01:25 - Source: CNN
See Florence's destruction in the Carolinas

Editor’s Note: Michael Bociurkiw is a global affairs analyst, at work on his first nonfiction book on screen and social media addiction. The opinions expressed in this commentary are his. View more opinions on CNN.

CNN  — 

About 41 million Americans live in areas that have a chance of flooding – and the number exposed to serious flooding is as much as 3.1 times higher than previous estimates.

Time is clearly not on our side. Sea levels are rising faster than predicted, and homeowners in particularly vulnerable areas, such as South Florida, could see their properties literally under water within their lifetimes. Relative sea levels there are roughly four inches higher now than in 1992; various projections, including by the Army Corps of Engineers, see rises in South Florida of 12 inches by 2030 and between 2 to 3 feet by 2060.

Michael Bociurkiw

What’s more, “rare events are going to become more common in the future strictly due to sea level rise,” William Sweet, an oceanographer at the National Oceanic and Atmospheric Administration (NOAA), told The Guardian.

And so it would make some sense that as officials tally the damage from Hurricane Florence in the Carolinas, with 41 dead and insured losses estimated at $2.5 billion, coastal homeowners and businesses might conduct their own tallies of the cost of continuing to live in places vulnerable to flooding and high winds.

Yet, national and local leaders appear to be sleepwalking toward climate catastrophe. Based on my own exchanges over the years with municipal mayors from both inland and coastal jurisdictions, my sense is that few view it as a top priority – especially those in places such as South Florida, where the property tax base is the main source of income.

Rather than curbing building in vulnerable areas or returning flood-prone areas to nature, jurisdictions such as Miami Beach have opted to spend millions on flood abatement projects.

And for their part, financial markets deflect reality. Climate change “is a very slow-moving disaster that may last decades before it has any effect on the markets,” Wall Street investor Michael Popow told me. “In the meantime it is another negative in the macro-economic environment which will, sooner than later, cause the markets to crash.”

But this disaster is not so slow-moving. Monster storms are coming faster and with more ferocity (last year was the first time in over a decade that four hurricanes made US landfall in one season), and a growing number of coastal dwellers have now lived through multiple storms, with some not even fully recovered from the last one.

By one estimate, from Seattle-based Zillow Research, based on current projections by NOAA of ocean levels rising six feet by 2100, almost 2 million properties – or roughly 2% of US housing stock, worth $882 billion – could be under water in a little over 75 years. Close to half of that loss in value would occur in Florida alone, where 1 in 8 properties, worth a total of $400 billion, are threatened.

As Zillow points out, given the insatiable appetite for waterfront properties, these numbers could be on the conservative side if development is allowed to continue in vulnerable areas.

In fact sea-level rise is already swamping coastal property values: research by the First Street Foundation has tabulated a home value loss of $14.1 billion across eight coastal US states since 2005.

Ironic, is it not, that some of the most coveted and expensive property in the US is also becoming the most vulnerable – and is on a depreciation cycle.

In my frequent trips to South Florida, I encounter more and more people who are contemplating moving away from the waterfront – especially in flood-prone Miami Beach, where even on clear days during high tides, and even with billions spent on flood alleviation measures, residents can encounter so-called blue-sky flooding. According to one study, such high-tide flooding there has increased by more than 400% in the last 12 years.

In short: if you’re a young to middle-aged homeowner near water in South Florida, there is a chance that your property will be under water by the time you are a senior - or more likely when the time comes to sign the title over to little Jane or Johnny.

John Hilliard’s approach towards rising sea levels is probably typical of many of those who reside on the Venetian Islands. The elevation of his new waterfront home in Miami Beach is at about nine feet above sea level. “That’s reasonably high,” he told me. “I do see larger rain events due to the greater water-holding ability of a warmer atmosphere. But that rain should run off my island into the sea,” instead of flooding and staying. “After 2100 we will be wishing we took this issue seriously as the loss of property will be enormous.”

What will be the trigger to cause mass panic or a collapse of the waterfront property bubble? The former mayor of Coral Gables, James Cason, offers a stark scenario: when water levels in that tony community rise to the point where the masts of sailboats are unable to pass under its main bridge, that is when people will “suddenly see their property values go down because they can no longer get a boat out. So that will be one of the first indicators (of sea level rise) and a wake-up call for people.”

Of course, outward migration from places like Coral Gables will translate into a slimmer property tax ledger for the seaside town, which in turn creates challenges for such municipalities to provide essential services. And municipal bonds, already in a precarious state, could sink even further when they are issued by jurisdictions known to have massive flooding problems.

While it would take a lot for cities like Miami Beach to be abandoned, rising tides and more frequent monster storms are becoming, like the ravaging forest fires in California, a new normal.

One study predicts there will be as many as 13 million “climate refugees” in America by the end of the century – with the hardest-hit county being Miami-Dade.

Even with inaction by a White House that prefers to ignore or deny climate change – withdrawing from the Paris climate agreement and activating rollbacks on the Clean Power Plan – there are localized measures that could defer a crash of the US coastal property bubble due to rising sea levels.

Mayors need to step up to the plate and use the tools and policies at their disposal.

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One, which has already been implemented in many developing countries in the wake of the 2004 Indian Ocean Tsunami, is to return vulnerable areas to nature. That happened in the US, in flood-prone Mastic Beach, New York, after Superstorm Sandy, where damaged homes were bought back and the land transformed into wetlands. Sea walls and strict building codes can force people to build away from vulnerable areas.

“Part of the solution is being smart about where we continue to develop,” said Steven McAlpine, an analyst with First Street.

Waiting to see what happens from this slow-moving disaster is not an option. Once Donald Trump, his supporters in the fossil fuel industry and others accept what is happening it’s going to be too late and too expensive for a fix.