No longer water under the bridge, statistics yields new data on sea levels

From Eurekalert

Public Release: 8-Aug-2017

Untraditional approach expected to save lives, businesses, and communities along East Coast shows rate accelerating at a pace in contrast to previously accepted data

American Statistical Association

ALEXANDRIA, Va. (August 8, 2017) – While the scientific community has long warned about rising sea levels and their destructive impact on life, property and economies of some of the United States’ most populous cities, researchers have developed a new, statistical method that more precisely calculates the rate of sea level rise, showing it’s not only increasing, but accelerating. The research, methodology and current findings was presented by Andrew Parnell of University College Dublin at the Joint Statistical Meetings (JSM) last week in Baltimore.

The new approach contrasts with previous ways scientists analyzed and came to conclusions about sea level rise because it is “the only proper one that aims to fully account for uncertainty using statistical methods,” noted Parnell, principal investigator of the study conducted collaboratively with researchers at Tufts University, Rutgers University and Nanyang Technological University.

By examining two data sets, one that consisted of measurements from sediment along the East Coast from 2,000 years ago and another that included tide gauges around the world dating back to the 1800s, Parnell and his team discovered the data they gathered from years ago contained uncertainties. For instance, with more tide gauges deployed today than hundreds of years ago, recent records yielded more certainty than older ones. The team honed their statistical models to further take into account such uncertainties and possibly created a statistical first. “This likely is the first time a group of statisticians have had really close examination of sea level data,” said Parnell.

Parnell’s team has been able to show that sea level rise on the East Coast has been much less than 1 millimeter (mm) per year for the entire period 0 AD to 1800 AD, and, since then, it’s skyrocketed. In fact, they’ve discovered the rate of sea level rise on the East Coast is the highest it’s been for at least 2,000 years, and the rate of global sea level rise is above 1.7 mm per year, estimated by the International Panel on Climate Change. “Some people argue that sea levels are not rising. We are showing them that sea levels are not only rising, but accelerating,” continued Parnell.

From their analysis, researchers made additional observations, including the following:

  • An increase in the rate of sea level change around the time period known as the “Medieval Climate Anomaly”
  • A small decrease around the time of the “Little Ice Age”
  • A rapid increase after the start of the Industrial Revolution

The new model has recently been put to the test in New York City, where the rate of sea level rise is more than 3 mm per year in an area that currently houses more than $25 billion of infrastructure at less than 1 meter above sea level. Researchers anticipate the model will be rolled out in other cities along the East Coast and hope governments will be receptive and prepared to take the issue of sea level rise seriously.

###

About JSM 2017

JSM 2017 is the largest gathering of statisticians and data scientists in the world, taking place July 29-August 3, 2017, in Baltimore. Occurring annually since 1974, JSM is a joint effort of the American Statistical Association, International Biometric Society (ENAR and WNAR), Institute of Mathematical Statistics, Statistical Society of Canada, International Chinese Statistical Association, International Indian Statistical Association, Korean International Statistical Society, International Society for Bayesian Analysis, Royal Statistical Society and International Statistical Institute. JSM activities include oral presentations, panel sessions, poster presentations, professional development courses, an exhibit hall, a career service, society and section business meetings, committee meetings, social activities and networking opportunities.

About the American Statistical Association

The ASA is the world’s largest community of statisticians and the oldest continuously operating professional science society in the United States. Its members serve in industry, government and academia in more than 90 countries, advancing research and promoting sound statistical practice to inform public policy and improve human welfare. For additional information, please visit the ASA website at http://www.amstat.org.

For more information:

Jill Talley

Public Relations Manager

(703) 684-1221, ext. 1865

jill@amstat.org

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So what caused the increasing acceleration from 1800 until CO2 started to play its alleged part? It’s impossible that it could have been the industrial revolution in the 1800s

Bryan A

Exactly. I thought that CO2 has only had an affect since around 1950ish. So what caused the accelleration between 1850 and 1950 and how does it differ from 1950 to 2017 (when CO2 has accumulated to the point of becoming the driving factor)?

Stephen Greene

These guys are hedging their bets. Sea level rise with or without the influence of CO2 forcing. This is not good for CAGW proponents, just AGW with less A!

Stephen Greene

I simply don’t believe anything that is semi-empirical in the Climate Change Realm. Garbage in, garbage out. You know, being a real scientist, skeptical and all, is hard work

Greg

Jevrejeva’s work shows that there was acceleration but it happened fairly abruptly around 1860. Rise has been pretty constant since. So if you wish to cherry-pick a period like “since the industrial revolution” you will indeed find “statistical” acceleration. But this is academic slight of hand because, while meantioning human activity , it skilfully avoids pointing out that period when the acceleration actually happened precludes CO2 as being the cause.
Nice “trick”. They manage to suggest the opposite of what the data actually reveals.

Greg

.

“Some people argue that sea levels are not rising. We are showing them that sea levels are not only rising, but accelerating,” continued Parnell.

Oh really, who is saying that? Can we have a citation please? I don’t think I have ever heard anyone “deny” sea level rise.
I suppose with a world population of around 4 billion people you are always pretty safe claiming that “Some people” say xxxxxxx is true or false of whatever. Some people, just requires more than one person to be technically true,

Parnell’s team has been able to show that sea level rise on the East Coast has been much less than 1 millimeter (mm) per year for the entire period 0 AD to 1800 AD, and, since then, it’s skyrocketed.

Oh, you mean you have discovered that it looks like a hockey stick. Haven’t we been here before.
…. researchers have developed a new, statistical method …
Yep, this definitely sounds familya.

The hiatus or even falling sea level before the mid-1800’s was due to advancing glaciers during neoglaciation. The advent of rising sea levels in the 1800’s was due to retreating glaciers after neoglaciation.

garyH845

Because of the naturally occurring global warming cycle, following the end of the LIA, correct?

That’s the ticket.
Sea level isn’t currently behaving any differently than it has since the mid-1800’s.comment image
Sea Level Reconstruction (Jevrejeva et al., 2014)
The current phase of sea level rise began in the mid-1800’s, at the end of the Holocene neoglaciation. Holocene sea level reached its peak during the Holocene Climatic Optimum (5-7 kya)…comment image
At that time, the climate generally began to cool, with intermittent periods of warming. This period is is called neoglaciation. Glaciers generally advanced and sea level generally fell. This cooling trend culminated in the Little Ice Age (LIA)…comment image
https://wattsupwiththat.com/2017/06/09/a-holocene-temperature-reconstruction-part-4-the-global-reconstruction/
The nadir of the LIA was the coldest phase of the Holocene. It was possibly as cold as Late Pleistocene glacial interstadial periods. Most valley and alpine glaciers reached their maximum extent at this time.comment imagecomment image
http://science.sciencemag.org/content/308/5722/675?variant=full-text&sso=1&sso_redirect_count=1&oauth-code=292fde90-8c5c-49af-be4b-2a9aba68fb84
The warming since ~1600 AD, the glacial retreat and sea level rise since ~1850 are simply manifestations of a millennial scale cycle super-imposed on the Holocene’s long-glide back down to the next Quaternary glacial stage. Humans are, at most, contributing a little bit of extra warming to the overall system. This is a very good thing, because advancing glaciers and falling sea levels are a lot worse than retreating glaciers and rising sea level.

Dave’s settled science.

It’s the science I’ve settled on… 😉

Love it when you do that!!

John Endicott

Mosh’s drive-by

Clyde Spencer

David,
I think that you make a good case for why statisticians alone (even with the invaluable help of English majors) looking at data is not sufficient. There needs to be subject-matter specialists such as geologists, glaciologists, and maybe oceanographers, to help interpret the data and provide alternative working hypotheses.

Clyde Spencer: There needs to be subject-matter specialists such as geologists, glaciologists, and maybe oceanographers, to help interpret the data and provide alternative working hypotheses.
I posted the author list, and web page where you can download their data and code down below. No need to remain ignorant of who they are and what they did.

Catcracking

Thanks David for the plots, they tell the story on SLR.
I always wonder how the CAGW crowd get away with their global warming claims by starting at the end of one of the most recent cold period. Looks like cherry picking to me.

Your graph ends in 2014. Sea level has been pretty flat, since mid 2015. https://climate.nasa.gov/vital-signs/sea-level/. I believe the proximal cause is Mother Nature anticipating Al Gore’s movie.

The graph ends in 2010. It’s a reconstruction of sea level from the early 1800’s to 2010. The data are from Jevrejeva et al., 2014… 2014 is when the paper was published. So, apart from me downloading the data and graphing it in Excel, it really isn’t may graph.
What sea level does over 1, 2, 5 or even 30 year periods aren’t particularly relevant to what it does over 100’s or 1,000’s of years.
Here’s the post-1860 portion of the Jevrejeva reconstruction:comment image
Sea level has been rising at 1.9 mm/yr since 1860. Within that trend, sea level rise has been quite variable… 3.1 mm/yr from 1930-1950… 1.2 mm/yr from 1951-1992 and 3.2 mm/yr from 1993-2011.
Sea level fell in 2011 and has been falling since 2016…
http://sealevel.colorado.edu/files/2016_rel4/sl_ns_global.png
However, the overall trend over the past 150 years has been about 1.9 mm/yr.

MarkW

Clyde, conversely, when geologists, etc. use statistics, they need to let someone who has studied review their work.

Richard G.

‘An increase in the rate of sea level change around the time period known as the “Medieval Climate Anomaly” ‘
Nice of them to re-name the Medieval Warm Period! I like the sound of ‘Medieval Climate Optimum’ better.

Samuel C Cogar

So what caused the increasing SLR acceleration from 1800
It was caused by the horrendous migration of European immigrants into North America that began in the 1600’s.
When the immigrants started cutting the forests, plowing the fields, digging/drilling water wells and digging canals, …….. zillions of tons of soil began being eroded off the mountains, the hill, the valleys and the plains and was washed away and deposited in the Chesapeake Bay, Atlantic Ocean and Gulf of Mexico ……. and the sea level began to rise. And is still rising because the erosion has not abated.
And due to the horrendous loss of surface biomass and eroded soil there is far less means of retaining the rainwater and it is quickly flowing into the oceans along with all the quadzillion gallons of well water being sucked and pumped out of the water table every minute of every day ….. which has greatly diminished the depth of said water table ……. and/or has pretty much caused its demise in many, many locales across North America, …… thus forcing residents to connect to water distribution infrastructure or to purchase “bottled” water from retailers.
The end is near. When the sea level rises far enough, ……. here will be …. “Water, water everywhere and not a drop to drink …… because it will all be saltwater.
Eritas Rabuf

Gloateus

Same thing happened in Europe, Asia and Africa, except usually by indigenees rather than immigrants.

Richard G.

Man walking the street with sandwich board that reads: “The end is near.”
Caption: “The scary part is that people are agreeing with me!”

Duster

There are really only a few places on the planet where you might be able to empirically measure actually changes in sea level itself. These would be locations where there are no isostatic rebound effects; either sinking locations like the Atlantic seaboard south of New York, that had been forced upward by the weight of nearby ice sheets, or areas that were under ice sheets and are now rising. I have seen no studies addressing these areas and nearly all data are contaminated by “adjustments” that insure an upward trend regardless of empirical tidal gauge records. It is reminiscent of the Australian BOM data debacle currently being thrashed out on sites like JoNova.

Duster wrote, “These would be locations where there are no isostatic rebound effects…”
In 2011 Dr. Jerry Mitrovica did a lecture on sea-level. It was a mixed bag. He spent the first 13½ minutes bashing skeptics by bludgeoning straw men, and he finished by erroneously conflating tide gauge and satellite data. But in-between those unfortunate parts he sandwiched a quite interesting discussion of the effect from shifting water mass from the Greenland Ice Sheet to the oceans, on the Earth’s gravity field, and hence on sea-level.
During that part of his lecture, he mentioned that his paper’s reviewers had forced him to examine a small number of “gold standard” tide gauge measurement records, at sites thought to have minimal vertical land motion. These are the sites he used:
http://www.sealevel.info/MSL_mitrovica23_trendtable.html
(Thumbnails here.)

Clyde Spencer

Duster,
Notably, the article says nothing about whether isostatic adjustment was taken into account in the statistical analysis. Even if it was for modern data, the issue of how that could have been taken into account for historical data is not discussed.

Louis Hooffstetter

Eventually we will be able to use data from Continuously Operating Reference Stations (CORS) to filter out the effects of subsidence and uplift:
http://www.nature.com/ngeo/journal/v2/n8/full/ngeo591.html?foxtrotcallback=true
This will allow us to determine the absolute rate of sea level rise.
In the meantime we will have to deal with lies, damned lies, and statistics.

No evidence of a role for emissions in sea level rise
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3011279

Thank you for this, chaamjamal!

Don Andersen

Don Andersen,
While I can accept that CO2 until now has little effect on temperature and thus sea level rise, I had several comments on other works of Jamal Minshi, where he never responds to any critique…
I was not aware of his work on the 14C decline, but I fear that there are -again- several flaws in it.
One point is that the deep oceans are a continous source of low-14C: what goes into the oceans is the isotopic composition of today (including the bomb pike). What comes out is the composition of ~1000 years ago, long before any human interference.
Independent of each other the atmosphere – deep ocean – atmosphere cycle is about 40 GtC/year as CO2, based on the 14C and 13C/12C ratio dilution (the latter of the low-13C human emissions by the high-13C deep coean releases), which is responsible for the fast decline of 14C after the peak of the bomb tests. That supresses the human influence which nowadays is ~9 GtC/year, but a lot smaller in the past. Once the pre-industrial 14C level is passed, the influence of the zero-14C emissions will be clear again, depending of future emissions. See Fig. 1 in:
http://www.pnas.org/content/112/31/9542.full.pdf
Besides the overall declining, there is a nort/south gradient: CO2 levels increase first in the NH, while 13C and 14C levels decrease first in the NH…
See further: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4534253/
Local influences of human CO2 are measurable:
http://www.sccg.sk/~lucan/apuc/_vol53/Apuc11.pdf
BTW, Jamal made an error: the drop in 14C levels before 1950 was not 20%. it was 20 per mil, or 2%…

Clyde Spencer

Ferdinand,
You said, “What comes out is the composition of ~1000 years ago, long before any human interference.” Minus what has decayed in ~1,000 years!
You also said, “…the influence of the zero-14C emissions will be clear again…” This statement is unclear to me. 14C is being created all the time. Were that not so, we wouldn’t be able to radiocarbon age date organic material.
Lastly, you say that “… there is a nort/south gradient: CO2 levels increase first in the NH,…” Anthropogenic CO2 is produced continuously. How do you define “first” for something that is emitted continuously. Also, the 40 GT of oceanic outgassing is shown by the OCO-2 satellite to occur primarily in the tropics. I would expect the Hadley Cell circulation to distribute that CO2 equally to both the northern and southern hemisphere. So, again, how do you assign a “first” event to something that is happening continuously and in a symmetrical manner?

Shanghai Dan

After a long a fruitful consultation with Congressman Hank Johnson, we believe that the sea level is NOT increasing. What has happened is the number of people on the East Coast has dramatically increased, and the US is starting to tip over…

george e. smith

“””””….. 195 thoughts on “No longer water under the bridge, statistics yields new data on sea levels” …..”””””
#196 Statistics is …. FAKE NEWS …. ; Stuff that was never measured or observed by anyone, anywhere at any time !!
G

Trebla

I think the Dutch found a solution to that problem. They built dykes.

MarkW

I’m pretty sure they built dikes. Though they are more likely to welcome dykes than most other European countries.

brians356

They built dykes:
dyke (n): a wall built to prevent the sea or a river from covering an area, or a channel dug to take water away from an area
http://dictionary.cambridge.org/us/dictionary/english/dyke
In Dutch it is spelled “dijk”.

dam1953

Not to be confused with “women in comfortable shoes”…..to quote Adrian Cronauer

Eric

Sure we build dykes because windmills don’t keep the sea out 🙂

Als het u blijft!

Does that play into this gender neutral bit?

RD

*“Some people argue that sea levels are not rising. We are showing them that sea levels are not only rising, but accelerating,” continued Parnell.*
Who’s arguing seal levels aren’t rising? I thought they’re rising 2-3 mm per year or so and have since the end of the last ice age.

PSMSL has about 145 tide gauges with differential GPS correction for vertical land motion. About 70 of these are sufficiently long record (>60 years) to provide trends. The rate is ~2.2mm/year and there is NO acceleration. The value must be approximately correct because it closes with ARGO estimates for thermosteric rise plus corrected GRACE and IceSat for ice sheet loss (2.2-2.3mm/yr). See my guest post here on SLR and closure a while back.
Lies, damn lies, and statistics to quote Mark Twain.

RD

Thank you!

brians356

You should note, however, they stopped rising from January 2009 to December 2015 – as promised.

brians356

Er, … 2009 to 2016.

Gordon

Yes I recall a certain presidential candidate telling us “we will be able to look back and tell our children that …..this was the moment when the rise of the oceans began to slow and our planet began to heal”

Gerry Parker

Not exactly. It’s pretty well established that the rate of sea level rise near the end of the last ice age was about 6 feet per century until about 6000 years before present, then about 9 inches per century until about 3300 years bp, then about 1 foot per 10 centuries until (1800-1930). Geological evidence seems to bear out that more recent slow rate. Remember, though, sea level in Florida has been 25 feet higher than it is now, also.
So, what could have changed? Anything, really. Soot is my personal favorite. We’re generally moving towards cleaner energy, and a lower soot rate on ice corresponding to that would indicate something. I don’t know that anyone is looking at that, however.

Duster

There is strong geological and geomorphological evidence of a Middle Holocene high stand that seems to have been at least 1.5 meters above current MSL, e.g.:
http://repository.upenn.edu/cgi/viewcontent.cgi?article=1022&context=ees_papers
There is apparently an active, but far less vocal, effort to make this disappear (just like the Medieval Warm Period).

RWturner

I argue that sea level is not rising but that’s because I have training as a sedimentologist/stratigrapher, concepts that these statisticians and climate alarmists are completely ignorant of. There is more to eustasy (global sea level) than water volume added or subtracted by ice caps, but global sea level really isn’t what matters to us and our coastal infrastructure.
Regional sea level and water depth (accommodation space) is what’s important. When eustasy is slowly rising or dropping, just like it has done throughout this interglacial and continues to do, sedimentation and regional uplift/subsidence easily overwhelms eustasy. If water level rises a mm from additional water in the ocean basins, a mm of sediment can be deposited, accommodation space does not change, or 2 mm of sediment can be deposited and accommodation space actually decreases.
The coast line may not only see the lack of landward movement in this scenario, it may actually move seaward (progradational). It’s the sedimentation rates and uplift/subsidence rates that are important in this situation –the situation of the past 10,000 years– not the slow addition or subtractions of the overall water volume. The biggest problems we face in this scenario is the cutoff of sediment supplies (Mississippi Delta) or coastal land use changes that affect sedimentation (building a city on a barrier island and removing mangroves).
As a geologist, I would only say that eustasy is rising or falling when eustasy overwhelms these local factors, and the last time this happened was about 10,000 years ago. That was when eustasy was increasing so rapidly that the water level overwhelmed local factors and the coast moved landward (transgression). When the next glacial period starts, eustasy will decrease so fast that local factors will be overwhelmed and the coast will move seaward (regression). Our current situation is either progradational, regressional, or still stand (yes, a mix of all three) which is typical of a highstand systems tract.
https://strata.uga.edu/sequence/tracts.html

RWturner

That second sentence should say: there is more to sea level than than eustasy…

RWturner

Ugh..the last paragraph should start with: …only say that sea level is rising or falling when eustasy overwhelms…

“There is more to sea level than than eustasy”… There’s isostacy too! 😉

Duane

RW – thanks for reminding us that the earthian system is much more complex than the “climate scientists” could ever begin to understand or appreciate.
Just taking one region of one continent into consideration, the western Rocky Mountain region of North America. The Rockies began forming about 80 MYA, and they did not start out as a low plain but rather a very high plateau with an average elevation of 20,000 ft above sea level!!! The mountains were formed both from uplift from the collision of techtonic plates and subduction under the North American continent, along with erosion of the rocky surface. Now, 80 MY later, the average elevation of the Rocky Mountain area is much closer to about 8,000 feet – how many cubic km of sediment went into the oceans, both Pacific and Atlantic, to cause a reduction in elevation of roughly 12,000 feet? How many meters would that alone add to sea level?
Regardless of what the climate is doing, erosion continues on .. the Rockies continue to elevate the peaks and ridges, but erosion continues to turn the entire plateau into ocean sediment at the same time.
I wonder how they account for that in the sea level models?
Thanks for your contribution to this thread.

Doug Huggins

There are lies, damned lies, and statistics.
–Mark Twain
I find it interesting that you can pretend there was minimal rise in 1800 years from zero AD to 1800 AD when tide gauges and measurements were few and far between. Lets see how that conclusion was arrived at, please, in detail….not by guess and by gosh.

MarkW

If it takes “advanced statistical” methods to tease the answer you are looking for from your data, the odds are the answer was never in your data in the first place.

Joel Snider

I remember when the Professor thought the island was sinking because Gilligan kept moving the stick he used for his tidal gauge.

It might be worse than that MarkW.
East coast sediments, isn’t that one of manniacal Mann’s projects a few years ago?
*- busted by contaminated sediment levels, false analysis and Manniacal’s odd statistics.
Then there is this little tidbit quote:
“The only proper one that aims to fully account for uncertainty using statistical methods”
“Fully account for uncertainty” and “using statistical methods” is oxymoronic. Known as p level derangement and rather common amongst egotist serial data abusers.
“The only proper one” There’s a wild claim! It ranks, (pun intended), right up there with “robust” and specious “high confidence” calculations.
Serial word abuse inflating claims, another mark of climate religious fanatics.
“Advanced statistics” is a dodge.

Ian W

Lord Rutherford said: “If you have to use statistics, you should have done a better experiment.”

seaice1

So we can ignore all those calls for error bars then?

MarkW

Excellent non-sequitor. Did you get a bonus for that?

seaice1

MarkW. Can you produce error bars without statistics? Thought not. Therefore not a non-sequitur. I cannot imagine what Rutherford was thinking if he said that, since it is clearly nonsense.

paul courtney

Seaice: So we’re only allowed to point out one fatal flaw at a time? Some have called for better experiments, I’ve been calling for AN experiment. Until they come up with one (the team is not interested in experiments), can’t we point out fatal flaws in their present approach? Like a lack of error bars when they insist on using statistics? Or chronic post-selection data mining? You must love CA.

Kaiser Derden

error bars ? in an experiment ? in the results maybe …

Jpatrick

Confessions of tortured data?

ChrisDinBristol

. . . And if I look at the data this way (kneels on floor with impossible contortion and squints sideways) . . .

Re: “much less than 1 millimeter (mm) per year for the entire period 0 AD to 1800 AD, and, since then, it’s skyrocketed.”
Well, sure, since 1800 — but all that acceleration was before the 1930s. I.e., all the acceleration occurred when CO2 was under 310 ppmv.
Since 1925, sea-level at Battery Park, NYC, has been rising at a remarkably steady 3.18 ±0.18 mm/year (and at least half of that is subsidence, rather than GMSL rise).
Despite a 33% (100 ppmv) increase in CO2 and a 83% (0.84 ppmv) increase in CH4, in all that time the rate of sea-level rise has not accelerated, at all.
http://www.sealevel.info/MSL_graph.php?id=battery&boxcar=1&boxwidth=3&c_date=1925/1-2019/12
http://sealevel.info/8518750_The_Battery_2017-01_since_1925.png

The green curve (above) is CO2. As you can see, it increased very slowly through the 19th century and the first half of the 20th century, until the the 1950s, when it dramatically accelerated (presumably because of the post-WWII industrial boom).
But when CO2 levels accelerated, sea-level rise (in blue) did not. There’s been no significant, sustained sea-level rise along the U.S. East Coast (or anywhere else) since the 1920s.
That obviously means CO2 isn’t driving sea-level rise. From 1800 to 1930, CO2 (measured from ice core trapped air samples) crept up from about 283 ppmv to about 308 ppmv, an increase of only 25 ppmv. Yet that’s when all the sea-level rise acceleration occurred.
From 1930 to present CO2 shot up by about 96 ppmv. Yet sea-level rise didn’t accelerate at all.
http://www.sealevel.info/co2_and_ch4.png
For an “interactive” version of the graph, in which you can over your mouse cursor over it to see the exact values, click this link: http://www.sealevel.info/co2_and_ch4.html

DB, your simpler SLR site is much appreciated. Great contribution to the skeptic cause. Permalinked by me under favorites. More people need to visit and use more often.

brians356

You should post this graph over at AccuWeather.com (I’m not on Facebook so I cannot post there):
https://www.accuweather.com/en/weather-news/5-major-takeaways-from-the-leaked-climate-change-report/70002412

Gerry Parker

I agree Dave, they make it sound like the acceleration is happening now, instead of 100 to 200 years ago.

daveburton August 9, 2017 at 12:35 pm
But when CO2 levels accelerated, sea-level rise (in blue) did not. There’s been no significant, sustained sea-level rise along the U.S. East Coast (or anywhere else) since the 1920s.

That’s strange since your own graph shows sustained sea-level rise since the 1920s from ~-0.28m to ~+0.10m.

South River Independent

Once again, changing the past to make the present seem more dangerous.

“Untraditional approach”
English Translation:
“We made it up”
Andrew

South River Independent

Becoming the “new” traditional approach.

Latitude

Parnell and his team discovered the data they gathered from years ago contained uncertainties….
I’ll bet they threw out the data from Ephesus

Moderately Cross of East Anglia

So when sea levels in the Middle Ages were much higher in the North Sea so that a huge inlet made the city of Norwich an accessible seaport and Dunwich further south was inundated and now lies off the coast underwater, presumably all the water must have come from the US east coast, or perhaps Mars to which it immediately returned when someone attempted to measure it. Clearly never seen before science is alive and well in Dublin and destroying the reputation of Irish scholarship.

John Law

The Ship at Dunwich was fantastic and still I hope (and know) above water!

Shanghai Dan

The water ran away with all that missing heat in it…

Andrew

What on earth has “Irish Scholarship” to do with all this ?????

Maybe NYC should spend its taxpayers money on sea walls, rather than on wind farms.

Don K

“A bit of basic arithmetic says that a 1 meter seawall will postpone the problem for 300 years.”
Unfortunately there’s storm surge. They’ve managed to flood the PATH tunnels (subway basically) from Manhattan to New Jersey twice in 30 years. Maybe after a couple of more such incidents, they might consider hardening them.

Michael Jankowski

…The new approach contrasts with previous ways scientists analyzed and came to conclusions about sea level rise because it is “the only proper one…”

Global average sea levels have not risen at all the last 2 years.
And if we look at the data from 1993 (the year satellite measurements began) the amount of sea level rise is not increasing.
The average sea level rise over the whole world is 3.4 mm/year or about a foot per century, and is not increasing more rapidly recently. We are still recovering from the last ice age. The planet is becoming less ovoid, more like a sphere. In the Bothnian Bay land is rising out of the ocean at a rate of about 3 feet per century and in Hudson Bay the rise is as much as 4 feet per century. It is by no means over yet. The displaced water gets redistributed over the rest of the earth. In addition the Mid-Atlantic ridge is expanding and rising with numerous undersea volcanoes, maybe up to one third of all undersea volcanoes are located between Jan Mayen and Svalbard. Teutonic plate movements explain the rest. The Eastern Seaboard is slowly sinking into the sea, more than the rest of the world. The expansion of the ocean is not accelerating.
https://lenbilen.com/2017/08/09/sea-levels-rising-not-so-fast-mr-gore-and-mr-obama/

Tectonic plate movements…

Schrodinger's Cat

We seem to going through another surge of alarmism with papers claiming that almost everything is worse than we thought. Perhaps it is, but more likely it is a response to fairly static temperatures, the Trump effect and time to renew the funding.

Bubba Cow

just cycling the alarm – perhaps ocean acidification will be next?
If I can find the time, I thought I’d look through the ‘trends’ of alarmist claims over some number of years toward predicting the next climate ‘news’ alarm.
Anyone with more spare time – feel free!

What kind of nonsense is this? No one I know of ever claimed sea levels were not rising. Years ago I heard sea levels were rising at a rate of around 1 foot per century – that is 1.2 inches per decade, or 30+ MM per decade or 3mm per year, which is much more than the claimed 1.7 mm per year mentioned in this article. Warmists were claiming over 3 feet per century, which is wildly larger than the figures mentioned here. The global warmists must be disappointed in these figures, which validate the sea level rise estimates by non-warmists.
I consider 1.7 mm per year as good news, not bad news.
Now how so they figure that the Atlantic Ocean in New York city is rising more than that same ocean in Norfolk Virginia? I’d love to hear that explanation – any diffences have to be due to subsidience, not sea level rising.
And that “acceleration” involves a long time span – seems pretty meaningless, like the rate itself.
A distinct lack of details in this article – if they are using statistics, where are their errors of measurement, etc. ? Very sparse article – doesn’t say much and won’t change any views of skeptics – it reinforces them.

Forrest – just so.
Beat me to it.

LdB

The cost of building that is also considerably less than what is proposed to be spent to save us.

commieBob

I’m not sure that Parnell et al are saying much new. This link seems to be saying much the same thing about historical sea level rise.
It makes sense that the sea level wouldn’t have risen much during the Little Ice Age when glaciers were growing. When we came out of the Little Ice Age and the glaciers started to melt again it makes sense that the sea level would start to rise again.
Sea level rise is very slow now compared to the first half of the Holocene. graph The sea level is around 450 feet higher now than it was when the present interglacial began. An increase of 0.1 inch (3 mm) per year is piddling in that context.

Pablo

Isostatic sea level change impacting upon eustatic sea level change versus statistics anyone?

Kurt

“a new statistical method that more precisely calculates the rate of sea level rise, showing it’s not only increasing, but accelerating.”
How did they test this brand-spanking new method to make sure it was more accurate than the old method? If measurements from long ago weren’t taken at the resolution of today’s measurements, there’s nothing you can do about it. That information is lost, and and can’t be recovered.
“Parnell’s team has been able to show that sea level rise on the East Coast has been much less than 1 millimeter (mm) per year for the entire period 0 AD to 1800 AD”
Utter nonsense. This team theorized (not showed) that sea level rise was less than 1mm a year since 0 AD. There’s no way of proving that theory, or even calculating the likelihood of it being true.
“The new model has recently been put to the test in New York City . . .”
And? Funny how the article never described anything remotely resembling a test.

DHR

Larson et.al concluded from reviewing data from historic coastal features such as peat bogs and marshes that global seas have been rising at about 1 to 2 mm/yr for the past 6,000 years.

Clyde Spencer

DHR,
At BEST, an average rate for the last 6,000 years, with no detail about variations at shorter intervals of time. One could have a three foot increase followed by a three foot decrease and it would look like no change over 6,000 years — or an infinite number of variations on the theme. If all you have is an average rate over a 6,000 year period you have no idea what the annual standard deviation is, nor whether there was any periodicity present. Those who prepare tide tables are well aware of multiple trends in tides.

Phoenix44

It may well be more precise. That is not the same as more accurate.

DHR

Perhaps I haven’t looked enough to reproduce daveburton’s numbers but I have found this.
-The NOAA Tides and Currents web page provides tide gauge data for The Battery in New York City going back to 1856. The data show a straight line rise from then to now of 2.84 +/- 0.09 mm/yr. There is no hint of a change in the rate of rise. The British tide gauge site, PSMSL.org also shows data for The Battery which is the same to my eye as NOAA’s but they also show data for the GPS land elevation gauge also at The Battery. It shows that the site is sinking at a rate of 2.12+/-0.62mm/yr. The GPS gauge is quite new only going back to late 2010. Thus at this time at least, the seas at NYC are rising at a rate of about 0.7 mm/yr, not “more than 3 mm/yr.”
Where do these guys come from?

Kurt

They come from the best math classes around the globe. A magical world where the harsh environment of reality never has to intrude on the theoretical confines of their charmed existence.

seaice1

This seems to be a good example of “red team” at work. A group of statisticians who have no investment in the previous conclusions looking dispassionately at the data.

D. J. Hawkins

Ehhhh, not so fast. Parnell’s particular interest is in statistical applications to ecology and paleoclimatology and he’s on a couple of climate change committees.
https://maths.ucd.ie/people/parnell_a

Clyde Spencer

seaice1,
One would hope that they have “no investment,” but Hawkins seems to have evidence that they are fully invested. It is convenient that your so-called ‘red team’ basically got similar results to the blue team, only worse.

Kurt

This hardly fits your characterization of statisticians merely reviewing the data anew:
“researchers have developed a new, statistical method that more precisely calculates the rate of sea level rise, showing it’s not only increasing, but accelerating.”
Again recognizing that precision does not mean accuracy, these guys are inventing data, not trying to find out what is there. And also note the Orwellian gibberish that the “new model has recently been put to the test in New York City, where [the model indicates that] the rate of sea level rise is more than 3 mm per year.” That’s not putting the model to any kind of “test.” There is nothing quoted in this press release indicating that these statisticians did anything at all to determine whether their new method produces accurate results. All they seem to care about is that it the right kind of results

Phoenix44

No Red Team would claim that they can make past data “more accurate”. The whole point of a Red Team is to stop this sort of pointless “science”. Absent a time machine, past data is lost, gone forever, so we can have no way of knowing whether this work produces anything of any value whatsoever.

seaice1

“The whole point of a Red Team is to stop this sort of pointless “science”.”
Oh, I thought it was to take another look and challenge the science. I was not aware that the conclusions of the red team were decided before they start.

Matt

“, Parnell and his team discovered the data they gathered from years ago contained uncertainties. For instance, with more tide gauges deployed today than hundreds of years ago, recent records yielded more certainty than older ones. The team honed their statistical models to further take into account such uncertainties and possibly created a statistical first.” – Interpretation: They “adjusted” the old data just like they do to temperatures to provide the desired results.

Mike

1000mm / 3mm /yr = 333 years. I think we have time on this one.
Here is a flood zone map of NYC https://www.floodzonenyc.com/
this is all getting a bit ridicolous

Chad Irby

Also not mentioned: On a typical desktop monitor, the chart in the Twitter feed is almost actual size…

“Parnell and his team discovered the data they gathered from years ago contained uncertainties” They also discovered the wheel and the fire!

Bruce Cobb

They tortured the data until it samg like a canary.

Bernie

More incongruous data splicing:
“By examining two data sets, one that consisted of measurements from sediment along the East Coast from 2,000 years ago and another that included tide gauges around the world dating back to the 1800s …”

Resourceguy

The science bar is how low for NY political finger pointing?

JohninRedding

I am very skeptical when talking about changes that are so small. The level of accuracy would seem to be a greater factor than the theoretical rate of change. It just seems like an excuse to cry wolf and keep the fear of climate change in the news.

talldave2

“Some people argue that sea levels are not rising”
Some people argue that climate change is going to kill us all within the next few years. Probably about the same number in both cases.

R.L.Wurdack

As authoritative and believable as political “approval” poles.

I love skeptics. They demand review from real statisticians until they read the results.
Then they claim stats are lies.
Tell that to nic lewis or steve mcintyre.
You don’t need stats or tests. Just ask Rud.
He disproved everything by waving his arms.
Data? Don’t need it..It’s all just stats and lies.

Words…

Parnell’s team has been able to show that sea level rise on the East Coast has been much less than 1 millimeter (mm) per year for the entire period 0 AD to 1800 AD, and, since then, it’s skyrocketed. In fact, they’ve discovered the rate of sea level rise on the East Coast is the highest it’s been for at least 2,000 years, and the rate of global sea level rise is above 1.7 mm per year, estimated by the International Panel on Climate Change. “Some people argue that sea levels are not rising. We are showing them that sea levels are not only rising, but accelerating,” continued Parnell.

Numbers…comment image
Now… Find an example of something “skyrocketing” at 1.9 mm/yr.

seaice1

Hey, I guess you would have to read the paper rather tha eyeballing graph.

Gerry Parker

Makes me sure they don’t know what “accelerating” means.Find accelerating on the graph above.

TA

That’s one heck of a good graph, David. Love the ruler. 🙂

The 1860-1900 ave. is 1.9 mm/yr. The 20th century ave. is 1.7 mm/yr so they claim. It slowed down! LOL

MarkW

If it ain’t in the graph, then no amount of “words” can make it magically appear.

JohnKnight

It is difficult for me to take nerds seriously when they use “skyrocketed” to refer to something rising ten times slower than my fingernails grow.

It always bugs me when they talk about a meteoric rise of something or someone.

SM, I am among various other things a PhD level econometrician (statistics applied to economics) and systems modeler– stuff like recasting the partial differential predator/prey calculus equations as propabalistic Markov chains then proving their model equivalence.
The reason I use only simple irrefutable facts (you know, like bogus regional expectations BEST qc on station 166900) is that most people here are not at that technical level. But they are intelligent thinkers. I do wave my arms at easy to verify, solid facts. Heck, even cite them, and link to the primary sources. Works great for the licensed lawyer I also am. My jury is the WUWT readership (or equivalent Climate Etc denizens). They get to decide whether I have made a case for ‘conviction’ on whatever the topic. Not you alone, as demonstrated many times. For factual examples of this generalization, see my recent guest posts here ‘SLR and Closure’ and ‘Why Models run Hot’. Your to do is to explicitly identify any of my alleged arm waves in those two posts.
Doubt WUWT will hear back from you concerning this modest rebuttal challenge.

mairon62

Your posts here wuwt ristvan are greatly appreciated by many.

Roger Knights

Ditto

jhborn

Although intelligibility coincides too rarely with relevance and truth in Mr. Mosher’s comments for me very often to divert my little remaining bandwidth to considering them, I am impressed by those who like Mr. Istvan can take the time to do so.
I am also impressed that Mr. Istvan is capable of “recasting the partial differential predator/prey calculus equations as [probabilistic] Markov chains then proving their model equivalence” yet restricts himself to “simple irrefutable facts” for the benefit of readers like me who “are not at that technical level.”
But I hope it will not be taken amiss if I make a modest suggestion regarding his contributions: that he give a little more thought before expounding. The errors that result from failing to do so compromise what confidence at least this layman accords those presumably worthwhile contributions.
I am prompted to make this suggestion by his last comment’s reference to “Why Models Run Hot.” It reminded me of another of Mr. Istvan’s posts, in which he referred to the mathematical derivation of Monckton et al.’s “irreducibly simple” equation as “impeccable.” Although I’m just a retired lawyer, I did not remain completely unaffected by those isolated scraps of mathematics that came my way, and it happens that Mr. Istvan’s post touched on one of the few things that actually stuck. As a consequence, I know that Monckton et al.’s derivation was the exact opposite of impeccable.
In effect the Monckton et al. paper said the response of a time-invariant system with state can creditably be approximated as that of a stateless time-variant system. In the relevant discipline, this is akin to saying that the product of two numbers is creditably approximated by their sum. So it strikes me as startling that someone capable of “recasting the partial differential predator/prey calculus equations as [probabilistic] Markov chains then proving their model equivalence” could pronounce such a remarkable proposition’s derivation “impeccable.”
It is perhaps unjust to Mr. Istvan that this misstep has placed an asterisk next to all of his contributions at least in my mind and possibly in others’. Still, such results follow from human nature, and maybe a little more care would reduce their occurrence.
(Also, providing actual links when he refers to his other writings couldn’t hurt.)

Phoenix44

Er no. Sceptics are sceptical. See how that works?
And bad statistics are what we sceptics call bad statistics. See how that works?
But let’s accept your point nevertheless – if we sceptics disagree only with what we don’t like, then you non-sceptics must be the same, yes? Or is your basic argument that you are virtuous and we are not? Those are your two choices: which one are you going for?

seaice1

I would go with the virtue one.

MarkW

Killing people is virtuous?

seaice1

Who mentioned killing people?
Pheonix44 offered a false dichotomy, but if forced to choose I would go with the virtue rather than that everybody disgrees with what they don’t like. Some of us look at all the evidence.

MarkW

To Little Stevie, nobody is permitted to review and criticize work that agrees with him.

whiten

I wonder what the result and what kinda of certainty will be produced by this statistical analyzing if the same data they use is scrambled randomly first……! or if only the 2000 year record mash-scrambled randomly first…!
I suspect that the “mash potato” would not be much different…..
cheers

Max

“The team honed their statistical models to further take into account such uncertainties and possibly created a statistical first. ”
The phrase that pays, “Statistical models”, and the giveaway “Possibly created a statistical first”, all in one sentence.
Looks like lowering the past and raising the present, again.

Phoenix44

To take account of uncertainties simply means increasing the possible range of the data. And if you do that, then historical rates of sea level rise could be lower than we thought. Which means sea level could now be rising faster than we thought compared with those rates.
There we go, I’ve written the paper.
I haven’t proven a single thing though, because it is literally impossible to do so with this methodology.

ossqss

So,,,, would NYC qualify as an Urban Subsidence Island (USI)?
What does all that man made structure do the ground below it? Kinda like man made glacial forcings?
Remember, you heard it here first 😉

BallBounces

Next: the acceleration is accelerating.

Geoff Sherrington

BB,
The term for the time derivative of acceleration is the “jerk”. Geoff

Of course, it is strange that the New York City regional tide gauges are all linear, and have stayed that way for over a century. No acceleration visible whatsoever! NONE!!!

tty

In Sweden we have some pretty long sea-level series. This is because the isostatic rise of the land is very noticeable, and has always been known to people along the coast and have attracted the interest of scientists all the way back to Linnaeus. And there are no tides to complicate things in the Baltic.
In southernmost Sweden the rise is so slow that the sea is gaining, but in most of the country the sea is receding. And after 200 years we know pretty well where the zero line is.
Here is sea-level data from Kungsholmsfort, an old coastal fortress situated almost exactly on the zero line:
http://www.psmsl.org/data/obtaining/rlr.monthly.plots/70_high.png
The (annual) relative sea-level in 2016 was 1 mm lower than in 1887. So at least we know for sure that the total change over 130 years is much less than the interannual variation.
Now in recent years GPS have been installed alongside the old (non)tidal gauges, and they show that the absolute rise at Kungsholmsfort is about 2 mm/year. So, yes, sea-level is rising about 2 mm/year. If it was 3,5 mm/year the zero line would be several hundred kilometers further north.
And no, there is no trace of an acceleration in the long series. Well, that is not quite true, in the very longest series there are some evidence for an acceleration around 1850.

That is a beautiful confirmation of Nils-Axel Moerner’s analysis of the diff GPS corrected long record tide gauges. Many thanks. If I write this up again (another ebook coming?) you will be given full credit and a link to this excellent comment. Many thanks for this Swedish fact contribution. Is now permalinked on my iPad and Mac.

Duster

Wonderful! I just complained above that no one had done this. I’m happy to be wrong!

scraft1

What is meant by “absolute” sea level rise? You say there’s isostatic land rise. So is 2mm the apparent rise according to tidal gauges?

TonyL

Willis E. has posted a couple of times recently showing the acceleration is SLR is not significant.
So I thought I would grab the data set for Boston and try my hand at it. (It goes back to 1921)
Wow, did I ever make a mess.
I loaded the data set into R-Studio, and did a linear fit, then a cubic fit.
All terms are *highly significant*
Apparently, the p values in the fit summary are not the ones I thought they were.
Anyway, here is the fit summary for the linear model:
Call:lm(formula = SLdata ~ xdata)
Residuals:
Min 1Q Median 3Q Max
-0.144354 -0.031264 -0.001789 0.029746 0.212170
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) -1.850e-01 2.926e-03 -63.21 <2e-16 ***
xdata 2.353e-04 4.379e-06 53.73 <2e-16 ***

Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.04982 on 1156 degrees of freedom
Multiple R-squared: 0.7141, Adjusted R-squared: 0.7138
F-statistic: 2887 on 1 and 1156 DF, p-value: < 2.2e-16
And for the cubic model:
Call:
lm(formula = SLdata ~ poly(xdata, 3, raw = T))
Residuals:
Min 1Q Median 3Q Max
-0.151159 -0.028853 -0.001482 0.025511 0.203899
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) -2.235e-01 5.609e-03 -39.843 <2e-16 ***
poly(xdata, 3, raw = T)1 6.255e-04 4.200e-05 14.893 <2e-16 ***
poly(xdata, 3, raw = T)2 -8.304e-07 8.438e-08 -9.841 <2e-16 ***
poly(xdata, 3, raw = T)3 4.734e-10 4.794e-11 9.875 <2e-16 ***

Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.04787 on 1154 degrees of freedom
Multiple R-squared: 0.7364, Adjusted R-squared: 0.7358
F-statistic: 1075 on 3 and 1154 DF, p-value: < 2.2e-16
As you can see, all the terms for the polynomial fit are utterly improbable. I have no idea where I have gone astray. The thing that is most vexing to me is I *used* to know how to do this. I could set up the ANOVA matrix, calculate the "Sums of Squares of Everything in Sight", and carry on.
Anybody who is handy with R stats, cares to sort this out for me, I would very much appreciate it.

tty

I suggest you look at the data first. If you can’t see a trend there isn’t any. If you think you can see a trend, check it statistically. It quite likely isn’t real. The human eye is incredibly good att spotting patterns, so good that it often sees patterns that aren’t there.
Also hydrological data frequently follow Hurst-Kolmogorov distributions. A Hurst-Kolmogorov distribution (a. k. a. Fractional Gaussian distribution) does not look random, but it is.

Clyde Spencer

TonyL,
Perhaps Mosher will be good enough to show you the error of your ways. He can probably do it in three words or less, as that is his usual mode of communication.

TonyL

*Thanks*
Actually, I was hoping for Willis E. because I know he uses R programming.
Maybe risvan, because he has looked extensively at sea level, as well as all kinds of other things.
Or anybody well versed in stats or R in the WUWT community.
So far, Zippo.

Duster

As the correspondents on rhelp often write, without a sample of the data in the format you employed, there are problems understanding your problem. What is “xdata” for instance? And, given the values of the simple linear fit, why did you bother with a poly fit?

John Law

The Ship at Dunwich was fantastic and still I hope (and know) above water!

Dave Millerr

Statistics are metadata, not new data.
Statistical methods can never add precision or new information to a data set. Only bias.

Peter Morris

If I lie often enough for long enough, eventually you rubes will believe it! It’s for your own good!

vukcevic

NASA ‘is’ finally realising it is the ocean currents taking heat pole-wards that are responsible for global warming and not the magic molecule. NASA’s Advanced Supercomputing (NAS) facility has been recruited into the task force to decipher mystery of the ocean currents
https://www.nas.nasa.gov/publications/articles/feature_ocean_vis.html

Don K

The paper might be here https://projecteuclid.org/euclid.aoas/1437397101. It’s paywalled. Here’s the abstract.

Abstract
We perform Bayesian inference on historical and late Holocene (last 2000 years) rates of sea-level change. The input data to our model are tide-gauge measurements and proxy reconstructions from cores of coastal sediment. These data are complicated by multiple sources of uncertainty, some of which arise as part of the data collection exercise. Notably, the proxy reconstructions include temporal uncertainty from dating of the sediment core using techniques such as radiocarbon. The model we propose places a Gaussian process prior on the rate of sea-level change, which is then integrated and set in an errors-in-variables framework to take account of age uncertainty. The resulting model captures the continuous and dynamic evolution of sea-level change with full consideration of all sources of uncertainty. We demonstrate the performance of our model using two real (and previously published) example data sets. The global tide-gauge data set indicates that sea-level rise increased from a rate with a posterior mean of 1.13 mm/yr in 1880 AD (0.89 to 1.28 mm/yr 95% credible interval for the posterior mean) to a posterior mean rate of 1.92 mm/yr in 2009 AD (1.84 to 2.03 mm/yr 95% credible interval for the posterior mean). The proxy reconstruction from North Carolina (USA) after correction for land-level change shows the 2000 AD rate of rise to have a posterior mean of 2.44 mm/yr (1.91 to 3.01 mm/yr 95% credible interval). This is unprecedented in at least the last 2000 years.

The word “Crackpot” comes to mind.

Clyde Spencer

Don K,
How can they claim “unprecedented” when they don’t have differential GPS correction for the last 2000 years, nor accurate dates for the sediment proxies for tide gauges?

Don K, thank you for the link.

RWIsrael

When did statistics become more accurate than actual observation. Silly me, I thought science involved ACTUAL observation and measurement. Statistics are applied mathematics.

Ground water levels are dropping by meters and sea levels rise by millimeters. Seems to make sense. How might one estimate soil erosion/depletion over the last 200 years?
http://www.waterworld.com/articles/wwi/print/volume-25/issue-5/groundwater-development-flow-modeling/groundwater-depletion-linked-to-rising.html

Brian Zelt

Has anyone analyzed the surface levels of the earth? It seems to me that shapes of the earth surface (and hence, the overall surface) and relative location of the continents are constantly changing by very small amounts. So if the shape of the bowl is changing and heights of the continents are changing (mountains formed, sub-sea mountains, post-glacial expansion, etc.), it is likely that the global waterline will also change, regardless of the whether or not the volume of water in the bowl is increasing or decreasing. If the mountains are rising at rates of mm/y (or faster for sub-sea), why is surprising that sea levels are changing. Instead of focusing on ice-melt, perhaps we should look at other causes for sea level rise changes.

Seems like we have been over this time after time with numerous “peer reviewed papers”. I’m sticking with 4 to 7 inches per century globally, with no noticeable acceleration in SLR…101.6 mm to 177,4 mm per century.

1sky1

It’s amazing how many here form their perception of sea level rise without any clear concept of what time-scales are disregarded (what frequencies are filtered away) in the assessment Parnell’s perspective is entirely on the highly smoothed millennial scale of proxy data (see Figure 6 in:
https://www.researchgate.net/profile/Benjamin_Horton/publication/281136939_Relative_sea-level_change_in_Connecticut_USA_during_the_last_2200_yrs/links/55dc3d6408aed6a199ac855d/Relative-sea-level-change-in-Connecticut-USA-during-the-last-2200-yrs.pdf )
All the purported counter-demonstrations here based on trend-fitting unsmoothed tide-gauge data are largely irrelevant to the point that he makes.

1sky1

Make that Figure 8.

knr

If you cannot measure it you do not know it , but you can ‘guess it’ and throwing statistics at it does not change that . There is no ‘magic’ that can over come past issues with measurements when you simply no idea what those issue even were . You merely add guess work into data which you consider has an problem but you have no idea of the range , direction or size of the problem .

Bunkum …. New York State Sea Level Rise Task Force Report to the Legislature — Dec 31, 2010 [ http://www.dec.ny.gov/docs/administration_pdf/slrtffinalrep.pdf ] gives (when translated to mm) a figure of 2.5 to 2.77 mm average Relative Sea Level Rise since 1960. (The last 50 years or so.)
The Battery at NY City is known from Continuously Operating Reference System (NOAA CORS) to be subsiding at a rate between 1 and 2 mm per year. The latest subsidence numbers for the Battery, NYC come from this paper Using global positioning system-derived crustal velocities to estimate rates of absolute sea level change from North American tide gauge records by Richard Snay et al. at NOAA NGS . A vertical movement of minus 1.35 mm/yr (SD 1.74). The Battery is sinking towards the center of the Earth. It speeds up and slows down, but that is the long term average lately. Some months it is up 10 mm, some months, down 10 mm….the error bars are even larger.
I must point out that statistics are not measurement. — not now, not ever.
Here are the MEASUREMENTS: (This is RELATIVE sea level rise, remember)
“The mean sea level trend is 2.84 millimeters/year with a 95% confidence interval of +/- 0.09 mm/yr based on monthly mean sea level data from 1856 to 2016 which is equivalent to a change of 0.93 feet in 100 years. ”
Not the statistically manufactured “0ver 3 mm/yr”.
Subtracting the subsidence of 1.35 from 2.84 leaves us 1.49 mm/yr of actual rising sea water less than the Global Average.
Of course, NY City only cares about relative sea level rise — its the only kind they wlll ever experience — but they are experiencing nothing out of the ordinary.

Thank you for this info, Kip!
Actually, 1.49 mm/yr is almost exactly equal to my best estimate of the current rate of GMSL rise.