Before Our Eyes: The sunny day floods of Miami

In previous posts, I’ve highlighted communities under ongoing assault by the direct effects of global climate change, including Shishmaref, Alaska and the nation of Fiji. And another nation, Kiribati, already doomed to submersion — in many of our lifetimes — beneath the rising Pacific Ocean. Make no mistake; in these cases we are talking about the preventable losses of the homes, livelihoods, and cultures of hundreds of thousands of fellow humans. These losses are happening right Before Our Eyes, by climate change driven processes that are well documented and obvious to anyone who cares to look. Softening permafrost. Shrinking beaches. Increasing storm damage. People suddenly erecting desperate sandbag seawalls around coastal communities that have persisted for thousands of years, until now. That we are continuing to contribute to these losses demonstrates a profound moral failing on the part of those of us who prioritize our continued ready access to cheap fossil energy (even though we have ready renewable alternatives) over the very viability of these distinct human cultures that have developed over thousands of years of people living in these locations.

But, for many readers of these posts, Shishmaref, Fiji, and Kiribati may seem like far-flung places. So let’s look at developments that may be closer to home.

You may be familiar with Miami, the 8th most populous metropolitan area in the U.S. and home to roughly 5.5 million people. What if I were to tell you that readily observable, direct consequences of climate change presently affect daily life in Miami, foreshadowing potentially existential challenges for that great U.S. city in the future?

In Miami, as any resident will attest (and as scientists have carefully studied and documented in peer reviewed journal articles), sometimes it floods on sunny days. It doesn’t require a hurricane, a storm, or even a rain cloud. Just a high tide and maybe a full moon. To see what that looks like, check out the photo at the top of this post, or simply search “sunny day flood Miami” in Google Images. That’s seawater flooding the city streets of Miami on a sunny day at high tide. It happens more and more frequently. Why? Because high tide has been getting higher since the streets of Miami were developed.

“This never used to happen. . . . I’ve owned this place eight years, and now it’s all the time.”
Eliseo Toussaint, laundromat owner, Miami Beach

Brian McNoldy, an atmospheric scientist and Senior Research Associate at the University of Miami, has been tracking the high tide level at Virginia Key, a Miami barrier island, for two decades:

McNoldy Plot with Inset
Main image credit: Brian McNoldy, Senior Research Associate, Rosenstiel School of Marine & Atmospheric Science, University of Miami. Analysis of high water level at Virginia Key utilizing publicly available tide gauge data collected by the NOAA. Inset at upper right: New York Times, 2016. Mean sea level rise in inches (light blue) and recorded number of yearly nuisance flooding events (purple bars) at Virgina Key over the same time period.

Clearly, high tides are getting higher. They are also getting higher at a rate that has been increasing over the past 20 years — nearly an inch a year, on average, over the past 5 years! An inch a year may not seem like much, until you consider that would result in a foot every 12 years, or over 6.5 feet in a typical American lifetime, and this is how the great city of Miami (built on porous limestone, so it can’t be protected by a seawall) is presently situated with respect to sea level:

Miami Photo
Image credit: Gunther Hagleitner. Presented in Encroaching Tides: How Sea Level Rise and Tidal Flooding Threaten U.S. East and Gulf Coast Communities over the Next 30 Years, Cambridge, MA: Union of Concerned Scientists, 2014.

The higher tides have resulted in a measured increase in incidents of “nuisance flooding” in the city (see inset bar chart in the graph above). More than just a “nuisance,” this comes at a real price; Miami Beach plans to spend $400 million over the next 20 years installing pump stations and raising the streets. “There is a lot of money going into these resiliency issues, so we are hoping to tap into that,” said City Manager Jimmy Morales, commenting on the city’s hopes of securing federal and state funds to pay for the improvements.

“Down here, people are actively dealing with climate change without calling it climate change.”
Tim Osborn, NOAA Manager, Central Gulf Coast

Miami is not the only U.S. coastal city facing chronic tidal flooding due to sea level rise. These are data on sea level rise since 1970, and associated increases in the frequency of tidal flooding events, measured in four other coastal cities:

Tidal Flooding 4 Cities
Figure 4 from a summary report by the Union of Concerned Scientists, 2014. Sea level has risen by about 3.5 inches globally since 1970, but more along the U.S. East Coast as shown in the upper left graph. This has resulted in a measured increase in the yearly number of days of tidal flooding — flooding caused only by high tide — in 4 U.S. cities.
Flooding in coastal cities
Image credits: Union of Concerned Scientists, 2014.

The President loves to highlight present signs of strength of the U.S. economy. Presidents have been taking credit for good economic performance, when it occurs, since the dawn of our Republic. And, the economy (for many of us) is performing great right now!

There is always a rich debate about whether presidents can rightly take much credit for a good economy. I say, go for it! All presidents claim credit when the economy is good.

But, I think we should think very carefully about claims of causality between deregulation of the fossil fuel industry and economic and job growth, particularly from a president and administration with a history of ignoring and denying climate science.

First, it’s highly debatable that the recent broad economic growth could not have been achieved, or even further enhanced, while investing aggressively in renewable energy sources as science says we need to if we want to avoid the most catastrophic outcomes of climate change. In fact, any suggestion of an obvious direct link between job creation in the fossil fuel industry and performance of the broader economy is demonstrably false. According to the U.S. Energy Information Administration and the Department of Energy, the coal industry employed 160,119 Americans in 2016 while generating 30.4% of U.S. electricity. Meanwhile, the solar industry employed 373,807 Americans while generating only 0.9% of U.S. electricity. If the strategy is about creating jobs, clearly expansion of the solar industry is a far better tactic than creating artificial advantages for a coal industry that is already dying of natural market-driven causes!

And, that tactic also happens to be consistent with what we need to do to prevent substantial economic harms in the long term. Whether Miami will get federal and/or state funding of the $400 million it needs to deal with flooding over the next 20 years remains to be seen, but I think we have recently observed there may be limits to federal spending on climate change driven problems:

Moreover, costs due to climate change driven coastal flooding will intensify greatly in the future; Miami is expected to experience 40 times as many tidal flooding events in 2045 as it did in 2014. The map on the right, below, shows how the Miami metro will look with 6 feet of sea level rise. It is now clear that it will be either technically of economically impossible to protect some areas of hundreds of U.S. coastal cities from climate change driven tidal flooding, and the word “retreat” is now being used in adaptation planning.

Miami Maps
Projected coastline of the Miami metropolitan area now (left) and with 6 feet of sea level rise (right). Shades of blue indicate depths of seawater coverage. I created these images myself using this nifty NOAA tool, which enables you to map many parts of the U.S. coast with various projected sea levels.

We have only recently recovered from the Great Recession, the worst global economic downturn since the Great Depression of the 1930’s, which is widely understood to have been caused by overvalued real estate in the U.S. market. Projecting forward the policies of our current federal government — active suppression of climate change information, defunding of climate science, reneging on international commitments, renewed investment in fossil energy, and the above false claims of causality between U.S. fossil energy investment and broad economic performance — it seems clear that we are building into our long-term economic outlook a slow-moving real estate bubble the likes of which we have never before seen. According to the U.S. Geological Survey, complete melting of the Greenland and Western Antarctic ice sheets would raise sea level by 10 meters, flooding out 25% of the current U.S. population. That’s a lot of high-priced coastal real estate — including the Palm Beach Mar-a-Lago! — that is on track to depreciate to zero value.

In 2018, we should demand more from our elected representatives.

More reading on this topic:

  • New York Times article (2016)
  • Summary reports by the Union of Concerned Scientists (2017 and 2014)
  • Summary report by the National Oceanic & Atmospheric Administration (2014)



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