Sunday, March 8, 2020

New study shows sea level rise has been slow and a constant, pre-dating industrialization

New study shows sea level rise has been slow and a constant, pre-dating industrialization




For those who seek to panic the public into handing control of all economic activity to the state, the prospect of rising sea levels inundating coastal cities has been the most useful tool.  By propagating the theory that your SUV, air-conditioning, and jet travel will drown New York and Miami, and submerge Pacific islands out of existence, the warmists plan to extract trillions of dollars from advanced economies and distribute them to cronies making solar cells, electric cars, windmills, and other expensive substitutes, and to the rulers of third-world countries alleged to be devastated (with "administrative costs" sticking to the fingers of the bureaucrats, of course).
It all makes intuitive sense, so children like Greta Thunberg are easily convinced that their futures have been stolen because you want to enjoy a first-world lifestyle.  Melt the polar ice caps, and we are doomed!
In real life, the problems with the theory have been understood by critical minds such as AT contributor and distinguished scientist S. Fred Singer (see below).  Now a new study that found a proxy measure to trace sea levels back before the advent of industrialization has confirmed what Dr. Singer told us years ago: sea levels have been rising very gradually at a near constant rate since the end of the last ice age.  The Global Warming Policy Forum (hat tip: Climate Depot) reports on the study:
A study by the University of York found evidence for a period of enhanced pre-industrial sea-level rise of about 2-3 millimetres per year in three locations — Nova Scotia, Maine and Connecticut, which were largely natural, without any human constructions or man-made factors.
These three locations are partly related to the North Atlantic Oscillation — a large-scale atmospheric pressure see-saw over the North Atlantic region – and to periods of enhanced ice melt in the Arctic, said the authors of the study, whose findings are published in Geophysical Research Letters.
The authors of the study say cities like New York and Boston will have to take into cognizance this natural variability that may affect these cities in the future as well. The team found sea level reconstructions based on salt-marsh sediments from the Atlantic coast and from microscopic salt-marsh fossils. Salt-marshes are good "archives" of sea levels as they contain several metres of sediment which contains data going back hundreds of years.
Faster than global average
Previous studies have shown that, since the 1950s, rates of sea level rise along the Atlantic coast of North America were faster than the global average — leading to this region coming to be known as a sea level rise "hotspot."
However, lead author Prof Roland Gehrels, from the University of York's Department of Environment and Geography, said this earlier rapid episode of sea level rise in the 18th Century wasn't known before. To find out what global warming is doing to sea levels today, the team examined the base level from historical times.
"In the 20th Century we see rates of up to three or four millimetres per year, faster than in any century in at least the last 3000 years. In the 18th Century they were slightly slower, but still much quicker than you would expect for the Little Ice Age, partly because the Arctic was relatively warm during the 18th Century," he noted.
No human factors in pre-industrial era
It was a pre-industrial phenomenon, so there were no anthropogenic forces — or human influences, he explained. In the 20th Century they might have played a key role but well before the industrialization, those rapid episodes of sea level rise on the north east coast of North America in the 18th Century might have been caused due to natural causes, he said.
There is much more, and it is understandable to lay readers.
Almost seven years ago, Dr. Singer wrote here about the complexities in understanding the actual sea level rise:
The difficulty with projections of sea level rise is nicely illustrated by the IPCC.  The estimates of its first assessment report (1990) showed a range of 10-367 cm for sea level in 2100.  The second report, published in 1996, narrowed the range to 3–124 cm.  Its third report, published in 2001, showed 11–77 cm.  The fourth assessment report, published in 2007, showed 14–43 cm in its draft form but changed it to 18–59 cm in the final printed version.  As can be seen, the maximum SLR decreased successively as estimates improved.  All these IPCC projections are very much smaller than the extreme values of about 600 cm by activist-scientist James Hansen (and by climate multi-millionaire Al Gore) — which assume excessive and rapid melting of the Greenland icecap.
This narrowing of estimates by the IPCC has caused great concern among alarmists who feared that the IPCC was being "too conservative."  Probably as a result of this peer-pressure, estimates have now increased[.]
There is much more of great interest in this lengthy article, as well as two others (here and here).  The takeaways include the realization that sea level rise is gradual and has been going on for centuries, may or may not be related in some small way to CO2 emissions, and can be adapted to because it is so slow.
Graphic credit: Pixabay.

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