Sea levels rising at fastest rate in 28 centuries.

Poor Debater · Feb 23, 2016

A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

We present the first, to our knowledge, estimate of global sea-level (GSL) change over the last ∼3,000 years that is based upon statistical synthesis of a global database of regional sea-level reconstructions. GSL varied by ∼±8 cm over the pre-Industrial Common Era, with a notable decline over 1000–1400 CE coinciding with ∼0.2 °C of global cooling. The 20th century rise was extremely likely faster than during any of the 27 previous centuries. Semiempirical modeling indicates that, without global warming, GSL in the 20th century very likely would have risen by between −3 cm and +7 cm, rather than the ∼14 cm observed. Semiempirical 21st century projections largely reconcile differences between Intergovernmental Panel on Climate Change projections and semiempirical models.

Glen Contrarian · Feb 23, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

Sounds to me that it's obviously part of the plot idea in your signature - "world's scientists, as part of their contrived environmental crisis, pretend to have worldwide evidence (backed up by satellite measurements) that the sea level is rising at a record pace."

But it's all just a plot, y'see, by the overwhelming majority of the world's millions of scientists, y'see, to impose socialism on everyone...and what's most amazing of all is that there's been precisely zero evidence of any such conspiracy. Golly gee whiz, Gomer, those scientists sure are smart, that they've been able to hide it all this time! Thanks to the billionaires and Big Oil and the Rabid Right, we all just know there's a conspiracy...who needs evidence, right? 'Cause when it's the world's scientists against the (almost exclusively American) Right, well, we all know that the Right MUST NOT BE QUESTIONED! So obviously it must be the scientists who are lying, and not Big Oil!

longview · Feb 23, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

The problem with many such statements like,

global sea levels are rising faster today than any time during the last 28 centuries,

is that we have a very limited number of data points to show what the sea level change was doing before.
The few we do have do not show any acceleration between the 19th and 20th century.
Global Sea Level Trends - Mean Sea Level Trend
Sea Level Trends - State Selection
Global Sea Level Trends - Mean Sea Level Trend
Global Sea Level Trends - Mean Sea Level Trend
http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.htm?stnid=680-471
I tried to select a few diverse places around the world, with records going back to the 19th century.
But feel free to look your self.
http://tidesandcurrents.noaa.gov/sltrends/mslGlobalTrendsTable.htm
The 14 cm per century rate appears to extend back to the early 1800's
The mechanical tide gauges are one place where the low tech beats out the
satellite measurements easily. The old tide gauges likely have a sub mm accuracy,
while the satellites only have a 30 mm accuracy.

MrT · Feb 23, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

But...but...but...the SATELLITES!

Tim the plumber · Feb 23, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

1, So what happened 3000 years ago to cause the sea level to rise more quickly than now?

2, So?

Jack Hays · Feb 23, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

Glen Contrarian said:
Sounds to me that it's obviously part of the plot idea in your signature - "world's scientists, as part of their contrived environmental crisis, pretend to have worldwide evidence (backed up by satellite measurements) that the sea level is rising at a record pace."

But it's all just a plot, y'see, by the overwhelming majority of the world's millions of scientists, y'see, to impose socialism on everyone...and what's most amazing of all is that there's been precisely zero evidence of any such conspiracy. Golly gee whiz, Gomer, those scientists sure are smart, that they've been able to hide it all this time! Thanks to the billionaires and Big Oil and the Rabid Right, we all just know there's a conspiracy...who needs evidence, right? 'Cause when it's the world's scientists against the (almost exclusively American) Right, well, we all know that the Right MUST NOT BE QUESTIONED! So obviously it must be the scientists who are lying, and not Big Oil!

The discussion continues . . . .

Is sea level rise accelerating?
Posted on February 23, 2016 | 55 comments
by Judith Curry
Estimates of the rate of sea level rise are diverging.
Continue reading →

longview · Feb 24, 2016

I thought it would be interesting to see what the average sea level increase was according
to the NOAA web site.
Sea Level Trends - MSL global stations trends table
No big deal 433 stations, with an average 116 year range.
I averaged the column mean sea level trends (mm/yr).
We get an average sea level increase of .97 mm per year.

Threegoofs · Feb 24, 2016

longview said:
I thought it would be interesting to see what the average sea level increase was according
to the NOAA web site.
Sea Level Trends - MSL global stations trends table
No big deal 433 stations, with an average 116 year range.
I averaged the column mean sea level trends (mm/yr).
We get an average sea level increase of .97 mm per year.

Will this extensive analysis be your first submission to PNAS? Or have you decided to present this at the AGU meeting?

longview · Feb 24, 2016

Threegoofs said:
Will this extensive analysis be your first submission to PNAS? Or have you decided to present this at the AGU meeting?

I am using NOAA's data.
Please load and average the mean sea level trend column for yourself,
and tell me where I am wrong.
Ultimately, sea level rise is a local concern, it is only a concern if the sea is rising
in respect to your own local section of coast.
The place to measure it is, well at the shore, which is what the tide stations do.
NOAA has a good historical reference for the tide stations going back to the early 1800's
The record contains a lot of data, but not much of it shows much acceleration,
in the rate of the rise.

ludin · Feb 24, 2016

longview said:
I am using NOAA's data.
Please load and average the mean sea level trend column for yourself,
and tell me where I am wrong.
Ultimately, sea level rise is a local concern, it is only a concern if the sea is rising
in respect to your own local section of coast.
The place to measure it is, well at the shore, which is what the tide stations do.
NOAA has a good historical reference for the tide stations going back to the early 1800's
The record contains a lot of data, but not much of it shows much acceleration,
in the rate of the rise.

this is AGW zealotry we are talking about you don't discuss facts or merits you only discuss hysteria and doom.

longview · Feb 24, 2016

ludin said:
this is AGW zealotry we are talking about you don't discuss facts or merits you only discuss hysteria and doom.

I was contemplating a list of the dogma items that must come free along acceptance
of the IPCC position.
Something like,
If you buy that doubling the CO2 level will cause 1.2 C of warming,
and that warming will be amplified to cause 3 C of warming....
Here is what we include at no additional charge!
Doom and Gloom!
Stronger Hurricanes!
More Hurricanes!
More snow!
Less snow!
sea level rise!
Drought!
Floods!
and Many more!

Disclaimer:
Side effects may include, reduction in lifestyle and freedom, an increase in taxes,
in addition to many regulations which could limit choices you might make!

Lord of Planar · Feb 24, 2016

I wonder how the last 100 years would look like in 500 years, when viewing it from proxy data?

Poor Debater · Feb 25, 2016

Jack Hays said:
The discussion continues . . . .

Is sea level rise accelerating?
Posted on February 23, 2016 | 55 comments
by Judith Curry
Estimates of the rate of sea level rise are diverging.
Continue reading →

No, actually the estimates are converging, on a rate that is politically unacceptable in Denierstan. Heavens! What's a denier to do? Deny, deny, deny, that we know what we actually do know. That's what.

Judith Curry says this line is flat. Judith Curry is an idiot.

Jack Hays · Feb 25, 2016

Poor Debater said:
No, actually the estimates are converging, on a rate that is politically unacceptable in Denierstan. Heavens! What's a denier to do? Deny, deny, deny, that we know what we actually do know. That's what.

Judith Curry says this line is flat. Judith Curry is an idiot.

I'm sure Professor Curry would be deeply wounded by your criticism. I'll let her speak for herself:

The key issue is whether the sea level rise during the past 50 years reflect an acceleration in sea level rise. The IPCC figure 3.14 suggests that there is no acceleration, given the large rates of sea level rise in the first half of the 20th century. Until we have an understanding of variations in decadal and multi-decadal sea level rise, we can’t make a convincing argument as to acceleration.

Poor Debater · Feb 25, 2016

Jack Hays said:
I'm sure Professor Curry would be deeply wounded by your criticism. I'll let her speak for herself:

The key issue is whether the sea level rise during the past 50 years reflect an acceleration in sea level rise. The IPCC figure 3.14 suggests that there is no acceleration, given the large rates of sea level rise in the first half of the 20th century. Until we have an understanding of variations in decadal and multi-decadal sea level rise, we can’t make a convincing argument as to acceleration.

Okay then, first half of the 20th century. In fact, the last 2 millenia:

Judith Curry thinks this line is flat, too. Judith Curry is still an idiot.

Lord of Planar · Feb 25, 2016

Poor Debater said:
Okay then, first half of the 20th century. In fact, the last 2 millenia:

Judith Curry thinks this line is flat, too. Judith Curry is still an idiot.

There you go again, mixing proxy and instantaneous data. It's worse than mixing oil and water!

Threegoofs · Feb 26, 2016

Lord of Planar said:
There you go again, mixing proxy and instantaneous data. It's worse than mixing oil and water!

Yeah, because amateurs know that mixing that data in graphs makes deniers look bad!

Everyone knows it's not appropriate, because Christopher Monckton said so!

Tim the plumber · Feb 26, 2016

Poor Debater said:
No, actually the estimates are converging, on a rate that is politically unacceptable in Denierstan. Heavens! What's a denier to do? Deny, deny, deny, that we know what we actually do know. That's what.

Judith Curry says this line is flat. Judith Curry is an idiot.

So you think that a range of values between 2mm and 5mm per year is anything other than F. all?

Tell me, how will a 16 inch sea level rise cause mass flooding over a century?

longview · Feb 26, 2016

Poor Debater said:
No, actually the estimates are converging, on a rate that is politically unacceptable in Denierstan. Heavens! What's a denier to do? Deny, deny, deny, that we know what we actually do know. That's what.

Judith Curry says this line is flat. Judith Curry is an idiot.

So when NASA says the accuracy of the satellites is more than 3 cm (30 mm),
I guess that means it is easy to see a difference between 3 mm/year and 5mm/year?
https://sealevel.jpl.nasa.gov/techn...umentdescription/instrumentdescriptaltimeter/

By combining this measurement with data from the microwave radiometer and with other information
from the spacecraft and the ground, scientists were able
to calculate the height of the sea surface to within 4.3 centimeters.

To be fair the theoretical maximum accuracy would be 2.2 cm, but there are many factors that limit this.
The point is with a accuracy of only 30 to 40 mm, the change shown on your graph,
would be a straight line.
Every single data point would show up withing the same least resolvable unit.

Steve Case · Feb 26, 2016

Poor Debater said:
No, actually the estimates are converging, on a rate that is politically unacceptable in Denierstan. Heavens! What's a denier to do? Deny, deny, deny, that we know what we actually do know. That's what.

Judith Curry says this line is flat. Judith Curry is an idiot.

One of the things you need to know about the satellite record is that like most
things global warming, the historical data isn't static. It's regularly rewritten.
Here's a little graph that compares ten years worth of data corrections:

It's a matter of opinion as to why those changes were made but it's a matter of
fact that they were. It amounts to a bump-up of nearly a full millimeter per year.

By the way, The Jason-3 satellite, with sea level altimetry sensing equipment,
launched on January 17th. I look forward to seeing what happens to the historical
data when it comes on line later this year. Colorado University's Sea Level Research
Group is overdue on up-dating their web page. They still show #version_2015_rel4
on their data page.

longview · Feb 26, 2016

Steve Case said:
One of the things you need to know about the satellite record is that like most
things global warming, the historical data isn't static. It's regularly rewritten.
Here's a little graph that compares ten years worth of data corrections:

It's a matter of opinion as to why those changes were made but it's a matter of
fact that they were. It amounts to a bump-up of nearly a full millimeter per year.

By the way, The Jason-3 satellite, with sea level altimetry sensing equipment,
launched on January 17th. I look forward to seeing what happens to the historical
data when it comes on line later this year. Colorado University's Sea Level Research
Group is overdue on up-dating their web page. They still show #version_2015_rel4
on their data page.

I have tried to explain to people that the satellite altimeters simply lack the accuracy
to produce the graphs they show.
Here is the data from the latest satellite.
Technology

After correction for atmospheric and instrumental effects,
the range measurements are accurate to less than 3 centimeters

CU Sea Level Research Group | University of Colorado
3 cm is 30 mm, if we plotted the rate of change shown with the limitation
of the stated accuracy, it would only have 2 or 3 steps.
Here is an example

Threegoofs · Feb 26, 2016

longview said:
I have tried to explain to people that the satellite altimeters simply lack the accuracy
to produce the graphs they show.
Here is the data from the latest satellite.
Technology

CU Sea Level Research Group | University of Colorado
3 cm is 30 mm, if we plotted the rate of change shown with the limitation
of the stated accuracy, it would only have 2 or 3 steps.
Here is an example
View attachment 67197702

Have you tried to explain it to the editors of PNAS?

Or are they not worthy of your in depth knowledge of this topic?

Renae · Feb 26, 2016

Poor Debater said:
A new study in Proceedings of the National Academy of Sciences confirms that global sea levels are rising faster today than any time during the last 28 centuries, and that human-caused climate change is responsible for at least half of that rise.

Sea levels move.. on their own, quite a bit. Here is an article about a port, heavily used by the Romans. It's 2 MILES Inland...
Face in the sand: Roman amphitheatre unearthed at ancient port | Daily Mail Online

longview · Feb 26, 2016

Threegoofs said:
Have you tried to explain it to the editors of PNAS?

Or are they not worthy of your in depth knowledge of this topic?

PNAS knows what significant figures are, and what they mean.
It is not possible to measure a 5mm change with a system that
is only accurate to 30 mm.
Perhaps you can enlighten us as to why a single dish altimeters,
with a 13.6 Ghz signal, only has a 30 mm accuracy?
(technically the absolute theoretical accuracy is 22mm, but we do not live in a vacuum)

Steve Case · Feb 26, 2016

longview said:
I have tried to explain to people that the satellite altimeters simply lack the accuracy
to produce the graphs they show.
Here is the data from the latest satellite.
Technology

After correction for atmospheric and instrumental effects,
the range measurements are accurate to less than 3 centimeters

CU Sea Level Research Group | University of Colorado
3 cm is 30 mm, if we plotted the rate of change shown with the limitation
of the stated accuracy, it would only have 2 or 3 steps.
Here is an example

Hey their data is accurate to 3 places here's the first line from their Raw Data link:

year msl_ib_ns(mm) #version_2015_rel4
1992.9595 -5.678
...

See! That's -5.678 millimeters! The United States spends over $3 Billion on Global
Warming research annually, and one of the things we get for that outlay of cash is
accuracy and precision. Nothing but the finest for our scientists!

My Mitutoyo calipers only gets 2 places after the decimal point:

Digital-Display-150mm-0-01vernier-caliper-mitutoyo-calibre-paquimetro-pie-de-rey-rule-micrometro-plicometro-schuifmaat.jpg

That's because it only costs about $100.

Why would anyone doubt the possibility of measuring sea level to an accuracy of a
thousandth of a millimeter from an orbit in space?

Sea levels rising at fastest rate in 28 centuries.

Poor Debater

Well-known member

Glen Contrarian

longview

MrT

Tim the plumber

Jack Hays

Traveler

longview

Threegoofs

Sophisticated man-about-town

longview

ludin

longview

Lord of Planar

Poor Debater

Well-known member

Jack Hays

Traveler

Poor Debater

Well-known member

Lord of Planar

Threegoofs

Sophisticated man-about-town

Tim the plumber

longview

Steve Case

longview

Threegoofs

Sophisticated man-about-town

Renae

longview

Steve Case