Death by a thousand cuts
Climate Change Daily Earth Science Hydrosphere Repost

Coastal inundation: Death by a thousand cuts

I recently listened in on a nearby conversation about seal level rise. I wasn’t snooping. They were just loud. “Miami is toast. They’re going under,” is the phrase I remember. Yes and no, I thought. Eventually, they will go under, but it will be death by a thousand cuts. The end won’t come as a catastrophic inundation below floodwaters. Instead, it will creep up slowly, wave by wave, relentlessly sapping life from the city. But from the human perspective, this is the nature of climate change. A stealthy foe, bidding its time, relying on apathy to work unnoticed in the background, taking baby steps year after year until it is too late to alter the outcome.

Oceans are on the rise from two factors: heat and melt-water. The heat from global warming melts ice, adding water to the oceans, and elevating sea levels. But heat is also a factor in-and-of-itself. Water, like many other materials, expands as it warms.

NOAA, in a 2019 report, tracked a global sea-level rise of 9 centimeters over a 25-year period. Thermal expansion from increasing ocean temperatures accounted for 40% of the rise, and the remaining 60% was new melt-water from ice caps.

The report also discussed the effects of rising oceans on coastal communities. Disaster flooding from major storms and nuisance flooding (high-tide flooding) plagues homeowners and businesses in low lying coastal areas. But nuisance flooding is the most direct indicator of a changing world. NOAA reports: “In many locations along the U.S. coastline, high-tide flooding is now 300% to more than 900% more frequent than it was 50 years ago.” So, ten days of high-tide flooding in 1970, now translates into 90 days of nuisance flooding.

A slow spiral downward

High-tide flooding is a growing problem, which is exacerbated when the earth, moon, and sun align, and the extra gravitational force creates exceptionally high tides we call “king tides.” This constant barrage of low-level flooding leads to a slow death for some coastal communities—death by a thousand cuts.

At-risk neighborhoods initially experience high-tide flooding as inundated streets and front lawns. The inconvenience factor is high, and salt-water corrosion from regularly driving through the flooded streets reduces the life of their vehicles. These salty waters also make their way into the ground, corroding water and sewage lines throughout the neighborhood. But this is just the beginning.

Eventually, as sea levels creep higher, nuisance flooding makes its way to the foundations of homes, maybe even lapping under the front door. Rot takes hold in the home’s wooden supports, and flooring, carpets, and drywall need replacing. Some homeowners have flood insurance for covering repair expenses; others don’t and must pay to mend the damage. Then there are those without insurance or extra money, and they continue living with the mold and damage.

By this point, real estate values in the neighborhood have fallen—buyers are spending their money on homes in dryer locations. Homeowners either lose equity in their homes or their mortgages go underwater as the value of the home drops to less than what they owe the bank. The neighborhood suffers an irreversible decline, and abandoned homes become the norm.

But sea levels keep rising, and the next low-elevation neighborhood finds its streets inundated more often by high-tide flooding. The city doesn’t fall to a single flooding event, sending it to a watery grave. Instead, thousands of small floods gradually force a long, slow, and painful decline into oblivion.

The Future

Key West made the news in 2019 when one of its neighborhoods reached the three-month milestone of continuous flooding. Three months seems a step up from nuisance flooding, and a bit more like a permanent problem.

Miami and other coastal communities are on the front line of climate change. They will be the first to submerge slowly beneath the rising tides. The painful demise of their communities will occur almost imperceptibly as rates of nuisance flooding increase, and neighborhoods progressively fall to the sea—death by a thousand cuts.

Our perceptions of time and urgency create a climate change conundrum. The rate of change is too slow to evoke a sense of urgency, despite our intellectual acknowledgment of the existential threat.


ArcheanWeb

Rising seas: Let’s look at the numbers (Source: ArcheanWeb) – https://archeanweb.com/2020/02/20/rising-seas-lets-look-at-the-numbers/  Also:

King tides, bringing reality home (Source ArcheanWeb) – https://archeanweb.com/2020/03/02/king-tides-bringing-reality-home/  Also:


Sources:

Climate Change: Global Sea Level (By Rebecca Lindsey; NOAA) – https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level Also:

Sunny day tidal flooding (Modified) – By B137 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=52334427

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.

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