Sediment cores from Western Lake provide a 7000-yr record of coastal environmental changes and catastrophic hurricane landfalls along the Gulf Coast of the Florida Panhandle. Using Hurricane Opal as a modern analog, we infer that overwash sand layers occurring near the center of the lake were caused by catastrophic hurricanes of category 4 or 5 intensity. Few catastrophic hurricanes struck the Western Lake area during two quiescent periods 3400–5000 and 0–1000 14C yr B.P. The landfall probabilities increased dramatically to ca. 0.5% per yr during an “hyperactive” period from 1000–3400 14C yr B.P., especially in the first millennium A.D. The millennial-scale variability in catastrophic hurricane landfalls along the Gulf Coast is probably controlled by shifts in the position of the jet stream and the Bermuda High.
I’ve updated a plot of Florida major hurricane strikes since 1900 with Hurricane Michael, and the result is that there is still no trend in either intensity or frequency of strikes over the last 118 years:
Les côtes de Flandre n’ont pas toujours été aussi paisibles qu’aujourd’hui, et je n’oublie pas le raz-de-marée du 31 janvier 1953 qui toucha les Pays-Bas et notre littoral, faisant plus de 1800 morts et des dégâts considérables. (photo : à Ostende).
Pêchés dans diverses chroniques et ouvrages (notamment “La Flandre mystérieuse” de Saint Hilaire), j’en ai fait une compilation qui n’a bien entendu aucune prétention scientifique ou historique, mais ces événements avaient laissé une trace dans la mémoire populaire, trace qui a hélas fortement tendance à s’effacer.
J’y ajoute quelques événements survenus en France et aux Pays-Bas, dont on peut raisonnablement penser au vu de leur localisation, qu’ils eurent des conséquences sur nos côtes
Even before Hurricane Florence made landfall somewhere near the border of North and South Carolina, predicted damage from potentially catastrophic flooding from the storm was already being blamed on global warming.
Writing for NBC News, Kristina Dahl contended, “With each new storm, we are forced to question whether this is our new, climate change-fueled reality, and to ask ourselves what we can do to minimize the toll from supercharged storms.”
The theory is that tropical cyclones have slowed down in their speed by about 10 percent over the past 70 years due to a retreat of the jet stream farther north, depriving storms of steering currents and making them stall and keep raining in one location. This is what happened with Hurricane Harvey in Houston last year.
But like most claims regarding global warming, the real effect is small, probably temporary, and most likely due to natural weather patterns …
All around the world the climate druids are at work.
Show me the error bars
Once upon a time a scientist talked about thirty year trends and anachronistic things like “confidence intervals”. Now, thanks to the discovery of Unscience, any noisy, random short data is fair game to be declared undeniable climate change. Periods of flooding also qualify, as do periods of nice weather, though strangely no one mentions those. Where are the headlines? If climate change caused drought on the East Coast of Australia, it’s also causing average rain and good crops in Western Australia.
In terms of scientific data analysis we don’t get that many droughts or six-day-August-heatwaves to analyze. They’re complex phenomena caused by multiple factors and we only have short records. This makes them ideal to be oversold to hapless folk as a “sign” of climate change.
One of the main difficulties with tornado records is that a tornado, or evidence of a tornado must have been observed. Unlike rainfall or temperature, which may be measured by a fixed instrument, tornadoes are short-lived and very unpredictable. If a tornado occurs in a place with few or no people, it is not likely to be documented. Many significant tornadoes may not make it into the historical record since Tornado Alley was very sparsely populated during the 20th century.
Much early work on tornado climatology in the United States was done by John Park Finley in his book Tornadoes, published in 1887. While some of Finley’s safety guidelines have since been refuted as dangerous practices, the book remains a seminal work in tornado research. The University of Oklahoma created a PDF copy of the book and made it accessible at John Finley’s Tornadoes(link is external)
What’s wrong with comparing Super Storm Sandy’s devastation with projected sea level rise? They are two different things! One is a storm surge, the other an incremental change in either sea level or land subsidence (sinking) or both. For one we can evacuate the immediate area where landfall is forecast to hit in order to save lives. For the other, we have the time to build dikes and barriers like those in England and Holland, or flood-proof, or move. Super Storm Sandy is not unprecedented, and neither are extremely stormy and erratic periods of climate with catastrophic storms, like the Grote Mandrenke — The Great Drowning of Men — of the Little Ice Age. Let me set some perspective.
For those that are sure there’s global warming driving tornadoes and other severe weather events, here’s some inconvenient news. Dr. Roger Pielke Jr. has updated his tornado loss data via his Twitter account. He writes:
Hurricane threat to East Coast due to natural factors
First at his most recent Saturday Summary, the 40-year meteorologist first warns that in-close developing hurricanes of the sort seen in the 1930s are a risk to the US East Coast this year, due the current Atlantic temperature pattern. The reason has nothing to do with CO2 in the atmosphere, but because of natural sea surface temperature cycles.
Sea surface temperatures see “pretty dramatic turnaround”
Researchers have published 4 new papers this year showing that both tropical cyclone activity and intensity have declined over the past decades. The findings mean atmospheric scientists and policymakers will need to reassess positions on climate change and tropical storms.
As readers of my posts know, I’ve held for many years that there are a variety of emergent phenomena that regulate the earth’s temperature. See my posts The Thermostat Hypothesisand Emergent Climate Phenomena for an overview of my hypothesis.
One of the predictions derivable from my hypothesis is that the earth should be relatively insensitive to small changes in forcing. According to my hypothesis, if the total energy entering the system changes in such a manner that the global temperatures start to drop, inter alia the system responds through changes in the time and strength of the daily emergence of the tropical cumulus field and the associated thunderstorms. This allows more sunlight to enter the system and decreases the thunderstorm-caused surface heat losses, balancing out the energy lost elsewhere and maintaining the temperature.
There’s periods where it’s busy and quiet and busy and quiet, but no trend,” said Landsea, “There’s no statistical change over a 130-year period. Since 1970, the number of hurricanes globally is flat. I haven’t seen anything that suggests that the hurricane intensity is going to change dramatically. It looks like a pretty tiny change to how strong hurricanes will be. It’s not zero, but it’s in the noise level. It’s very small.”
A highly precise method to determine past typhoon occurrences from giant clam shells has been developed, with the hope of using this method to predict future cyclone activity.
A team of researchers led by Tsuyoshi Watanabe of Hokkaido University has discovered that giant clams record short-term environmental changes, such as those caused by typhoons, in their shells. Analyzing the shell’s microstructure and chemical composition could reveal data about typhoons that occurred before written records were available… (…)
The whole Tridacna maxima valve. The shell was cut in two sections along the maximum growth axis.
Credit: Komagoe T. et al., Journal of Geophysical Research: Biogeosciences, April 19, 2018
Global mean sea level (GMSL) has increased by about 8–9 inches since 1880, with about 3 inches occurring since 1993. As discussed in Part VI, scientists expect that GMSL will continue to rise well beyond the 21st century because of global warming that has already occurred and warming that is yet to occur.
The recent NOAA Report Global and Regional Sea Level Rise Scenarios for the United States has stated that even the relatively small increases in sea level over the last several decades have been associated greater storm impacts at many places along the U.S. coast. Further, the frequency of intermittent flooding associated with unusually high tides has increased rapidly in response to increases in local sea level, becoming a recurrent and disruptive problem.
by P. Homewood, March 22, 2018 in NotaLotofPeopleKnowThat
You may recall the above report by the BBC, which described how bad last year’s Atlantic hurricane season was, before commenting at the end:
A warmer world is bringing us a greater number of hurricanes and a greater risk of a hurricane becoming the most powerful category 5.
As I promised, I fired off a complaint, which at first they did their best to dodge. After my refusal to accept their reply, they have now been forced to back down.
The above sentence now no longer appears, and instead they now say:
Scientists are still analysing what this data will mean, but a warmer world may bring us a greater number of more powerful category 4 and 5 hurricanes and could bring more extreme rainfall.
Correction 29 January 2018: This story has been updated to clarify that it is modelling rather than historical data that predicts stronger and wetter hurricanes.
(…)
La géologie, une science plus que passionnante … et diverse
