This is a continuation of a remarkable thread that has now received 10,000 comments running to well over a million words. Unfortunately its size has become a problem and this is the reason for the move.
The history of the New Statesman thread goes back to December 2007 when Dr David Whitehouse wrote a very influential article for that publication posing the question Has Global Warming Stopped? Later, Mark Lynas, the magazine’s environment correspondent, wrote a furious reply, Has Global Warming Really Stopped?
By the time the New Statesman closed the blogs associated with these articles they had received just over 3000 comments, many from people who had become regular contributors to a wide-ranging discussion of the evidence for anthropogenic climate change, its implications for public policy and the economy. At that stage I provided a new home for the discussion at Harmless Sky.
Comments are now closed on the old thread. If you want to refer to comments there then it is easy to do so by left-clicking on the comment number, selecting ‘Copy Link Location’ and then setting up a link in the normal way.
Here’s to the next 10,000 comments.
Useful links:
Dr David Whitehouse’s article can be found here with 1289 comments.
Mark Lynas’ attempted refutation can be found here with 1715 comments.
The original Continuation of the New Statesman Whitehouse/Lynas blogs thread is here with 10,000 comments.
Max,
I’m not holding up Bjorn Lomborg as the fount of all knowledge on the climate question, and in fact, he probably is playing to the gallery a little and trying to promote his new book.
He’s now saying things like:
“If we want to have a world that’s eventually not emitting carbon dioxide, it requires a dramatic change in energy production. Instead of using a little less of the power that comes out from your coal-fired power plant, make solar panels so cheap that they replace coal-fired power plants. “
http://www.foreignpolicy.com/articles/2010/09/03/interview_bjorn_lomborg?page=0,0
And that sounds marvelous of course but is it possible? Its not just the solar panels, but the storage systems which have to be considered too. They are technologically much less well developed than the panels themselves.
And how do we “make” these this so cheap? Its going to cost a bit and using carbon taxes is perhaps sensible and effectively using a carrot and stick approach to the problem.
But I don’t want to nit-pick, and if Bjorn Lomborg wants to get down into the details of how his plan would work without exposing too many devils, then it could be worthwhile.
Peter
Ok, so you’ve back pedalled in your belief that this slide demo was conclusively proving what you thought.You said;
“Yes it would be good if we had a world wide network of tidal gauges with scientifically well kept records going back thousands of years but unfortunately that isn’t the case.”
Let’s scale the time back to hundreds of years, which is what the IPCC try to claim. We have 7 records that go back 100 years or more representing gauges that haven’t physically moved(although the physical circumstances around them have).
They take a snapshot of slightly rising sea levels as the ice melts as the LIA recedes.
We can see from lots of other empirical evidence around the world that in recorded history-such as the MWP and Roman optimum-that sea levels have been higher.
The Angles and Saxons were driven from the Low countries by the dramatically rising waters and were a major cause of the demise of the Roman empire-settling in previously peaceful Roman held lands (including Britain-it is thanks to (real) climate change that you are of an Anglo Saxon descent)
The IPCC have tried to foster this idea of dramaticaly increasing sea levels that have actually escalated in recent years. This is simply not true. I have detailed Chapter and verse what they have done as has Max.
They have stuck records from unreliable satellite data on top of a ludicrously small and unrepresentative number of tidal gauges dating back a few years and tried to claim this shows something it clearly doesn’t.
You refuse to read either Chapter 5 of AR4, nor my links, nor the material Max and myself have forwarded here in the past including Max’s graph #1723
This is the text from the paper that goes with the graph.
“According to S. J. Holgate, a recognised world authority in geophysical research at the UK-based Proudman Oceanographic Laboratory in Liverpool, in his paper published in 2007, the following results represent the most comprehensive measurements of decadal sea-level change rates during the 20th century.
Between 1904 and 1953 global sea levels rose by 2.03 mm per year, whereas from 1954 to 2003 they rose by only 1.45 mm per year, giving an annual mean rate of 1.74 mm per year over the 100 years to 2003, or seven inches per century. Importantly, there was no increase in the rate of change over the whole century.”
So, based on these peer reviewed and generally accepted numbers, 20th century sea levels rose at a 25% slower rate in the second half of the century than the first which, on any reasonable interpretation, contradicts the notion that global temperature increases during the last 50 years contributed to any dramatic sea level rise!
Incidentally the sea level rise from around 2005 has been barely measurable at around 0.6mm a year.
Peter, in 1900 there were 20 tidal gauges in the NH and 2 in the SH. All were of very short duration other than 3 dating back to the 1700’s which have huge chunks of data missing that have been susequently interpolated. In in any other science these would have been discarded as essentially worthless.
The IPCC have created a global record based on the equivalent-allowing for size-of 6 short lived land based thermometers which have had development grow around them!
These sea level records are even more ludicrous than the global land based temperatures you are so fond of parsing to a fraction of a degree.
tonyb
PeterM
No need for me to write to NAS about sea level projections. I am not that interested in any regurgitated IPCC stuff they parrot – I have already read that (and deconstructed the worst exaggerations) directly.
In a classical bit of double-talk, you opined:
Incorrect, Peter. Read IPCC AR4 SPM, p.13 (Table SPM3).
You will see that the various ranges listed for projected sea level rise in (meters in 2090-2099 relative to 1980-1999)\ are 0.18-0.38 for the lowest “scenario” (B1) to 0.26-0.59 for the highest “scenario” (A1F1).
So the upper end of the IPCC range is 0.59 meters, not one meter (as NAS erroneously stated in the blurb you cited), and the “mid-point” of the range for the worst “scenario” is (0.26 + 0.59) / 2 = 0.425 m.
Yes, I prefer empirical data based on actual physical observations to recreated proxy data from paleo-climate studies or (even worse) model simulations based on various hypothetical deliberations and assumptions.
These empirical data tell me (Russian Arctic studies previously cited) that, in addition to wide inter-seasonal swings, Arctic sea ice goes through multi-decadal cycles of net annual expansion and retraction, with an overall cycle length of around 60 years. The latest retraction cycle started from the 1979 high point (when satellite measurements started). It followed a period of net growth from the late 1940s, which was preceded by a period of retraction, starting in the 1920s.
As with the “globally and annually averaged land and sea surface temperature construct”, there is no statistical correlation to atmospheric CO2 levels.
You then opine:
Even IPCC (with all its exaggerations) does not agree with you (as pointed out above). As for “several centuries”, who knows what will happen between now and then? You do not. I do not. Even IPCC is not stupid enough to claim that it does.
Until you can demonstrate a statistically robust correlation based on empirical data between atmospheric CO2 and “average sea level” (whatever that is supposed to be), you have no sound basis for your “crystal ball prophesy”.
I’d suggest you forget about it. It is fantasy.
Max
PeterM
Further to my 1728, please refer to the chart in 1723 for the empirical data, based on actual physical sea level observations over the 20th century from tide gauges (with all the caveats raised by TonyB).
You will see that there is no statistical correlation between sea level and atmospheric CO2.
The first half of the 20th century had a slightly greater average rate of increase (2.0 mm/year) than the second half (1.4 mm/year), and there were multi-decadal swings from -1mm to +5mm in the average decadal rate of change), none of which correlates at all with CO2.
Sorry to disappoint you, Peter. Your claim that “empirical data” support the projection of “one meter sea level rise” this century or (even more absurd) “several meters” over the next “several centuries” caused by increasing atmospheric CO2 released by humans is pure fantasy.
Just look at the data.
Max
PeterM
We have discussed Lomborgs views on the relative importance of AGW, his thoughts on using a carbon tax versus new research, etc.
Re-read this key sentence, which pretty much summarizes his conclusions:
Did you get that? It’s not about “cutting carbon emissions”, but about developing new “technologies”.
Forget the “carbon tax” (direct or indirect), a.k.a. “guilt tax”. It will achieve absolutely nothing (just hamstring the world economy, so there is no discretionary funding left to finance research into new technologies for the future).
Max
PeterM
Two of the links on the chart in 1723 have been changed since the chart was drawn:
Holgate 2007 report on 20th century sea level trends
http://www.agu.org/journals/ABS/2007/2006GL028492.shtml
IPCC AR4 WG1 SPM 2007 report
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf
Max
Max,
The correlation isn’t so much between CO2 and sea level rise as between temperature and sea level rise.
In the last interglacial period temperatures were 2-3 degrees warmer than they are at present. CO2 levels were about 280ppmv. Was the extra warmth due to a more active sun at the time or a other Milankovitch factors such as angle of the Earth’s precession. I’d say the latter, but either way we do have empirical evidence that an extra 2-3 degrees of sea level rise translates to an extra 4-6 metres of sea level.
TonyB,
I don’t believe I’m backpedalling. But tell me about your claim that sea levels were 50cm so higher 1000 years ago.
Do you have a scientific reference to support this claim? Or have you just made it up?
Sorry should be “we do have empirical evidence that an extra 2-3 degrees of warmth translates to an extra 4-6 metres of sea level.
Peter #1732
How many times do I have to cite something before you read it? Here it is yet again
“To put our constantly fluctuating sea levels into context may I quote from Brian Fagan, Professor of Archaeology at the University of California and author of ‘The Little Ice Age’ from which this short excerpt is taken.
“Ten thousand years ago the southern North sea was a marshy plain where elk and deer wandered…England was part of the continent until as recently as 6000 BC when rising sea levels caused by post ice age warming filled the North sea. By 3000 BC the ocean was at near modern levels. Sea levels fluctuated continually through late prehistoric and Roman times but rose significantly after 1000 AD.
Over the next two centuries the North sea rose as much as 40-50 cms above today’s height in the low countries then slowly retreated again as temperature fell gradually in the north”
We can usefully take up the story with this book-it’s all interesting, but on page 552 (halfway down the left column then continue on to the right) it talks of ‘innundation’ around 1200AD of many parts of low land coastal Europe including Holland and Britain. This displaced thousands of coastal dwellers and caused conflict with those whose land they tried to move on to, further inland. Sea levels were about 0.50cm higher than today
http://books.google.co.uk/books?id=yRMgYc-8mTIC&pg=PA552&lpg=PA552&dq=sea+level+height+britain+viking+times&source=bl&ots=OCN9aJt2PG&sig=2lMDcr4rE7WegGy1okZyqyEWJU4&hl=en&ei=UqWGTO2hIIuOjAeUopybCQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CBsQ6AEwAjgU#v=onepage&q&f=false
Tonyb
Tony B,
I’m not sure if Brian Fagan is correct in his estimate of seal levels. The 50 cm claim needs to be referenced better than a page in a book. Maybe some scientific reference?
In any case I wouldn’t say he’s one of you. He’s predicting big droughts which will affect up to 30% of the world’s population as a result of global warming. From computer models would you believe?
Only half jokingly he refers to himself as a “prophet of doom” !
Do you go along with this too?
Link to Brian Fagan on the “Daily Show”.
http://archaeology.about.com/b/2008/03/18/brian-fagan-on-the-daily-show.htm
Peter
You are doing your usual trick of homing in on one small part of the total whilst studiously ignoring the rest because it doesn’t suit you.
I suggest you take up Brian Fagans assertion with his publishers and whilst you are about it remove all the other lines of evidence that Fagan and people like him have based their information on over the years. A good read of your new best friend Hubert Lamb would also throw much light on the subject, as would a study of the Vikings and the earlier movements of the Angles and Saxons and othe peoples who had to move when the seas rose.
You could also usefully examine the construction of sea castles around that time which are now mostly high and dry irrespective of any land movement or deposition.
I have pulled all the information together in my post sept 11th 4.32
http://wattsupwiththat.com/2010/09/10/sea-level-rise-hype-and-reality/
There are around 30 links you can explore.
Do you think it satisfactory to base a global sea level industry on 7 tidal gauges in 1880,(all subject to development around them) on to which is tacked satellite data from 1993 inaccurate to up to 8cm?
Is that OK because it comes from the IPCC?
tonyb
PeterM
Let’s do a quick “sanity check” on your fear (1732) that sea level could rise by 1 meter by 2100 and by “several meters” over the next “several centuries”
The next “several centuries” is a long way off, Peter. You and I have no earthly notion what is going to happen to our climate over the next decade, so it is totally absurd to be concerned about what is going to happen over the “next several centuries”.
So let’s return to your postulation of a 1-meter rise by 2100.
The “driver” in your AGW hypothesis is “greenhouse gases” emitted by humans, i.e. principally CO2.
This has risen exponentially (CAGR of around 0.4% per year) since Mauna Loa measurements started in 1958 (this is also the CAGR observed over the latest 5-year period).
Temperature has risen a bit since 1958, notably over the late 20th century (i.e. from around 1976 to 2000), during which period it rose by 0.40C.
Temperature rose about the same amount (0.53C) in the early 20th century (around 1910 to 1944); there were no regular CO2 measurements then, but ice core reconstructions (for what they are worth) show us a much slower increase over this period (CAGR of around 0.1% per year).
So atmospheric CO2 does not show a statistical correlation as the “driver” of the temperature increase (we have covered this point before).
Sea level rose a bit more in the first half of the 20th century (2.0 mm/year) than in the second half (1.4 mm/year), and this happened in multi-decadal swings (average decadal rate between +0.5 and –0.1 mm/year), so there is no correlation there, either.
There is a long-term correlation between major temperature changes and sea levels (as TonyB has reported they were higher during the MWP, when temperatures were a bit higher than today). Studies have shown that they were also possibly several meters higher during the last interglacial, when temperatures are believed to have been 3 to 6C higher than today over an extended time period.
IPCC ties a “worst case” sea level rise of 0.26 to 0.59 meters by year 2100 to a predicted “worst case” temperature rise of 2.4 to 6.4C.
But how reasonable is this “worst case”?
It is based on atmospheric CO2 levels increasing at almost 4 times the CAGR we have seen over the past 5 or past 50 years (1.52% CAGR versus 0.4%), and reaching levels that exceed the total amount of carbon in our planet’s total fossil fuel reserves, despite the fact that the UN projects population growth to year 2100 to be at a CAGR of one-sixth to one-third of that actually experienced from 1960 to today and (in addition) calculated at a 2xCO2 climate sensitivity that has been shown by physical observations on cloud feedbacks to be exaggerated by a factor of 3!
Factor up all those exaggerations and you get an exaggerated temperature increase of around 15:1 (and a resulting exaggeration of the resulting sea level increase of around 4:1.
So the logical conclusion is (if human GHGs are the only “driver” of climate, which, in itself is already a silly assumption), temperature might rise by 0.3 to 0.6C between now and 2100, with sea level rising by somewhere between 0.1 and 0.2 meters by then.
As sea-level expert, Nils Axel Mörner, has said, any prediction that exceeds 0.2 meters is nonsense.
Sorry. Your prediction of a 1-meter rise by year 2100 does not pass the “sanity test”, and the more likely estimate is 0.1 to 0.2 meters, instead, i.e. the low end of the IPCC estimate.
Max
Another cold Arctic summer
http://opinion.financialpost.com/2010/09/09/lawrence-solomon-another-cold-arctic-summer/
The red line – this year’s temperatures – falls below the green bell curve starting just before Day 150 (late May) of 2010, indicating that just about every day this last summer was colder than normal. The green bell curve represents the historical record — the temperatures that the Arctic has experienced since 1958.
TonyB,
Look, if I ask you for a reference on falling sea levels several hundred years ago it isn’t the correct answer to say “here are 30 links you can explore!” Incidentally if there was even one tidal gauge, never mind the seven you claim are insufficient, you might have some evidence.
I’m not saying that Brian Fagan is incorrect but I’d just like to know where he got his information from about sea levels having fallen.
He may think they have. He also may think that 30% of the earth’s population are about to suffer from devastating droughts. I’d like to know where he got that information from too.
I’d say that he is likely wrong on both counts. He may not be , I agree, but the evidence just isn’t there. It doesn’t make any sense on your part to accept, without question, what he says on sea level, because that’s what you like to hear, but when he talks about droughts you just don’t want to know. It’s just not a scientific approach. I seem to remember you doing the same with Hubert Lamb’s work too.
Peter said
“I’m not saying that Brian Fagan is incorrect but I’d just like to know where he got his information from about sea levels having fallen.”
It is not just Brian Fagan. It is Hubert Lamb.It is a variety of researchers through the ages. It is records from Holland from Britain from all over the low countries.It is the Anglo Saxon Chronicles. It is the records of villages, of landed estates. It is of displaced peoples and of empires that collapsed as they fled from rising waters. It is of drowned forests. Of workings flooded by the sea. It is of sea castles.
I appreciate that higher sea levels are a threat to your belief system which is why you choose yet again to ignore the evidence of history. I keep referencing these things but you just won’t read them.
What Brian Fagan writes about the researched past and what he THINKS about the speculative future are two quite different things.
You haven’t answered my question about if you think seven imperfect tide gauges are sufficient to base a global record on.
tonyb
TonyB,
You obviously don’t have any faith in the scientific method so it’s probably a waste of time asking you, but I’d just like one decent scientific reference to back up your claim of sea levels being higher in the past 1000 years and how they are now lower.
OK Hubert Lamb and Brian Fagan may well believe that sea levels were higher but where is the scientific evidence?
TonyB,
I have found:
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1240
Does this agree with what you are saying?
Too many links. Wil try again in two parts.
Peter
You are being highly illogical.
The reason I guided you towards my 30 link post is that it contained the evidence you say you require concerning IPCC methods of calculations and references to sea level heights in the past. It is therefore extraordinary that you subsequently complain about it being too detailed .I then pointed you to a well known warmist professor who says the same and you complained about that!
Can I refer you in particular to Prof Morner (referenced) and his many papers on sea level rise.
If you don’t like those, how about those well known sceptics Al Gore and Dr Ian Stewart who researched and wrote extensively on climate change and acknowledged numerous past episodes of warmth, cold and flooding which they used as a warming of what we could bring on ourselves.
These folowing studies are from Britain, Holland, The US, and middle East. Also the long epoch of the Vikings and the MWP demonstrate the reasons behind the rise in sea levels.
http://www.sciencedaily.com/releases/2009/01/090108101629.htm
http://www.physorg.com/news150645386.html
(nice graph)
“By linking the two sets of information together Aslak Grinsted could see the relationship between temperature and sea level. For example, in the Middle Ages around 12th century there was a warm period where the sea level was approximately 20 cm higher than today and in the 18th century there was the ‘little ice age’, where the sea level was approximately 25 cm lower than it is today.”
http://www.ryemuseum.co.uk/index.php/category/local-history/romney-marsh/
The Calm before the Storm
By the 12th century the vulnerability of sea walls within the marsh caused concern. Grants of land carried provision for tenants to maintain the walls and waterways from damage by tidal water. Laws were passed by the 13th century for the administration of the marsh to be carried out by 24 elected men who would enforce the paying of levies or ‘scots’ for the upkeep of waterways and embankments. The expression ‘scot free’ has its origins in exemption of a person having land above marsh level. The system of levies or ‘scots’ continued until the Land Drainage Act, 1930
The 13th Century Storms
The river (which we now call the Rother) made its way south east from Appledore across the marsh to an outfall into the sea at New Romney; by the 12th century this marsh river was converted into a canal 6 miles (9.7 kms) long to Old Romney. The 13th century was remarkable for a series of storms accompanied possibly by a rise in sea level. The first was in 1236 followed in 1250 when the town and port of Old Winchelsea were overwhelmed; there was a temporary recovery until it finally succumbed in the storm of 1287 by which time the new town of Winchelsea on the hill of Iham was being colonised.
OK, will try 3 parts!
http://www.lancewadplan.org/Cultural%20atlas/WaddenSea/waddensea.htm
There appears to have been a general abandonment of settlements across the region during the late Roman Iron Age and the Migration period, probably due to rising sea-levels and storm-tides in the 4th century. Settlement recommences in the 7th or 8th centuries, often in areas that had been previously favoured as settlements sites in the Roman Iron Age. However, these settlements were always vulnerable to storm-tides, of which the most famous and best recorded is probably the Grote Mandränke or ‘Great Drowning’ of 1362 which devastated the entire Wadden Sea region, submerging villages and islands and re-modelling the entire coastline.
http://www.seftoncoast.org.uk/hist_intro.html
On the Sefton Coast the present dune system probably began to form about 800-900AD in a period of rising sea-levels.
http://www.roman-britain.org/places/tanatus.htm
Rectangular and curvilinear enclosures have been recorded at Dumpton Gap and Broadstairs on the east coast of the island, both of which may indicate small subsistence farming communities whose incomes were bolstered by the extraction of salt from sea-water, as evidence linked to this activity has been found at both of these sites. The industry was probably curtailed by the early 3rd century at these sites, however, due to the rising sea-levels. Burials have also been recorded at both sites
part 3
http://academic.emporia.edu/aberjame/ice/lec19/lec19.htm
In North America, pollen and charcoal in sediments from Chesapeake Bay record climatic changes over the last 1000 years (Brush 1991). During the Medieval climatic optimum, large influxes of charcoal, sediment, and metals indicate more frequent forest fires and higher rates of erosion in the surrounding basin. Forest in the Chesapeake basin recovered, and erosion diminished, during the following few centuries of cold climate. In southern Florida, sea level was at least ½ m higher than now from the first through tenth centuries (Froede 2002).
http://ecology.com/ecology-today/2009/01/09/ocean-level-expected-to-rise-faster-than-previously-predicted-ice-sheets-will-melt-faster/
http://people.rses.anu.edu.au/lambeck_k/pdf/237.pdf
Israel
During the detailed excavations of ancient Caesarea, Israel, East Mediterranean, 64 coastal water wells have been examined
that date from the early Roman period (with the oldest occurring in the 1st century AD), up to the end of the Crusader period
(mid-13th century AD). The depths of these coastal water wells establish the position of the ancient water table and therefore the
position of sea level for the first century AD up to 1300 AD. The connection between the coastal water table and changes in sea
level has been established from modern observations in several wells on time scales of days and months and this is used to
reconstruct sea level during historical time. The results indicate that during the Byzantine period, sea level at Caesarea was
higher by about 30 cm than today.
http://books.google.co.uk/books?id=eBwQzsBTWWAC&pg=PA114&lpg=PA114&dq=rising+sea+levels+in+the+12th+century&source=bl&ots=KyZhabZa_Z&sig=-7es_kab48FTmL_GgbzbLr_hAPI&hl=en&ei=2hOMTObrA4_f4gbH29XnCg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBsQ6AEwAThk#v=onepage&q&f=false
page 114
I don’t know why you are trying to refute what is well referenced. I suppose the same motivation as when Max tries in vain to demonstrate the reality of the MWP by posting dozens of links on that subject.
It was at times warmer in the past. As a result sea levels rose. The IPCC took very poor measurements from a few tidal gauges to which they stuck on unreliable satellite data. I show you chapter and verse where this was done but you won’t read the links.
Personally I also went on numerous field trips to such as Beaumaris, Pevensey and Beaumaris castles to help dig out the evidence.
tonyb
Tonyb
TonyB,
Look, what I’m looking for is a link
something like this
http://www.nature.com/climate/2010/1004/full/climate.2010.29.html
which shows the scientific evidence which you say is there. I’m not particularly interested in what some bloke who happens to live on the Sefton Coast thinks may, or may not, have occurred there several hundred years ago.
Peter #1747
Clue to the pedigree of the links
physorg
science daily
rye museum
academic emporia
ecology.com
Israeli govt funded study
Various govt funded local organisations tasked with scientifically researching their local area using the professional input of academics and archaeologists.
You said;
“I’m not particularly interested in what some bloke who happens to live on the Sefton Coast thinks may, or may not, have occurred there several hundred years ago.”
Proving yet again that you don’t bother to read any links you dont like, the ‘bloke’ from Sefton in whom you have no interest is the highly respected Dr Jennifer Lewis who has referenced over 100 academic studies in order to write her piece.
http://www.seftoncoast.org.uk/hist_biblio.html
People like Dr Axel Morner, Hubert Lamb and recently Brian Fagan, Al Gore, Dr Ian Stewart and many others have travelled the world looking for evidence of climate change in all its myriad forms, whether to indicate cooling, warming, or flooding.The latter three are hard core warmists who have no interest in exaggerating past climate change. We lose sight that they are trying to draw attention to climate change in the past as a warning to what we may do in the future, they are not in denial as to what has happened.
I think we are up to 45 links. All of these reference exactly what you say you are looking for but still you try to change the rules of the game and disqualify those you don’t like.
I don’t know how many links you want or how specific you want them to be? Ones that don’t use any vowels? Studies that have authors beginning with the letter ‘J’ ? As you have just amply demonstrated you won’t read any of them anyway.
Your own link from Dr Jeff Masters (a meteorologist and warmist) confirms what I say about two specific periods of sea level rise with a useful graph which I have also previously referenced but you didn’t read. The records describe these rises as ‘inundations’ in as much they happened relatively quickly and were assisted by storm surges and according to the records substantial increases in temperature.
The Roman, MWP, and Elizabethan era seem to have been much stormier than today.
Your link with the graph says;
“The highest global sea level of the past 110,000 years likely occurred during the Medieval Warm Period of 1100 – 1200 A.D., when warm conditions similar to today’s climate caused the sea level to rise 5 – 8” (12 – 21 cm) higher than present. Image credit: Grinsted, A., J.C. Moore, and S. Jevrejeva, 2009, “Reconstructing sea level from paleo and projected temperatures 200 to 2100 AD”, Climate Dynamics, DOI 10.1007/s00382-008-0507-2, 06 January 2009.
As the author says these are ‘observed’ rises. Sea levels would change at different rates in different places and averages contain a wide range of estimates. You can’t get much more warmist than Brian Fagan who after worldwide study concluded it was up to half a metre. I am happy that we settle on around 30-50cm.
Perhaps we can move on now that you are accepting that such rises occurred. What I am trying to point you towards are the bold assertions made by the IPCC concerning the last 300 years from highly fragmented data from three gauges (all of which have moved) and their dogs breakfast of using a figure from 1900 using 20 NH and 2 SH gauges all of which but 7 had moved, and all of which had development affecting them. On to these scant records the IPCC tacked satellite records with an acknowledged high degree of error and tried to claim a global record with a high degree of accuracy.
As your author Dr Jeff Masters remarks; ‘according to the IPCC…’
So once again we have a catch 22 when we are referencing material from the very organisation we say has got it wrong and do not match our own observations.
Look at Chapter 5 and their caveats and the information concerning satellites. Holgate gave an authoritative study referenced above by myself and Max demonstrating the slow down in the last half of last century and a further slow down in more recent years.
We are in a period of change well within the bounds of previous epochs. All the big names on ‘your’ side acknowledge our past. I don’t know why you want to side with Dr Mann and refute the overwhelming evidence that contradicts his views.
I have no hope that you will read the links provided by Max and myself that demonstrate the assumptions and mistakes carried out by the IPCC in their cobbled together records.
Still at least you seem to be coming round to the idea that the weight of evidence concerning historic sea level rise is on my side and I can count Al Gore amongst my allies on this!
Look just either give me your best creditable scientific link or admit you haven’t got one!
PS Your link to the Sefton coast was written by John Houston not Dr Jennifer Lewis and contained no scientific references whatsoever!
Its just a waste of time trying to get any sense out you at all!