Fastest sea-level rise in two millennia linked to increasing temperatures

Jun 20, 2011
Fastest sea-level rise in two millennia linked to increasing temperatures
A foraminifera fossil

(PhysOrg.com) -- An international research team including University of Pennsylvania scientists has shown that the rate of sea-level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years and that there is a consistent link between changes in global mean surface temperature and sea level.

The research was conducted by members of the Department of Earth and Environmental Science in Penn's School of Arts and Science: Benjamin Horton, associate professor and director of the Research Laboratory, and postdoctoral fellow Andrew Kemp, now at Yale University's Climate and Energy Institute.

Their work will be published in the journal on June 20.

" is a potentially disastrous outcome of , as rising temperatures melt land-based ice and warm ocean waters," Horton said.

"Scenarios of future rise are dependent upon understanding the response of sea level to climate changes. Accurate estimates of past sea-level variability provide a context for such projections," Kemp said.

In the new study, researchers provided the first continuous sea-level reconstruction for the past 2,000 years and compared variations in global temperature to changes in sea level during this time period.

The team found that sea level was relatively stable from 200 B.C. to 1,000 A.D. During a warm climate period beginning in the 11th century known as the Medieval Climate Anomaly, sea level rose by about half a millimeter per year for 400 years. There was then a second period of stable sea level associated with a cooler period, known as the Little Ice Age, which persisted until the late 19th century. Since the late 19th century, however, sea level has risen by more than 2 millimeters per year on average, which is the steepest rate for more than 2,100 years.

To reconstruct sea level, the research team used called foraminifera preserved in from coastal salt marshes in North Carolina. The age of these cores was estimated using radiocarbon dating and several complementary techniques.

To ensure the validity of their approach, the team members confirmed their reconstructions against tide-gauge measurements from North Carolina for the past 80 years and global tide-gauge records for the past 300 years. A second reconstruction from Massachusetts confirmed their findings. The records were also corrected for contributions to sea-level rise made by vertical land movements.

The team's research shows that the reconstructed changes in sea level during the past millennium are consistent with past global temperatures and can be described using a model relating the rate of sea-level rise to global temperature.

"The data from the past help to calibrate our model and will improve sea-level rise projections under scenarios of future temperature rise," research team member Stefan Rahmstorf said.

Explore further: Hurricane Edouard right environment for drone test (Update)

More information: www.pnas.org/content/early/201… /1015619108.abstract

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User comments : 32

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Howhot
1.8 / 5 (10) Jun 20, 2011
Just another indicator pointing to the same conclusion; AGW has lots of side effects leading to us to extinction.
Shootist
1.5 / 5 (17) Jun 20, 2011
Rise of sea levels is 'the greatest lie ever told' - Telegraph

Hmmmm, facts getting in the way of a theory, again:

http://www.telegraph.co.uk/
comment/columnists/christopherbooker/
5067351/Rise-of-sea-levels-
is-the-greatest-lie-ever-told.html

Rise of sea levels is 'the greatest lie ever told'
The uncompromising verdict of Dr Mörner is that all this talk about the sea rising is nothing but a colossal scare story, writes Christopher Booker.
malapropism
5 / 5 (10) Jun 20, 2011
@Shootist:
Not saying that either these researchers or Mörner are right or wrong as I haven't looked at the original research papers to form a conclusion and it's not my field anyway, however on reading the Telegraph article and the Wikipedia article on Mörner (Nils-Axel), it struck me that there is a basic flaw in his (and your) reasoning wrt this research in the Physorg article.

Mörner's conclusion is made on the basis of actual measurements over 300 years and that the IPCC sea-level rise he takes issue with is based on a model and only a few data points. Fair enough; it seems to me however that you neglect to note that the research above also took 300 years of globally-based sea level measurements and detailed measures over 80 years in a location - North Carolina - and found an apparently significant trend. Thus Mörner's basis for criticism, on technique at least, disappears.

I submit to you that you and Mörner are perhaps letting prejudice and his theory get in the way of facts?
NotParker
1.6 / 5 (13) Jun 20, 2011
Fabrication.

"the data used in the charts is clearly not the data that it says it is. The graph in the paper shows significantly more warming that the data it claims to be."

http://theinconve...ann-use/
Telekinetic
1.7 / 5 (12) Jun 20, 2011
"This rising sea-level-BLUB-BLUB- report is full-BLUB-BLUB-BLUB-
of inconsistencies-BLUB-BLUB-BLUB-BLUB." (Fish swims past face)
Canman
4.3 / 5 (11) Jun 20, 2011
Not Parker and Shootist, do you guys know each other? Whenever there is a global warming article, you guys pounce on it. You both do it very consistently. Do you believe there are any other conspiracies or hoaxes? Would be interested to know.
newsreader
4.6 / 5 (10) Jun 20, 2011
Just another indicator pointing to the same conclusion; AGW has lots of side effects leading to us to extinction.


Extinction is probably a bit extreme, but I can see a future where we have some very serious problems to deal with. The sad part is that you look at the idiots that respond to these articles and then you start to understand what a truly uphill battle we have.
malapropism
5 / 5 (7) Jun 20, 2011
Fabrication.

Are you commenting on the Mann data and charts that you referenced or on the research in this Physorg article?

If the former, I have no comment as I've skimmed the site you linked but done nothing more than that. Though I have to suggest that the 2 articles, here and at your linked site, appear not-very-related on the face of it.

If the latter then that is an extremely serious charge to level at these researchers (and by association the PNAS and peer reviewers). Since the 300-year and 80-year sea level records are presumably a matter of public record then your assertion of falsification must have some pretty impressive backing to it. Are you able to present us with this please?

(A link is fine... though since the above research was published only yesterday any critique was *very* quick off the mark.)
Howhot
3 / 5 (10) Jun 21, 2011
Notpark is a paid for shill. Just ignore it. Who ever is awake at the time will post for it.
DKA
3.8 / 5 (11) Jun 21, 2011
Canman
it is the same person. This website is being used by paid persons by oil firms to make comments to deny global warming. I am sure if something can be done. It is a real shame. You can't argue with them, they do not "reason" because they are gettting paid to do this. Very sad people who do not realize what wrong they are causing to people.
tkjtkj
1 / 5 (8) Jun 21, 2011
Re: Malapropism: "I've skimmed the site you linked but done nothing more than that. Though I have to suggest that the 2 articles, here and at your linked site, appear not-very-related on the face of it.


I'm astounded that you can make such an assertion while simultaneously admitting that you attempted NO, ie: 'zero' analysis of that which you comment upon.
Get thee to some degree!! Then perhaps you would learn to be more thoughtful in scientific (and other) matters.
3432682
1.8 / 5 (17) Jun 21, 2011
If the sea is rising quickly on the US east coast, it must be doing so elsewhere, everywhere. But it is not. Ergo - baloney.
ted208
1.8 / 5 (16) Jun 21, 2011
SEA LEVEL = SIMPLE AVERAGING SHOWS NO GLOBAL TREND IN 150 YEARS
http://oi52.tinyp...e0es.jpg

Here's an article on the Pacific Islands growing: http://www.theaus...75237545

The University of Colorados Sea Level Research Group decided in May to add 0.3 millimeters -- or about the thickness of a fingernail -- every year to its actual measurements of sea levels, sparking criticism from experts who called it an attempt to exaggerate the effects of global warming.

"There really is no reason to do this other than to advance a political agenda,"

Billybaroo
1.8 / 5 (15) Jun 21, 2011
Another attempt by Michael Mann to use his fabricated hockey stick!
FrankHerbert
1.2 / 5 (55) Jun 21, 2011
Seems like a pattern here...

Billbaroo recently commented on:

Salt marsh sediments help gauge climate-change-induced sea level rise, 4 minutes ago

Panel: Problems with oceans multiplying, worsening, 12 minutes ago

Antarctic flowering plants warm to climate change, Mar 30, 2011

The rise in sea level of the Mediterranean is accelerating, Feb 25, 2011

Melting icebergs causing sea level rise, Apr 28, 2010

The age of Aquarius? Nope, it's the Anthropocene epoch, Apr 15, 2010

Disputed isle in Bay of Bengal disappears into sea, Mar 24, 2010

Climate projections underestimate CO2 impact, Dec 11, 2009

Rich countries 'should pay' to transfer low carbon technology, researchers says, Nov 12, 2009

Greenland ice sheet larger contributor to sea-level rise, Jun 12, 2009
NotParker
1.7 / 5 (17) Jun 21, 2011
This just in:

Mann dishonestly used upside down proxies again.

http://climateaud...al-2011/

North Carolina has been hit by dozens of hurricanes in the last 120 years.

They must have smashed those salt marshes over and over again.

How can anyone claim they know what the sea level was after the salt marshes were smashed over and over again.

PS I don't get paid to post here. But I am terrified that the latest IPCC report recommends spending over 180 trillion dollars over the next 38 years on windmills and solar.
malapropism
4.6 / 5 (9) Jun 21, 2011
Re: Malapropism: ...


I'm astounded that you can make such an assertion while simultaneously admitting that you attempted NO, ie: 'zero' analysis of that which you comment upon.
Get thee to some degree!! Then perhaps you would learn to be more thoughtful in scientific (and other) matters.

Well, actually, my undergraduate Degree was in Science with a major in Botany and my Postgraduate Degree is in genetics (my thesis concerned generating and analysing some particular mutations in a crop plant). I also have 2 (different majors and tertiary Institutions) Postgraduate Diplomas in IT, have taught undergrad and postgrad level at two different Universities and a private tertiary college and am contemplating starting a Philosophy Degree next year, just for fun. And also perhaps to have a bit more and better ammo against the creationists who tend to lurk around here.

I didn't say "zero analysis" (your words), I said I merely "skimmed" the article.
jyro
2.3 / 5 (7) Jun 21, 2011
There was never any chance of controlling global warming. Use this information to prepare for the future. Resources spent on trying to control the uncontrollable are wasted.
Howhot
3.9 / 5 (11) Jun 21, 2011
NotP... Ok your argument about hurricanes; how often in the past 1000 years have hurricanes struck the NC coast. 1/yr? 1/5yr 1/10yr? It's probably 1/10yrs, so 100 times the NC coast was pushing waters up into the salt marshes. So averaged over time it doesn't effect the statistics or the conclusion, there has been an abrupt increase in the rate of sea level change. So your conclusion is full of it.
Telekinetic
3 / 5 (8) Jun 21, 2011
There was never any chance of controlling global warming. Use this information to prepare for the future. Resources spent on trying to control the uncontrollable are wasted.

Yeah, let's rescind the ban on chlorofluorocarbons and tear a new "hole" in the ozone layer as big as you.
NotParker
1.9 / 5 (11) Jun 21, 2011
how often in the past 1000 years have hurricanes struck the NC coast. 1/yr? 1/5yr 1/10yr? It's probably 1/10yrs,


"The list of North Carolina hurricanes includes 403 known tropical or subtropical cyclones that have affected the U.S. state of North Carolina. "

"According to statistical hurricane research between 1886 and 1996 by the North Carolina State Climatology Office, a tropical cyclone makes landfall along the coastline about once every four years. "

"The list of North Carolina hurricanes before 1900 encompasses 139 tropical cyclones that affected the U.S. state of North Carolina."

"Between 1900 and 1949, 75 tropical cyclones or their remnants affected the state."

"A total of 79 tropical or subtropical cyclones affected North Carolina between 1950 and 1979."

"The period from 1980 to the present encompasses 110 tropical or subtropical cyclones that affected the state. "

http://en.wikiped...rricanes
NotParker
1.7 / 5 (11) Jun 21, 2011
... or the conclusion, there has been an abrupt increase in the rate of sea level change. So your conclusion is full of it.


Actually, the "abrupt increase" took place before 1900 according to the paper.

Quoting from the abstract:

"Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892. "

Co2 was only a couple of ppm above "normal" in 1865, so it certainly wasn't CO2 that caused sea level to rise. It was most likely paper author error anyway ... but it sure wasn't CO2.

You get everything wrong all the time howhot.

deepsand
2.9 / 5 (19) Jun 21, 2011
NP = Not Plausible
thermodynamics
4.6 / 5 (8) Jun 22, 2011
NotParker: As you point out the paper says: "...stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892."

You seem to find fault with this by implying that there were no SUVs scuttling around spouting CO2. However, there was extensive land use change leading up to that period and this period was the beginning of the coal age. Yes, it was early and CO2 was not being belched out as rapidly as a bit later but the CO2 level was rising (by proxy indicators). However, if you look at Wikipedia:

http://en.wikiped...mosphere

You will see that in 1832 CO2 was 285ppm and in 1960 it was about 315 ppm. They have a nice curve showing the increase during the 1800s as land use changed and industrialization started. (continued)
thermodynamics
4.6 / 5 (9) Jun 22, 2011
Continued: What you (and others) do is use cute terms such as "where were the SUVs in 1890?" Do you really think that people do not recognize your disingenuous approach? Do you think that we don't realize that humans have been changing the face of the earth at an ever increasing rate? There are two factors. 1) There are more people on the earth every day. 2) The methods we can use to change the earth have improved during industrialization.
The bottom line is that we can destroy forests faster, dam up rivers faster, and use energy faster. So, the rate of CO2 equivalent releases (or not absorbed) has been increasing. Luckily, the oceans and land are soaking up a lot. However, the amount of CO2 has been steadily increasing. Show me a link or paper that says it has not. Show me a link or paper that says that the CO2 content of the atmosphere was not increasing in the 1800s due to the reasons I mentioned. Show us the references. I showed you mine.
NotParker
1.3 / 5 (12) Jun 22, 2011
So what you claim is ... 285ppm to 290ppm caused a huge jump in sea level rise.

And 290ppm to 380ppm caused no change in sea level rise.

Yaaayy ... no more sea level rise changes due to CO2 after 1892!!!

It wasn't CO2. It was something else. Bad science. Fraudulent science.
Doom1974
4.4 / 5 (13) Jun 22, 2011
So what you claim is ... 285ppm to 290ppm caused a huge jump in sea level rise.

And 290ppm to 380ppm caused no change in sea level rise.

Yaaayy ... no more sea level rise changes due to CO2 after 1892!!!

It wasn't CO2. It was something else. Bad science. Fraudulent science.


As said before, nothing will convince anybody if they don't want to or are getting paid. For a 100 years now, all analysis, calculations, evidence show that CO2 increases, temperature increases, through the feedback mechanism of Earth's thermostat. Water is the heating element CO2 is the thermostat. You know that you can control a very large heating power with a low voltage switch right? CO2 is your switch, water vapor the main heating element. You don't need thousands of ppm rise for CO2 to see the effect. You don't understand that simple explanation, nothing will make you understand. So do not bore us by bringing pseudoscientific arguments to this forum. Go with the trolls of NRA/GOP etc.
Shootist
1.3 / 5 (16) Jun 23, 2011
@malapropism

Not so much my prejudice, just knowing the fact that sea-levels have been rising since before the end of the last glaciation, is enough knowledge to question any claim for another cause.

Add that to the rebounding Northern Hemisphere and it becomes clear that "sea-level" isn't a precise measurement anyway.

One cannot go far wrong by continued questioning of the 'facts' provided by Government funded studies into politically sensitive issues.

@Doom1974

Well, the NRA is more trustworthy than Hansen, anyway.
NotParker
1.6 / 5 (14) Jun 23, 2011
For a 100 years now ...


For over 100,000 years CO2 rises have FOLLOWED temperature increases as seen in ice core data.

The earth got very cold -- as much as 3C colder -- during the Little Ice Age. During that time glaciers advanced to their furthest levels. Since the LIA came to an end, temperatures have risen a small amount. maybe a whole .8C.

It comes down to philosophy.

AGW believers think the coldest period in 1000 years is "normal" and any temperature above that -3C baseline is warming.

Sane people think that super cold period was not normal, and the earth is just warming a bit after that cold, as it has done for 1000s of years.

Think of it this way ... if someone told you -20C in the dead of winter was normal and everything else was too warm and we should do everything in our power to return to that cold cold time, you would think they were insane.

I don't want the LIA back. Too damn cold.

kivahut
2 / 5 (8) Jun 26, 2011
Whoa! Sea levels have risen a whole 8 inches in the last 110 years. I'm glad I live in Colorado.
braindead
3 / 5 (4) Jun 27, 2011
Whoa! Sea levels have risen a whole 8 inches in the last 110 years. I'm glad I live in Colorado.


200 mm (8" in silly units) is a lot if you live below sea level and your dykes are vulnerable to surges (which would presumably also be 200mm higher.) You should be OK in Colorado though;). Coastal protection redesign for future increases in sea level is just one more cost that might be mitigated and taken off the total bill by reducing GW (anthropomorphic or otherwise).
Howhot
3.8 / 5 (10) Jun 27, 2011
It always amazes me how the stooges will come out in force when serious environmental consequences of global warming are reported in the scientific literature after very significant study only to have the right wing toady forces try to set the standards for social engineering by misstating facts and insulting people!!!

As a fellow human who has studied the works of Hansen, and read the reports from the IPCC on Global Warming. I can assure you with 100% certainty, that the low lifes like NotPark, R2, Shootist are lying to you and want to obscure and obfuscate any facts that would effect the economic conditions of their fat-cat friends.

AGW is real, and the coast lines are going to change very quickly as the sea levels rise from melting glaciers an other ice melts. And it will be significant and noticeable by 2025.