increased 34%. Then, in 2021, Hurricane Ida smacked Terrebonne with 150 mile-per-hour winds, put the parish under more than three feet of water and caused billions in damages all over again. 

This is the spiral that’s spreading to communities around the U.S. It’s no longer prudent or even possible to write off the specter of re-destroyed cities as a dystopian vision, or to laugh off re-re-built homes on stilts along oceans and riverfronts. Climate disasters are driving shared costs up, people out and property values down. The fragmented, illiquid world of municipal bonds is slow to change and sensitive to interest rates above all, but tax bases, revenues and municipal creditworthiness can’t remain immune forever. 

About 565 miles east of Houma, Terrebonne’s largest city, John Ruggieri erected a two-bedroom, four-bathroom blue house on Vilano Beach in St. Augustine, Florida in 2002. The blue house became famous because it was on stilts and managed to survive multiple hurricanes. At the time it was built, it didn’t even require flood insurance. But tides and storms washed away its driveway and ground-floor breakaway wall, and local officials told Ruggieri he needed to make repairs to keep up with safety codes. In March 2023, he said the blue house would stand as long as the sand beneath it didn’t keep eroding. He also put it up for sale for $1.2 million. Instead, St. Johns County ordered it torn down and the property ultimately sold for $175,000.

During the final days that it was standing, literally over the beach, local opinion about the blue house was split. Some neighbors along the coast said Ruggieri had the right to do whatever he wanted. Others called the structure an eyesore and said they wished they could be rid of it. Stories about the demolition didn’t mention anyone saying they worried the same thing might happen to them.