Archives par mot-clé : Sea level

The clever ruse of rising sea levels

by J.  Lehr & T. Harris, December 6, 2018 in WUWT


For the past 50 years, scientists have been studying climate change and the possibility of related sea level changes resulting from melting ice and warming oceans. Despite the common belief that increasing levels of carbon dioxide (CO2) in our atmosphere could result in catastrophic sea level rise, there is no evidence to support this fear. Tax monies spent trying to solve this non-existent problem are a complete waste.

Sea level rise: what’s the worst case?

by Judith Curry, November 30, 2018 in WUWT


Draft of article to be submitted for journal publication.

Well, I hope you are not overdosing on the issue of sea level rise.  But this paper is somewhat different, a philosophy of science paper.  Sort of how we think about thinking.

I would appreciate any comments, as well as suggestions as to which journals I might submit to.  I have two in mind, but am open to suggestions (and I may need backups).

Thanks in advance for your comments.

Sea level rise: What’s the worst case?

Abstract. The objective of this paper is to provide a broader framing for how we bound possible scenarios for 21st century sea level rise, in particular how we assess and reason about worst-case scenarios. This paper integrates climate science with broader perspectives from the fields of philosophy of science and risk management. Modal logic is used as a basis for describing construction of the scenario range, including modal inductivism and falsification. The logic of partial positions and strategies for speculating on black swan events associated with sea level rise are described. The rapidly advancing front of background knowledge is described in terms of how we extend partial positions and approach falsifying extreme scenarios of 21st century atmospheric CO2 concentrations, warming and sea level rise. The application of partial positions and worst-case scenarios in decision making strategies is described for examples having different sensitivities to Type I versus Type II errors.

Special Report on Sea Level Rise

by Judith Curry, November 27, 2018 in ClimateEtc.


I have now completed my assessment of sea level rise and climate change.

The complete report can be downloaded here [Special Report- Sea Level Rise  ].

My preliminary compilation of information was provided in the 7 part Climate Etc. series Sea level rise acceleration (or not).

This report reflects 18 months of work on this topic. Why have I devoted so much time to the sea level rise issue? First, I regard sea level rise to be the most consequential potential impact of predicted global warming. Second, there is a great deal of public confusion about the issue, including decision makers. Third, a number of CFAN’s clients have queried me about a range of specific concerns that they have regarding sea level rise (and I have been doing consulting on this topic).

Why do I think an independent assessment of the sea level rise issue by yours truly is needed, given the plethora of international and national assessment reports? My clients are concerned about the alarmist predictions they have encountered. I have seen various ‘experts’ make public statements projecting 21stcentury sea level to be as high as 9 m [30 feet]. My clients are looking for someone that they trust to provide an objective assessment that focuses on their issues of concern.

Climate Alarmism Dies In 2018 As Modern Ice Melt, Sea Level Rise Has No Net Impact On World’s Coasts

by Kenneth Richard, November 15, 2018 in NoTricksZone


The year 2018 could mark the beginning of the end of climate change alarmist reporting.  Projections of catastrophic melting of the ice sheets and sea level rise swallowing up the Earth’s coasts are increasingly undermined by observation.

Despite the hackneyed practice of reporting “staggering” ice sheet melt for both Greenland and Antarctica in recent decades, the two polar ice sheets combined to add just 1.5 centimeters to sea level rise between 1958 and 2014 (graphfrom Frederikse et al., 2018) as global sea levels only rose by “1.5 ± 0.2 mm yr−1 over 1958–2014 (1σ)” or “1.3 ± 0.1 mm yr−1 for the sum of contributors”.

That’s about 7.8 centimeters (3.1 inches) of global sea level change in 56 years.

Hothouse claims from ‘Trajectories of the Earth System in the Anthropocene’ are in a virtual world, not the real world

by Albert Parker, November 2, 2018 in WUWT


A recent paper Trajectories of the Earth System in the Anthropocene (Ref. [1] below) claims that even if the CO2 emission reductions called for in the Paris Agreement are met, our Earth may still enter what they call “Hothouse Earth” conditions, a long-term stabilization at temperature 4-5 °C-higher than pre-industrial temperatures, and sea-level 10-60 m-higher than today. They conclude calling for an accelerated transition towards a CO2 emission-free-world-economy. There is, however, very little evidence that the apocalyptic prediction is scientific grounded. Where really measured, the temperatures haven’t increased dramatically, and similarly, the sea-levels haven’t risen dramatically. More importantly, any acceleration of the temperature warming, or any acceleration of the rate of rise of the sea-level, are hard to detect.

Figure 1 –sample long-term-trend thermometer results (Alice Spring, NT, Australia). The temperatures were recorded in the Post Office / City and Airport locations. Data downloaded from www.bom.gov.au/climate/data/.

 

Climate Study: 90 Percent Of Atolls And Islands Either Stable Or Growing

by J. Delingpole, October 30, 2018 in ClimateChangeDispatch


Another global warming scare story bites the dust: fragile islands and atolls in the Pacific are not sinking beneath the waves because of global warming. In fact, they are doing just fine.

The bad news (only bad for alarmists, of course) comes in a study by Virginie Duvat of the University of La Rochelle-CNRS, France, titled ‘A global assessment of atoll island planform changes over the past decades’.

It surveyed 30 Pacific and Indian Ocean atolls, including 709 islands, and found that 90 percent have either remained stable or have grown in the last few decades.

CNN: “Climate change endangers dozens of World Heritage sites”… Unmitigated horst schist

by David Middleton, October 19, 2018 in WUWT


Holocene Sea Level

I didn’t take the time to look up the dates of these World Heritage sites… But I’m going to guess they’re OLD.  Many of them probably date back to the Early to Mid-Holocene.  [My bad… That was a bad guess.  The Late Holocene (Meghalayan Age) begins in 4200 BP (2250 BC)]  Here’s a Holocene sea level reconstruction for the Arabian Gulf, with a recent reconstruction of global sea level since 1800 (Jevrejeva et al., 2014) and the satellite sea level trend from CU…

1989 UN report: ‘By 2000, coastal cities will be underwater’

by David Hilton, September 30, 2018 in EndtimesHerald


By the year 2000, according to the 1989 story:

Coastal flooding and crop failures would create an exodus of ″eco- refugees,′ ′ threatening political chaos, said Noel Brown, director of the New York office of the U.N. Environment Program, or UNEP.

He said governments have a 10-year window of opportunity to solve the greenhouse effect before it goes beyond human control.

Well we’re here in 2018, Noel, it’s nearly October, and I’m sitting here in South-East Queensland at midday in a jacket because it’s cold.

Sea Level Speculation Irresponsibly Threatens Property Owners

by Jim Steele, September 26, 2018 in WUWT


The suggested steady 3.3 mm/year rise since 1992 conflicted with CO2-driven model predictions of acceleration. So, based on the difficulties of calibrating altimetry with tide gauge data, various researchers claimed satellite drift and biases had over-estimated early estimates of sea level rise from 1994-2002. Various adjustments were then evoked, and varying rates of sea level rise published. New global sea level estimates rose at an accelerating rate from 1.8 in 1993 to 3.9 mm/yr today, others at 2.2 mm/yr in 1993 to 3.3 mm/yr in 2014, yet others found satellite adjustments lowered the average rate of sea level rise to 2.6 mm/yr over that same period. Elsewhere Harvard geophysicists were analyzing the effects of mass change on the earth’s rotation and wobble and were disturbed by the misfit between geophysical observations and sea level estimates. They argued that only if 20thcentury sea level rise was limited to 1.2 mm/yr could there be a good fit with geophysical expectations.

Retracing Antarctica’s glacial past

by Louisiana State University, September 25, 2018 in ScienceDaily


More than 26,000 years ago, sea level was much lower than it is today partly because the ice sheets that jut out from the continent of Antarctica were enormous and covered by grounded ice — ice that was fully attached to the seafloor. As the planet warmed, the ice sheets melted and contracted, and sea level began to rise. Researchers have discovered new information that illuminates how and when this global phenomenon occurred.

More recently in 2002, in the northern part of Antarctica called the Antarctic Peninsula, the Larsen Ice Shelf collapsed. The collapse of this ice shelf quickly led to inland glaciers buttressed by the Larsen Ice Shelf to break up and melt. Scientists have thought that a similar process could have occurred when the Ross Ice Shelf collapsed thousands of years ago in the West Antarctic Ice Sheet.

However, Bart and colleagues from the University of South Florida, Auburn University and the Polish Academy of Sciences found that there was a centuries-long delay from when the Ross Ice Shelf collapsed and the grounded ice began to contract. In the Ross Sea, the delay was between 200 to 1,400 years later. This new information adds a layer of complexity for sea level rise computer simulations and predictions.

30 YEARS AGO OFFICIALS PREDICTED THE MALDIVES WOULD BE SWALLOWED BY THE SEA. IT DIDN’T HAPPEN

by Michael Bastasch, September 21, 2018 in TheDailyCaller


Environmental officials warned 30 years ago the Maldives could be completely covered by water due to global warming-induced sea level rise.

That didn’t happen. The Indian Ocean did not swallow the Maldives island chain as predicted by government officials in the 1980s.

In September 1988, the Agence France-Presse (AFP) reported a “gradual rise in average sea level is threatening to completely cover this Indian Ocean nation of 1196 small islands within the next 30 years,” based on predictions made by government officials.

Then-Environmental Affairs Director Hussein Shihab told AFP “an estimated rise of 20 to 30 centimetres in the next 20 to 40 years could be ‘catastrophic’ for most of the islands, which were no more than a metre above sea level.”

COTES DE FLANDRE, SUBMERSIONS FAITS ET LEGENDES

by Jo Moreau, 20 septembre 2018, in Belgotopia


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

Holocene Sea Level Trends

by P. Homewood, August 22, 2018 in NotaLotofPeopleKnowThat


There seems to be a general acceptance about overall sea level trends during the Holocene.

There was naturally a very rapid rise in sea levels at the end of the ice age, until 6000 years ago, since when the rise has been much more gradual. Some research puts the rate of rise in the last 2000 years at 0.07mm/yr, and this reflects the fact that ice caps left over from the ice age are still melting, rather than that the world is warmer than before.

However, the impression is often given that, until the 20thC, this rate of rise has been pretty steady. This is despite the fact some of the authors of the above studies have warned of the existence of significant short-term fluctuations in sea level such that the sea level curve might oscillate up and down about this ~1 kyr mean state. [The above graph is based around 1000 year averages].

 

HH Lamb looked carefully at many expert studies in his day, and wrote about the very significant fluctuations they found. The following excerpts come from “Climate, History and the Modern World”:

1) The most rapid phases [of sea level rise] were between 8000 and 5000 BC, and that the rise of general water level was effectively over by about 2000 BC, when it may have stood a metre or two higher than today.

2) …

….

https://commons.wikimedia.org/wiki/File:Holocene_Sea_Level.png

 

New Paper: 54% Of ‘Vulnerable’ SW Pacific Islands Studied Had Shorelines That EXPANDED From 2005-2015

by Kenneth Richard, July 26, 2018 in NoTricksZone


Despite a rapid local sea level rise rate nearly 3 times the global mean (1.8 mm/yr), 15 of 28 studied atoll islands in the southwest Pacific increased in shoreline area during 2005 to 2015 according to a new study (Hisabayashi et al., 2018). For the 3 islands that experienced extreme shoreline erosion – with one atoll island even “disappearing” – a Category 5 cyclone was identified as the most likely causal factor. 
Consequently, the authors conclude that “the dramatic impacts of climate change felt on coastlines and people across the Pacific are still anecdotal.