Sandbags protecting the eroding east coastline. (Adobestock/69295946_digidreamgrafix)
George Harvey
For the September 22edition of NPR’s “Fresh Air,” Terry Gross interviewed Brady Dennis about climate change. The show was titled, “Extreme heat, flooding and wildfires: How climate change supercharged the weather,” and it can be heard online at https://n.pr/3Cme3JJ.
Brady Dennis is an environmental reporter for The Washington Post. He has written extensively about climate change. While he spoke of fires and droughts on the “Fresh Air” broadcast, the thing that may have really stood out for those who live in the Northeast was the issue of rising sea levels and floods.
Green Energy Times has visited the issue in the past, but it is not something that can be stated once and left alone. For one thing, both the sea level rise and knowledge of it are changing.
Melting ice from glaciers and polar regions has already caused the sea level to rise. We have had a fairly accurate understanding of this in recent decades because satellites can measure the rise by satellites for nearly all ocean areas, with small margins of error.
What the measurements show is very close to what scientists expected, given the amount of ice that has melted. For us in the Northeast, the east coast of the United States is one of the areas in the world where the seas are rising fastest, according to Brady Dennis.
According to Climate.gov (), the sea level has risen by eight inches since 1880. That might not sound like much, but when the consequences are considered, it becomes clear that it is quite a lot.
High tide flood in Charleston, S.C. (NOAA image)
For example, a search of internet sites tells us that sandy beaches have slopes ranging from 1% to 8%. If we take an intermediate value of 4%, each inch of rise in the sea would mean a loss of 25 inches of beach. A rise of eight inches would mean a loss of over 16 feet of beach. Sea levels are currently rising at 0.14 inches per year. Between now and 2050, the sea may rise by close to four inches ().
While losing beach area can help us visualize what an inch of sea level rise means, there are other effects that are much more important. Dennis made this clear when he spoke of the 152,000 acre Alligator River National Wildlife Refuge (ARNWR). It was established in 1984 to protect a rare type of wetland, called a pocosin, which exists because unusual geology produces a rare type of ecology based on a relationship of salt and fresh water.
Unfortunately, ARNWR is already being destroyed by sea level rise. Salty water is infiltrating into areas where the underground water is fresh. This is happening because the rising sea is causing salt water to move farther than previously, overwhelming fresh water with devastating ecological results.
ARNWR had marshland, shrubland, and forest. Since its establishment, trees in some areas of forest have died, because they could not survive with the amount of salt in their water. This produces what is termed a ghost forest. The dead forest is overtaken by shrubs that have greater salt tolerance. Not far off, however, shrubs have died because of even higher amounts of salt in available water, so the shrub land is becoming marsh. And not far off from that, the marsh has been overtaken by the sea itself.
Another type of damage from sea level rise comes from high tide flooding events. These have come with the high tides that accompany periods of the full moon and new moon, when the tides are highest because the sun, moon, and Earth are aligned. With sea level rise, they are much higher than ever before, and floods increasingly happen at other times of the month.
Because most streets in East Coast cities were designed before engineers knew about sea level rise, they are vulnerable to higher tides than we had in the past. At the highest tides, sea water runs up the storm drains and comes out on the streets causing floods that can even happen on sunny days. This is already a problem in a number of coastal cities.
Higher tides are not a remote problem in the Northeast. Nor is it confined to coastal regions. At Hartford, Connecticut, the Connecticut River is at about the same level as the ocean, and so it could be affected by tides. In fact, communities along the Hudson River will almost certainly have similar problems.
Ghost forest in the Alligator Forest National Wildlife Refuge. (NC Division of Water Resources, CC0 1.0, public domain)
Green Energy Times has had articles before about the effects of sea level rise in places like Florida and Louisiana. One example, published in 2018, is “The Time to Act is Now!” () Nearer to us, a forecast for New York City says that average sea levels at Battery Park in Manhattan have risen six inches in the last 48 years, but they are expected to rise another six inches in the next sixteen years (). NOAA has expected seas to rise another 10 to 12 inches by 2050 (). But there is more news about that in the article “Zombie Ice in Greenland,” on page 22 of this issue.
On the U.S. Atlantic coast, flooding is expected to be far more frequent, very soon. Cities on the East Coast and Gulf Coast have seen increases of 400% to 1,100% since the year 2000, according to NOAA (). By the year 2050, flooding in some areas is expected to happen as many as 75 days per year. That is enough to put a serious dent in business.
Storms cause more damage with greater sea level rise. The federal government has tracked insurance claims, because it has guaranteed them since 1968. Finding that some homes were being rebuilt repeatedly, Congress passed the National Flood Insurance Act of 2004, which limited the number of claims a property could have to two claims of over $1,000 during a period of ten years. Properties with more claims lost their guarantee of insurance.
Nevertheless, the National Flood Insurance Program went into debt. Congress canceled $16 billion in debt in 2017, so the program could pay claims. By the end of 2020, the program owed over $20 billion (). And as we write this, Hurricane Ian is said to be the most expensive storm ever to hit Florida.
The sea level is rising, and with that, things are getting worse much faster than many of us might have thought possible. The best time to act on this has already passed. But it is vital that we act now, to limit the upcoming damage as much as we can.
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