Monday, November 2, 2015

Newsweek Peddles Chesapeake Climate Pessimism

Smith Island Is Sinking Into the Chesapeake Bay Thanks to Climate Change

The article starts with a new view of a familiar object, the last house on Holland Island:
. . . Marshall pilots us to the outer banks of the wildlife refuge, where the horizon is nothing but the blue waters of the Chesapeake and a faint speck in the distance—the remains of Holland Island, whose 360 residents fled rising waters and eroding soil in 1922, and which serves as a constant reminder to the people living on Smith Island that they might be frogs in a pot of slowly boiling water. Smith Island too is disappearing, its land eroding as it submerges into the Chesapeake.

Smith Island comprises the wildlife refuge and a stretch of islands directly south, where roughly 280 residents live in three small villages about 5 feet above sea level. But erosion nips away at Smith Island’s banks at a rate of roughly 2 feet each year, and a 2008 report predicted that by 2100 Smith Island will be “almost completely under water as the Bay’s average level goes up nearly one-foot.”
Predicting one foot of sea level rise in 85 years? That's about right. 3.08 mm per year turns out to be about 10 inches in 85 years. However, salt marsh islands like Smith can grow upward to match this rate of sea level rise, if the original vegetation is allowed to grow unmolested, as the build up of peat (decayed grass) and captured sediment increase it's height. The process is well known. Sea level rise at this rate, and even higher, poses no great threat to most of Smith Island, only the parts covered by roads, houses, and other man made objects. Those will have to be raised or protected as sea level rises. But that is not out of the question if the land is valuable enough visa a vie the Netherlands and Venice, Italy.

But, as noted, the real threat to Smith Island, and the other Eastern Shore islands is not sea level rise, but lateral erosion. Waves from the Bay erode the soft peat at the edges, continually moving the land back. The only way to stop it is to harden the shore line with structures like rip rap, and bulk heads, and move those upward slowly as sea level rises. If you do it right, you might save the salt marsh behind it, and keep the island intact.

Typical Eastern Shore Island at high tide.
Even if the Chesapeake can be kept at bay, there’s no guarantee islanders will stay: In the past 15 years, a growing number have moved out, seeking better opportunities on the mainland. The question today is what will vanish first—the island or its people?

Inaccessible by car, Smith Island is reached by a 45-minute boat ride from Crisfield, Maryland, to the east. Bridges and gravel roads connect the villages of Ewell and Rhodes Point, but the only way to get to Tylerton is on a boat. Smith Island is quaint: There are no chain stores, ATMs or police stations, and mail and supplies arrive daily by boat.
Which is to say, it's pretty much the antithesis of the kind of place that attracts the typical global warming/sea level rise enthusiast. who is more likely to be drawn to Manhattan Island, which has survived and even grown during similar sea level rise by doing the obvious. Adding dirt:

Today, just 276 people live on Smith Island. There are efforts to raise that number, but it’s hard to bring new residents to a place that, as Chesapeake Climate Action Network Executive Director Mike Tidwell wrote in The Baltimore Sun in 2009, “will almost certainly disappear even faster than the Maldives and faster than several much-publicized South Pacific island nations.” Global warming appears to be the bandit that can’t be stopped. The melting glaciers and loss of ice from Greenland ice sheets have contributed to the rapid sea-level rise in the Chesapeake. The Army Corps of Engineers estimates that some 3,300 acres of Smith Island land have eroded over the last 150 years. Currently, only 900 acres of the island chain are habitable.
As you have seen, global warming, other than the general warming at the end of the last ice age, has absolutely nothing to do with the loss of Smith, and the other islands of the Eastern Shore. The loss is entirely natural.  Will some climate change in the future speed that process? Perhaps, but as of yet, there is zero evidence for sea level rise as caused by excessive CO2 in the atmosphere, and greenhouse warming.

Incidentally, the last couple of times I was out with Pete, there was heavy activity around Smith Island as they are now using federal funds, and other matching funds to shore up parts of Smith Island.

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