Guest post by Steven Goddard
One of the most cited “proofs” of global warming is that sea level is rising, as can be seen in the graph below.
http://sealevel.colorado.edu/current/sl_noib_global_sm.jpg
This is a nonsensical argument, because sea level would be rising even if temperatures were going down, as they have been since 2002. The main reason why sea level rises is because the equilibrium between glacial ice and temperature is out of balance, and has been for the last 20,000 years.
http://www.globalwarmingart.com/wiki/Image:Post-Glacial_Sea_Level_png
Note that from 15,000 years ago to 8,000 years ago, sea level rose about 14mm/year – which is more than four times faster than the current rise rate of 3.3mm/year, as reported by the University of Colorado. During the last ice age, sea level was so low that people were able to walk from Siberia to Alaska across the Bering Strait. One of the more stunning pieces of evidence of this is the remarkable similarity of appearance and culture between the indigenous peoples of Eastern Siberia and North America.
In 2002, the BBC reported that a submerged city was found off the coast of India, 36 meters below sea level. This was long before the Hummer or coal fired power plant was invented. It is quite likely that low lying coastal areas will continue to get submerged, just as they have been for the last 20,000 years. During the last ice age, thick glaciers covered all of Canada and several states in the US, as well as all of Northern Europe. As that ice melts, the water flows into the ocean and raises sea level.
http://uk.encarta.msn.com/media_461527006/ice_extent_during_the_last_ice_age.html
The IPCC has stated that sea level may rise two meters this century, which would be a rate of 22mm/year, nearly seven times faster than current rates. Do we see such an acceleration? The simple answer is no. There has been very little change in sea level rise rates over the last 100 years, certainly nothing close to the immediate 7X acceleration which would be required to hit 2 meters.
Sea level is rising, and the abuse of this information is one of the most flagrantly clueless mantras of the alarmist community.
Even if we returned to a green utopian age, sea level would continue to rise at about the same rate – just as has done since the last glacial maximum.
Even a blind blond can see that first chart works better as a CURVE, closer in shape to the second chart, than as a straight line.
However, it’s more in line with the concensus to use that straight, scarey line.
What? The sea level is rising no faster that Solar Cycle 24?
Indeed, I can go visit my favorite places on the seashore, and I cannot tell you that even a half of a foot has gone under over the span of 50 years.
Eight inches rise since 1880.
Imagine that.
In my lifetime the sea has risen 3-1/8″. Wow.
Los Angeles’ Basin’s graben must be going down faster than that.
Catastrophic.
Unbeleiveable.
Oh dear, the top graph looks like the sea is dropping.
Hey, now is the time to invest in that hot beachfront property that extends out to sea that’s cheap because the water is too close.
Your neigbors to landward will be kicking themselves.
Other sealevel references at this post.
http://solarcycle24com.proboards106.com/index.cgi?board=globalwarming&action=display&thread=459
is there any more comprehensive data around than the 23 tide gauge records selected by the ipcc ?
is the satelitte raw data still flat and the slope still “corrected” from the tide gauge records (without annotating this in the grapics) ?
I am not sure that the sea levels are all that constant. According to The Indian National Institute of Oceanography the tidal gauge at Mombai, which has been recording water levels since 1875, does not show that trend.
Sea-level variability at Mumbai, which has the only more-than-century-long sea-level record in the Indian Ocean. Annual sea level (cm) is plotted as a function of time to reveal the variability of the annual sea level over the length of the data record (1878 to 1988 in this figure) (red), showing the inter-annual variability in sea level at Mumbai. Filtering annual sea level with a 10-year boxcar filter (10-year running mean) (blue) reveals inter-decadal variations. At Mumbai, these inter-decadal variations are as large as are the variations from year to year.
(If the image doesn’t come through I write about it here .
In the Bristol Channel between England and Wales, sea level varies by nearly 50 feet between high and low tide. Incoming high tides make a wave that people surf on. People there are smart enough not to build their homes on the mud flats.
I wonder if it is worth spending trillions of dollars in a vain attempt to save a few villages on Pacific Islands?
Does anyone else remember the Gilligan’s Island episode where the Professor determines that the island is sinking… and SO rapidly that they had only days to prepare. At the end of the episode it turned out that Gilligan had been moving the stick that the Professor was using as a sea-level indicator.
Somehow, every time I hear these Global Warming / Climate Change / Sinking Island / Rising Seawater stories, I flash back to that episode of Gilligan’s Island… and this is how I keep it all in perspective.
In 2002, the BBC reported that a submerged city was found off the coast of India, 36 meters below sea level.
That city would be more than 8 thousand years old if your graph 2 is correct Steven!
The BBC Time Team also reported on bronze age settlements on the floor of the North Sea off Dogger Bank from a similar period, so the indian city isn’t an isolated instance which could be written off as a ‘local’ phenomenon due to subduction either.
The level of historical ignorance in the alarmist community beggars belief. They look at 100 years of sea level change and extrapolate doom on the basis of a spurious co2 correlation. Talk about cherry picking data!
I have been doing a lot of reading on sea level rise and while I think IPCC’s temperature predictions are an exaggeration, they may be underpredicting sea level rise. They’re 2007 report states the best confidence interval at 8-17 inches and wider interval at 7-24″. From everything I am reading, a better estimate would be 10-35″ by 2100. There is a lot of uncertainty in the field of glaciology and it is very possible that melt will accelerate. Modeling indicates Greenland and west antarctica will accelerate melting. Don’t get me wrong, I agree 2m is not possible and I think 1.8C-4.0C is highly unlikely (from everything I’ve read on here and elsewhere I believe .5-1.5C to be the correct range for 2100). But I do think it is likely melting rates will accelerate beyond the 3mm of SLR/year we have seen so far. Read up on some scientific articles (but as always avoid anything by Hansen).
If sea level were to rise 2 meters (6 feet) in this century, the level would then be the same as it was 5000 years ago during the Climatic Optimum when fauna inhabiting the present Sahara Desert included hippos and cattle.
This does not deny a human role in modern global warming, but does imply that natural warming has occurred in the past on the same scale as projected by the models used to support IPCC recommendations.
If the causes of recent sea level rise are natural, then it is likely that money would be better spent in mitigating the effects of sea level rise than in trying to stop the inevitable. Phasing of mitigation efforts over a long period would also reduce the net present value of the costs and thus their adverse economic impacts.
References:
The Hanabuth Curve, Hanebuth T, et al. (2000). Rapid flooding of the Sunda Shelf – a late-glacial sea-level record. Science, 288: 1033-1035.
URL: http://www.geoscience-environment.com/es551/back_ground.html#quaternary
Topographic evidence for Quaternary sea-level change
Ara Valley, Penang Island, Malaysia , URL: http://www.geoscience-environment.com/ge703/index_sungai_ara.html
Steven Goddard (22:31:05) :
We’ve spent trillions of dollars in a vain attempt to save a few banks.
What difference does it make?
Today Obama announced the saving of 25 jobs in Columbus, Ohio. As we have spent some three trillion dollars on various bailouts, that works out to about $120 billion per job. See http://www.nytimes.com/2009/03/07/us/politics/07obama.html.
I’m tempering my enthusiasm for this heartwarming and cheering information with the following observation made in the article:
Or, you could just look at the $787 billion on the latest bailout signed here in Denver. Then, each job in Columbus, Ohio cost us only $31.48 billion per job.
Similar calculations need to be run on the carbon-free, alternative energy jobs about to be generated with a carbon cap and trade program being proposed now.
Cheers to all.
The pre-historic civilisations in India are now quite well-known, the Harrapan dates back to c 3300BC, the discoveries in the Gulf of Cambay are contentious, relying on sonar scans and a few pieces of wood dated to c 7500BC
http://en.wikipedia.org/wiki/Ruins_in_the_Gulf_of_Cambay
(OK, it’s Wiki, so not the most reliable of sources!)
Items of terrestrial origin are regularly dredged up from the North Sea, worked flints, Mammoth bones etc. http://news.bbc.co.uk/1/hi/sci/tech/7735544.stm
Steven Goddard (22:31:05) :
Remember that all those threatened Pacific islands have a maximum elevation of about four metres or so because they are made of coral. (The volcanic ones can be several thousand metres high but even the pinkogreenpeaceecofreaks haven’t quite got the nerve to claim that they are threatened). As far as I’m aware there are neither coral islands a couple of hundred feet high nor very many shoals a couple of hundred metres deep (yes, there are some flat-topped seamounts, but surprisingly few). We therefore have to postulate a huge population of flat-topped islands during the last glaciation with a uniform height of about 120m, and virtually nothing 100m or 150m high. Doesn’t sound very likely, does it?
Perhaps a more realistic view might be that coral islands can happily keep up with rises of sea level at rates of metres per century but will never manage to grow more than a couple of metres above the ambient sea level for fairly obvious reasons.
Remember King Canute! (or Knut if you prefer)
Steven,
Further to your reference to a suberged Indian city, and the above posts referring to Dogger Bank and fossils dredged from the North Sea.
I have always accepted reports that the English Channel covers large salt flats, ancient forests and entire river systems at about 20m depth. these included reports that the UK was recently connected to the mainland European continent. This was given as explanation for wolves, bears and wild pigs (now hunted to extinction) on this island, now separated from the mainland continent by about 20 miles of open water.
Nice short video here by Wessex Archaeology here:
Infio: “Archaeologists have created a 3D visualisation of a whole prehistoric landscape now submerged 20 metres under the English Channel, and 8 miles off the West Sussex coast. This is how we believe it may have looked over 8000 years ago, based upon environmental and geophysical surveys; an estuary populated by families living from the river, sea and land; a river surrounded by salt marsh and forest.”
More on the video author:
http://www.wessexarch.co.uk/about
You can get more up-to-date sea level data to the end of 2008 from Aviso (which has been operating the Jason-1 and Jason-2 satellites during the calibration period).
Sea level at the end of 2005 is still the highest.
http://www.aviso.oceanobs.com/fileadmin/images/news/indic/msl/MSL_Serie_J1_Global_NoIB_RWT_PGR_NoAdjust.png
There are quite different results however when one uses the different algorithms to remove the seasonal signal and for the inverse barometer correction.
Does anyone have links to parts 1 and 2? — John M Reynolds
Jordan (02:37:28) :
Steven,
Further to your reference to a suberged Indian city, and the above posts referring to Dogger Bank and fossils dredged from the North Sea…
There was also a program the BBC did about an island (one of the Scilly Isles off Cornwall) where there are many bronze age burials, but little room for farming. A hill connected by an isthmus to the mainland makes more sense as a burial site.
Fred Colbourne,
The reason why sea level rose quickly 5,000 years ago, was because there was a lot of ice to melt at lower latitudes and altitudes. Almost all of the remaining ice is at locations where the temperature never gets above freezing. The average altitude of the ice surface in Greenland and Antarctica is close to 10,000 feet. Little ice is going to melt at those high latitudes and altitudes, and in fact is accumulating rather than declining.
There are also underwater ruins off the coast of Yonaguni, an Okinawan Island just east of Taiwan, submerged in up to 25 meters of water. There is still controversy as to whether they are natural or manmade (judging from the photos and being a geologist, I tend to go with the manmade theory). The ruins are estimated to be around 5,000 years old. Another question not answered yet is whether these so-called ruins are the result of tectonic activity or were originally at that depth and rising ocean levels covered them. There are also ruins discovered off the coast of the main island of Okinawa at approximately the same depth which suggests to me that they were covered by sea level rise. The jury is still out on this one.
Another important point for why sea level rises during interglacial periods is glacial rebound. Basically, the weight of the ice depresses the earth’s crust during continental glaciations. Because the crust is rigid, that downward flex also depresses the adjacent ocean basins. Once the ice melts, the crust “rebounds back”- like a spring – thus decreasing ocean basin volumes along the edge of the basins & driving a small, long period increase in sea level. Thats a significant factor in why sea level is still rising even though the ice has long since melted. On the second plot of the post, you can see the long slow rising tail from 8000 years to present – that’s from the rebound effect. This tail is not well correlated with the temperature history, so this is not , in general, thermal expansion (although there would be a thermal expansion / contraction component of a shorter periodicity layered on.
See wiki on the subject – it is a pretty reasonable summary :
http://en.wikipedia.org/wiki/Post-glacial_rebound
To their credit (and maybe because few outside the geologic world have knowledge of the subject) , in the Global Warming section of this wiki entry, they actually recognize the significance of separating out the rebound signal & call it the most significant factor:
“Thus, to understand global warming from sea level change, one must be able to separate all these factors, especially postglacial rebound, since it is one of the leading factors.”
I am reticent to even post this as it may draw attention to it from some AGW self appointed wiki-editor who will change the entry, but these are the geologic facts – establish before any science associated with GW was corrupted by political agendas. Let’s watch & see if it does get edited. That will say a lot about the AGW crowd (although it certainly wouldn’t be surprising).
As I have said before, there is far too little geological input into the debate. Outside of climatologist, geologists have some of the most important data & perspective to offer on the debate.
Steven,
The background sea-level rise can be extracted from http://www.globalwarmingart.com/images/1/1e/Holocene_Sea_Level.png. The fit on this plot is shown as currently flat, but there is considerable scatter in the data. At a stretch the rate over the last six thousand years might be at most a rise of 1m/millennium. Hence the satellite-derived current rate of 3.3+/-0.4 m a year is at least three times the background level, and probably many more times larger.
Your basic geology seems to be letting you down here.
Jeff L,
Not sure I buy the glacial rebound theory wrt average global sea level. When the crust depresses into the mantle due to the weight of overlying glacial ice, it has to rise somewhere else. Remember that the weight of the oceans have the same effect of depressing the sea floor. The total amount of sea water decreases during ice ages, causing the sea floor to rise. Averaged out over the earth, it should be a wash.
Tom P,
The scarcity of data and standard deviation of the Holocene sea level graph you linked are much too large to make any meaningful conclusions about the “background .” This one is much better.
http://www.globalwarmingart.com/images/thumb/0/0f/Recent_Sea_Level_Rise.png/700px-Recent_Sea_Level_Rise.png
Tom P.,
Hence the satellite-derived current rate of 3.3+/-0.4 m a year is at least three times the background level…
That should read mm/year otherwise that would be a 3,000 fold increase over background.
Steven,
I don’t think you can establish a natural background prior to any possible anthropogenic contribution by looking at the data from 1880 to the present. The Holocene sea-level rise rate dropped dramatically 7000 years ago from 14mm/year to 0.4+/-0.4 mm/year. I see no justification for comparing the current rate of sea-level rise of 3.3mm/year to the rate before 7000 years ago when there is just an accurate rate that can be used for the last few thousand years.
The plots you show contradict the point you are trying to make.
Tom P,
I looked closer at the Holocene graph you linked and thought it needs further comment. The drawn linear inflection point at 2,000 YBP is complete statistical nonsense. That is the kind of garbage which keeps AGW alarmism alive.
Tom P (07:32:57) :
Steven,
The background sea-level rise can be extracted from http://www.globalwarmingart.com/images/1/1e/Holocene_Sea_Level.png. The fit on this plot is shown as currently flat, but there is considerable scatter in the data. At a stretch the rate over the last six thousand years might be at most a rise of 1m/millennium.
And the explanation for those sunken cities and settlements is?
Which do you trust more – proxy reconstructions or concrete archeological evidence?
Your basic logic seems to be letting you down here.
To anyone interested in sea level changes and global lithospheric response, this paper is a must read and still a reference today:
J.A. Clark, W.E. Farrell and W.R. Peltier, Global Changes in Postglacial Sea Level_ a Numerical Calculation, Quaternary Research, 9, 265-287, 1978
Fascinating discussion – I keep following all the links and have managed to avoid my real work for about 4 hours as a result.
As a dam designer/hydro engineer, I have worked with many of the best engineering and pure geologists in the world.
I do not know any geologist who is an “alarmist”, although there are some who concede that CO2 may me marginally contributing to the warming seen over the past 200 years.
I thank my geologist colleagues for imparting to me a better understanding of processes and enabling me to reserve judgement on the AGW hysteria.
It’s tempting to think of that (comparitively) sudden rise in sea level as the source of the flood legends.
A bit of historical fiction that features a different sea level for the English Channel is The Forest by Edward Rutherford.
The town I grew up in, where my grandparents have lived for over 90 years, has a section of fill and lagoons that is at sea level. The waves still arch over the sea wall only in really big storms at peak high tide and the one low bit of roadway floods only at those times. We have always joked about what will happen when the glaciers melt, but so far the empirical evidence, for our town anyway, is that sea level isn’t changing much.
Steven Goddard (07:57:49) :
The Earth has some elastic compressibility, so it doesn’t necessarily have to rise else where if you depress it in one spot. You are correct in pointing out the decreased mass of the ocean, but it is spread out over the entire ocean (roughly 3/4 of the earth) vs concentrated in ice in smaller areas. This change in stress is diffused over a large area, so the relative effect isn’t as great. Also, you are dealing with oceanic crust vs continental crust, which the most significant factor. Ice is is loading continental crust & lower ocean levels are de-loading oceanic crust. Continental crust is far more buoyant on the mantle than ocean crust (which of course is why ocean basins are low points on Earth start with). Because oceanic crust is less buoyant, changing the load on it has less spring effect on it & vice versa. So, in short, it is not a wash due to non-homegeneous properties of the earth (compositionally & aerially) & the elastic properties of the earth.
Sea levels are a fluid affair (pun intended) and a rise in one place is often matched by a fall in another, so information has to be heavily averaged, smoothed, interpreted, interpolated, sent through all sorts of computer models and emerges as pretty useless.
There are some obvious factors that need to be considered, such as a high or low pressure weather system at time of measuring, together with the state of the tide-both within its twice daily cycle and also within the longer lunar cycle. Add waves of varying sizes and thermal expansion, and it becomes extremely difficult to measure to the ocean surface-wherever that may be at any one time.
Satellite drift and the averaging already mentioned create further problems and account must be taken of obstructions such as new docks, build up of sand bars, the nature of the sea bed and the stasis of the land-is it rising, falling, or static?
Officially satellites are accurate to within plus or minus 3cm or so (yes 30-50mm) unofficially probably double that level of inaccuracy which is all smoothed out of the final data.
The following sites give a good description of the process-which is being constantly refined but doesn’t get more accurate as the inherent flaws in measuring capabilities can’t be resolved.
http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/15_1/15_1_jacobs_et_al.pdf
http://jchemed.chem.wisc.edu/Journal/Issues/1999/dec/abs1635.html
The following site deals with problems of the data;
http://www.climateaudit.org/?p=859
This with reliability
http://lightblueline.org/satellite-tracking-sea-levels-set-launch
The UK Environment Agency like to use physical tide gauges as well, which are both visually observed or can send data electronically. Best of all is gathering information from local people such as the Harbour master or those who work the fishing boats as they know what the sea height is doing (generally nothing much)
Sea level rises are being hugely exaggerated. In many places they are actually falling as per Newlyn UK.
http://tidesandcurrents.noaa.gov/sltrends/resids/170-161.gif
and Helsinki. http://tidesandcurrents.noaa.gov/sltrends/resids/060-351.gif
and generally around the Baltic coast.
Others are rising modestly- so the two above are cherry picked as illustrations- but show the rises and falls over decades rather well.
The worlds leading sea level expert Professor Morner has called the IPCC figures ‘a lie.’
The following link leads to a graph produced by the Dutch Govt sea level organisation-the Dutch certainly know a thing or two about the subject and confirm sea levels are stable and are somewhat lower now than during the MWP.
http://www.climateaudit.org/?p=61
This is confirmed by various UK studies-allowing for the various factors mentioned- such as the research done on the entrances to British castles which could formerly be accessed by sea when first built, higher rivers which the Vikings used to their advantage in sacking inland cities in Europe, old battle sites etc.
TonyB
From the IPCC:
“Geological observations indicate that during the last 2,000 years (i.e., before the recent rise recorded by tide gauges), sea level change was small, with an average rate of only 0.0 to 0.2 mm yr–1 (see Section 6.4.3). The use of proxy sea level data from archaeological sources is well established in the
Mediterranean. Oscillations in sea level from 2,000 to 100 yr before present did not exceed ±0.25 m, based on the Roman-Byzantine-Crusader well data (Sivan et al., 2004). Many Roman and Greek constructions are relatable to the level of the sea. Based on sea level data derived from Roman fish ponds, which are considered to be a particularly reliable source of such information, together with nearby tide gauge records, Lambeck et al. (2004) concluded that the onset of the modern sea level rise occurred between 1850 and 1950. Donnelly et al. (2004) and Gehrels et al. (2004), employing geological data from Connecticut, Maine and Nova Scotia salt-marshes together with nearby tide gauge records, demonstrated that the sea level rise observed during the 20th century was in excess of that averaged over the previous several centuries.
The joint interpretation of the geological observations, the longest instrumental records and the current rate of sea level rise for the 20th century gives a clear indication that the rate of sea level rise has increased between the mid-19th and the mid-20th centuries.”
So, before you can claim that “sea level would continue to rise at about the same rate – just as has done since the last glacial maximum” you have to show why you think the IPCC is wrong about sea level rise rates for the last 2 millennia. The last 100 years _have_ been anomalous in the past several thousand.
“The IPCC has stated that sea level may rise two meters this century”: Really? I thought the IPCC upper bound was 59 cm, plus possible additional amounts from dynamical changes in ice sheet flow that they chose not to quantify. Other authors have hypothesized a possible 2 meter rise – Pfeffer et al, for example, got 2 meters if they assumed that every dynamical uncertainty was resolved in the pessimistic direction, 80 cm with more reasonable assumptions.
In any case, pretty basic physics indicates that _IF_ temperatures increase, the rate of sea level rise will increase compared to the case without temperature increases. I suggest that you go back and restudy some of your “Basic Geology”.
So you state that “abuse of this information is one of the most flagrantly clueless mantras of the alarmist community” and then you draw your own conclusions from HALF A CYCLE of data?
You also state that “There has been very little change in sea level rise rates over the last 100 years” referring to the Recent Sea Level Rise chart. However comparing the first 60 years (~5 cm rise) to the next 60 years (~15 cm rise) tells a different story.
Have you ever shared your scientific credentials with us? Other than your “guest posts” here, all I can find through Google are a few climate posts on a UK technology site that appear to conclude with a retraction. (I happen to have a B.Sc. in Geology from the University of Toronto.)
ps. Tallbloke: “And the explanation for those sunken cities and settlements is? Which do you trust more – proxy reconstructions or concrete archeological evidence? Your basic logic seems to be letting you down here.”
If you read the BBC news piece, it notes that the sunken city is dated to more than 9000 years in the past. Basic logic can be applied to show that a claim of <1 mm rise for the last several thousand years can be perfectly consistent with your concrete archeological evidence if your concrete evidence comes during the time period that alarmists and skeptics alike agree was having extremely large SLR changes.
Er. That should have been <1 mm rise/year, not <1 mm rise absolute in my last post.
Jeff L,
The density of the continental crust vs. oceanic crust shouldn’t make any difference to this analysis, because it is changes in water thickness, not crust thickness we are talking about.. The total weight of water is more or less fixed, whether in solid or liquid state, and will on average have the same net global effect on compressing the mantle, regardless of the particular distribution of ice at the time.
Marcus,
You might want to check your math. The city is currently 36,000 mm below sea level. Over 9,000 years that averages to 4mm/year.
Steven Goddard:
The seal level is still slowly rising, because the planet is still emerging from the last Ice Age. AGW has nothing to do with it. That is made clear by the failure of AGW proponents to provide any real evidence showing that AGW causes the sea level to rise.
Steven,
You state:
“The drawn linear inflection point at 2,000 YBP is complete statistical nonsense. That is the kind of garbage which keeps AGW alarmism alive.”
I’m not using the trend line to make my point, but the data points to derive my upwards slope of 0.4+/-0.4. There is no statistical basis for plotting a line of 3.3+/-0.3mm a year through the data. If you think there is, perhaps you could show the plot. You actually have posted, without obviously realising it, one of the strongest pieces of evidence for an anthropogenic warming, a rapidly increasing sea level for the last one hundred years way beyond anything seen in the last 7000 years.
Tallbloke,
You state: “And the explanation for those sunken cities and settlements is?
Which do you trust more – proxy reconstructions or concrete archeological evidence?
Your basic logic seems to be letting you down here.”
If the data that Steven published can’t be trusted, why do you think he posted it? He thought it proved his point – and you certainly didn’t express any doubts about the data until I pointed out it actually indicated the exact opposite.
Robert Woods says:
You might be tempted to think so. I think it more likely that those legends are a result of the Sea of Marmara breaching the Bosphorous around 5600BCE.
Tom P says:
What is the mechanism? How is anthropogenic warming connected to sea warming.
Ben Lawson,
Over the past 100 years, going back to the invention of the automobile, sea level has risen at an average rate of 2mm/year, pretty close to current rise rates of 2.4mm/year as reported by Aviso, and much less than the average during the interglacial.
http://www.globalwarmingart.com/images/thumb/0/0f/Recent_Sea_Level_Rise.png/700px-Recent_Sea_Level_Rise.png
http://www.aviso.oceanobs.com/fileadmin/images/news/indic/msl/MSL_Serie_J1_Global_NoIB_RWT_PGR_NoAdjust.png
I have B.S. in Geology and many years professional experience. Are you trying to suggest that sea level has not risen nearly continuously since the peak of the last ice? Good luck with that theory, geologist. My advice is don’t write a paper on it.
http://www.globalwarmingart.com/wiki/Image:Post-Glacial_Sea_Level_png
Steven,
You state “You might want to check your math. The city is currently 36,000 mm below sea level. Over 9,000 years that averages to 4mm/year.”
You might want to check your plot – this city’s 36m depth sits right on the sea-level data trend you posted. And that data shows the rate slowing to well below 4mm/year 7,000 years ago. To derive your linear trend value from a single data point you have to ignore the very data you presented.
Tom P:
Wrong.
Sea levels are not currently rising: click
That statement is confirmed by the leading international expert on sea level changes: click
If the sea level was actually rising faster than average since the last Ice Age — or even rising noticeably — there would be confirmation by endless front page, above the fold news reports.
The fact that the mainstream media isn’t red faced, spittle-flecked and arm waving over the sea level tells you all you need to know about it.
[For a gif showing sea level anomalies from 1997 through 2008: click. Notice that except for the unusually warm 1997/98, the sea level during most years has been flat to declining.]
Tom P,
State something specific or cut the ad hominem attacks.
CO2 levels have only been rapidly increasing for the last 50 years or so. Don’t try to blame rates from 100 years ago on your neighbor’s Hummer.
Sea level normally goes down at the beginning of the year. Data from the first image from colorado.edu used to be available in almost real-time in the past, but now it lags behind. Is something not being shown?
Another interesting question is where was the sea in the Medieval Warm Period. We have empirical evidence in Portugal where history might put the sea some 3/4 metres above what it is today. If someone has got issues/ideas to exchange on this domain, please email me.
Ecotretas
Steven,
“State something specific or cut the ad hominem attacks.”
My criticism is very much ad verecundiam – and your response is to accuse me of ad hominem attacks! I’d rather you responded to the very specific point I’ve made:
Where is the evidence in the plots you present that the trend in the last seven thousand years is much more than 0.6 mm/year, way below the current trend of 3.3 mm/year?
Tom P,
The graph you linked shows periods when sea level rose quickly and slowly over the last 8,000 years. Did global warming cause sea level to rise 15 meters from 8,000 to 7,000 years ago? Sea level rose quickly from 3,000 to 2,000 years ago. Was that caused by Hummers? From 1900 to 1950, sea level rose at 2mm/year – similar to current levels, yet that was before most of the rise in CO2 levels.
But the really astonishing thing is that you are willing to accept the IPCC claims of 10-20cm/year, yet you quibble over noise in the 1-3mm range. That is why I describe the thought process as “astonishingly clueless.”
You said the data is posted “can’t be trusted.” Which data? But you trust the IPCC when they claim 2,000mm/century? Give me a break.
and “IPCC claims of 10-20mm/year” instead of “IPCC claims of 10-20cm/year”
Sea level in Hawaii has hardly risen at all since 1980, and since 1950 only at 1.5mm.year.
http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=1611400
“I have B.S. in Geology and many years professional experience.” I think it’s reasonable to expect something a bit more specific.
“Are you trying to suggest that sea level has not risen nearly continuously since the peak of the last ice? Good luck with that theory” You’re trying to put words into my mouth. My unanswered criticism is that you are drawing conclusions using only half a cycle of data. As far as the limited data you present here, I see an uncontroversial sea level increase that came to practical end somewhere around 6000 years ago.
“My advice is don’t write a paper on it.” Apparently you take your own advice to heart.
Steven,
The rise up to 7,000 years ago was obviously the last part of the melt from the previous ice age caused by naturally induced global warming. From 7,000 onwards there is in comparison no rapid increase. The trend line from 3,000 to 2,000 years ago is about 1mm/year, the trend to present is 0mm/year, both less than the current 3.3mm/year. I’m actually rather surprised you’re paying any attention to the trend line, which you previously dismissed.
Where have I stated I’m willing to accept IPCC claims of 10-20cm/year, if indeed such claims have ever been made? I am concentrating solely on the data you have presented, with a current trend of 3.3 mm/year. Why do you now consider 3.3mm/year as noise? It certainly seems a clear trend from the first plot you presented, and indeed you presented it as such in your original posting:
“Note that from 15,000 years ago to 8,000 years ago, sea level rose about 14mm/year – which is more than four times faster than the current rise rate of 3.3mm/year, as reported by the University of Colorado.”
Finally, I most certainly didn’t say the data couldn’t be trusted – that was what Tallbloke implied when he wrote:
“Which do you trust more – proxy reconstructions or concrete archeological evidence?”
This is a false choice – I have no reason to doubt either as they are consistent with each other and imply the sea level was rising over the last 7,000 years far slower than the last 100 years.
Tom P,
The sea level rise rates have varied considerably over the last 7,000 years – sometimes fast and sometimes slow – just as the global temperature has varied greatly over that time. There is no valid reason to compare the 7,000 average vs a time frame as short as 100 years, as there is a significant degree of variability shown during the 7,000 year period.
Given that rates haven’t changed much from the first half of the twentieth century, it is going to be very difficult for you to construct an argument that CO2 has anything to do with the current rise rates.
So why aren’t you criticizing the IPCC for their claims?
Global warming hero Dr. James Hansen said-
As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.
http://www.newscientist.com/article/mg19526141.600
That claim is more than 55mm/year, coming from the world’s most respected climatologist.
Ben Lawson,
The article uses graphs covering three time frames. 20,000 years, 100 years and 15 years. They all show that Hansen’s claims of 5mm by 2095 (55mm/year) are absurd, as is your claim that I am only considering “half a cycle.” This article is about the interglacial, which started 15,000 or so years ago. I have considered the entire period in some detail.
Steven,
You state: “There is no valid reason to compare the 7,000 average vs a time frame as short as 100 years.”
But that is EXACTLY what you did in your original post:
“Note that from 15,000 years ago to 8,000 years ago, sea level rose about 14mm/year – which is more than four times faster than the current rise rate of 3.3mm/year, as reported by the University of Colorado.”
All I did was derive the most recent trend for the last 7,000 years of 0.4+/-0.4 mm a year. Why is the trend from 15,000 to 8,000 years ago valid, while the trend from 7,000 to present invalid?
Smokey,
US tidal gauge figures are here,
http://upload.wikimedia.org/wikipedia/en/7/7f/U._S._Sea_Level_Trends_1900-2003.gif
and don’t support your view that on average the sea level around the US isn’t rising.
Of course the clear trend of the global satellite data is the basis for Steven’s post. Why do you reject the data he presented?
There’s actually been plenty of coverage about rising sea levels in the press – I’m surprised you missed it.
Tom P,
Who to believe, the NOAA, or Wikipedia?
The gif above comes from the NOAA. Complain to them if you think it’s inaccurate. Also, I don’t reject Steven Goddard’s data. Take your best guess about what I meant by “currently.”
In either case, it’s a silly argument. Any sea level rise is well within normal, historical parameters since the last Ice Age, and can not be attributed to AGW unless the well established theory of natural climate change is falsified.
So let’s just cut to the chase: are you claiming that a rise in CO2 causes a rise in the sea level?
Tom P,
Because 2 mm/year is within the range of variability for the last 7,000 years, but much lower than that from the period from 15,000 to 7,000 years ago.
Again, why are you quibbling over 1-2mm when the IPCC claims are an order of magnitude higher?
Smokey,
The sea level is currently not rising here in Texas. And the trends are between one and two feet per year rise per one hundred years. Might not be a bad idea for all you east and west coasters to move on down here to Texas. You may not know it, but we still have the right to life, liberty and the pursuit of happiness down here. Besides real estate is pretty cheap right now and we could use all the sane people we can get.
No, I don’t belong to the chamber of commerce. I just feel that the more producers we have down here the better off we’ll be. Oh yeah no income tax down here either.
Mike Bryant
Oops i meant one to two feet per one hundred years…
Mike Bryant,
How are the fire ants these days? Texas is a great state with probably the most sane populace, but 20 years ago the kids couldn’t go to the lake without getting attacked, even swimming 100 feet offshore. Has that gotten better?
Smokey,
“Who to believe, the NOAA, or Wikipedia?”
The plots I gave came originated from a dataset maintained at the UK Proudman Oceanographic Laboratory. It’s very difficult to quantify the NOAA data in the animations you linked to. The trend data from NOAA is clearly presented here:
http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml and is in good agreement with the POL data, probably as they’re based on the same tidal-gauge measurements. I have no reason to doubt either of these datasets.
“Any sea level rise is well within normal, historical parameters since the last Ice Age.”
Certainly not according to the data Steven presented. The trend for the last 7000 years has been 0.4+/-0.4 mm/year. The current rate of 3.3+/-0.4 mm/year is indeed far outside the trend for the last 7000 years.
Jack Simmons (01:31:34) : Said,
“Today Obama announced the saving of 25 jobs in Columbus, Ohio. As we have spent some three trillion dollars on various bailouts, that works out to about $120 billion per job.”
Failing, of course to credit the new jobs generated in the Columbus Doughnut Industry! Give credit where credit is due.
The beach I hang out at is rising due to isostatic rebound from the last ice age.
You’d think that sea level was lowering if you did not know any better.
Ben
This file has reconstructed sea level data for about 50 places around the world over the last 14,000 years (most are only about 7,000 years).
The first column is Years Before Present, and the third column is the relative sea level rise over the period.
This data has NOT been corrected for glacial rebound, uplift or land subsidence but it should tell you that it is an absolute must to take this into account for every single tide gauge around the world (inlcuding very short timelines). There are some huge differences in the rates based on this (tens of metres over just a few thousand years).
The data shows most areas have had rising sea levels over the past 1,000 to 2,000 years as well as the 120M rise since the ice age ended.
In addition, the glaciers in northern Canada and Greenland did not melt completely until about 3,500 years ago so there was still a glacial melt contribution up to this date.
Tuktoyaktuk, NWT holds the record for -42M sea level change/reduction over the last 8,000 years (glacial rebound that is).
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleocean/relative_sea_level/sealevel.dat
Tom P,
You are playing games with the data. For the last eight years, temperatures have been declining at a rate of several degrees per century. Does that prove global cooling using your logic? Through the last 7,000 years, there have been centuries when sea level rose faster than the average and slower. For the last three years, sea level has hardly changed at all.
http://sealevel.colorado.edu/current/sl_noib_global_sm.jpg
The rate for the last 15 years (2.4 mm/century) is within the normal variation for the last 7,000 years, and much less than IPCC claims of 22mm/year and Hansen claims of 55mm/year.
BTW – the map you linked showed higher raise rates along the Gulf Coast, where the effect is due to subsidence caused by subsurface pumping.
From a State of New Jersey sea level study-
When the data from all New Jersey sites are examined together, a linear regression from at least 7500 yBP to present provides an excellent fit, suggesting a constant rate of sea level rise for approximately the past 7500 years.
http://www.state.nj.us/dep/dsr/climate/holocene.pdf
Comparison of our sea-level data with the Barbados/Western North
Atlantic reef sea-level record of Fairbanks (1989) shows (Fig. 5) that the reef data
indicate a major decrease in rate from 12 mm/y to ~ 2 mm/y between 7000 and 8000 yBP. Data from NJ (all sources) and the reefs are consistent with a constant rate of rise
http://www.state.nj.us/dep/dsr/climate/holocene.pdf
Interesting as discussions of sea level rate rises are, the thing to bear in mind is that sea level changes lag climate changes by long periods, and it is unlikely we are seeing a substantial contribution from recent warming (however much warming occured).
There are two main contributions to sea level rises.
1. Thermal expansion from warmer temperatures – about %70 of the total. While thermal expansion is an immediate result of water warming, how long it takes for seawaters to warm takes us into the warming in the pipeline discussion. Suffice it to say, average sea water temperature changes lag atmospheric temperature changes by decades.
2. Icesheet and Glacier melt. – somewhat less than %30 of the total. No one has an accurate measure of the sea level change from ice melt and it’s little more than a guess. Anyway, glacier and icesheet melt lags atmospheric temperatures changes by long perionds – hundreds to thousands of years. The most important contribution to current icesheet melting (however much is occuring) is likely the warming up to the Holocene Optimum 6,000 or so years ago.
The frequent claims of x amount of sea level rise this century if icesheet y melts are nonsense because of the huge thermal inertia of the ice volumes involved. Even if temperatures warmed dramatically it would take many hundreds if not thousands of years for these ice volumes to melt. And hence any sea level rise would take the same amount of time.
Which BTW is why you see so many reports of glaciers accelerating. The only plausible way of melting the icesheets and glaciers is to transport them to somewhere warmer and spread them out over a much larger area.
Philip_B,
Interesting comments you made about sea level rise. You say that 70% of sea level rise is due to thermal expansion? That would imply that nearly 300 feet of the 400 feet of sea level rise since the last ice age was due to thermal expansion. I don’t think that is going to fly, since global temperatures have been going down for the last 8,000 years and are about the same as they were 10,000 years ago – when sea level was 200 feet lower.
http://commons.wikimedia.org/wiki/File:Holocene_Temperature_Variations.png
You might also remember that a basic tenet of global warming is polar amplification, where the polar ice caps are supposed to heat up much faster than the rest of the earth.
What I am trying to do is to get people to think for themselves, rather than repeat AGW catchphrases.
Fire ants are still mean… But they are only in the water after a hard rain. They don’t attack unless you step on the antpile… More of an annoyance than anything else.
Philip_B (17:11:17)
“There are two main contributions to sea level rises.”
Perhaps climate driven sea level changes, but I would argue the greatest control on sea level is the rate of new ocean floor production. I suppose rates of sea floor spreading happen on much greater time scales.
Geologically “soon” you can expect to see some major changes in the rate of sea floor production in the Atlantic.
But good points none-the-less.
“There are two main contributions to sea level rise”.
No, there is a third more important reason and that is changing land level.
The data I linked to above shows that local land deformations outweigh the sea level rise due to thermal expansion and glacial melt by more than an order of magnitude.
If you are using the satellite data, presumably this is not a factor. But I have seen write-ups that say the satellite data is calibrated to local sea level gauges which are suspected to suffer from land subsidence.
So again, we are just back to square one (as we discovered with the NCEP humidity data as well.)
Steven Goddard (10:24:43) :
I am not just making this up & it is not my theory – it has been known & published in the geological literature for years. See :
http://www.homepage.montana.edu/~geol445/hyperglac/isostasy1/
See bottom of the page – note the relative size of marginal depression & forebulge – they are not equal as I stated before – due to the elastic nature of the deformation of the crust (vs the visco-elastic nature of the mantle)
See:
http://www.earthscape.org/t1/low01/low01d.html#hydroisostasy
Again – ocean basin deformation is not of equal magnitude to continental deformation (and continental shelf deformation – which does effect ocean volume) – as I stated before
See:
http://www.agu.org/books/gd/v001/001GDp0111/p00111-p00128.pdf
Look at figure 3 & how much large an area of the ocean basins were depressed – again because the lithosphere is rigid & that stress field is represented by a much wider strain field. All that ocean is rebounding & with a net decrease in ocean basin volume, driving a subtle world wide sea level rise of the last 8000 years, as seen in your graph. The shape of increased sea level is exponentially decreasing, just as the shape of isostatic rebound curves are exponentially decreasing.
As I said up front, this is not my theory – this is what the geologic data says. I hope you can appreciate that.
The 2002 BBC report has never been verified in any science write up.
Got a good, confirmed example? Cambay Bay isn’t a city under water.
Smokey: Try http://tidesandcurrents.noaa.gov/sltrends/sltrends.html for Sea Level Trends. The page you linked to shows sea level anomalies: “A sea level anomaly, as defined by NOAA’s National Ocean Service, occurs when the 5-month running average of the interannual variation is at least 0.1 meters (4 inches) greater than or less than the long-term trend. ” ie, the reason you don’t see any long-term sea level rise is because the long-term sea level rise has been detrended out!
Steven Goddard: Ok. So your State of New Jersey study disagrees with other studies. The other studies claim a “high rate” of sea level rise followed by a slowing at about 2500 year before present. I personally trust the IPCC collection of references more than a single New Jersey reference, but lets take your reference at face value:
They state that for the past 7000 years New Jersey has averaged 2 mm/year of rise – of which _half_ was subsidence, meaning that their best estimate for the last 7000 years was 1 mm/year. Therefore, the reference you cite concludes “Thus, human-induced effects on sea-level in New Jersey are 1-2 mm/year which is up to one-half of the total observed rate of sea level rise”.
So: have we seen long-term sea level rise at the current rate in the past several thousand years? If we believe the state of NJ, the answer is no, the past couple thousand year rate was half of current. If we believe the IPCC the answer is also no, it was 1/10th of current rates. Now, does sea level rise rate vary? Yes. Both on a decadal scale (eg Holgate et al., and the IPCC chapter too) and on a longer term scale. But the long-term variations of sea level rise occur on the same time scale as long-term variations in temperature. Therefore, IF CO2 can lead to temperature increases, then CO2 can lead to increased sea level rise. (Note that if some other factor leads to a temperature increase, that would also lead to sea level rise – no one is pretending that CO2 emissions are the _only_ thing that can cause SLR)
Finally, on the “70% of SLR is thermal expansion”: that is an estimate for _current_ sea level rise, and potentially, for sea level rise over the next century depending on what Greenland + Antarctica do. Yes, the immediate post-glacial period was dominated by ice sheet melt, but for the past decade we have various measures of G&IC and ice sheet mass loss, and they only add up to about 30% of SLR.
I suggest you actually read the IPCC chapters on sea level rise. You don’t have to take it all at face value, but you should at least try to be familiar and understand the logic behind the consensus statements before you toddle off into left field and make your own random statements about the “basic geology” of interglacial sea level rise.
ps. I still stand by my previous statement “Basic logic can be applied to show that a claim of <1 mm rise for the last several thousand years can be perfectly consistent with your concrete archeological evidence if your concrete evidence comes during the time period that alarmists and skeptics alike agree was having extremely large SLR changes.” Let’s try some simple logic: if we suppose that between 9000 and 6000 years ago sea level rose by about 30 meters (seems reasonable from your long term SLR graph), then between 6000 years ago and present sea level rose by <1 mm/year. Voila! Consistency!
Philip_B,
You say that 70% of sea level rise is due to thermal expansion? That would imply that nearly 300 feet of the 400 feet of sea level rise since the last ice age was due to thermal expansion.
I meant recent (last 100 years or so) sea level increases. The 70% contribution from thermal expansion is generally accepted. Although that doesn’t make it correct.
Anyway, my main point was that climate changes over the last 50 to 100 years have had little impact on recent sea level changes. So the whole discussion, while interesting, has little or nothing to do with AGW.
Similarly, claims of substantial sea level rises from melting icesheets have no scientific basis, without introducing extraordinary (IMHO) mechanisms to transport the ice somewhere warmer.
Benjamin P.,
As one ocean gets larger through sea floor spreading, another gets smaller through subduction. If this weren’t true, the area of continents would shrink over geological timescales and they don’t. Sea floor spreading per se has no longer term effect on sea levels and any shorter term effect could be in either direction, ie to raise or lower sea levels.
Bill Illis (18:56:46) :
“But I have seen write-ups that say the satellite data is calibrated to local sea level gauges which are suspected to suffer from land subsidence.”
Satellite altimetry Topex/Poseidon data is adjusted by the University of Colorado for NASA to match the rate of sea level rise measured by a set of 64 tide gauges. Any difference between the raw satellite measurement and the tide gauge measurement is assumed to be the sum of satellite measurement drift error and the vertical land movement at the tide gauge location. A separate estimate of land motion is made. The difference is assumed to be altimeter drift, which is applied to the raw satellite data.
Therefore, the slope of the reported satellite sea level data is determined by the 64 tide gauges and the accuracy of the vertical land movement estimates of those tide gauges. This doesn’t mean the estimate is wrong. But it is wrong to think the sea level rise from satellite data is independent of tide gauge measurements.
The calibration is described here:
http://sealevel.colorado.edu/calibration.php
Folks here spend a lot of time intently looking at a specific square inch of bark on a specific tree in this particular forest.
When was the last time anyone here took a look at a ruler? More importantly, when was the last time anyone here went down to the ocean, stuck a stick in the sand/mud and was able to measure a millimeter of change in the ocean? Do it with a stick; do it with a laser; do it with a satellite – the result is the same.
Adding useless noise on top of useless noise does NOT add up to a legitimate result (it’s a variation of two wrongs equalling a right).
More importantly, what 23 tidal gauges are these? Where are they? Who monitors them? WHO, exactly, was measuring a MILLIMETER of change in sea level in Holland on August 8, 1888? What are these guages made of? If wood, does it expand or contract? What are the guages stuck in? Mud? Sand? Is there no erosion or silting where these are located? Did the guages ever move left? or right? or forward? or back? or TILT? Did anyone notice? Are all the guages measured by the same people? At the same times? With the same MILLIMETER level of precision?
In short, it’s all utterly preposterous.
Imagine yourself in a highschool science class and asked to conduct a SCIENTIFIC experiment. Would ANY highschool (or elementary school) science teacher accept data gathered in this way? I know that kids don’t get “F”‘s anymore, but this kind of garbage would have warranted an “F” when I was a kid. But that was back when SCIENCE required observations gathered in a SCIENTIFIC fashion – not some cobbled together mishmash of two dozen different sources, each of which is as questionable as the next.
There is NO CREDIBLE evidence of ANY sea level rise. Why? Because of the ridiculous way in which this data was compiled. Yet everyone accepts it and tries to figure the why’s and wherefore’s of it. IT’S JUNK. USELESS. MEANINGLESS. And anyone who would accept this 100+ years of sea level measurements as serious scientific data is a PUTZ.
Keep tilting at invisible windmills guys, I’m sure you’ll win someday.
mörners claim was that the satellite data showed no trend and was later adjusted with poor gauge data.
http://www.climatechangefacts.info/ClimateChangeDocuments/NilsAxelMornerinterview.pdf
the other side wrote this reply:
http://www.imedea.uib.es/goifis/OTROS/VANIMEDAT/documentos/intranet/Bibliography/Nerem_et_al_Global_Planet_Change_2007.pdf
they confirm that there was no trend in satellite data.
however they say, there were errors in the satellite data due “to drift in the TOPEX Microwave Radiometer” and “A second major error was
introduced when the redundant TOPEX altimeter was
turned on in early 1999”.
it is not clear from the article, to what extent gauge data was used to quantify these errors and to correct them, or anything about the quality of the possibly used gauge data.
Steven,
So you are now taking the first plot you posted, from which you previously used the trend of 3.3 mm/year in your article and are claiming it actually has a slope of 2.4mm/year for the last fifteen years and shows no change at all in the last three years. I invite any interested readers to draw your suggested trend lines on this plot. I certainly had difficulty seeing it as an improvement to the initial linear fit of 3.3 mm/year – who is playing with the data here?
Please can you give me your derived trend for the data from 7000 years ago to present? You keep on stating the current trend is within historical variation, but do not give any values.
The 2004 Interim New Jersey State Report you cite was work done by a team at Rutgers and was included in a Science article published in 2005. This article specifically studies the current and historical rates of sea-level change along the New Jersey coast. The associated press release is at http://ur.rutgers.edu/medrel/viewArticle.html?ArticleID=4858
“In an article published in the Nov. 25 issue of the journal Science, Rutgers professor of geological sciences Kenneth G. Miller reports on a new record of sea level change during the past 100 million years based on drilling studies along the New Jersey coast. The findings establish a steady millimeter-per-year rise from 5,000 years ago until about 200 years ago.
In contrast, sea-level measurements since 1850 from tidal gauges and more recently from satellite images, when corrected for land settling along the shoreline, reveal the current two-millimeter annual rise. “Without reliable information on how sea levels had changed before we had our new measures, we couldn’t be sure the current rate wasn’t happening all along,” said Miller. “Now, with solid historical data, we know it is definitely a recent phenomenon.
“The main thing that’s changed since the 19th century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases,” he added. “Our record therefore provides a new and reliable baseline to use in addressing global warming.””
Manfred,
You state:
“mörners claim was that the satellite data showed no trend and was later adjusted with poor gauge data.
http://www.climatechangefacts.info/ClimateChangeDocuments/NilsAxelMornerinterview.pdf
the other side wrote this reply:
http://www.imedea.uib.es/goifis/OTROS/VANIMEDAT/documentos/intranet/Bibliography/Nerem_et_al_Global_Planet_Change_2007.pdf
they confirm that there was no trend in satellite data.”
I read the article and the authors make no such confirmation. Rather they write:
“In light of this, the statement by Mörner that “This means that this data set does not record any general trend (rising or falling) in sea level, just variability around zero plus the temporary ENSO perturbations” is completely false and is based on his erroneous data processing.”
The main thing that’s changed since the 19th century …
is that the little ice age had ended – the coldest period in several thousand years, that was accompanied by a massive buildup of glaciers. melting of these hase increased the rate.
I’m no historical sea level rise denier, but this field is complicated too. (Of course the thermal expansion is real, and should have effect on century time scale.)
I’m no geology professional either, but google is fun! 🙂 Here’s some maybe interesting links:
1) Daily Tech article about University of Colorado, Boulder data, but where also Vincent Gray mention calibration errors:
http://www.dailytech.com/Defying+Predictions+Sea+Level+Rise+Begins+to+Slow/article13679.htm
2) Till Hanebuth made a study (“Rapid flooding of the Sunda Shelf – a late-glacial sea-level record” (2000)) , and I think it shows sea level rise almost continually (maybe with a few centuries during the last ~5000 years of temporarily declining level?). But I found this chart which — I don’t know why — shows declining sea levels during this interglacial period:
http://www.geoscience-environment.com/es551/back_ground.html
3) India’s National Institute of Oceanography present data measured at the west coast of India (which in the chart don’t seem to be that trust-worthy…) of almost constant sea level since 5000 year ago. they say “After 7,000 years B.P. it fluctuated to more or less the present level.”
http://www.nio.org/WaterFront/Civilization/SeaLevel.jsp
Any skeptics here? 😉
Tom P (01:31:35) :
Mörner obviously referred to the satellite raw data.
the other side writes:
“Because the details of the analysis are not presented in his paper, we are left to speculate on how this result could have been obtained, based on our years of experience as members of the T/P and Jason-1 Science Working Team. Mörner was apparently oblivious to the corrections that must be made to the “raw” altimeter data in order to make correct use
of the data.”
this is again just one of these lengthy unnecessary explanations used to make somebody look stupid. actually they acknowleged, that mörner used uncorrected raw data.
as has been written in a previous posting, the satellite data slope was and is still generated from gauge data. there is no independant satellite trend measurement.
graphs produced by these offices are still lacking a comment or footnote, that the satellite data slope is not measured but adjusted to match some gauge data trend.
The simple chart in my previous comment may give Hanebuth bad reputation, so this sea level chart is based on Hanebuth et al., 2000:
http://tetide.geo.uniroma1.it/igcp464/Brazil/Immagine%208.jpg
So it’s inconsistent with the simple chart, and presented on this page:
http://tetide.geo.uniroma1.it/igcp464/Brazil/Brazil%20conference.htm
It appears that the sea level record is as hopelessly flawed as the temperature record. Those who feed at the public trough can (and do) make of them what they will.
Tom P,
It is pointless explaining things to you, because you obviously have an agenda.
CU shows 3.3 mm/year Aviso shows 2.4mm/year Both are within the normal range for the last 7,000 years. Are you claiming that Aviso is incorrect? Based on what data?
The New Jersey study stated unequivocally an average 2mm/year for the last 7500years. Instead of reading the study, you quote a press release.
Hansen claims 55mm/year. IPCC claims 11-22mm/year. Both are completely out of line with observations. You choose not to think about this, and instead quibble over a few tenths of a millimeter..
This is my last message to you, because it is a waste of time trying to get you to think rationally.
Steven Goddard,
It is pointless explaining things to you, because you obviously have an agenda.
The New Jersey study stated unequivocally an average ONE mm/year for the last 7500 years after correcting for subsidence, and noted that in the last 100 years there was a definite human signal. Instead of reading the whole study, you cherry pick one sentence out of it.
The IPCC claims a sea level rise rate of 0.18 to 0.59 meters over the next century (1.8 to 5.9 mm/year average), not including dynamical changes to ice sheets (and for these estimates, Antarctica is assumed to be a net negative contributor due to increased snowfall in the interior). Go and READ THE IPCC REPORTS ALREADY instead of lying about what they claim. Pfeffer et al. (not the IPCC) stated a possibility of 2 m sea level rise if all the uncertainties in dynamical processes were resolved in the high-melt direction, but did not claim it was likely. In either case, neither the IPCC nor Pfeffer nor even Hansen (whose claim of a possible 5 m rise in an interview, not a published article, I don’t defend at all) claim that sea level rise is expected to be linear for any of these scenarios. As temperatures increase, both thermal expansion and glacier/ice cap melt are expected to increase, and ice sheet melt rate may change but we do not have a good handle on ice sheet dynamics yet. Therefore, an SLR of 2.4 or 3.3 mm/year today or whatever can be consistent with an SLR of 1 m over the next century under high scenarios of temperature change. If you want to argue about temperature projections, fine, but that’s a different issue entirely.
This increase of sea level rise over the next century would be consistent with the increase in sea level rise observed during the last century’s temperature increase, as compared to the smaller rate of sea level rise increases over the past 2 millennia.
FYI: Aviso: http://www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/ estimates 3.045 mm/year sea level rise since 1993 (with inverse barometer correction). Which is within the error bars of the CU estimate of 3.3 plus/minus 0.4 mm/year.
This is my last message to you, because it is a waste of time trying to get you to think rationally.
Steven,
I’m very unclear as to why you feel you have to bow out of the discussion. You leave hanging my repeated question of why you feel the recent trends of 3.3+/-0.4 mm/year lies within the normal range for the last 7,000 years.
The most AVISO data is here: http://www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/
and gives a current trend of 3.0 mm/year, so consistent with the trend you first used from the University of Colorado analysis. I don’t think either dataset is incorrect.
Instead of using data from an interim report, I presented the data from the peer-reviewed Science article, which states the background rate over the last 5,000 years of 1mm/year from the New Jersey sea level analysis. There is a clear difference between this rate and the current rate.
The IPCC and Hansen figures you quote are projections based on various models. They are not relevant to a discussion of the historical data.
If you feel unable to discuss why the current sea-level rise rate is two to three times the prior historical rate for the previous 5,000 years, I wonder why you brought up this data for discussion at all.
Steven Goddard (05:46:48) : “Hansen claims 55mm/year. IPCC claims 11-22mm/year.”
I agree that not only Hansen but also AGW promoting IPCC exaggerate sea level rise prediction. But if IPCC claims 11-22mm/year it means between 1.1 and 2.2 m/century! That’s not exactly right, is it? I believe they say between 0.4 and 0.6 m this century. That’s “only” two or tree times as fast sea level rise as we’ve had (0.2 m/century, which I rather think may drop this century if a Gleissberg cycle with low solar activity brings cool climate for 60-100 years:
http://ncwatch.typepad.com/dalton_minimum_returns/2009/02/no-warming-until-after-2014-and-maybe-not-then-.html .)
Marcus,
IPCC lead author David Randall told me personally that he expects “1 to 2 meters” this century, and Gavin at Real Climate defends that and Hansen’s 5m prediction here. That is the standard position in the AGW community.
http://www.realclimate.org/index.php/archives/2008/09/on-straw-men-and-greenland-tad-pfeffer-responds/
The New Jersey paper states-
Data from NJ (all sources) and the reefs are consistent with a constant rate of rise of 2 mm/y since ~7,000 yBP. This suggests a background, preanthropogenic sea-level rise of 2 mm/y for the entire east coast of the U.S.
Is this somehow confusing to you?
Marcus,
You are quoting outdated Aviso data. Their latest number is 2.4mm/year.
http://www.aviso.oceanobs.com/fileadmin/images/news/indic/msl/MSL_Serie_J1_Global_NoIB_RWT_PGR_NoAdjust.png
Steven,
You state:
“You are quoting outdated Aviso data. Their latest number is 2.4mm/year.
http://www.aviso.oceanobs.com/fileadmin/images/news/indic/msl/MSL_”
Your figure is for the seven year trend. You first quoted the University of Colorado fifteen year trend on 3.3+/-0.4 mm/year. Marcus and I are quoting the AVISO analysis, which is right up to date, for the fifteen year trend of 3.0 mm/year. Do you agree there is no discrepancy between the two trends for the same time period?
You further write:
“The New Jersey paper states-
Data from NJ (all sources) and the reefs are consistent with a constant rate of rise of 2 mm/y since ~7,000 yBP. This suggests a background, preanthropogenic sea-level rise of 2 mm/y for the entire east coast of the U.S. Is this somehow confusing to you?”
What is confusing is that the original data in the interim report you cite has not been corrected for subsidence effects. This is what is written in the Science paper which reports on the same data:
“Sea-level rise slowed at about 7 to 6 ka. Some regions experienced a mid-Holocene sea-level high at 5 ka, but we show that global sea level has risen at 1 mm/year over the past 5 to 6 ky. We present new core data from New Jersey covering the past 6 ky that show a rise of 2 mm/year over the past 5 ky. This New Jersey curve is remarkably similar to sea-level records from Delaware (46) and southern New England, with a eustatic rise of 1 mm/year over the past 5 ky once corrected for subsidence effects, virtually identical to that obtained from Caribbean reef localities accounting for subsidence.”
Science 25 November 2005:Vol. 310. no. 5752, pp. 1293 – 1298
What we are still left with is a current rate of sea level change which is more than twice the background level.
Tom P,
You have just stated that according to Aviso, sea level rise rate has declined recently to 2.4mm/year. This despite rapidly increasing CO2 levels and unprecedented warming according to Hansen, who expects a record high global temperature this year or next.
What is interesting from the NJ study is the raw data which showed 2mm/year for the entire East Coast for the last 7,000 years. Their theoretical analysis of the much less interesting. Glacial rebound in Florida is not a concept that is going to fly.
For the last 7 years, sea level rise (2.4mm/year) has been scarcely different from the 7,000 year trend. Hansen believes we are headed for 5000mm this century. If you want to argue with someone, take it up with him.
POP QUIZ
Sea levels are…
__RISING?
__FALLING?
__STATIC?
__ALL THE ABOVE?
Crib sheet…
http://www.john-daly.com/ges/msl-rept.htm
Tom P: I suggest we stop feeding the troll. It is unfortunate that Watts chooses to give the troll top-level space on his blog, but that is Watts’ choice.
It is obvious that Goddard is deliberately choosing to blatantly cherry pick sentences and numbers from a New Jersey study, AVISO, and realclimate when any person with reasonable reading comprehension can go and read the New Jersey study to see that they estimate 1 mm/year global sea level rise (which, because of subsidence, yields 2 mm/year rise on the eastern seaboard), go to the AVISO website and see that their current best estimate is 3 mm/year linked to off the main page (rather than some historical image linked to from who knows where), or go to the RealClimate site to see that the whole point of the entry was “While we liked the paper very much, we also complained that Pfeffer and colleagues had created a bit of a straw man, by implying that it had been seriously proposed that Greenland’s near term contribution to sea level rise could be much larger than [2 meters]” and not in any way a suggestion that 2m to 5m is “the standard position in the AGW community”. (For those interested: I’d think the “standard AGW position” is closer to something like a likely range this century of 30 cm to 1 m, with 1 m to 2 m plausible but unlikely, and >2 m very unlikely)
So, Tom P, I suggest we leave this website of cherry picks, straw men, etc. Maybe one day they can actually host discussions on the many real, existing uncertainties that abound in the field of climate science without inventing fake ones out of whole cloth, but until that day we should realize that fixing everything that is wrong on the internet is impossible. http://xkcd.com/386/
(and obviously, from the mere fact that I’m posting this, I am having a hard time letting go of the idea that sufficient repetition of logic and reading comprehension lessons might possibly help some readers realize just how misleading Steven Goddard can be)
Hasitbeen4years, tell me what phase an oceanic oscillation is in and I will tell you, without looking at a graph, whether or not the seas in that ocean or rising, stalling, or falling. The Pacific is falling, especially along the US West Coast. The Atlantic is stalled in some places, falling in others, and rising in others (its such a big ocean and there are several sub-oscillations within it). Am I close?
Marcus and Tom P, you are making the same mistake made when quoting Arctic ice changes. The Arctic has many different areas that behave quite differently from each other. It is always best to use these individual areas when quoting ice depth, area, and extent, instead of bundling them. Your sea level rise data quote follows the same mistaken path. If you can tell me where sea level has fallen and where it has risen, you will have data worth debating in terms of causality.
Marcus
So you’re suggesting that in the next forty years or so we might be back at last to the sea level height during the MWP?
You said;
(For those interested: I’d think the “standard AGW position” is closer to something like a likely range this century of 30 cm to 1 m, with 1 m to 2 m plausible but unlikely, and >2 m very unlikely)
You also quoted;
“…go to the AVISO website and see that their current best estimate is 3 mm/year linked to off the main page.”
It seems to me that perhaps James Hansen at Nasa and yourself are confusing imperial and metric once again? That’s 1 cm ( or 10mm) a year every year for the top end of this scenario, and up to 20mm a year for the ‘plausible’ scenario. Did you really mean to say this?
The reality from actual observations is very much lower than this-have you taken into account the (enormous) margin of error of Satellites, or perhaps you don’t examine the information contained in tide gauges?
Prof Morner is a good person to consult if you are a little unsure at to what sea levels are actually doing in the real world, as opposed to that in a computer room. Why don’t you visit your nearest stretch of coast and see what is happening there?
In our part of the world the sea level has been static overall for the hundred years that the records cover, which takes into account periodic rises and falls. Perhaps these don’t get captured within the time scales of the data you are looking at?
Tonyb
Steven Goddard (14:26:11) : The article uses graphs covering three time frames. 20,000 years, 100 years and 15 years. They all show that Hansen’s claims of 5mm by 2095 (55mm/year) are absurd, as is your claim that I am only considering “half a cycle.” This article is about the interglacial, which started 15,000 or so years ago. I have considered the entire period in some detail.
“Basic Geology” indeed. Shall I be clearer for you? A CYCLE is from BOTTOM to TOP and BACK to BOTTOM. And even then one cycle is not a reliable pattern. All you have considered in detail is your own navel. Let me ask you again, what school gave you a “BS” in Geology? I’m asking quite seriously.
Marcus,
I am hoping you aren’t as daft as you pretend. If you don’t like my article, then perhaps you shouldn’t waste your time here. Maybe you could contact Hansen about his 55mm/year instead of wasting my time arguing over 1mm.
The disagreement on RealClimate was about >2m per century. If you have ever spent any time discussing this issue with climate scientists like Gavin, you would know that 1-2meters is what they expect to see. You can contact IPCC lead author David Randall at randall@atmos.colostate.edu and find out for yourself.
How can scientists measure 2mm/year for the last 7,000 years along the entire east coast, and come to the conclusion that it corresponds to a global 1mm/year? It is the norm in the climate science world to throw in some gratuitous AGW interpretation about the raw data, to avoid censure from their peers. Do you think glacial rebound is having a strong effect in Florida? Do you think the Vikings did a lot of oil and gas pumping? The NJ measured data says 2mm/year for the last 7,000 years. Take it at face value.
I have been wondering for some time about the amount of water we use globally for irrigation, a lot of which is from aquifers that are not being replenished. This water must be in the atmosphere or oceans (including all bodies of water). Using water volumes from the UN FOA data from 2000, I would bet it is more now, some 2200-3800 KM^3 are used annually. Since satellite data are telling us it is not in the atmosphere, it must be on the earth. Dividing this by the planet’s water bodies’ surface area, this is enough to raise all water body levels by 8.3 mm/yr. Assuming that it falls equally on land and water it is still enough to add 5.9 mm/yr on the water bodies levels. So whether we think the ocean levels are rising by 2 or 4 mm/yr, we don’t need fantasies about glaciers and icecaps melting to explain the increase. I used the FOA mean, of 3000 KM^3 for these back-of-the-envelope calculations.
Steven,
Your refusal to countenance any correction for subsidence in the New Jersey data (what I presume is meant by a “theoretical analysis”) directly contradicts your earlier statement:
“BTW – the map you linked showed higher raise rates along the Gulf Coast, where the effect is due to subsidence caused by subsurface pumping.”
Why should subsidence be considered in Texas but not in New Jersey?
Ben Lawson,
You are obviously motivated by animosity. Why is that?
Steven Goddard doesn’t have to tell you squat, and if I were him, I certainly wouldn’t.
Why? Because it’s clear that any information he gives you will be thrown back at him in a hostile manner.
Rather than engaging in your ad hominem attacks, why don’t you try to answer the question asked way upthread: are you claiming that a rise in CO2 causes a rise in the sea level?
If so, please tell us how that works, and explain why we can’t accurately measure any putative sea level rise. You might also try to explain how tide gauges give accurate readings, while considering Bill Illis’ point about land changes. Explain how a tide gauge can tell the difference between a 0.4 mm sea level rise or fall, and land uplifting or subsidence.
Pamela,
You state “It is always best to use these individual areas when quoting ice depth, area, and extent, instead of bundling them. Your sea level rise data quote follows the same mistaken path.”
Not at all. The individual data sets are colour coded in http://www.globalwarmingart.com/wiki/Image:Post-Glacial_Sea_Level_png
and the Science article plots the individual sites in figure S1 of the supplementary material: http://www.sciencemag.org/cgi/data/310/5752/1293/DC1/1
They all show consistent trends as was summarised in the text:
“This New Jersey curve is remarkably similar to sea-level records from Delaware and southern New England, with a eustatic rise of 1 mm/year over the past 5 ky once corrected for subsidence effects, virtually identical to that obtained from Caribbean reef localities accounting for subsidence.”
1mm/year is therefore a consistent figure for the historical sea level change.
I have to smile at that word “ad hominem”. I swear on my Mother’s Catholic Bible that I sang that phrase in every Latin Mass tune I learned in catechism. Or at least that is what my small child mind thought I heard when I was being taught by the black floaty people.
Now you be talkin Tom. So expand a bit. What were the various Atlantic oceanic oscillations doing during that time? Did they also correct for the known rise in sea level from the warm phases?
@Pamela Gray (08:59:23) :
“…Am I close?”
I can’t say, as I’m not sure what you mean by “oscillations.” The term is only used twice in that reference, and they are…
1. in reference to “…the impact of the El Niño Southern Oscillation on sea levels in the western Pacific.”
2. and that “…if sea levels were today what they were 6,000 years ago, the present site of the Sydney 2000 Olympic Games would be underwater. Similar rapid oscillations in sea level took place elsewhere on the southeast Australian coast throughout the last 4000 years…”
You may well be able to guess better than I can, because I wouldn’t have been able to at all without the historical results presented in the “crib sheet” I gave.
My point is just that it seems meanigless to talk about a “mean sea level rise,” although it might be interesting to talk about a local rise, but it would be appropriate to know a lot more than just the atmospheric [CO2]. Just like with the “fiction” of global temperature or with ocean pH, the latter being highly variable with temp, location, depth, etc., sea level isn’t constant, so sea level isn’t something we can point to as an indicator of any recent drastic change. It just isn’t sensitive or precise enough, from what I’ve seen.
Tom P,
Subsidence along the Gulf Cast is due to water, oil and gas pumping.
Trying to claim a common mechanism and rate for 7,000 year old subsidence from New England to the Caribbean seems odd, to say the least.
See the following paper on causes of sea level changes. Now, before you say this is just noise and the paper mentions atmospheric warming, we have learned since 1999 that the PDO flips from cold to warm, and back again, causing quite a bit of that atmospheric warming and cooling then thought to be related to CO2. Each phase can be as short as 10 to 15 years, or as long as 30 to 60 years. The cold phase means that La Nina’s predominate. The warm phase means that El Nino’s predominate. To understand this data in relation to trends in sea level rise, fall, or static conditions, you must compare the oceanic oscillation period and sea level measurements in the same area. Why? Because different ocean oscillations oscillate in and out of unison. So a simple global statement of sea level rise is not very informative in regards to causality.
http://pubs.usgs.gov/fs/1999/fs175-99/
@Steven Goddard (09:50:41) :
“Do you think glacial rebound is having a strong effect in Florida?”
Well I live in Cent.Fl, and I can tell you my dramamine bill has gone through the roof since I moved here.
But seriously, I don’t know what, if any, effect it might have, but there is some plate movement in the Gulf. There was a pretty strong earthquake there not long ago,…
http://www.foxnews.com/story/0,2933,213221,00.html
…so there is movement. Whether FL will be elevated or not, I don’t know, but it seems that could be possible.
“It is the norm in the climate science world to throw in some gratuitous AGW interpretation about the raw data, to avoid censure from their peers.”em>
Welcome to the Climate Sauna, data masseuses always on duty. Come in calm, and leave anxious, but at least your job will be secure, …for now.
Pamela,
If you’re referring to decadal oscillations, these would not be in the data – the error bars in the Steven’s second plot look as though they’re at least one hundred years in duration.
The corrections certainly included changes in mass loading by both ice and water during the warming period. These were of course different for each location.
As you know what you’re looking for, you might want to read the original papers and draw your own conclusions.
Steven,
You state:
“Trying to claim a common mechanism and rate for 7,000 year old subsidence from New England to the Caribbean seems odd, to say the least.”
It would be odd if I had. But as you well know I mentioned neither a common mechanism nor a rate, and you are being less than honest in suggesting I did. In fact the Science article indicates that subsidence in the Carribbean is much lower than that along the Eastern seaboard.
Subsidence is occurring around the coasts for various reasons now and in the past. Are you suggesting we ignore this subsidence when we calculate sea-level changes?
Decadal oscillations are actually a misnomer in way, as they lead people to surmise that oceanic warm and cool oscillations occur in ten-year cycles, kind of like the Sun and its aproximately 11 year cycle from minimum trough to minimum trough. The AMO’s “multidecadal” term is also misleading to the general readership. This oscillation is noisy, with short as well as long somewhat random cycles and with several co-occurring oscillations, as it is such a big pond. A better term would be “Atlantic multi-oscillating multi-gyres cycles”. Any sea level rise or fall must have the nearby oceanic oscillation affect on the top surface of the ocean calculated out of the measurement to determine if sea level is rising or falling due to some other non-natural cycle. That measurement must also include removing the seawater and freshwater melt at the end of a naturally occurring cold trend.
Smokey: My comments here are directly on topic. I view Steven Goddard’s post as either incomplete or misleading and my criticism is made solely on that basis. Presented as “Basic Geology”, this makes his still-vague credentials highly relevant.
Your presumptions about my motivation and suggestion that I instead address an incidental matter are misdirection. Tom P. and Marcus are handling the current rising sea level component of this discussion quite well.
@ Philip_B (21:30:06) :
As one ocean gets larger through sea floor spreading, another gets smaller through subduction. If this weren’t true, the area of continents would shrink over geological timescales and they don’t. Sea floor spreading per se has no longer term effect on sea levels and any shorter term effect could be in either direction, ie to raise or lower sea levels.”
No, that’s not what I am talking about.
I understand that the surface area of the earth is fixed, so as new ocean floor is produced other ocean floor is consumed via subduction. But the part the controls the sea level is how ‘hot’ is that ocean floor. Warm things are less dense, regardless of the material (with water being one of a few exceptions) and the earth’s crust is no different. When there are high rates of sea floor spreading, and thus high rates of new sea floor production, we have a greater area of the sea floor which is warmer, and less dense, and therefore “floating” higher in the earth’s matle. As this sea floor is “floating higher” it pushes the water higher with it and this, higher sea levels.
Check out the topography of the Atlantic. We talk often of “Mid oceanic ridges” and the reason the ridge exists is due to the less dense ocean floor that was just produced at the ridge axis. As you move further from the axis of spreading, the ocean floor cools, becomes more dense, and sinks lower in the mantle.
Google Isostasy.
@Steven Goddard (10:37:46) :
“Trying to claim a common mechanism and rate for 7,000 year old subsidence from New England to the Caribbean seems odd, to say the least”
Sediment loading and thermal adjustment of the oceanic crust?
The temperature at the depths is so cold that water there actually expands a bit, just like water right before it freezes, capturing the expansion and making it visible to the naked eye in the ice cube. The water layer nearer the top expands because it is getting warmer, or contracts because it is getting colder. It’s the top layer that changes the sea level.
Ben Lawson:
Misdirection? Nope. That ‘incidental’ matter is in fact the entire basis for the AGW hypothesis, which claims that a rise in CO2 will lead to runaway global warming. It is not incidental, but rather, the CO2 question is central to the entire
global warmingclimate debate.If, as the empirical evidence suggests, a rise in a minor trace gas has no measurable effect on the planet’s temperature, then it should normally merit no more than a minor footnote in an obscure journal.
Instead, the CO2 question has devolved into arguing over literally $Trillions in tax increases to fight a harmless, non-threatening event. So I ask the central question once more: is a rise in CO2 causing the supposed rise in the sea level?
Ben Lawson,
Dr. Hansen is considered very highly credentialed, and he claims 55mm/year average through the remainder of the century. Do you accept his analysis? You certainly do not have the credentials to question the world’s most respected climatologist. In fact no one does. We have to take his word as unquestioned fact. That is what democracy and free speech is all about.
So you choose to quibble with me over 1cm instead. I am not impressed.
In the not too distant past, folks assumed that rising SST’s were caused by global warming. Now that more information is known about oscillations between cold and warm oceanic temperatures, that argument has been tabled. So if that argument is brought up, that increased SST is caused by AGW, one will have to ask if AGW also causes decreasing SST. The same is true for the Sun argument. If the Sun is heating up the oceans directly, then the same argument must accompany colder ocean oscillations. The problem is that solar output cannot explain both sides of the same argument, just as increasing CO2 cannot. In fact, the degree of warming or cooling in the records cannot be explained by CO2 or its supposed affect on water vapor or ice melt. One must put into the calculation an overwhelming oceanic, jet stream, and trade wind affect that results in weather system responses consistent with these prevailing causes. These natural colder or warmer weather pattern variations are characterized by both short and long term oscillations that easily stretch through the temperature trends, both up and down, known in this interglacial period.
a few “decadal oscillation” links…
…herald cooling…
http://www.rightsidenews.com/200807201494/energy-and-environment/pacific-decadal-oscillation-shift-assures-global-cooling-for-next-30-years.html
…affect clouds, and subsequently the weather/climate…
http://www.drroyspencer.com/research-articles/global-warming-as-a-natural-response/
…and solar forcing…
http://www.john-daly.com/theodor/pdotrend.htm
With respect to sea level rise/fall…
http://cat.inist.fr/?aModele=afficheN&cpsidt=15732081
“Satellite altimetric data from September 1992 to January 2002 and hydrographic data from 1927 to 1999 reveal the presence of low-frequency variability of sea surface height (SSH) within the Japan/East Sea (JES). SSH interannual variability amounting to approximately 15 cm is in phase with the Pacific Decadal Oscillation (PDO), with higher SSH, warmer, fresher surface (upper 200 dbar) layer during negative phases of the PDO; and lower SSH, cooler, saltier surface layer during a positive PDO.”
Peer reviewed paper based on IPCC data, showing 90cm rise this century as the most likely scenario – ranging up 140cm. See figure 4. Reference is from Gavin at RealClimate.
http://www.pik-potsdam.de/~stefan/Publications/Nature/rahmstorf_science_2007.pdf
Many climate scientists have upped the ante to 100-200cm since.
From that same paper.
On the other hand, very low sea-level rise values as reported in the IPCC TAR now appear rather implausible in the light of the observational data.
The observational data being that rates have dropped from 3mm/year to 2.4mm/year over the last decade?
4years, The solar forcing paper is the odd duck in the bunch. While it is true that solar heating is an important part of our planet, and no one I know can or would dispute that without lottsa alcohol, its variation is so small that temperature variation can not be explained by solar variation. If all these weather related causes stopped then maybe. Here is what it sounds like. No wind, no jet stream, no tides, no Earth spin, no water sloshing, just an enclosed container with air, water, and some land masses just sitting there under the Sun…do you see where I am going with this? We would have to get rid of everything that causes weather pattern variation except the Sun. By the time we did that, we would still find that the Sun’s variation will not cause the now static system to swing up and down in temperature to the degree it does. The Sun warms us. The Earth varies that warmth.
INCONVENIENT TRUTHS ABOUND
FOUND, HERE…
http://heliogenic.blogspot.com/2008/11/decadal-oscillation-in-sea-level-change.html
Smokey: “Misdirection? Nope. That ‘incidental’ matter is in fact the entire basis for the AGW hypothesis” [etc.] This post is called “Basic Geology Part 3 – Sea Level Rises During Interglacial Periods”. You can argue about anything you like, but if you are not on-topic don’t expect me to indulge you.
Steven Goddard: “Dr. Hansen is considered very highly credentialed”… …”We have to take his word as unquestioned fact.” Why are you talking about Hansen’s credentials when the question is about yours? If I knew yours I might not be so… dare I say it… skeptical. (I’d love to hear whether Hansen thinks he’s getting some sort of free ride. Snort.)
“So you choose to quibble with me over 1cm instead. I am not impressed.” I “quibble” over the fact that you are presenting clearly incomplete data as proof of your arguments, regardless of what the disputed measurements are. This has been the thrust of my criticism throughout this thread, which you still fail to address. Are you familiar with the previous Quaternary interglacial cycles (Sangamon, Yarmouth and Aftonian)? What was the character of their sea-level changes? What were their peaks and troughs? It still only a few iterations, but the predictions that might flow from that analysis would be taken a bit more seriously.
Steven,
I’m really not sure what you’re now trying to demonstrate here, except that there’s a range of projections by climate scientists which fall short of Hansen’s upper-bound estimate.
In the meantime, and rather more germane to your original article, you still leave unanswered why subsidence should be left out of sea-level calculations – no oceanographer, including Nils-Axel Morner himself, would support your position here.
But no matter. As I’m sure your basic geology would tell you, if you leave subsidence out of the historical data, you should also take it out of the current trend to make a valid comparison. According to your plot which sits at the head of this post, we are still left with over a 2 mm/year present rate of increase in sea level above the natural background of the last 5,000 years.
Tom P, re: your comment about what we are left with. Would you please add your understanding of oceanic thermal expansion during positive and negative oceanic oscillations. Do you believe them to be short term or long term trenders? Specifically, which oscillations have been positive during your statement, “we are still left with over a 2 mm/year present rate of increase in sea level above the natural background of the last 5,000 years.” Also, do you know what the error bars are for that “natural background of the last 5,000 years”?
On second thought, my question to you Tom is unfair. The mean sea level statistic, the graph with a trend line and the stair step data, to me, is a nonsensical analysis. It’s like saying the average annual incident of frost-kill in the US is such and such. Such an analysis completely ignores the fact that there are many growing zones in the US. Some zones experience a much higher frost-kill than other zones. You can’t make any kind of statement that is useful to those who buy plants by telling them what the frost-kill is for the entire US.
Tom P,
So far I haven’t seen any objections to the article. What I see is a couple of people who tried to hijack the thread by going off on a pointless tangent about the last 7,000 years.
The points of this article are that sea level would be going up, even if temperatures were going down – and that Hansen et al estimates are completely out of line with observational evidence.
You appear desperate to keep those topics off the table.
Ben Lawson,
If you want to write a blog about some favorite topics and can find someone to publish it, then go for it.
Do you dispute that sea level has been going up for the last 20,000 years? Do you dispute that temperatures have been going up for most of the last 10,000 years? Do you understand that sea level would be going up, even if temperatures weren’t? Do you accept Dr. Hansen’s claim of 5m this century?
I’m not going to be dragged off topic into an irrelevant academic exercise. Save that for the classroom.
@Pamela Gray (15:19:37)
T’WAS THE SUN WHAT DONE IT, GOV’NER…
http://www.jennifermarohasy.com/blog/archives/002945.html
…maybe.
(another look at that Holgate data)
Once again we find that solar activity correlates well with warming, and/or the effects of warming. To just say that there’s so little heat it couldn’t make a difference doesn’t seem reasonable when solar variations seem to be having a marked effect. Obviously we don’t yet know, so more observations are needed. Still, the correclation is a lot better between the sun and many climate parameters than with CO2 and same.
It appears that someone moderating the thread changed my last post?
It did and should read “Do you dispute that temperatures have been going down for most of the last 10,000 years?
as seen here-
http://commons.wikimedia.org/wiki/File:Holocene_Temperature_Variations.png
REPLY: I don’t think either moderator on duty would have done that for any reason. Don’t rule out the possibility that you may have accidentally put in one word when you meant another. I’ve done the very same thing. It happens. – Anthony
Steven,
You write an article comparing current trends with natural trends, and now regard my establishing the prior historical trend of the last few thousand years as going off at a tangent? I’m afraid there are problems deeper than your basic understanding of geology here.
Pamela,
I’m not quite clear as to what you’re implying, but to give you another analogy, I take it you see the worth of measuring changes in the life expectancy of Americans, without such a number being of direct relevance to the health of any particular American?
If you reject using globally derived measurements, how can we hope to understand the relationships which are globally driven by say solar input, orbital dynamics and atmospheric gas concentrations?
“If you reject using globally derived measurements, how can we hope to understand the relationships which are globally driven by say solar input, orbital dynamics and atmospheric gas concentrations?”
Reminds me of the statistician who drowned in a river with an average depth of only 3 inches.
And all those factors you list have different values, and so behave differently, in different areas, therefore a ‘one size fits all’ model is bound to give inaccurate results, as in fact they all do.
Tom P (18:16:29)
“I take it you see the worth of measuring changes in the life expectancy of Americans, without such a number being of direct relevance to the health of any particular American?”
That’s right. The life insurance premium of some 35 year old alcoholic with pancreatic cancer is going to be a lot higher (if he can get it) than a 50 year old in good health and with good habits.
You have answered your own question by the example you give. Life expectancy is a measure that says very little about what is being measured, what to fix, how to help, or who to help. Is it more babies surviving? Or old people surviving longer? Smoking rates going down? Epidemics easing? Not to mention that you have narrowed your data from a global number to a more localized number. You need to know more about the, yes, noisy data that makes up the global data. How about this one: Globally averaged stock is going down. Tell me how you can use that number to address your stock portfolio without looking at the stocks themselves in your portfolio? Are they going down? How do you know, based on the single stock market number? Are you willing to jump ship with just that single number, or would we find you late at night studying the performance of the individual stocks in your portfolio?
Steven Goddard: “I’m not going to be dragged off topic into an irrelevant academic exercise. Save that for the classroom.” What I am disputing is the core evidence of your post, which you relentlessly refuse to address. The only conclusion I can draw at this point is that you have no defensible response and simply won’t to admit it.
“Do you dispute that sea level has been going up for the last 20,000 years?” Nope, I don’t dispute this. What happened in the years before though? If all you look at is “up” how do you know what “down” looks like?
“Do you dispute that temperatures have been going [you meant down] for most [emphasis mine] of the last 10,000 years?” Nope, I don’t dispute this. Slightly down overall (~0.5C) over the last ~10,000 years. This is after a comparatively rapid increase (~6.0C) in the previous ~10,000 years. The record (adjacent to your link) also shows that in very recent times this gradual 10,000 year decline has been overwhelmed in the blink of an eye by that new temperature increase that the “alarmists” are talking about. Gee, I guess there is some relevance to looking past the last half of the last cycle of glaciation!
Etc., etc.
Anthony,
I still had the original post (awaiting moderation) open in a different window, and it said Do you dispute that temperatures have been going down for most of the last 10,000 years?
But it appeared posted as “up” rather than “down” so I am quite certain that someone must have thought that they were correcting a typo.
Tom P,
I think you have completely missed the point of this article. John Kerry said last week that rising sea level is proof of global warming. This is nonsense because it implies that sea level was not rising prior to the recent upturn in CO2. In fact, sea level rose through the last 8,000 years of continuously falling temperature, and it also rose during the ice age scare of the 1960s and 1970s. It was rising at nearly the same rate in 1910 when there were only a few hundred or thousand automobiles in the world.
Hansen claims 55mm/year average through the rest of the century. Right now we are at 2.4. Does that seem realistic? If you actually cared about the truth you would be going after him, instead of wasting everyone’s time here arguing with me about 1mm of subsidence.
Pamela, HasitBeenFourYears,
I said specifically that such a number is not applicable to an individual, so your posts just reiterate that basic aspect of a statistical average in various different ways. I had actually thought it rather obvious that knowing the underlying change in life expectancy in a country would be of some worth…
But I’ll give you one more example which might make more obvious the statistical validity of your positions.
A batting average obviously says very little about the performance of the batter in a particular game. Would you therefore on that basis advocate not calculating such a number as it is “nonsensical analysis”?
Steven,
“I think you have completely missed the point of this article.”
So it had nothing to do with comparing the current rate of sea-level change against the natural background?
Why then did you choose to conclude your article:
“Even if we returned to a green utopian age, sea level would continue to rise at about the same rate – just as has done since the last glacial maximum.”
My simple point, your conclusion is wrong. Based on the very data you have presented, if we could turn back the clock the rate of sea-level change would be one half to one third of what we now are seeing.
But I fully understand why you want to move the discussion on from your faulty analysis.
Tom P,
Like I said, you are obviously not interested in the truth about sea level.
Do you disagree that sea level will continue to rise, even if temperatures go down?
Do you understand the meaning of the word “about?” 1mm/year is 54mm less than Hansen’s figure. 2mm/year is 53mm less than Hansen’s figure? 1.5mm is 53.5mm less than Hansen’s figure. Nobody cares. They didn’t have satellites before 30 years ago measuring sea level. No one knows what the exact figure from 7,000 years ago.
Your analysis is based on a clueless parsing of words, yet you ignore Hansen’s mountain of error.
Ben Lawson,
So now you are implicitly suggesting that we would be currently headed into an ice age, if not for AGW.
In that case, I will immediately increase my CO2 production.
Steven,
In your conclusion you are comparing the historical and present sea level rise rates to each other, not to a projected rate. You are attempting to rewrite your own article now.
But what really concerns me is that you don’t feel it’s worth either disputing or wondering why your data indicate sea levels are now rising two to three times the natural background.
Tom P,
From 1910 to 1960 sea level rose at a fairly steady rate of 2mm/year. Over the past three years the rate has been much lower than this. Does that prove global cooling?
Your concept of “natural background” is meaningless at the sensitivity you are looking at. If you have any knowledge of statistics you should know that in a Gaussian distribution, there is a range of “normal” values.
Once again you are trying to hijack the discussion and claim that the article is about what is going on inside your own head. If you had read all four or five short paragraphs of the article, you would have known that Hansen’s prediction is a central point, which you refuse to think about.
Steven,
You wrote: “Your concept of “natural background” is meaningless at the sensitivity you are looking at.”
So the subsidence-corrected sea-level-rise historical trend of 0.9 mm a year you first drew attention to in the document http://www.state.nj.us/dep/dsr/climate/holocene.pdf
has now become meaningless?
“If you have any knowledge of statistics you should know that in a Gaussian distribution, there is a range of “normal” values.”
This statement just by itself demonstrates your own very limited grasp of statistics.
“If you had read all four or five short paragraphs of the article, you would have known that Hansen’s prediction is a central point.”
So central you omit to mention either his name or his prediction (55mm/year rise) in the article.
I gather you already have a past record in misinterpreting ice-area time series data. Your retraction is here: http://www.theregister.co.uk/2008/08/15/goddard_arctic_ice_mystery/
You can now add misinterpretation of sea-level time-series data to your score card. Perhaps Anthony Watts would like to consider if your articles really do much to enhance the scientific credibility of his site.
Tom P,
The Register piece most certainly is not a retraction. Thee article is about a very real discrepancy between NSIDC and UIUC sea ice >15% concentration maps. NSIDC got upset that I implied the problem “might” be at their end, and I explained that that implication.probably is not valid. This became obvious only after extensive discussions with NSIDC and UIUC people. Your reading comprehension is deficient, again.
As far as the Hansen 55mm, I posted above the link to the Hansen 5m before 2100 paper. I’m assuming that you know how to do math well enough to divide 5,000mm/90 years.
You have to understand, most of the readers are highly intelligent and don’t need everything to be spoon fed to them. But obviously not all.
.
Sea levels falling??
http://www.john-daly.com/ges/msl-rept.htm
.
Tom P,
Perhaps you can explain something to me.
Why is ad hominem attack and desperately attempting to silence dissidents, the standard operating mode of people of your persuasion?
“Steven Goddard”
[post removed]
Reply: Sorry, over the top. Complain all you like, but be respectful ~ charles the moderator
Steven,
I’m not quite sure why the last post was censored – please be assured there was no personal abuse in it.
You wrote: “As far as the Hansen 55mm, I posted above the link to the Hansen 5m before 2100 paper.”
I’m not disputing that, but stating that the link to Hansen’s prediction was posted in the subsequent discussion flatly contradicts your previous assertion:
“If you had read all four or five short paragraphs of the article, you would have known that Hansen’s prediction is a central point.”
And I’m not trying to silence you – I’d very much welcome seeing any further contributions to the science you think you can make. I’m just not so sure how Mr Watts feels.
If you shrunk the Earth to the size of a billiard ball and then carefully dried the oceans and all water from it’s surface, would it be smoother than a billiard ball?
OK, first, how smooth is a billiard ball? According to the World Pool-Billiard Association, a pool ball is 2.25 inches in diameter, and has a tolerance of +/- 0.005 inches. In other words, it must have no pits or bumps more than 0.005 inches in height. That’s pretty smooth. The ratio of the size of an allowable bump to the size of the ball is 0.005/2.25 = about 0.002.
The Earth has a diameter of about 12,735 kilometers. Using the smoothness ratio from above, the Earth would be an acceptable pool ball if it had no bumps (mountains) or pits (trenches) more than 12,735 km x 0.00222 = about 28 km in size.
The highest point on Earth is the top of Mt. Everest, at 8.85 km. The deepest point on Earth is the Marianas Trench, at about 11 km deep.
Hey, those are within the tolerances! If you shrank the Earth down to the size of a billiard ball, Earth would be smoother. (discounting the oblating effect caused by centrifugal force)
Maybe the heat within the Earth is more of a factor than anyone thinks. And perhaps the sea temperature lag is shorter than conventional wisdom dictates.
Batting average is created as a percentage of runs caused by your hitting the ball compared to the number of opportunities you were at bat. It is a statistic that compares opportunity to score with actual scores. Your batting average in any one time series is not compared to your average runs over a longer time series. Global warming is an average of MANY batters measured at one time (some with high averages and some with low averages), compared to an average number calculated over a long time series. Your batting average is for you. Not for anyone else. It is therefor a useful measure of how you are performing because it measures only you. It says nothing about your neighbor and is never used for that purpose.
The global average sea level is mistakenly used to do what it should never do. It tries to say what you are doing. It cannot do that. What if the sea raised a bunch somewhere else, but your sea actually went down? Don’t laugh. This has happened. Therefor the global average is meaningless. You cannot say that the seas are rising. They are rising in some places, but lowering in others. Try again.
I once saw a man’s batting average go from 0 to 1000 in a single appearance at the plate. Nolan Ryan, in his first at-bat with the Houston Astros, hit a home run.
(…assuming I remember that correctly)
Pamela,
The average height of the sea compared to the Earth’s gravitational potential is a well defined number. No oceanographer, including Nils-Axel Morner would dispute that.
The fact that the sea may be higher in some locations than others does not challenge the validity of the number any more than we would be surprised if a batter performed above or below his batting average in any particular game in a season. One is just the average over a surface for a particular planet, the other an average over a season for a particular batter. I hope this much is accepted.
Westhoustongeo, I do the same thing with my jeep that Nolan did with his first at bat. Kind of. I have a V-8 jeep commander with tow package (farmer thing) that gets between 17 and 18 mpg. I go up and down mountain passes every week. When I get tired of my number I just hit the reset button while going down the other side of some mountain pass and presto! I have the gas mileage of a two-door mid-sized Subaru!
Hot off the front page of the always hysterical BBC Anyone claiming to be a scientist can get front page coverage by upping the Armageddon ante
http://news.bbc.co.uk/2/hi/science/nature/7934046.stm
‘More bad news’ on climate change
Matt McGrath
BBC environment reporter
File photo: Heard Island in the Southern Ocean (17 December, 2008)
Scientists will present the most recent data on sea level rise
More bad news on climate change is expected as more than 2,000 climate scientists gather in Copenhagen.
They will be trying to pull together the latest research on global warming ahead of political negotiations later in the year.
The scientists are concerned that the 2007 reports of the Intergovernmental Panel on Climate Change (IPCC) are already out of date.
Their data suggests greater rises in sea levels this century.
Sea level rise rates have declined this decade, so the study quoted in the BBC claims that the predictions need upwards adjustment. Completely irrational.
What we are witnessing is a rebirth of scientific method, according to the 16th century Vatican. i.e. someone decided that the IPCC numbers aren’t scary enough yet, so they did a study to fix the political problem. The actual observed data makes no difference.
More from the BBC.
The IPCC was widely criticised for stating that sea level rise this century would only amount to 59cm (23in).
The most recent data, to be presented here, will suggest a far higher figure with dramatic implications for many island nations and coastal regions.
Sea level is rising at 2.4mm/year, so these geniuses conclude that 6+mm/year is too low. Welcome to the dark ages.
Ralph Ellis
I think we miss John Daly. He posted considered and thoughtful material which I also used just today.
It does our cause no good at all to hear the sometimes shrill voices on these pages proclaiming the truth of unsubstantiated material that only confirms the warmists opinion of our case.
Having said that this remains a blog where mostly civilised discourse can take place. I just wish that the wilder excesses of Ad hom attacks from either side could be thought through before posting.
Tonyb
Actually wouldn’t that have been no average since he hadn’t batted before? Zero and no average aren’t the same. If he had struck out or otherwise not made it to the plate, then his average would have been zero.
Er, not to the plate, but on base.
Steven Goddard (06:21:36): ~snip~ Please… ~dbstealey, mod.
Kindly resolve my quary,
If any body have Indian city SEA Level Height , Kindly send me.
Amit,
Yeh dekho
http://pmindia.nic.in/Pg01-52.pdf