Not only have you saved lots of someone elses the bother, you have shown a textbook case of how pseudo-scientizations get passed around and jam the actual signals that homo sapiens is capable of getting about climate. You have also made what should become a textbook case of how to deconstruct such scientizations.
But there’s more–which you nailed, too. It’s a little like whiskey: if you know what you’re doing, you sniff it first. It helps to be a good sniffer. If you’ve smelled enough bad whiskey, you know the scent, and you get the drift.
It is such a great scientific service that you dissect this deception.
But given the enormous consequences of this deliberate misinformation – calling it a whopper of a golden horseshoe – well, it kind of discounts the harm it does, don’t you think?
This deception promotes further delay in adaptation – causing real harm by sabotaging the future. This is a form of information treason that has been going on for decades. And even though it takes place in the common culture of newsmedia instead of academic journals still means that people will be harmed by bad information and opinion manipulation.
Thank you for exposing this. But lets not underestimate the harm it does.
Perhaps we need a site that goes beyond the ‘most common denialist claims’ so nicely debunked at Skeptical Science to include these kinds of finer grained fabrications?
A minor note in a generally well crafted piece: the last sentence in the paragraph that starts “The easiest way to look for this…” needs a bit of work. Right now it reads: “…means that people quoting it often claim that the this is a ‘recent’ claim.”
This kind of detective work is vital if climate scientists are to persuade the population enough to generate action. It’s high-gain political stuff, but probably low-gain for individual scientists. Political campaigns are constantly on the lookout for disinformation about candidates, and answer it quickly. In the realm of politics that strategy is necessary.
There should be a letter to the editor refuting the false claim, not just here but in other journals publishing false claims. Also it would help if there is a central repository of specific false claims and authorative answers that people can use to refute the claims. This claim about sea level should not have persisted for 5 or 6 years without, I assume, challenge.
A good friend of mine has lived on Tuvalu at Funafuti for the past four years.
Prior to that he was stationed there nine years earlier. On his return he asked why they had moved the fence of his accommodation( pre-fab from Australia) closer to the lagoon, SLR was so obvious. Some parts of the island (coral) have been growing and to date have been keeping up with SLR,other places losing the fight. A Japanese team was there last year trying to reactivate coral growth in those areas.
At the HAT the ocean now comes up through the coral and covers a lot of the island. Quite scary he tells me. A sinking feeling.
Willy and Kate used his house on their recent visit
Wow I got to the end of a RC post. Cool story. And not at all a waste of time – people I meet are always coming out with weird stuff when I tell them I do climate science for a living. I usually find it hard to relate to their stories as they sound like they come from an alternative universe… now at least I’m ready for this one when it makes its way over here…
I go through this debunking process several times a week on a climate/energy message board at Investor Village. But I’m not as efficient at it as you. I have the RbutR button on my browser, but it never seems to help.
Interested readers can also consult this comprehensive study of recent sea-levels at tropical Pacific islands, which integrates informations from tide gauges, altimetry, ground motion and ENSO variations:
This Skeptical Science post I wrote on sea level rise at Tuvalu is especially relevant too. There is a link to the South Pacific Sea Level and Climate Monitoring Project webpage near the end of the post.
Thanks, Gavin, for going to the trouble of writing this article.
It raises the question of why so little effort, generally, is made by the scientific community to counter the misinformation, particularly on climate related issues, that appears in a constant stream in newspapers.
Newspapers, after all, are the source of such information for most of the population, every one of whom has a vote. It is not as though there are not competent scientists, and indeed climatologists, in every region that could respond. Yet they rarely do, and so the tides of misinformation are rarely competently countered. Websites such as Realclimate and Sceptical Science provide a great service for those more deeply interested, but the great majority of the population never access them.
It does appear to me that there is a need for the scientific community to become far more involved in countering misinformation in the popular press. It needs to become far better organised and co-ordinated so that the burden falls more evenly on more shoulders. Frankly, it is an indictment of the scientific community that Gavin, who already does more than his share on the Realclimate site, should feel the need to respond from across the pond to an article in a Scottish newspaper. Where are the Scottish climatologists, and why are they so silent?
[Response: The fact of the matter is that it simply isn't anyone's job to go looking for nonsense to rebut. Most scientists are already overwhelmed with the stuff that they need to be doing - running samples, debugging code, writing papers, writing grants, reviewing, serving of committees, going to talks, keeping up with the literature, keeping promises to colleagues etc. So even taking a couple of hours to document something dumb they read somewhere is not a good use of their time. If one pays any attention to the internet firehose, you are bombarded with strawmen arguments, cherry picking, basic confusions, misinformation, overstatements, exaggerations, etc. stemming from combinations of ignorance, over-eagerness or hostility. What, if anything, should any one person do? - gavin]
If you enjoy wading through such tripe, I don’t for one minute think that you do, as you find in comment threads to articles in the mainstream media then this article and the comments which follow are classic:
where serial dis-informer David Rose adds to his ever growing list of creative writings. Note how the sensible comment have been voted to the bottom by the pack dogs in this particular Magic Roundabout.
Ah, this sounds so familiar. I recall deconstructing this claim–well, actually a question; it came from an honestly confused commenter:
I thought it has been established that the chief of the UN dept for Globalwarming had fiddle the statics to gain millions of dollars and rising of temperature at the moment is part of a natural cycle.
Of course there is no such ‘chief’, and it goes on from there. It was a good educational opportunity.
But it does illustrate pretty precisely Gavin’s description of the “drumbeat of disinformation.” Just last evening I was debunking, for about the three hundredth time, a repetition of the idea that MBH 98 was ‘discredited’ by Wegman.
Thanks for this great piece of digging. Your efforts were not time wasted, but necessary to counter the concerted disinformation campaign by the deniers and skeptics who only need to sow doubt in the mind of the public about the scientific research on global warming.
Referring to the source report http://www.bom.gov.au/pacificsealevel/presentations/briefing_paper_spslcmp_nov_2006.pdf it is interesting how looking at different pieces of information may serve different purposes.
Yes, the first Table (Recent short-term sea level trends in the Project area based upon SEAFRAME data through September 2006) lists trends of 2.7 to 17 mm/yr. But quite close to it is a figura that shows that much of the variablity comes from early periods of measurements, and the trends seem to decrease with time. The paper warns about using the data.
What is much more interesting is looking at Table 2 – historical data, where the trends are much smaller in absolute magnitude – despite longer observation periods, in almost all cases the standard deviation is larger than the trend and the mean trend of all data is 0.67 mm/yr – an order of magnitude smaller than the short term SEAFRAME data.
So, depending on what we decide to look for, we may see both a significant trend – or not so much…
The lesson from the cited paper is “Longer-term data sets for all stations are required in order to separate the effects of the different signals. Caution should be exercised caution in interpreting these data – they will almost certainly change over the coming years as the data set increases in length. The trend value is highly variable for the abovementioned reasons.”
PAber, you correctly note that “It is interesting how looking at different pieces of information may serve different purposes.”
The comment to Table 2 notes: “In general, these historical gauges were designed to monitor the sea level variability caused by El Niño and shorter-term oceanic fluctuations rather than long-term sea level change, for which a high level of precision and datum control is required.”
Rebutting this stuff could easily be a full-time job and people believe what they want to believe.
Just last week (at a discussion about the movie Fuel) I encountered someone who still believes the completely absurd claim that a Toyota Prius consumes more energy than the lifetime energy cost of a Hummer. That the story originated from a PR company that among other things assumed a Hummer lasts 3 times as long as a Prius has not penetrated public consciousness to the same extent as the original lie.
Gavin, thanks for taking the time. Someone has to do it. I try as well, and anyone who takes the need for translating science to sensible policy should too.
Even more interesting is the differences observed between sites. Since the turn of the century (when all sites have continuous data), the most western sites (FSM, PNG, and Solomons) show extremely high rises of 12, 14, and 18 mm/yr. The most eastern island (Cook) also shows a rather high increase of 10 mm/yr. The three southern islands (Samoa, Tonga, and Vanuatu) show medium rises of between 4 and 5 mm/yr. The most northern island (Marshall) shows a medium increase also, 6 mm.yr. The three middle islands (Kiribati, Nauru, and Tuvalu) show no change or a decrease (0, -1, and -2 mm/yr). Several islands showed a large drop (0.5 m or more) from 1997 to 1998. For this reason, many of the S.D.s were higher than the trend.
I have noticed that some denier claims seem to have no source whatsoever. There is a claim that CO2 did not initiate the end of “the ice age”. This is true (planetary orientation changes are viewed as the initiator) but misleading (greenhouse gases were a necessary driver of the overall warming trend).
I have never found any source of this claim, much less a scientific source. Seems to have started like a rumor.
The British Admiralty charts drawn 200-300 years ago provide a very clear picture of what has happened to sea levels. These charts were drawn to a very high level of precision, by sailors who’s lives depending upon their accuracy.
These charts are still in use today, because they remain the single most accurate record of sea level on the planet. While they have datum corrections for latitude and longitude due to the introduction of GPS and more accurate clocks, they do not show a datum correction for global sea level rise.
Given that sailor’s lives still depend on the accuracy of these charts, this suggests that sea level rise is not global, or it is cyclical on timescales measurable in 1 human lifetime. Over longer timescales of 200-300 years the evidence suggests that sea levels are static globally.
[Response: This is just more wishful thinking. No source is given for your conclusion, no reference to the obvious contradiction to the long tidal gauge or satellite records, no assessment of the precision of the original source (i.e. would you expect an additional 10 to 15 inches to show up on a global bathymetry map?) etc. etc. Please up your game if you want to be taken seriously. - gavin]
You spent time researching this because for some reason you care about the truth, about reality. And all of us, sometimes, have to roll up our sleeves and clean the intellectual toilet without a brush, as it were, because otherwise these tangled, foul clots of falsehood never get challenged and there is no limit to how much (collectively) they can do. So — thank you.
I noticed a review from Dr John Cameron on amazon that states “The British public, media and politicians have a spectacularly poor knowledge of science and technology as debates over such things as windfarms and GM crops makes clear.”
I sympathise with Gavin’s position and anyone else who has more pressing matters to attend to, but this kind of debunking is invaluable.
In the mid 1990s websites and message boards sprung up doubting whether man had set foot on the lunar surface or not. It sounds silly now–and indeed it is–but the doubters gained enough momentum (in print and television) to influence public opinion. It was a real pleasure to witness Jay Windley and Philip Plait pick apart various myths and arguments, without ever losing their cool.
It’s one of the reasons I enjoy visiting Sceptical Science and Peter Hadfield’s YouTube channel. Not solely because persuasive critiques give me a warm fuzzy feeling inside, but because of their obvious educational value.
The most effective way to combat climate disinformation is through posts like this one. Crush them, under the weight of evidence, and pound them into dust. Over and over and over.
Dan H has just rediscovered that sea level rise is not uniform. This is interesting but it of course is not a refutation that sea level is not rising. There are many things such as currents or also interesting is the movement of the solid earth. Policy and development planners need to focus more on relative sea level than the global mean. For instance the sinking of the land in New Orleans is occurring about 3 times as fast as the rise of the global sea level. This of course compounds the problem there. It is important to not let the interesting details obscure our vision of the broader picture which is that the global mean sea level has been and continues to rise. sorry for typos as I am on my phone.
Comment by Unsettled Scientist — 15 Oct 2012 @ 1:47 PM
Not a wasted life.. I find the methodology of deconstruction of how myths get spread fascinating, if this myth make another cut&paste appearance I will know where to redirect it to. It actually makes for a good case to have a dedicated climate myth buster wiki. The latest skeptic ruse I have noticed and did a bit of background research concerned windturbines.
JUDGE SAYS WINDTURBINES CAUSE PROPERTY DEPRECIATION, bad for health and terrible etc.
Despite being posted now it turns out the court case was back before 2004 and concerned a house sale in 1998. It wasn’t actually to do with the turbines but simply because the sellers had lied to the new buyers that they hadn’t objected to them. A £15k award was made to the defendants.
Not quite AGW but green energy and climate change are frequently mixed.
Rebutting this stuff could easily be a full-time job and people believe what they want to believe.
Propagating this stuff is a full-time job for some individuals, and it’s a lot easier to make up nonsense for publication than it is to refute it. I think the best we can hope for is that alert members of the reality-based community will see it, and direct the honest-but-unconvinced to sites like this one and SkepticalScience.
Slioch, me old pal. You know as well as I do that:
1) there are limits on the amount of spare time scientists have to counter nonsene.
2) the media are still wedded to the false balance idea
3) the amount of stupidity in newspaper letter writers is infinite, as you personally have seen.
Gavin asks “What, if anything, should any one person do?”
Comics are often looking for material. The New Yorker highlights goofs in other publications, Dave Letterman often has a segment on stupid newspaper articles, and Craig Ferguson grabs stupidity from the internet. If it is topical, SNL Weekend Update or the pair of fake news shows on Comedy Central might go for it. Feeding this kind of thing to their writers might turn out to be useful. This particular story might work for Ferguson because he likes to play with a Scottish accent.
> … anyone’s job to go looking for nonsense to rebut
Someone could be researching how lies have spread, given the availability of timestamps and mapping software. Where’s the Journal of Internet Epidemiology?
By analogy consider the research identifying which members of social networks are likely vectors for contagion. A few people who talk with or touch many others can keep an epidemic spreading that would die out in a more cautious or introverted community.
This is one reason statisticians and epidemiologists are such a threat to business as usual. In the paper-print days, most people didn’t believe in risk studies showing externalized costs and collateral damage — because odds were nobody in their family, or on their street, or at their job had died of whatever the risk was. They hadn’t seen it so it didn’t happen.
Nice to see that you may be able to understand concepts like plate tectonics and uplift. Overall, the global sea level has been (and continues) to rise at ~ 2mm/yr, and some regional planners will have a more difficult time than others.
[Response: Ah yes, proof by assertion - and just a teensy weensy bit twisted from the actual facts. Just enough as to allow for some reasonable claim of misreading, but misleading enough to actual give the casual reader a completely wrong impression. Classic. - gavin]
Among some of the usual “scientific” nonsense that appears in the readers’ comments on WTFUWT, I’ve recently seen a few new ones. Not able to quote word-for-word, but from memory. In reference to the big meltdown in Arctic sea ice this year…
“When the ice at one pole declines, the ice at the other increases. Scientists call this ‘polar reversal.’”
“Scientists have discovered that the radiation from Fukushima and the change in the Earth’s angle due to the quake are responsible for the recent sea ice melt.”
Of course, no sources were cited for these “scientific facts.” Admittedly, I haven’t investigated to see if I could find the original source. I suspect these theories originated in a flash of inspiration during a late-night beer drinking session while watching pro-wrestling or a monster truck rally on cable TV.
Even more interesting is the differences observed between sites. Since the turn of the century (when all sites have continuous data), the most western sites (FSM, PNG, and Solomons) show extremely high rises of 12, 14, and 18 mm/yr. The most eastern island (Cook) also shows a rather high increase of 10 mm/yr. The three southern islands (Samoa, Tonga, and Vanuatu) show medium rises of between 4 and 5 mm/yr. The most northern island (Marshall) shows a medium increase also, 6 mm.yr. The three middle islands (Kiribati, Nauru, and Tuvalu) show no change or a decrease (0, -1, and -2 mm/yr). Several islands showed a large drop (0.5 m or more) from 1997 to 1998. For this reason, many of the S.D.s were higher than the trend.
I am a physicist by education, and I have an ingrained aversion to trusting data where the effect signal/noise ratio is smaller than 1. Of course, there are circumstances when even high noise may allow digging the signal right. But in this case, as we consider multiple effects: local sea level changes, global sea level changes, island up/down movements vs crust – all of which seem to have comparable (within an order of magnitude) scale, determining what is signal and what is noise is much more debatable. When standard deviation comes from gaussian noise – the treatment is easy. But when it comes from nontrivial combination of various mechanisms … much care is required.
The comment to Table 2 notes: “In general, these historical gauges were designed to monitor the sea level variability caused by El Niño and shorter-term oceanic fluctuations rather than long-term sea level change, for which a high level of precision and datum control is required.”
True. But these historical gauges have much longer history and could not be *designed* to track long term sea level changes (especially AGW related) because this notion was not *fashionable* then. Still, in pure numerical terms they do provide significant data, and unless a good explanation for the differences between new/historical measurements is provided we are faced with a problem. Quite typical for science in general.
What pushed me to write the comment was the selective use of observations to achieve a *nice picture*, that would be *well received* by the readers of the Realclimate web site. This is not science, this is propaganda.
If the data do not agree we should not be cherrypicking only those measurements which we like (for whatever reason). If we do not know what causes the discrepancy we should:
– work on it;
– clearly state our state if knowledge (or lack of it) in the meantime.
Part of the problem is that people like Gray get by with such disinformation with impunity. Gavin’s careful research on this case could result in Gray paying some penalty for his dishonesty (or incompetence), which is so damaging. How about a carefully drafted addition to his Wiki entry? How about an article, like the one here, submitted to an appropriate publication? Scientists should not get by with ignoring scientific standards in the statements they make, just because the statement is not in a paper submitted for peer review.
Gavin: ‘it simply isn’t anyone’s job to go looking for nonsense to rebut’
I believe the major political parties employ people whose job is exactly that. It might be worth getting hold of contact details for those people, and making sure they’re thoroughly briefed on key elements of the evidence in climate science, and provided with access to the peer-reviewed literature.
On the specifics: this story about tide gauges on Pacific islands, in one form or another, has a rather older provenance than 2007: for example, something similar appeared in the Daily Telegraph on 6th July 2000. The Telegraph did at least contrast the sea level fall at the tide gauge with remote sensing data showing general sea level rise, although it neglected to mention that the remote sensing studies relate to a broader spatial scale than the tide gauges.
(By the way, I’m not the same Dan H as at comment numbers 24 and 41 – I guess it’s quite a common name!)
Gavin, it’s good that you’ve done it, but just don’t get carried away in this slippery slope. It’s easy to get overwhelmed and frustrated trying to get the record straight in this level of all-spread BS.
Well, I’m sure you know this better than anyone…
Keep up the great work you guys do here. Cheers from a regular reader in Brazil.
Might be cool to have a Kindle/e-book put out that uses Gavin’s format/methodology to diagram maybe 50 different similar “living legends” (you might even be able to identify the universe of repeating memes). Then, folks could apply the same Google search to suspiciously specific comments and see if they match one of the examples (or are a near version of). I think would be emensely useful, and a good source for journalists (the few that still do the digging anyways).
Perhaps a RealClimate associate could take on the task, and then run it by you guys for review before publishing. No need for the prefunctory preamble of the science at the beginning of the book–could just reference that with recommended sources, and then get to the meat.
Yes, this is only a very short snapshot of breaking US (local) temperature records. And the UK and northern Europe are on the other side of some effects from the wobble of jet stream, Rossby waves, Arctic exhalation, overturning current changes, and the whole basket of complex interacting phenomena. Whatever means are used to describe and measure, there are noticeable phenomena for laypeople in the flesh and blood world we inhabit.
One telltale sign is to go over to something like Woodfortrees and fiddle with the start date. Without question, once you get past the overly short timeframes (8 years? 12 beginning to be long enough?) each increase in length of records gives you a steeper curve. So why is anyone trying to keep people for eyeballing the longer trends for themselves getting away with not being called dishonest. The records are there, ferludssake!
The whole thing reminds me of a time in hospital when I had a hard time getting doctors to look at a suppurating wound in plain sight while they told me they didn’t see anything on the CT scan.
MEvidence in plain sight is now overwhelming theory, and should be heeded.
Comment by Susan Anderson — 16 Oct 2012 @ 11:15 AM
DanH, if you are not Dan H, I’d suggest you expand your moniker at least slightly. Dan H is a persistent manipulator of information here, and I suspect many will not notice the very slight difference. His water drips on stone, and fraying patience is likely to overflow on to you.
(Yours from the peanut gallery, though I have to admit my real name is a useful out in plain sight disguise, being so common.)
Comment by Susan Anderson — 16 Oct 2012 @ 11:20 AM
Still appropriate for posts by Dan H., classic, consistently misleading, misinformation expertly spun. His mimicry of scientific language improves; his content doesn’t.
>>> Dan H. …
>>> Overall, the global sea level has been
>>> (and continues) to rise at ~ 2mm/yr ….
>> [Response: Ah yes, proof by assertion ....
>> twisted from the actual facts.... misleading
>> enough to actual[ly] give the casual reader
>> a completely wrong impression. Classic. – gavin]
PAber #46: If you consider pointing out several untruths about the SPSLCMP, such as it supposed demise and not finding any upward trends, as propaganda, you should get yourself a new BS meter. Yours appears to be inversed, as this is all hardcore scientific data.
I am a climate activist, have followed the science as closely as I am able, and have wrestled with how to communicate it to the public. I, like many others, have little success to report, and don’t know what the solutions are (maybe some problem reframing would be helpful). I would like to offer some observations, and would welcome other thoughts.
1. For years we have been engaging in social marketing, public relations, psychological investigations, popular media (e.g., “Inconvenient Truth,” “Day After Tomorrow,” NOVA, etc.), disinformation deconstruction, activist blogs (e.g., ClimateProgress, SkepticalScience), remedial information, etc. Lewandowsky and Cook is another excellent addition to the collection. But we still haven’t figured out how to move public opinion. In the U.S. there has indeed been a change over the summer, but I would venture to say that the agent was the dire weather, not reasoned, even well strategized, argument. It should be amply clear by now that human beings do not make decisions based on reason, in no small measure because we can’t predict the future and the unintended consequences of our decisions. But most probably because the cerebral cortex is a late-comer in the survival game, and we “trust our feelings” first.
2. It seems to me that, consistent with your training, climate scientists have been understandably reluctant to communicate your deepest misgivings about the implications of climate change. In order to do so I suspect you would have to take steps beyond the boundaries of the peer review and be subject to severe collegial criticism. In the normal course of science, those rules make sense, but the normal course of science unfolds over decades or longer; in the global warming world we don’t have anywhere near that kind of time. I have seen this paradox first-hand, in conversations with climate scientists over the years who relate to me privately the acute anxiety and anguish that they are reluctant to communicate to the public. They tell me that they fear that if they express themselves the public will “shut down” and not listen to reason, although the public doesn’t appear to be listening to reason in any case.
3. Climate science has been, as it turns out, extraordinarily conservative in its predictions about the pace of change; this has become especially apparent over the past five years. Time frames for expected planetary response to increasing greenhouse gas concentrations have collapsed by decades, with uncharacteristic astonishment appearing regularly in the literature. The public doesn’t know this very well. How can they respond accordingly when we don’t communicate the bare truth? I wrote an online article about this around three years ago at http://grist.org/article/2009-11-10-we-have-met-the-deniers-and-they-are-us/.
4. Climate is sold to the public as an energy problem. It is, of course, a fossil-fuel energy problem, but the problem is a symptom of a much greater problem, one that touches every corner of our lives. It is an issue of gross transgression of planetary carrying capacity, and if global warming were to disappear tomorrow we would still be facing catastrophic resource depletion and pollution issues. Of course, the pace and consequences of climate change dwarf the others, but we have to do far more than switch to solar energy (at an apparently impossible pace).
5. Global warming, like fossil-fuel depletion, are qualitatively different from other problems we currently face: as they accelerate they threaten the very existence of our exponential-growth culture and the fantasy of prosperity for all. I don’t know if it’s possible for people to address that kind of change until we’re pressed so firmly up against the wall that we can barely move. When that happens with climate, it will be far too late. As far as I can tell, from the windows of climate opportunity that keep closing then inching open again, it’s already likely too late (recent shift in the emphasis on mitigation to adaptation is one sign of that). But I doubt that you will ever say “too late.” Maybe if you did people would pay attention. Maybe there are better ways of saying it. Maybe saying it somehow would be a first step in turning things around. Maybe not, but we haven’t tried it yet (except for Lovelock, and now even he’s backpedaling).
In closing, I want to say that I have the greatest respect for the work you have done over the past couple of decades. You have collected and analysed mountains of data in the most extraordinary scientific undertaking in history. You were then thrust into a foreign and vicious arena which you handled with remarkable equanimity and grace (although I’m sure it often didn’t feel that way). It has been essential for beginning to address climate issues: were it not for your dedicated efforts, we would know nothing of global warming, it would all just be “weird weather.”
But something is still missing, something which perhaps shouldn’t be thrust on you, but is thrust on all of us. I think that “something” is an understanding of how culture works, how civilizations play out (for one perspective, see Joseph Tainter, Collapse of Complex Societies), and most mysteriously of all, what we can possibly do about it.
Nice post, which clearly demonstrates how factitious “facts” propagate in society. I am a wildlife ecologist who studied wolves in SE Alaska during the last 20 years. Wolves are always controversial and the bizarre “facts” circulated by the public about them and my own work are astounding. Many haven’t even the least connection with reality but they fill the need of many to reaffirm their prejudices and beliefs. I think we need to always realize that for many, perhaps most people, reason is in the service of rationalizing their emotions not the other way around. For the most part, scientists transcend that dilemma with the help of the scientific method and peer-review, but we are a very small minority in the world and perhaps we expect too much from others with regard to skeptical thinking. We complain about disinformation, but to be effective, that propaganda must have fertile ground in which to take seed. In the U.S., that ground may be particularly productive and fearful because if US citizens reflect at all on the consequences of and solutions to greenhouse gas emissions, they must realize that their entire way of life needs to be reorganized, particularly those living in suburban and rural areas. Moreover, climate change is just one symptom, albeit a horrendous one, of human overpopulation and overconsumption. We have many more battles ahead even if we resolve anthropogenic global warming. Unfortunately, with respect to the climate crisis, until events overtake the deniers in ways obvious to an obtuse public, we will be mired in a “he-said she-said”, “bunk de-bunk” series of debates.
The recent trend in sea level rise has been in place since the start of the latest temperature rise (~150 years). I know there are those who quote higher or lower values, but they are usually based on shorter, 10- or 20-year trends. Had temperatures been rising steadily since the Roman Empire, then I guess 4 meters would be a reasonable guess. Of coursBy why stop at the Roman Empire? Sea levels have risen about 16m in the past 8000 years, just not at a constant rate.
“I am a climate activist, have followed the science as closely…”
Here are skeptical my thoughts:
Fossil fuel dependent economies/ societies may cause serious global warming (+ 2 deg C).
Therefore, some form of insurance (emission reduction) should be used to reduce the risk.
Risk management can be aptly described as “prepare for the worst, hope for the best”.
While I’m sure many climate scientist are “hoping for the best”, when it comes to the literature they are always “preparing for the worst”.
I suppose my point is when dealing with science which deals with policy, you need to acknowledge that policy should also influence science…I remember a study which showed bread cooked in a high temperature oven is linked to cancer. You don’t see the authorities banning bread though… If anybody is at risk its the baker (flour on the lung). More people are dead from mining coal then AGW, so if you wanted to ban it…..
10 deg C by the end of the century would be “hell on earth!”, quite an alarming projection is equally matched by a world where there are little fossil fuels left to burn, leading to mass war and upheaval.
Thus, there should be a concerted scientific effort to show that AGW may not be all that serious at all, as well as the opposite. The problem lies in its uncertain nature, rather than a given outcome.
This I think explains why ordinary peoples’ “gut feeling” is telling them to ignore the guy on the street corner with a sign sayn “fossil fuels running out” or “get ready to cook!” or “ban bread”, etc…
In many ways your art is better than mine. If you have time this weekend, come to FP Open Studios and introduce yourself. No doubt we’ll hate each other on sight, but it would be amusing. Others also welcome.
Comment by Susan Anderson — 17 Oct 2012 @ 12:04 AM
Isotopius … “10 deg C by the end of the century … is equally matched by a world where there are little fossil fuels left to burn”
You haven’t even begun to understand these matters, have you?
Note how the paleo sea level markers and the glacial isostatic adjustment modelling completely refutes the flawed idea of a globally warm Roman, or Medieval Period.
Relative sea levels were declining throughout the Roman & Medieval Periods because there was no glacial meltwater addition, nor thermal expansion of seawater, to counteract the siphoning of water into the regions of ocean floor that were collapsing.
Global sea sea level is, indirectly, the best proxy for global temperature because it reveals the status of global ice cover. All of which vindicates a certain Penn State University Paleoclimatologist, and Real Climate co-founder…..
This post is grand, but it is missing the critical bit of information which would make it encompassing instead of trivia, which is a graph of sea level rise rate (not sea level itself) over the last 2000 years. As it is, it doesn’t really refute the skeptics, who say sea level rise is merely an ongoing event, either from the last ice age or the little ice age. This was covered in the comments, but standard-issue pre-refutations are good to put up front, especially if the skeptic argument isn’t even noted. (Sometimes noting and refuting only grows the beast)
55 Susan A said, “once you get past the overly short timeframes (8 years? 12 beginning to be long enough?) each increase in length of records gives you a steeper curve”
Yes, but unfortunately, since the skeptic argument is that this is a natural oscillation and we’re at the peak, you’re describing their exact claim. (at least in their eyes)
PAber concerns are very valid. I have been following the SEAFRAME data for some years. The trend series change published in their reports is flawed. Their caveat that the short time series makes their ‘headline’ trend table unreliable is somewhat disingenius (sp.?). As PAber notes the trend series has been coming down in most years. why is this? The massive dip in 97/98 (which is caused i think by el nino) means all later years data become an upward trend change. You can try this at home by downloading the data from the website. Smooth out the 97/98 outlier dip and the trend increases all at least halve. In some cases they disappear entirely.
I dont think this is a professional statistical job being done by their team. In fact if i remember they are running simple linear trends through the data. You can virtually replicate their results simply in excel chart with the trend stats option.
I suppose i am picky with this type of thing as i do statistics for a job and seeing the big el nino effect or whatever in 97/98 in their graphs and then seeing how it impacts on the headline trends they are publishing makes me quite annoyed.
The SEAFRAME data is a great resource and you should at least look at the graphs to understand what is happening in the pacific islands in the last 15 years.
Thank you Gavin.
Alvin Toffler is quoted as saying “The illiterate of the 21st century will not be those who can’t read and write, but those who can’t learn, unlearn and relearn.” Perhaps, but I tend to believe it will be those who cannot (or will not bother to) perceive the difference between information that has merit and that which does not. My wife is a teacher and I have gently implored her to take this up in her teaching. So I just forwarded your piece to her, and I suspect it will show up in a lesson.
“10 deg C by the end of the century would be “hell on earth!”, quite an alarming projection is equally matched by a world where there are little fossil fuels left to burn, leading to mass war and upheaval.”
Had temperatures been rising steadily since the Roman Empire, then I guess 4 meters would be a reasonable guess. Of coursBy why stop at the Roman Empire? Sea levels have risen about 16m in the past 8000 years, just not at a constant rate.
But the papers you’ve linked to actually highlight the problem with your silly misrepresentation. They indicate that sea levels haven’t risen significantly for around 4000 years.
You linked to a very old paper by Kurt Lambeck. But if we look at Lambeck’s analyses of sea level rise since the Roman period, your rather blatant misrepresentation (a rise of “4 meters”) is directly contradicted:
Lambeck K (2005) Sea level in Roman time in the Central Mediterranean and implications for recent change Earth Planet. Sci. Lett. 224, 563-575
For which Lambeck concludes:
”Part of this change is the result of ongoing glacio-hydro isostatic adjustment of the crust subsequent to the last deglaciation. When corrected for this, using geologically constrained model predictions, the change in eustatic sea level since the Roman Period is -0.13 +/- 0.09 m.”
In other words far from a “4 meter” sea level rise, sea levels have actually gone down a tad for the 2000 years before the modern era.
The three other papers you linked to highlight your misrepresentation, and actually focus the problem, namely that an increase in temperature causes sea levels to rise for a very, very long period unless the temperature rise is reversed.
So the post glacial melt as a result of rising earth temperature at the glacial-postglacial transition lasted well into the early part of the Holocene, and up to 6-7000 years ago. Eustatic sea level rise has been small since then and pretty non-existant for the 4000 years before he modern era – since the papers you linked to show exactly that it’s odd that you use them to pursue a misrepresentation.
P.S. You need also to be careful about addressing true (eustatic) sea level rise (corrected for the effects of post glacial rebound which can have a very significant effect on apparent local sea level changes). Rather than focussing on the very local analyses you’ve linked to it would be helpful for understanding if you read some more general reviews that address global scale eustatic sea level changes throughout the Holocene.
Pirazzoli PA (2005) A review of possible eustatic, isostatic and tectonic contributions in eight late-Holocene relative sea-level histories from the Mediterranean area Quart. Sci. Rev. 24, 1989-2001
Church JA et al. (2008) Understanding global sea levels: past, present and future Sustainability Sci. 3, 9-22
Milne GA (2009) Identifying the causes of sea-level change Nature Geosci. 2, 471-478
The entire exercise was an attempt to show Marco how extrapolating the recent SLR back to the Roman Empire was futile. He claimed (not me) that 2mm/yr for 2000 years would yield a 4m SLR since the Roman era. I simply showed that if you extrapolate far enough back, you can intersect the SLR since the end of the last glacial maximum (whether that occurs at 8000 or 10,000 year BP is relatively minor). The papers to which I referenced point that out – sorry that you missed my sarcastic representation of Marco’s claim.
I agree that SLR mimics temperature rise. Research has shown that periods of higher temperatures lead to sea level increases, and lower temperatures lead to decreases. This was not an attempt to misrepresent, but to emphasize the errors in extrapolation.
It’s even worse than that. A very well science-educated and cliamate skeptic person I know once sent me a newspaper article. According to that person, the article was explaining how the rise of CO2 was NOT linked to global warming. In fact, the article was clearly stating the opposite. It just had the typical structure of “at fist the data seems odd but carefully analyzed it proves global man-made warming.” I conclude people can read what they want to read, and by some sort of psychological blindness, even turn clearly stated conclusions the otherway round. The battle is unwinnable my friends…
O.K Dan H, but aren’t you making exactly the same extrapolating error you are mocking? You state earlier on the thread that:
“The recent trend in sea level rise has been in place since the start of the latest temperature rise (~150 years). I know there are those who quote higher or lower values, but they are usually based on shorter, 10- or 20-year trends.”
But we know that sea level rise has accelerated during the anthropogenic period. Just to take one of the examples you linked to (the recent Bay of Biscay paper in Quat. Sci. Rev. by Leorri et al), this group infer a pre-anthropogenic sea level falling trend up to around 1900, and a 20th century sea level rise of 0.63 mm/yr (Brest)/1.42 mm/yr (S. Biscay)/0.69 mm/yr (Cascais).
that’s somewhere around 0.9 mm/yr 20th century averaged. But sea levels are rising at around 3 mm/yr or a bit higher now.
O.K. that’s only a broad single location (‘though it is a paper you’ve cited to pretend a different message). But the evidence indicates rather robustly that sea level rise has accelerated during the anthropogenic era [I'm using "anthropogenic era" in the way Loorri et al are using to indicate the dominant period of anthropogenic-induced warming].
And since you agree that “SLR mimics temperature rise”, that acceleration is presumably pretty much what you expect…Yes?
Obviously as the earth continues to warm under enhanced greenhouse forcing, sea level rise will continue to accelerate…yes again? That seems to be what your “SLR mimics temperature rise” predicates…yes?
I have debated Dan H for around four years on different web sites. Hank is absolutely correct – his basic strategy of denying anthropogenic global climate change behind a facade of scientific reasoning is totally consistent, despite embarrassing himself on many occasions.
Dan H – do you believe that the sea level rise observed in the past 100 years is accelerating? Do you believe that the observed sea level rise is the result of AGCC? Do you think that this acceleration of sea level rise should cause any concern for human civilization? Do you see how what you are doing is exactly what this particular post is pointing out?
Dan H – I’m well aware of the paleo sea level research since the last Glacial Maximum. If you read my post you’ll see that the Fleming (1998) paper is contradicted by the physical evidence. Their reconstruction eliminates the Holocene Sea Level highstand. Something we know for sure did in fact occur.
And your linking to papers which you clearly don’t understand, doesn’t impress. It would have been much simpler for you to simply confess you knew next to nothing about this topic. Now you have to furiously search for papers that you think support your erroneous opinion, and try to bring yourself up to speed.
I can tell you now, you’re going to be shit out of luck.
What started as a facetious extrapolation by Marco has ballooned into the absurd. Yes, if the 2mm/yr trend was extrapolated back to the Roman era, it would overstate the sea level substantially. Likewise, extending that trend back another 8000 years, it would understate the trend. And, if we extrapolate back a million years, we could walk to every continent.
Some people are taking these examples of the improper use of statistics to wage their own private war. Take a step back, read the recent posts, laugh a little, and move on.
Sea levels have risen about 0.25m since the start of the industrial revolution (Church & White). Higher during the periods of greater warming, lower in others.
I think you’ll find it was Martin (not Marco) that made the extrapolation.
It’s not that big a deal, but it is worth establishing every so often what the inescapable evidence indicates, and where individuals that profess a rational approach to the evidence pretty much have to agree.
We’ve found it here, I think. Sure, Dan H is trying to sell a misrepresentation and the very papers he cites highlights his misrepresentation. But we’ve established a pretty fundamental point of agreement, namely that in a world with rather massive amounts of meltable land ice, the rate of sea level rise increases with the extent of temperature rise (at least in the early periods of melt). Even Dan H. asserts that rather fundamental truth. I think we all agree that the rate of sea level rise has accelerated during the anthropogenic era (the papers that Dan H. cites, for example, indicate that)…and so on.
That’s useful isn’t it? These aren’t exactly profound truths but it is useful to see that even someone who invests a considerable amount of his time in misrepresenting science, is rather constrained by realities to align with inescapable evidence-based interpretations.
Jeffrey Davis quoted the bible earlier on this thread (Luke 4:23), but I would say that John 8:32 is rather more appropriate for this thread (and for science-based policy in the round), namely:
Ya know, I noticed after the US debate last night many online services proclaiming just how amazingly fast their user base/watchers/followers/friends list was growing on the new topics about the debates.
And not one of them mentioned whether they were checking to see if the astonishingly fast pace of signups meant they had the attention of meat people, or were being added to bots’ lists.
I suspect a massive species-wide Turing test failure in progress. We can’t distinguish simulated attention of fake-attention-grabbers from real attention by meat people.
And attention is a profoundly strong reinforcer.
People who think they’re getting attention do more of what makes them think they’re getting attention.
Thus it’s easy enough to trap them into wasting their time.
Think “monkey trap” — except it’s not our fists we’re putting into that narrow-necked bottle to grab the bait and be trapped.
It’s our brains.
Eschew the fake attention that never changes what it posts, but always improves the shiny wrapper around the bogus claims.
Real people change with better information, once they learn the people trying to inform them give a damn about them and their families and their grandchildren.
That’s the point here. Real problem, real people, real consequences.
And lots and lots of chaff, smoke, and mirrors distracting.
The “not even wrong” smackdown actually belongs to Wolfgang Pauli. He used it to criticize a research paper that was rather vague. The full quote goes, “Not only is that not right, it isn’te even wrong!”
Charles -“Likewise, extending that trend back another 8000 years, it would understate the trend”
Charles you don’t appear to be paying attention – current sea level rise is anomalous. The Earth has not seen anything of this magnitude for 10,000 years – according the the scientific research. See this video by Jerry Mitrovica for instance.
This make perfect sense as the natural orbitally-driven warming rid the Earth of vulnerable land-based ice, and this ceased after we passed the Holocene Climatic Optimum. The gradual cooling as the Earth began its slow descent toward the next glacial maximum stopped the addition of glacial meltwater to the global oceans, and with the ocean volume remaining static, the collapse of glacial forebulges, and continental levering, siphoned seawater away to fill these collapsed regions. Therefore relative sea level fell, and this is why we see “3 metre beaches” throughout the equatorial ocean.
What erroneous opinion do you think I am furious trying to support? That sea level rise has not been constant over time? I would be happy to entertain any research which shows that I am wrong. Funny how you are quick to ridicule that which you misunderstand. I prefer scientific papers over internet videos.
Yes, periods of rising temperatures has correlated quite well with rising seas. The highest increases recently have been aligned with the 30s and 90s. I would expect any future large temperature increase to be accompanied by a correspondingly large sea level rise.
No and No. Sea level rise has accellerated in the past, but not in the past decade, and poses no immediate concern. I have never denied that humans have influenced climate. Do you not see that I have attempted to emphasize exactly what this article is about, and it flew right over so many people’s heads?
First off, my apologies for confusing your post with Martin’s. With regards to the papers referenced: see figure 6 in the Fleming paper (first link) shows more detail than 3a, and shows ~16m lower sea levels 8000 years ago (at least Rob acknowledges that the paper shows 16m SLR, although he claims other research contradicts those conclusion). In the second link, the Leorri paper, you stated that the sea level reise over the past 7000 years was much lower. You are correct. However, my statement concerned the past 8000 years. This is similar to the presidential candidates in the debate arguing different statistics, both of which are correct, but extend over different time frames. Some have claimed that the Bruckner paper should be disregarded, because it focised on local sea levels. Well, the last I knew, the Mediterranean sea level was similar to the Atlantic (certainly not off by the several meters that would be necessarily to discount the paper). No one mentioned the McGriffiths paper. Probably because it showed 16m lower sea levels 7500 years ago. Again, don’t rely on what others (or myself) say, but read the original work – the entire paper. It is enlightening. I noticed no one showed any contradicting work.
Hmm. The graphic appears to show that island downdrop as a result of a falling seafloor ridge is responsible for landbased sea level changes. Open ocean seems to be 1.8 mm/yr, which has been standard for a long time.
[Response: Nonsense - look at the last figure - that is the open ocean field for this region over the same period. - gavin]
In any situation where the background is steady, the outliers, if not random, will determine the mathematically correct average of the group. But if the two groups (background and outliers) are not casually connected in their behaviour, the appearance will not represent the reality.
Darwin’s atolls and seamounts like under Bermuda create havens for carbonate organisms because what once was at sealevel sank at a rate acceptable to the organisms’ ability to maintain their preferred sealevel position. If all but a few, new oceanic features sink, rather than rise, then the data of the islands will pull the oceanic averages to the positive, sinking side. Is that what is going on?
If this is the case – sinking is the standard, only maintained by organisms’ debris-shedding, then Tuvalu have a problem that is organic, rather than sea-level. The question to be asked is what level of total buildup they are capable of, and whether sinking + sea-volume increase is within their capabilities. If CO2-enhanced melting is bringing only a 1.8 mm/yr added demand, I suspect that it is sinking, rather than glacial melting that is the problem.
Either that or local environmental degradation of the reef-building organisms.
Dan H, I’ll accept the apology, but not much the rest of your comment. Brückner should be discarded because it even specifically mentions the issue of tectonic movements and its large role in sea level changes in this region. Did you even get as far as reading the abstract?
Dan H – “What erroneous opinion do you think I am furious trying to support?”
You demonstrated it earlier with this comment:
“Sea levels have risen about 16m in the past 8000 years, just not at a constant rate”
The peer-reviewed scientific literature has shown this to be wrong. Very wrong. You simply made this up this claim – without having done any research whatsoever. No amount of scrambling through the literature is going to cover this gaffe.
Remember all those 3 metre beaches throughout the equatorial ocean?
To Gavin and company regarding the Golden Horseshoe Award:
I think that this post should go directly to the Bore Hole because it marks an important Bore Hole landmark. I am not kidding- read on.
Because I am already convinced about what climate science is telling us and one of my primary motives for being here is a fascination with anti-science denialism, I have decided that now is the time and this topic is the place to report on one of our very own disinformation stars. It is both scary and illuminating how effective very inept denialist propaganda can be, so the purpose of this geeky post is to honor one of our very own inept denialists- Dan H.
I have been monitoring the Bore Hole and with 150 posts in the Hole (yes I said geeky), Dan has demonstrated excellence in his trolling hobby. There is no one poster at Real Climate who can even reach up to Dan’s knees in providing incorrect information. Furthermore, Dan has displayed exceptionally relentless trolling (with the exception of a 6 month lapse in 2011) of the Real Climate forum.
I would like to, humbly, nominate this great trolling star here in our own backyard for one of Gavin’s Golden Horseshoe awards. With 150 posts and tens of thousands of words I can’t think of anyone who is more deserving. We should all put our hands together to honor our Dan.
Even more significant I think that it is important to recognize Dan’s contribution to the education of those who come to Real Climate for real science information. His predictable denialist methods, when combined with his easy to debunk misinformation, have provided innumerable excellent bad examples for educational correction purposes. Posts and counter posts could be collected into a training manual for understanding anti science methods. It would be a shame to not recognize Dan’s contribution to climate science education. I am overcome with emotion.
I think that this post should appear just after, Dan’s 150th post in the Bore Hole. On the other hand, if it doesn’t appear at all I could hardly complain. Steve
Here’s a chart for the past 8000 years. Note that between 8kya and 7kya sea level was skyrocketing. From 7kya to 4kya it rose a bit, from 4kya to 2kya it varied upwards, and since 2kya it has been FLAT. Dan H, in his infinite wisdom(?) decided to slather that 8-7kya rise across the board, thus enlightening(?) us all about how the current rise is typical. Take a sheet of paper to extrapolate the current rate back, and it hits the 8kya level a bit before 5kya, so even this inventive(?) analysis is wrongish, as the current rise is approaching double the average of the last 8000 years.
So, over the last 7000 years nothing nowhere for any amount of time comes remotely close to the current rate of rise, over the last 2000 years sea level has been flat, and Dan H wins the Most Misleading Poster Award.
And that 8kya to 7kya rise bears notice, as if that trajectory resumes it would really ruin our day…
Dave Person @61: Thank you. I copy your perspective. I used to think that
indignation about real climate science was just Galileo and Darwin all over
again. I don’t think that now: I think it’s Galileo and Darwin continued.
Don’t burn yourselves out.
People didn’t like it when their planet was cast out of the center of the universe, even though it was a step to greater learning. Now they don’t like it when they find that the planet is feeding back effects of their presence, in numbers over seven billion, and of their choices, decisions, minds, and best-laid schemes.
Dan H – You did not answer all my questions. I asked 4 questions, and you gave me 2 “nos.” Was it your intention to be confusing? I asked:
1) Do you believe that the sea level rise observed in the past 100 years is accelerating?
2) Do you believe that the observed sea level rise is the result of AGCC?
3) Do you think that this acceleration of sea level rise should cause any concern for human civilization?
4) Do you see how what you are doing is exactly what this particular post is pointing out?
If we assume that your “nos” answer questions one and two, then please produce ANY peer-reviewed science that states that sea level rise is not accelerating. And if you believe that AGCC is not causing the observed sea level rise, then please produce ANY peer-reviewed science that contains an alternate explanation as to why sea levels are rising. And if your answer to that is “we don’t know,” then please produce evidence of ANY kind of scientific consensus that shows that the majority of climate scientists agrees with that assessment. It would be helpful if you could do this all without having your post lost down the borehole again.
If you cannot do that, then please SERIOUSLY consider an answer to my last question.
please produce ANY peer-reviewed science that states that sea level rise is not accelerating
There are publications making this claim, but they’re unreliable. There is for instance Houston & Dean, and there has recently been a concerted effort to dispute sea level acceleration in the journal Natural Hazards such as this and this. Fascinating story.
I actually answers all your question, but will repeat them with clarity. Answers to your questions in order:
1. No. Sea level rise has shown two periods of acceleration during the 20th century, as mentioned previously. SLR did accelerate (past tense) during the 1990s, but data for the most recent decade is no different from the 20th century trend. There has been much debate as to the reasons and significance of this change. See tamino’s post for additional references.
2. The observed SLR is a direct result of the warming temperatures that have occurred since the late 19th century, both natural and anthropogenic.
3. Not at the present rate.
4. I will combine this answer with a response to Jim’s post. The SLR during the 20th century was higher than the average over the past two millenia – this is a direct reponse to Martin’s (not Marco’s) earlier comment about extrapolating back to the Roman Era. As Jim pointed out, which if you read my earlier posts is similar to my contention, if you average SLR over the past 8000 years, it is similar to that observed suring the 20th century. However, most of that rise occurred over the first 500-1000 years, with much smaller intervening rise. This is the point that I have been trying to make for the past few days, but people seem to have trouble distinguishing the forest from the trees. Cannot you not see how others have confused an average rate with a continuous rate? All the references I provided previously show this. Somehow, people here are trying to misinterpret these references, in a manner similar to the gist of this thread, which I have continued to acclaim.
- The glacal/interglacial (Holocene) transition was associated with a warming that drove a massive sea level rise. Since the ice sheets take a very long time to come to equiibrium with a new temperature, the ice sheets continued to melt well after the warming transition ended, so that melting and sea level rise continued to 6-7000 years ago. (the papers you linked to show this).
- Sea levels have changed rather little, if anything falling a tad, since the Roman period 2000 years ago to the start of the anthropogenic era. (Lambeck’s work especially).
- The small falling sea level trend up to the start of the anthropogenic era reversed in the middle to late 19th century to become a slow increasing trend at the start of the 20th century, accelerating through the 20th century. From 1870-1920 sea levels were rising around 1 mm/yr; throughout the middle to late 20th at around 2 mm/yr. Sea levels are rising a tad upwards of 3 mm yr-1 now. (see e.g. link in Charles’s post #84.)
- This observed acceleration of sea level rise as global temperatures increase in very much what one expects from a combination of thermal expansion and ice sheet melt, with the rate of both increasing as the global temperature increases. You said as much with your perceptive “SLR mimics temperature rise” assertion.
- Since “SLR mimics temperature rise”, we expect that SLR will continue to accelerate throughout the coming decades as the radiative imbalance at the top of the atmosphere continues to drive temperatures upwards.
- The sea level rise under the influence of enhanced temperatures resulting from anthropogenic enhancement of the greenhouse effect will continue for a very long time indeed, unless the temperature rise is reversed.
104 Dan H said, “Cannot you not see how others have confused an average rate with a continuous rate? ”
Lawyering is interesting but not useful. “Over the five minutes my client interacted with the so-called victim he inflicted an average of a small woman’s touch’s worth of force.” Yep, an apt description of shooting someone in the head, but we’d expect the jury to “not get” the argument “right”.
Excellent summary, although I made no forward going statment. I am not sure that I could decipher your quoted trend from the referenced link, but it does show 225mm of rise over 140 years, with a few hesitations in the 1880s, 1920s, and 1960s. The highlighted trend is slightly lower than that observed in the 1940s.
Excellent analogy, and I think it hammers home my point quite effectively.
One could search US media and be more likely to find an error filled climate story than an accurate one. The reason is not reporting incompetence, but self censorship and messaging from the owners. Much media income is derived from cars and various profligate consumer items. Journalists are the last ones to rock the boat.
There is no widely read and comprehensive climate change media criticism in this country. Reporters (as opposed to beancounters) would actually like to see this happen, and their bad stories checked.
About 87% of Europeans believe that climate change is a serious problem, a stat that is not even comprehensible in our country.
Their media is less entwined with fossil fuel advertisers, and there is still a public service tradition. Here in the US, that is considered quaint. We must revive it.
Regarding the idea of consistent SLR over the last several thousand years being “not even wrong”, I’d suggest this idea has been easily falsified in this thread which would make it just plain vanilla wrong. There is nothing unusual about the wrongness of the idea. Maybe it’s a nitpick but using “not even wrong” as a streetcorner perjorative for ideas that are just dumb makes no sense to me.
Dan – So you agree with Chris’ post? That is very surprising, judging from what I can get from you answer @104. If you agree with Chris, then why would you answer “no” to question 3?
Your answer to question 4 is about as clear as mud. This whole post is discussing how some people take the scientific facts and try to twist them around (sometimes far past any truth and into the realm of fantasy) to support their own contentions. Combining your answers @104, your answer of “no” to question 3, and your agreement with Chris’ analysis, I think you have binders of facts without any bit of rational analysis.
Dan H – “As Jim pointed out, which if you read my earlier posts is similar to my contention, if you average SLR over the past 8000 years, it is similar to that observed suring the 20th century”
Wrong – note the three metre beaches which are endemic to the equatorial oceans. Rates of sea level rise as small as 0.5mm per year during the last 4 thousand years would have completely submerged these exposed coral, wave marker notches, and sediments. Their dating, and their existence proves you are wrong.
And your previous reference to the Fleming (1998) paper was a predictable move. I already anticipated the obvious contrarian tactic of referencing outdated research – that’s one reason why it was included in my post on Holocene sea level highstands.
Have you watched this Jerry Mitrovica video yet? The evidence expounded by one of the world’s foremost experts on this topic is aimed squarely at the myths you are attempting to propagate here. Little wonder you don’t want to watch it. Never mind, it is useful to bring to the readers attention again and again.
Chris @ 105 – One further thing. As the analysis by Tamino makes clear, there have been short-term periods throughout the 20th Century where sea level rise has decelerated, but the long-term trend has been one of global sea level acceleration.
If we look just at the trend over the satellite altimetry period (1993 to 2011) it appears to have decelerated yet again. Part of this trend over the satellite-based observational period is due to the preponderance of La Nina in the latter part of the record, because La Nina is an interval when greater-than-normal rainfall is concentrated over land – and that rainfall is ultimately derived from the global oceans, which causes global sea level to temporarily fall. This sea level “pothole” trend has completely reversed this year as ENSO neutral conditions have taken hold.
The other contributor to the temporary deceleration is probably due to the slowdown in ocean heat content accumulation between 2004-2008. I say temporary because the Earth’s energy imbalance is close to 0.6 W/m2 over the last decade or so, and the Earth must warm to come back into balance. This warming will melt more land-based ice, and induce further thermal expansion of seawater over the coming decades. So the long-term expectation is that sea level will continue to rise, and will accelerate if the vast ice sheets of Greenland and Antarctica begin to disintegrate.
Now you probably know all this, but the casual reader may not.
Nature | Letter 日本語要約
Inland thinning of West Antarctic Ice Sheet steered along subglacial rifts
Nature 487, 468–471
(26 July 2012)
“… Here we report the discovery of a subglacial basin under Ferrigno Ice Stream up to 1.5 kilometres deep that connects the ice-sheet interior to the Bellingshausen Sea margin, and whose existence profoundly affects ice loss…..
… the ‘Belgica’ trough, which today routes warm open-ocean water back to the ice front7 to reinforce dynamic thinning….”
Dan H – I sincerely hope that you looked at the Jerry Mitrovica video that Rob posted, as he blows your answer to my question number 1 completely out of the water, along with a couple of your other arguments, to boot. I would be interested in hearing how you believe that he gets it wrong, and you get it right.
Your answer to my question number 2 is also evasive. What percentage of observed recent sea level rise do you believe has been caused by AGCC, as opposed to “natural” causes? What would those other causes be, what might be driving them, and where is your scientific evidence to support your claims?
In the four years I have been discussing this topic with you, it appears that your opinion has not changed in the least about any of this. Am I wrong? Does your opinion ever change? What causes it to change, if or when it does?
It is a pity that you did not do this several months ago. At that time, I was engaged in countering the “good Doctor’s statement on a denilaist blog. I did not have a good explanation. Good enough, though.
At 117+ comments this may just fall off the end BUT, this kind of thing is all too common in regional newspapers and in English language newspapers in non English speaking countries.
My old “local” paper The Border Watch frequently carries letters and opinion pieces that are “skeptic” in view. This may not be surprising as this is the “home town” of famous climate researcher and skeptic Leon Ashby.
Except for the Murdoch owned exceptions in Australia the skeptics don’t neccesarily dominate the news in the major papers. But in the smaller regional local papers hungry for content the situation is different.
The same may be true in non English speaking countries with an English language paper.
The sheer number of rubbish letters published from Queensland in a newspaper in a country in which Mr Forbes can have no actual interest is suspicious. Does he get paid for every published piece?
The army of darkness is focussing their attention on the lesser but still widely read “local” papers. Their message is especially well received where the local population is employed in traditionally “anti greeny” occupations like forestry, mining and farming/fishing. At this grassroots level is the climate message being heard?
Given that anti greens sentiment also appears correlated with anti intellectual sentiment, any “city expert” who appears to state the actual facts can be expected to meet a less than friendly reception.
Denialists play up to the country vs city (or intellectual vs “I ain’t got no uni education but…”) identity politics of this. A speaker at these meetings needs not only to “win” the factual debate but the emotional debate as well.
For all his flaws Steve Irwin was the kind of person for this audience.
Very interesting, if unsurprising. “Skeptics” have been given the green light by the US media to go ahead and lie like hell. Nobody is calling them on it in a systematic way, since it is a big task, requiring a lot of man hours (as you discovered in debunking a single comment).
We need infrastructure to do this properly, something I and some colleagues are working on. Interested parties can email me at firstname.lastname@example.org
Mike, please you and others can use this place http://climatestate.com/forum/other-projects.html to announce your project. With a weblink on other websites (backlink) your project also gains in google rankings and you help to improve the content and inspire others.
“… The Ferrigno Rift’s “existence profoundly affects ice loss,” Bingham and co-authors from the British Antarctic Survey wrote in a paper published in Nature … (July 25).
… the study authors write, the rift is providing a channel for warm ocean water to creep toward the interior of the West Antarctic Ice Sheet, gnawing away at the Ferrigno Glacier from below.
…. the overall effects could have implications for the stability of the West Antarctic Ice Sheet, which is responsible for 10 percent of global sea level rise that is currently happening.
Scientists are still only just beginning to understand the myriad mechanisms that control the seemingly dramatic melting observed in regions of West Antarctica, and how climate change is affecting all the moving parts….”
I agree that it’s way past the time for scientific reticence.
I have met laymen who were interested enough to actually read parts of the AR4 and said “if AGA is so certain, why don’t they plainly say so?”
The broader public will not figure out the physics for themselves and then demand an according policy from their government. It’s unrealistic to count on that level of public knowledge to enable change.
The message to the public should be as short and straight as that we have about tobacco in some countries. I picture credible institutions like NOAA or NASA or USGS endorsing billboards saying something like
“We thought Arctic sea ice would be as low as this only in fifty years. It’s happening now.”
“Remember last summer’s heatwave? That will be our mild summer in 2060. Protect our children’s future. Stop global warming.”
“40% of our freshwater comes from that glacier. Protect our water. Stop warming.”
At this point, no caveats, no graphs, no uncertainty ranges. If 9 out 10 planes crash over a certain route, we don’t say “It’s very likely that an unwanted outcome would take place. On the other hand, the survival rate suggests further research could yield different practices to be adopted”. The proper answer would be more like “no way”.
The present issue is no longer a scientific issue. It’s a PR one. PR has its own rules and laws, and they must be observed if you want to successfully get your message across.
I was unable to access the posted site for the video referenced, but was able to access it from Youtube (assuming it is the same Jerry Mitrovica video). I fail to see how this video “blows my answer completely out of the water.” His graphs shows SLR since 1930 from tidal gauges to average 2.3mm/yr, yet the most recent 10-yr trend is also 2.3mm/yr.
You also asked if my opinion ever changes, and what may cause it to change. Simple, a change in the scientific data. In the four years that we have been debating climate change, the GISS 120-month trend in global temperatures moved from +0.022C/decade to -0.093C/decade (lest you think I cherry-picked those value, the last 180 months shows a similar change in rate). During that time, the 120-month trend in SLR dipped from 2.88 mm/yr to 2.28 mm/yr. Since you are always asking for possible alternative explanations, Rob gives a few of the possible explanations for the recent observances in post #114.
Contrarily, the Arctic sea ice has shown a greater rate of decline during the past four years, resulting in my opinion changing to an ice-free summer Arctic in 2028. Jim can attest to this. Last I knew, I was still alive.
So, I will ask you the similar question, what will cause your opinion to change?
Global mean sea level (GMSL) dropped by 5 mm between the beginning of 2010 and mid 2011. This drop occurred despite the background rate of rise, 3 mm per year, which dominates most of the 18-year record observed by satellite altimeters. Using a combination of satellite and in situ data, we show that the decline in ocean mass, which explains the sea level drop, coincides with an equivalent increase in terrestrial water storage, primarily over Australia, northern South America, and Southeast Asia. This temporary shift of water from the ocean to land is closely related to the transition from El Niño conditions in 2009/10 to a strong 2010/11 La Niña, which affected precipitation patterns world-wide.
Geophys. Res. Lett.
Dan H, when asked, “Do you believe that the sea level rise observed in the past 100 years is accelerating?” answers: “No. Sea level rise has shown two periods of acceleration during the 20th century, as mentioned previously. SLR did accelerate (past tense) during the 1990s, but data for the most recent decade is no different from the 20th century trend.”
To that same question, Jerry Metrovica of Harvard says; “2mm of sea level rise per year, which is roughly the rate during the 20th Century, was anomalous, and is something the Earth has not seen for about 10,000 years – when it was in the midst of the last ice age deglaciation. [...] The rate of sea level rise has increased from the 20th century average of 2-2.5mm per year to over 3mm per year during the record of satellite-based observations (1993-present). [...] The future sea level rise projections of the 2007 IPCC report were too low. Current sea level rates are already at the uppermost range of projections, which reinforces this view. ”
The video to which I (and others) linked gives very strong evidence as to why this is true;
Dan – for a reasonable discussion, please watch the video and respond to Metrovica’s evidence.
I also asked you this question, to which you have not yet responded: “What percentage of observed recent sea level rise do you believe has been caused by AGCC, as opposed to “natural” causes? What would those other causes be, what might be driving them, and where is your scientific evidence to support your claims?”
What causes my opinion to change is by considering scientific evidence produced by knowledgeable people, and then having discussions and asking questions of such people. I must admit that I also learn a lot by researching and responding to claims I believe to be false (such as some of your claims). This web site is just such an invaluable resource that allows me to do all these things.
I am not even going to attempt to estimate what percentages are contributing to SLR. There are simply too many factors involved; glacial runoff, glacial isostatic rebound, thermal expansion of the oceans, groundwater pumping, not to mention the negative affect of dams. All this is without calculating what percentage of warming due to AGCC, other manmade influences, or natural causes. Maybe someone else here can help you with this one.
By the way, I did watch the video. That was where I got some of the data for my previous post. Did you even read my previous post?
Dan H – you said: “His [Jerry Metrovica's} graphs shows SLR since 1930 from tidal gauges to average 2.3mm/yr, yet the most recent 10-yr trend is also 2.3mm/yr." Metrovica says: "The rate of sea level rise has increased from the 20th century average of 2-2.5mm per year to over 3mm per year during the record of satellite-based observations (1993-present)." You and Metrovica completely disagree, but Metrovica fills the video with interesting and compelling evidence to support his opinions. You also said: "That [Metrovica's video] was where I got some of the data for my previous post.” Where did you get the rest of it? You are obviously cherry picking again, Dan. So tell me, why should we believe the disappearing logic of the mysterious Dan H over Jerry Metrovica of Harvard, particularly when you won’t even clearly identify your arguments or sources of information, and won’t even acknowledge the arguments of your opponent? You are not partaking in an honest scientific discussion – your are engaging in some kind of weird debate where you are trying to trick someone into agreeing with you based on your own private logic, supported by untraceable “facts,” pretending that you actually AGREE with your opponents.
And then when I ask you what else might be contributing to the observed sea level rise, you say, essential, I don’t know, there are way too many possibilities – go ask someone else to defend my indefensible statements! You act like I am asking you because I somehow TRUST your information and would accept it at face value. What I am actually trying to do is MAKE YOU DEFEND your illogical arguments, if you can. Really, Dan, is that the BEST you can do?
You are not paying attention close enough. Metrovica and I do not “completely disagree,” in fact, we actually agree. His figure of 3 mm/yr is over the timeframe 1993-2011. I am not disputing this. I used a figure from 2002-2012, and acknowledge that the rate was higher from 1993-2002 (in fact, the SLR was ~4mm/yr then).
[Response: Why? What happened in 2002 that makes it a particularly important point to break a calculation? Surely it couldn't be because that has a smaller trend? Hmm... - gavin]
The data comes from the University of Colorado, which uses the satellite altimetry (see the link in post #129), this data is not “untraceable,” but readily available to anyone.
Your last post is rather humorous in that you criticize my use of scientific data from research journals in favor of a Youtube video. Then, make some inane arguments about logic, just because I do not have all the answers to your questions. If you are really interested in all the particulars about contributions to sea level rise, I suggest you do some research of your own.
What may have given your intuition a hint that something was amiss here was perhaps the way the author kept referring to the goal of the research as being an effort to validate whether or not the islands were sinking, when in fact it was to see if sea levels are rising. This may seem like mere semantics, but the difference is one of accuracy over illusion. A difference that good science (and scientists) strives to maintain.
Kelley et al 2012, “Maximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century.”
…We find that many land-terminating sectors of the ice sheet, in addition to our study area, may have attained their maximum late Holocene extent during the 20th century. This suggests a lagged ice-margin response to prior cooling, such as the Little Ice Age, which would imply significant retreat of land-terminating sections of the Greenland Ice Sheet in response to 20th and 21st century warming may be yet to come.
I really don’t know how much SLR there will be this century, but the evidence is clear enough that the seas will rise – based on likely increases in temperature and paleo-climate data. If I was thinking of buying a coastal property and wanted it to go to heirs; I wouldn’t go any lower than 10m ASL. That’s giving a large safety factor to allow for increased erosion and brine percolation into ground water. IMO the time has definitely come for people to accept that they buy coastal properties at their own risk. That just leaves us to worry about what international aid we give to the destitute in countries like Bangladesh.
We will face enough problems this century without bailing out idiots who ignore the science.
> Nothing special, just the most recent decade. The data comes from the University of Colorado.
It is important to note the reason for the lower number in the most recent decade is because of the unusually strong 2011 La Nina. That fact (and link) was already provided by Hank in post 130, but since someone has missed it and instead tried to use the average to imply a slowing of sea level rise it is worth repeating.
“Global mean sea level (GMSL) dropped by 5 mm between the beginning of 2010 and mid 2011. This drop occurred despite the background rate of rise, 3 mm per year, which dominates most of the 18-year record observed by satellite altimeters. Using a combination of satellite and in situ data, we show that the decline in ocean mass, which explains the sea level drop, coincides with an equivalent increase in terrestrial water storage, primarily over Australia, northern South America, and Southeast Asia. This temporary shift of water from the ocean to land is closely related to the transition from El Niño conditions in 2009/10 to a strong 2010/11 La Niña, which affected precipitation patterns world-wide.”
The clear point here is that the average for the most recent decade is not because of some change in the underlying processes contributing to sea level rise, but is simply a reflection that for a year excessive rains dumped the ocean water on land. All the melting and heating is still increasing the sea level. It is actually more concerning that we can lose mass in the ocean due to inland sequestration and still have an average sea level rise.
In fact, if that poster implying a slowing of the sea level rise had read the links he shared he would know this. It is in fact the title of his second link in post 135. You’ll note that link clearly states the rate of SLR is *not* 2mm/year. There is in fact no sign of slowing. Using “the most recent” decade smoke & mirror is the same as using ENSO anomalies to pretend that global warming isn’t real.
Comment by Unsettled Scientist — 23 Oct 2012 @ 4:40 PM
I mention a cite with a link;
Dan claims it supports his claim.
Comment by John E. Pearson — 23 Oct 2012 @ 8:22 PM
Dan H – I did not post, or in any way refer to, a Youtube video.
Metrovica says in the video: “2mm of sea level rise per year, which is roughly the rate during the 20th Century, was anomalous, and is something the Earth has not seen for about 10,000 years – when it was in the midst of the last ice age deglaciation. […] The current rate of sea level rise varies from place to place, however this is to be expected due to the location and presence of land-based ice sheets, and gravitational changes brought about by the disintegration of these present-day glaciers and ice sheets. […] The rate of sea level rise has increased from the 20th century average of 2-2.5mm per year to over 3mm per year during the record of satellite-based observations (1993-present). […] The future sea level rise projections of the 2007 IPCC report were too low. Current sea level rates are already at the uppermost range of projections, which reinforces this view.”
Do you agree with all of that? If not, with what do you disagree? Those statements are in the video to which you claim to “actually agree.”
What I pointed out is that you haven’t posted the science to back up your own statements about the cause of the observed SLR. I do not believe that the observed SLR over time has any other major component than AGCC.
Your first link is a very small amount of water, which is BY DEFINITION an anthropogenic effect. Your second link is to a temporary and transient phenomena, and cannot support a continued rise over time. The third link says that Antarctica is melting and is contributing to SLR. Are you claiming that this melt is not an anthropogenic effect? The POSSIBLE 60-year oscillation of SLR mentioned in the fourth link is not global in effect, and the full amount cannot yet be measured. The fifth study refers to glacial and icecap melt. I would consider this to be an anthropogenic effect, also. If you disagree, what else would you claim is causing it? None of these studies support your claim that a significant proportion of the observed SLR is non-anthropogenic.
I do not know where you got your assumptions. When did I ever make the claim that you state in your last sentence?
Everything I stated, I backed up scientifically. There are many more papers on the various contributions to SLR, if you care to search them. Several posters have added to the possible cause(s) of the slowing in observed SLR recently. Do you disagree with them and the scientific links they posted also? Are you truly interested in the SLR contributions? You seem to be extremely critical of the views of others. What is your view on the contributions to SLR, and can you cite evidence to support it?
As I mentioned earlier, I was unable to open the link provided to the Mitrovica video, but was able to view it on Youtube. It does not appear to be available in scientific venues.
Here is a graph similar to that which Mitrovica presented:
148 Dan H said, “I will stop replying to his questions, if you insist.”
Great example of a GH, and I’m impressed with your writing skills. So few words, yet it infers, but does not explicitly say:
1 That the disruption was the question.
2. That your replies were on-point (as opposed to evasions)
3. That your initial comment did not initiate the chain of response.
4. That you’re ever so helpful and compliant.
I take your point that your opinion does change. Hyperbole is always technically incorrect, which feeds into your strengths (if one is keeping score instead of learning)
150 SecularA said, “You mean this isn’t Dan H’s blog? Because, you know, looking over this thread, he seems to own it.”
IEHR this nonsense with the tidal gauges started in the 1990s with the late John Daly Nil nisi and all that.
Us old timers remember the Isle of the Dead. However the lesson is bayonets and horses. When someone starts with such nonsense you need a memorable and amusing way of pointing out that they are clueless. After that, details are just details, you don’t have to confront each response, merely point out that they are a few fish short.
Dan H – here is a comment made by you on 11/9/09 on the change.org web site: “I am not challenging the greenhouse effect. [...] I am questioning the effect that a trace gas in the atmosphere has on the overall effect. There is a lot of evidence pointing towards human-induced climate change. There is also a lot of evidence that climate change is largely natural. What will it take to convince me? How about some solid scientific proof that CO2 is the primary climate driver? Until then, I remain highly skeptical.”
From the same site, 12/26/09: “To say that CO2 has no effect is probably under-estimating its effect. To say that it is the dominant or even a major player is probably over-estimating its effect. The sun and the oceans are the most influential forces on our climate, and yes, both are currently working together resulting in the recent temperature decrease.”
So what do you actually believe is causing SLR? Has your opinion changed since 2009?
Of course, you did not answer my first question @144 above, so something that might actually be interesting, like discussing Mitrovica’s (thanks, Hank) lecture, and what you may or may not agree with, remains undone. As a matter of fact, you did not answer most of my questions. This is no longer much of a scientific discussion if you will not directly respond to questions.
As for those of you who think that “Dan H” “owns” this thread – Dan H is EXACTLY what this thread is all about – someone who is spreading misleading information. What’s wrong with debunking him?
Thank you for the compliment, and yes, all four are accurate. Everyone should have an opinion that changes when new data is presenteded which overrides the preceding work. Otherwise, the discussion degrades into a barroom argument, which appears to occur here at times. I would gladly accept ownership of this thread, except that there is someone else who is more prevalent, with less infomative posts than myself.
I already answered all your questions – twice. Mitrovica showed a plot that sea levels increased ~2.3 mm/yr from 1930-2010. I agree. He then showed the satellite measurements indicating that SLR since 1993 has been 3.1 mm/yr. No disagreement there either. My main disagreement is with his contention that sea level has continued to accelerate. Over the first 10 years of the satellite record, the SLR was ~4 mm/yr, while during the most recent 10 years, it has fallen to ~2.3 mm/yr. Read some of the other posts here. The decrease in SLR over the past decade is well documented. Here is a detailed plot showing the SLR vs. ENSO, and a second order plot presented over at skeptical science (the same site which posted the Mitrovica video).
> while during the most recent 10 years, it has fallen to ~2.3 mm/yr
Once again this poster uses an average of the most recent decade to imply a slowing of of the sea level rise, failing to understand his own source. The link to Colorado Sea Level site has been posted here repeatedly and he continues to ignore it. IMO, unless it is acknowledged that the rate of sea level rise in the most recent decade is actually 3 mm/year, according to this poster’s own source, further repetition of this nonsense should be bore holed.
Dan H, here’s the quote from source you posted, again.
“The 2011 La Niña: So strong, the oceans fell
- Sea level drop in 2011 mainly caused by water exchange between ocean and land
- Exchange related to 2010/11 La Nina driving regional changes in precipitation
- Sea level decline is temporary as water will return to the ocean through runoff
Global mean sea level (GMSL) dropped by 5 mm between the beginning of 2010 and mid 2011. This drop occurred despite the background rate of rise, 3 mm per year, which dominates most of the 18-year record observed by satellite altimeters.”
Continually repeating that most recent decade has a rate of 2.3mm/year is to misrepresent the data, not to accept new data. Will you now acknowledge the fact that the data shows your calculated average is temporary? That this average you calculated does not reflect a change in the processes that are driving the current sea level rise? That it is not a decrease in SLR, it is only a temporary drop in the SL due to the excessive dumping of ocean water on land for one year? Or are you going to keep ignoring the scientific resources you posted?
General readers, I think it should be blatant that Dan H is misrepresenting the science at this point. He is cherry picking a decadal average in which a La Nina event distorts that average to imply a slowing of SLR when his own source says that is not the case.
Comment by Unsettled Scientist — 25 Oct 2012 @ 11:55 AM
Continually repeating that most recent decade has a rate of 2.3mm/year is to misrepresent the data, not to accept new data. Will you now acknowledge the fact that the data shows your calculated average is temporary?
Dan H knows exactly what he is doing and no, he won’t acknowledge the fact that the source he cites does not support his position. He’s never done so before, why would you expect him to do so now?
People continue to engage DanH as though he’s posting in good faith, for reasons that I fail to understand.
> People continue to engage DanH as though he’s posting in good faith, for reasons that I fail to understand.
I may have addressed him directly, but I try to write for the general readership which in my mind requires something of good manners rather than good faith. If I had faith in that person I wouldn’t have said to bore hole him if he just keeps repeating this same misleading point over and over and over. I probably should have left the questions out though, and stuck with just the facts.
The thing to understand about the most recent decade is that the physical processes driving sea level rise have not reversed, and are actually getting worse. The reason the arithmetic works out to appear as if there is a slow in the rise of the sea level is that very large La Nina a couple years ago. As the scientific resources point out, this appearance of a slow down is only temporary. When, instead of just looking at a line on a graph and doing a little calculation, we understand the physical processes driving sea level rise then we can see that we are not turning around to better times.
Comment by Unsettled Scientist — 25 Oct 2012 @ 12:53 PM
oops. Another lovely talking point slain by a perfidious observation
There is no misrepresentaion of the data. Over the entire data set, the rate is 3.1 mm/yr. During the first portion, it was higher, and lower during the second half. Claims of El Ninos influencimg the rate to the high side, and La Ninas influencing to the low side are fine. Scientific explanations to esplain the decrease in SLR are always welcome. To claim that this misrepresents the data is false. The current decadal trend is 2.3 mm/yr, and may indeed be temporary. Hanks most recent post shows that the trend has already decreased to 2.8 mm/yr.
Dan H – you have said you agree with Mitrovica, except where you don’t agree with him, depending on which post I am looking at. Mitrovica thinks that SLR is accelerating, but you do not. I would call that a pretty big disagreement, as that observation dictates how critical it would be to respond to AGCC. As many posters have pointed out, a good, scientifically valid interpretation of the raw data is not as straightforward as you claim. Cherry picking short-term data isn’t credible. I concur with Jim Larsen – would you care to respond?
Dhogaza – Dan H may or may not be posting in good faith. Does that really matter? His goal seems to be to be the archetypal denier’s goal – to attempt to create enough doubt about the science in anyone who will listen to delay their taking any kind of meaningful action to address AGCC. As the Buddhists say, the world is changed one person at a time (or not). And as the Hindus say, the true enemies of Krishna are the ones who go around attempting to make the unimportant things important. Dan H used to do the exact same thing on another blog. I’ll tell you one thing – ignoring him will not make him go away. Neither will condemning his posts to the borehole. So what is left? Calling him out and asking him once again to defend his indefensible position…
Laboratory for Satellite Altimetry / Sea level rise
“… estimates of sea level rise based on measurements from satellite radar altimeters. ….
… The estimates of sea level rise do not include glacial isostatic adjustment effects on the geoid, which are modeled to be +0.2 to +0.5 mm/year when globally averaged.”
Dan H wrote > “Scientific explanations to esplain the decrease in SLR are always welcome.”
Welcome, perhaps, but you have blatantly and repeatedly ignored it. You even ignored it from your own source. Please read your own source. For the final time, the quote below is cut & paste from the peer-reviewed scientific literature which you have linked to but have either not understood or have misrepresented.
“Sea level drop in 2011 mainly caused by water exchange between ocean and land. Sea level decline is temporary as water will return to the ocean through runoff. This drop occurred despite the background rate of rise, 3 mm per year, which dominates most of the 18-year record observed by satellite altimeters. This temporary shift of water from the ocean to land is closely related to the transition from El Niño conditions in 2009/10 to a strong 2010/11 La Niña, which affected precipitation patterns world-wide.”
That is the scientific explanation. It is not a a decrease in sea level *rise*, it is a temporary decrease in sea level. The background rate of SLR remains the same. Those key points are made both at the Colorado Sea Level site (from which you get the data) and the AGU peer-reviewed paper to which you linked.
Comment by Unsettled Scientist — 26 Oct 2012 @ 12:58 PM
> Hanks most recent post shows that
> the trend has already decreased
No, it doesn’t show that, Dan H.
You didn’t read the captions or the FAQ; you compared pictures from two different sources charting different analyses.
From that fake comparison you claimed a change in trend.
You take bits from what others wrote in the thread, add an unchanging talking point, and post something that looks superficially like an actual comment.
Kids, don’t believe everything you read on the Intertubes.
Some of them are just delivering sludge you don’t want.
For the exercise, here’s how to check the claim “Dan H.” made:
This: Colorado (source for the first trend number)
Read their FAQs linked on the page.
Colorado: “Glacial isostatic adjustment … contributes 0.3 mm/yr … a small effect since it is less than our estimated error of 0.4 mm/yr.”
This: NOAA (source for the slightly lower number Dan H. misused claiming it “decreased”)
Read their captions and linked text.
NOAA: “The estimates of sea level rise do not include glacial isostatic adjustment effects on the geoid, which are modeled to be +0.2 to +0.5 mm/year when globally averaged.”
[Response: Why do you think I can accept or not accept a figure that has no provenance, no reference, and appears to be detrended - when the exact issue is the trend? If you want to interact on scientific level here, please cite sources and describe methods of any results you want others to accept - it's really not that hard. - gavin]
I’ve often found myself doing exactly what will make others think the least of me possible. Holding onto a position, such as you’re doing by saying raw data trumps all ONLY in sea level rise, but in other cases, such as heat islands, raw data is useless, well, that makes folks think you’re a twit and a jerk. So, your choice is to grasp your initial comment tightly and ensure everyone else thinks the absolute worst of you…
or man up and evolve. Do you know how many Brownie Points you could earn by bragging about how much you’ve learned? There’s few better ways to boost your star than by starting with, “I was wrong, but now…”
#169–Yes, Canada has friends of science, Oz has–well, I misremember the name, but nutso bunch. Even read recently as how Japan’s anti-nuclear crowd has a strong denialist streak. Denialism is not nearly so well contained as one might wish.
Gavin & Didactylow, it appears that uncited random graph of the detrended Pacific Ocean sea level was made by Bob Tisdale for an August 2011 post on WUWT. Not what any of us would consider to be a scientific resource, and it is certainly not peer-reviewed nor in any well respected journal. There really is no reason to discuss that graph any further. Gavin’s point about the lack of rigor and silly baiting attempt is enough.
Comment by Unsettled Scientist — 26 Oct 2012 @ 11:26 PM
Didactylos, sorry about misspelling your moniker.
Comment by Unsettled Scientist — 26 Oct 2012 @ 11:27 PM
Yes, that’s the guy! He specialises in numerical gymnastics that eventually arrive at a tautology, but get presented as meaning something else. I see why Dan didn’t give the source – if he had, nobody here would even have looked at it.
PS: I can’t believe you still haven’t fixed the spam filter to whitelist real words like specialise. And I can’t believe that the spam filter can be defeated so easily!
Dan H – refer to 170, Gavin’s response at 176, plus 174, 175, 178, and 180 (I may have missed some). Do you still insist that SLR is slowing down? If so, how do you explain the strongly supported arguments in 174 and 175? Don’t get coy on us now!
Tamino has a new post on Sea Unlevel… I don’t know if it’s worth sending Dan H over for a read or not… Following this whole sequence I can’t help but be reminded of Doug Bostrom’s comments on a similar wild goose chase a while back: “Those aren’t the droids we’re looking for…”
Hanks most recent post shows that the trend has already decreased to 2.8 mm/yr.
But, but, but… The trend shown on that chart is, as you say, 2.8mm/yr; but (firstly) your claim was that the trend had dropped to 2.3mm. Given that the error on the chart is stated at 0.4mm, it disproves the claim (and, of course, Mitrovica’s 3mm/yr is within the error bars…).
Secondly, looking at the current trajectory of sea level rise on that chart, which way would you guess the trend is going to go?
Thirdly, you are still including the reduction in sea-level due to the change in ENSO phase as reducing the background trend. Take that out, and the 2.8mm/yr trend in the chart would go over 3mm/yr.
The trend for the entire Jason data (2002-present) is 2.3 mm/yr. The trend for the Topex data (1993-2002) is higher, 3.3 mm/yr. The posted 2.8 mm/yr may be an average of the two data sets (as it covers the entire time frame). Yes, the most recent La Nina is included in the Jason data. As are the La Ninas from 2009, 2008 and 2006. Also included are the El Ninos from 2010, 2007, 2004, and 2003. The ENSO index was neutral at the start of the data, and in currently neutral today. The data show no current trends toward an increase or decrease in SLR. Be careful to whom you listen, some people just cannot add.
So true. While the icecap article yielded a supporting conclusion, the graph displayed did not. The poster then admitted that he was wrong in using that article to support his position. Thatwas just one of four references, and the other three were valid.
Dan H – once again, you did not answer my questions.
So Jerry Mitrovica of Harvard says that SLR is definitely increasing. When you compare tide gage readings of the early 20th century with the satellite data since 1993, and interpret them properly, there has been a definite increase in SLR in the last part of the 20th century into the first part of the 21st. Dan H, of unknown employment and education, and without providing any support for his statements, disagrees, and implies that Jerry Mitrovica cannot add.
Dan H – Icecap is a ridiculously biased web site that includes blatant name-calling in the titles of many of its articles. Of course, you did not link to the article to which you were referring. Is that the best you can do to try to defend your reputation, NOT LINK to an unidentified article on a highly biased web site?
Out of curiosity, are you aware that JoNova covered this topic and the data your refer to in the SEAFRAME study; however, the report you posted goes only to 2006. Data continued. Here is a post from 2010 seems to indicate that the trend is such that, in 50 years, it will have zeroed out. What are your thoughts?
[Response: Your claim makes no sense since you are not only extrapolating a trend, but the second derivative of sea level, without any understanding of what is driving either. Nova's headline is simply untrue. The trends from the early 90s to the near present (2011 in the second tide gauge data figure, 2012 in the satellite-derived field) are shown in the last two figures in this post and flatly contradict Nova's statement. How can you support that? The trends are not only still all positive, all-but-one are larger than the global mean change! Going forward, one might expect them to converge on the global mean trend in the absence of any climate change impact on ENSO, but the idea that they are suddenly going to go to zero makes no physical sense. - gavin]
As Tamino told you, “You might begin by wondering why you choose to get your information from websites like “icecap” which pontificate on the subject of drought when they don’t even know the right sign for the PDSI. Perhaps they’re simply not trustworthy?”
Robin and any others following the link I provided will note that you were given a good whipping on all of your points.
Thanks again for exemplifying this thread’s topic.
The trend for the entire Jason data (2002-present) is 2.3 mm/yr. The trend for the Topex data (1993-2002) is higher, 3.3 mm/yr. The posted 2.8 mm/yr may be an average of the two data sets (as it covers the entire time frame)
“An average”? No; it is the trend for the entire period – that’s what that graph thingummy is telling you.
Yes, the most recent La Nina is included in the Jason data. As are the La Ninas from 2009, 2008 and 2006. Also included are the El Ninos from 2010, 2007, 2004, and 2003.
Oddly enough, it makes a difference how strong the event is. Simply eyeballing the graph, the recent El Nino had an exceptional effect upon the figures.
The ENSO index was neutral at the start of the data, and in currently neutral today.
the Multivariate ENSO index was pretty positive (value c1.0) at the start of the data; and is significantly less so (value .27) now. That would imply, all other things being equal, a drop in sea-level between then and now.
The data show no current trends toward an increase or decrease in SLR.
The way that the current numbers are rocketing above the trend-line doesn’t suggest to you that the next move in the trend is likely to be upwards?
> Yes, the most recent La Nina is included in the Jason data. As are the La Ninas from 2009, 2008 and 2006. Also included are the El Ninos from 2010, 2007, 2004, and 2003
Yes, this is why your simplistic averaging is meaningless. It’s not about El Ninos offsetting La Ninas. But you know this and continue to ignore the scientific explanation in your own sources. Once again, it was during the transition from El Niño conditions in 2009/10 to a strong 2010/11 La Niña that an enormous amount of ocean water was dumped on land, and this effect on sea level is large but temporary.
If you’re gonna bring up another topic, like the index, you might want to cite which one you are referring to. As has been pointed out, you often misinterpret these kinds of things, especially if they have “index” in the name. For example, if you mean the Multivariate ENSO Index then its being neutral has absolutely no impact on this discussion. The six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). Mentioning the ENSO index being neutral is also meaningless to this discussion except that it serves your ability to confuse the general readership.
I am not sure at what data you are looking, but the MEI Index from the noaa link lists -0.21 for Feb, 2002, which is quite close to neutral. Today it is slightly positive (0.27), but both this readings can be classified as La Nada (ENSO neutral). JISAO data, to which unsettled linked at #197, shows similar readings. While I do not disagree that sea levels fell during the recent La Nina, the trend was not rising prior to its onset. In fact, the Jason trend from 2002 – May,2010 (at which point ENSO switched from positive to negative) was 2.5 mm/yr. The trend was already falling before the LA Nina kicked in.
I answered your questions previously. I think everyone here agrees that SLR increased from the early 20th to late 20th century. However, the increase did not continue into the 21th century. Several posters have responded that the recent La Nina was responsible for all or part of the decrease measured recently. What other question do you have to which you think I have not responded?
Enough with the sea level. The horse is long dead, can we stop beating it?
Reading the post (and there are many), I cannot see much difference. Therefore, I propose that we agree on a few statements and go on:
1. Sea level started rising in the early 20th century, and averaged ~2mm/yr based on tidal gauge data (the exact figure being dependent upon the database and years chosen).
2. After the launch of the TOPEX satelite in 1993, sea levels were observed to rise at a higher rate than previously measured, possibly due to the persistent El Ninos.
3. Starting in 2002, after the launch of the Jason satellites, SLR slowed slightly, again possibly due to the recent La Nina.
Most of the disagreement appears to hinge on the last statement, and whether it is a significant trend change or just a temporary dip. Is this satisfiable to everyone?
RE: 194. Suppose your right Gavin. Well, ‘cept the report you published ends with:
“Historical sea level trends, and even to an extent the current SEAFRAME sea level
trends, would suggest that we could expect sea level rises of less than 0.5m over the
next 50 years, which is considerably at variance to current scientific commentary. It
is possible, therefore, that the effects of recent accelerations in climate change have
not yet started to have a significant contribution to or impact on current sea levels; but
based on international scientific opinion, it is more a case of when, rather than if.”
What do they mean by “variance to current scientific commentary?” I think there is a typo in there too because the last sentence says “scientific opinion”, don’t they mean consensus?
[Response: Working out what people mean by vague and unsourced statements is always difficult. However, 50cm in the next 50 years is quite serious and at the high end of predictions. Acceleration is expected because of both (small) accelerations in thermal expansion and (larger, though more uncertain) accelerations in ice sheet loss - which is indeed a widely held opinion, and indicative that scientists don't think that linear extrapolations are particularly informative. - gavin]
Dan H, you don’t understand what you are saying. I repeat since you ignore it, MEI index is meaningless for this discussion. You are refusing to acknowledge the science in your redundant posting. You don’t acknowledge the physical processes in the real world, and you didn’t acknowledge that the MEI is not related to sea level rise. There are no variables in the MEI that are for sea level rise. Who cares what the index is, positive, negative or neutral… it has nothing to do with sea level rise.
Comment by Unsettled Scientist — 31 Oct 2012 @ 3:32 PM
Re: 203 Gavin, I have to agree that their summation was subjective, I could clearly see that. I was seriously asking what they thought it was diverging from. I know that Dr. Hansen, as late as 2001, was saying he expected water to be over the West Side Hwy in 20 years (that would be 2021). I believe that would be anywhere from 5 to 10 feet. I image we all know that’s not going to happen so I was trying to figure out who they were referring too. Again, subjective. (okay, the consensus comment was snarky, the consensus survey didn’t come out until 2009 and the SEAFRAME report was from 2006)
I understand from the literature that the various ice sheets on water in the arctic and Ross are melting, but the ice sheet on land over the Antarctic is growing currently, is this not the case? (Mass Gains of the Antarctic Ice Sheet Exceed Losses, Zwally et al, 2008) You asked in 194 how the sea level trend could to go 0, that would do it wouldn’t it (speculation, but there is a probability greater than 0, true?)
[Response: The most recent assessment of mass loss in Antarctica just came out (and we will have a post on this at some point) (King et al, 2012) and suggest +0.19 ± 0.05 mm yr−1 sea-level equivalent. Previous discussions of sea level rise can be found here, here and here. Barring some huge volcano, asteroid impact or other completely unforseen tectonic disaster, there is no conceivable way that sea level will stop rising any time in the next century. None. - gavin]
Re: 205 That was rather definitive, thank you. And I assumed Dr. Hansan’s comments were simply hyperbole. I thought so at the time for what it’s worth, I wish he wouldn’t have said that because it’s been used as a hammer (I’ve been on both sides of the argument, positionally that is). What drew me to this thread was that I did some work with the University of Hawaii with the Micronesian group. I did some initial programming for one of the sites that eventually became part of SEAFRAME, at the time to be setup in the future, so I had an interest). Thank you for your thoughtful responses.
brief quote from one of many links at the Bathtub page
==== start quote====
How to keep New York afloat
With sea levels rising, once-a-century floods may become once-in-20-years events. One solution: huge storm-surge barriers.
By Moises Velasquez-Manoff, Contributor to The Christian Science Monitor / November 9, 2006
Like many New Yorkers, Radley Horton often frets about tomorrow’s weather. Unlike many, it’s his job. A scientist at NASA’s Goddard Institute for Space Studies (GISS) and coauthor of a forthcoming study on the effects of climate change in New York City, he is particularly concerned about an often-overlooked aspect of global warming: bigger, stronger storms.
“It’s not a linear relationship,” he says on a subway ride to Manhattan’s South Ferry station, which would be mostly underwater in a Category 2 hurricane….”
Dan H – Questions I have asked that you have not answered:
“Refer to 170, Gavin’s response at 176, plus 174, 175, 178, and 180 (I may have missed some). Do you still insist that SLR is slowing down? If so, how do you explain the strongly supported arguments in 174 and 175?”
Dan: “The increase (SLR) did not continue into the 21st century.” It seems that the great majority of the scientists who study SLR closely completely disagree with you. Can you refer me to a peer-reviewed study that says that SLR increase did not continue into the 21st century? Is the best argument you can muster that these scientists can’t add, as opposed to Dan H, who can?
Charles – the important points about SLR that I can ascertain from the scientific evidence I have seen are that sea level is rising, the rise is accelerating, and that this rise is unprecedented since the end of the last ice age. The best evidence is all pointing in that direction. We also have a very good explanation for the observed SLR – anthropogenic global climate change. Yes, the signal is noisy. There are good explanations for the recent noise. Yes, SLR is geographically uneven – we have good explanations for that uneveness, also. Claims that SLR has “slowed” recently are not well supported (sounds just like “global warming has stopped since [insert recent cherry-picked date here]“). Claims that the observed SLR has been going on for over a thousand years or that the observed SLR is not significant in terms of impact on human societies is hogwash. Please see Atlantic City.
Re- Comment by Hank Roberts — 31 Oct 2012 @ 8:28 PM:
I am not really sure about this but I thought that the problem with New York City is that all of the street drains empty into the ocean and would also have to be blocked from surges. Once blocked any rain would have nowhere to go. Steve
RE: 207::Hank Roberts, you are correct, I amend the 2021 to 2028, I was talking off the top of my head on that one, should have double checked. At this point, I don’t believe that will make a difference that the Hwy will be underwater in 2021 or 2028, the models have been amended since 1988. He did say he’s sticking by his predictions in 2001 so, well, that doesn’t make sense to me. That amount of sea level rise is not predicted as Gavin points out; 50cm in 50 years will not put the hwy under water (as Gavin points out, that’s the upper end of the forecast). I still take that as Hyperbole and not helpful to the discussion.
With regards to the arguments about SLR slowing, Hank, Unsettled, and Robin presented an explanation that the slowing was due to the strong La Nina event. See posts 129,130,142,157,163,198, and your example of 174. I have neither agreed nor disagreed with this explanation, as it is plausible. Since you refuse to accept an explanation that I give, why not check out their explanations? Here is the same link to the paper by Steve Nerem that Hank provided in post 157, followed by additional published work by Nerem.
I am not sure at what data you are looking, but the MEI Index from the noaa link lists -0.21 for Feb, 2002, which is quite close to neutral.
I appreciate that this is probably a silly question, but why select February 2002, which is before the TOPEX time series starts, rather than say November or December 2002, closer to the start of that series (wthe very end of 1992), where the values of MEI are at 1.057 and 1.109 respectively?
Today it is slightly positive (0.27), but both this readings can be classified as La Nada (ENSO neutral).
Well, today’s can…
JISAO data, to which unsettled linked at #197, shows similar readings.
And the JISAO data shows even more clearly that you are cherrypicking your readings. The temperature anomaly was negative in only one month in 2002 (and then only marginally); the astute reader can guess which month that is.
While I do not disagree that sea levels fell during the recent La Nina, the trend was not rising prior to its onset. In fact, the Jason trend from 2002 – May,2010 (at which point ENSO switched from positive to negative) was 2.5 mm/yr. The trend was already falling before the LA Nina kicked in.
Are you trying to say that if you adjust for the anomalies caused by El Nino and La Nina moving water from ocean to land or vice versa, sea level rise is slowing down?
Feb. 2002, was the start date of the Jason satellite data. When viewing the graph of SLR from U of Colorado, the data switches from TOPEX to Jason-1 at that date. I did not select the data based on JISAO, which was referenced by Unsettled in 198, and the values in the preceding and subsequent months are not all that different.
I have done no adjusting for ENSO anomalies in sea level calculations. Others have made such a claim that the cause for the recently observed decline in SLR can be attributed to such. As I stated to Craig, I make no acceptance or rejection of this explanation. My last statement was simply that the SLR was trending lower in the Jason data (2/02 – 5/10) before the 2011 La Nina occurrence. Afterwards, the SLR fell further. Gavin and I already had a discussion concerning detrended SLR graphs.
Yes. It shows how a flat or slightly negative trend can get lost when lumped together with a longer, positive trend. A similar occurance has been occurring here. Very good analogy. Perhaps the slowing in global temperatures is responsible for the slowing in SLR.
220. another example of missing the point, intentionally, by no-analysis Dan.
Astounding it may be, but “The continuation of the linear trend from August 1975 to July 1997 (green dashed), would have predicted a temperature anomaly in August 2012 of 0.524ºC. The actual temperature anomaly in August 2012 was 0.525ºC.”
Congratulations, Dan H. ! You’ve gone full circle. After muddying the waters on sea level rise, you now link your incorrect statements on sea level to your original incorrect statement on a ‘slowing in global temperatures’.
Just like Abbott and Costello (although they were funnier) http://www.youtube.com/watch?v=sShMA85pv8M&feature=related
The “hogwash” that SLR has been going on for over a thousand years was a facetious statement made by Martin, that was misinterpreted by several posters. Yes, I was the one who originally confused Martin and Marco, which led to more confusion.
I presume you are referring to hurricane Sandy coming ashore near Atlantic City. I hope you are not implying that the damage would have been significantly less without the eight inches that the sea level rose during the 20th century. The fact that Sandy came ashore at high tide during a full moon had a bigger impact.
218 Dan H said, “Others have made such a claim that the cause for the recently observed decline in SLR can be attributed to such. As I stated to Craig, I make no acceptance or rejection of this explanation.”
Ah, one core of this thread. When provided with additional data, does Dan H modify his position?
No. He simply ignores the data. I stand by, and elevate from hyperbole to nearly universal truth:
Dan H – SLR has increased since satellite data has been available. You are the one who has arbitrarily picked a start point (as Gavin pointed out) to suggest a SLR “slowdown.” – “the most recent 10-yr trend is also 2.3mm/yr.” As a matter of fact, on this thread, you have also said, “Overall, the global sea level has been (and continues) to rise at ~ 2mm/yr,” which TOTALLY IGNORES the recent satellite data. You continue to use or ignore data and to cherry pick start and end points as you see fit to try to make your case. The Mitrovica tape, which you refuse to discuss, clearly states the research supporting why SLR has accelerated. Nevertheless, here is a good analysis that shows the recent SLR increase, contrary to your claims, without cherry picking:
Dan, you have said: “The sun and the oceans are the most influential forces on our climate.” Now you want to avoid acknowledging that ocean phenomena such as El Niño might have any effect on SLR – “I have neither agreed nor disagreed with this explanation”. Brilliant.
Charles – Dan H stated: “Sea levels have risen about 16m in the past 8000 years, just not at a constant rate” earlier on this thread. That’s hogwash.
When you add eight inches of floodwater on top of an already record-high flood, increased atmospheric moisture, increased ocean temperature, and very widespread winds, I would say that hurricane Sandy damage was “significantly” enhanced by global warming and the accompanied SLR. It might be interesting to attempt to calculate the added kinetic energy of an extra 8 inches of wind-driven water spread out over the entire New Jersey and New York coastline. What portion of the early estimated $50 billion of hurricane Sandy damage was caused by this eight inches of water would be hard to say, but just arbitrarily, 1% of that would be $500 million. I guess it comes down to what you consider “significant.” I would consider $500 million significant.
“… Lying is an initiation into the conservative elite. In this respect, as in so many others, it’s like multilayer marketing: the ones at the top reap the reward—and then they preen, pleased with themselves for mastering the game…. Sneering at, or ignoring, your earnest high-minded mandarin gatekeepers—“we’re not going to let our campaign be dictated by fact-checkers,” … is another part of closing the deal.”
226 Dan H said, “What is this data which I am supposedly ignoring? How would such data cause me to modify my position?”
My last comment, and yes, I know it’s useless. (Sorry, Susan)
If extra rain pulls water out of the ocean and dumps it on land, then one would expect sea level to drop. Since that water will mostly run back to the ocean, the drop doesn’t “count” and sea level measurements *must* be adjusted to account for the temporary anomaly. You were presented this data repeatedly. Your choices were:
1. Accept the new information and change your position.
2. Deny the accuracy of the information and provide substantiation.
3. Ignore it so your position can remain static.
218 Dan H said, “Others have made such a claim that the cause for the recently observed decline in SLR can be attributed to such. As I stated to Craig, I make no acceptance or rejection of this explanation.”
I have accepted the new information and stated it as a plausible cause for the decline in sea levels over the past 24 months. It is others, such as Craig, who has disputed that SLR has slowed as a result. As I posted previosuly, SLR had slowed prior to the recent La Nina; the increase was 2.5 mm/yr from the launch of Jason-1 until the end of the last El Nino in 2010. While I accept that the recent La Nina has lowered SLR further, the decrease is less than the decrease that occurred prior to its onset. No one has offerred an explanation for the decrease prior to the La Nina.
You seem to attack me for acknowledging the information concerning the recent La Nina, but what about those who deny that SLR has slowed since 2002?
Re- “Comment by Susan Anderson — 3 Nov 2012 @ 10:36 PM:
I agree. To spend the time to produce long, detailed, rebuttals to a troll is making his/her trolling successful. Write very short (e.g. a few sentences) factual responses (e.g. “That is not true, provide evidence). Or just don’t feed the trolls. Steve
Dan H says in essence – No, no, it wasn’t me, it was people like Craig who got it wrong!
I said nothing about SLR over as short a period as 24 months – NOTHING. You just made that up. That time period is too short to be meaningful for the long-term trends being discussed, which is particularly true for the short end period of a longer sequence. My shortest timeframe was almost 20 years, and the timeframe to which I was referring was that short only because that is the maximum length of time we have been getting that type of satellite data.
You are the only one trying to make arguments about the longer trend based on cherry-picked time frames as short as that.
You have made some pretty outrageous (and unsupported) claims here, so suck it up and accept the criticism that comes with making such claims, and stop trying to blame others for your statements.
Susan – I feel your pain. I have been arguing with “Dan H” about this same stuff for years. He doesn’t quit. He’s right now depositing his droppings of climate-change doubt on the newest post on RealClimate, hoping he can get some new poster there to take him seriously.
“You complain about cherry-picking, then say you only use the data for a 20-year timeframe. Why not use the other data?”
Because there is no satellite data before 1992.
However, if one use tidal gauges, data from 1870 is available. Church, J. A., and N. J. White (2006), “A 20th century acceleration in global sea-level rise”, Geophys. Res. Lett., 33, L01602, doi:10.1029/2005GL024826.
Note the title of the paper. No cherry picking on Craig’s part after all.
No matter how often that has been pointed out,
in threads where the “Charles” poster would have seen it,
the “Why not use the other data?” talking point
gets rebunked; seems like old text, maybe an
automated posting triggered by keywords.
in the 21st century a bunch of ocean water was dumped on land causing what some with weak minds interpret as a change in the underlying sea level rise while ignoring the scientific explanation that this change in decadal average is only a temporary change sea level and unrelated to sea level rise. some people have been told this repeatedly in this very thread and still ignore it with posts designed to confuse lay readers. those people ignore the physical processes in the real world and only talk about the trend in the data.
Comment by Unsettled Scientist — 6 Nov 2012 @ 7:13 PM
Exactly! But those weak-minded people keep ignoring this no matter how much it is repeatedly pointed out to them. Those people look only at the trend over the entire period and compare it to the trend from a century ago. Look at the Jason satellite data prior to the recent La Nina.
Dan H said: “The issue is was has [sic] happened in the 21st century.” Actually, there is no scientific issue. The noise is too large in a short time span to determine any statistically significant change in signal. The issue is why somebody would fall for such foolish nonsense, or propound it.
I agree that it appears likely that La Niña is responsible for the slightly lower SLR in the past 24 months. In fact, I believe that this supports my point that short-term fluctuations do little to inform us about the longer-term trend. We usually need more data to understand the most recent short-term fluctuations, but that will always be true for every new short-term variation during the most recent time periods. This does not mean that the clearly observed long-term trend is not real or has no explanation.
Which brings us to Dan H – trying to claim that the most recent change in the tail end of any data set somehow is significant to the long-term trend, as you continue to do (I assume to try to cast doubt on the reality of AGCC, since that is what you have always done in the past) is getting old. In a noisy system, noise at the end of a data set is still only noise. That’s like interpreting the observation that each wave recedes means that the tide may have changed after each and every wave, regardless of what our more long-term observations (like the tide charts) are telling us.
How much data is needed to detect a trend? It depends completely on which data set and how much of it you’re testing (and whether you are doing a one-tail or two-tail test, I expect). Look at examples:
One comment on a paper seems to say two decades of data would suffice:
“… climate models … in the last two decades … failed any validation with the much more reliable tide gauge measurements”
(that’s a criticism of a paper that assesses storm surge risk for Long Island as it may change with global warming, worth a look since it describes what areas are most at risk: http://dx.doi.org/10.1007/s11069-011-0046-8. Parker didn’t like the notion that warming causes sea level to rise so he claims 20 years of data shows it’s not happening, there.
A different paper says a
“Minimum of 60 years of tide gauge recording are needed to compute a long-term SLR”
And that’s the same Albert Parker, for both of those statements.
Delve deep enough into the details and you might make sense of the way he’s making what appear on the face to be contradictory claims about what the statistics can show.
Point being, if all you want is a talking point without a cite or an understanding — they’re easy to find. That’s why ‘reverse citation’ using Google (finding something after the fact to back up any claim at all) is easy. You can find anything on the Internet whether it exists or not.
Only a fool would think that the tide is changing based on every single wave. Also, only a fool would try to compare to differenct datasets without independent confirmation. You may want to read the following about data validation:
These papers acknowledge the higher rate observed with the Topex satellite, and the slightly lower rate with the Jason satellites, and also gives an in-depth analysis about comparison between tidal gauges. Pay particular attention to Figure 6 in the Cazenave paper. This shows the data observations prior to recent ENSO events. For argument sake, let’s ignore the recent slowing (you should have no problem with this), and assume that the satllite measurments can be directly compared to the tidal gauges. Let’s use the data from the Mitrovica video, which you espouse, for this example. The SLR from 1930-2000 was 2.3 mm/yr, and the rate from 1993-2012 was 3.1. Let us further assume that the previous rate was constant for the 19 years prior to the satellite observations. We arrive at a 0.8 mmm/yr increase over 19 years. If a similar acceleration occurred throught the 21st century, than SLR would reach 6.3 mm/yr by the year 2100. Integrated over the next 88 years, would yield a total sea level rise of ~400 mm (16 in). In order to reach some of the higher projection values, SLR would need to start accelerating soon. Especially to overcome any slower observed in the data.
Dan H, do you realize you said exactly to my pint which is that sea level rise has not changed in the 21 century? the moat recent decadal average does not represent sea level rise so focusing on the last ten years is meaningless. there is no “slower trend”
Comment by Unsettled Scientist — 7 Nov 2012 @ 10:13 AM
Dan H – you have a very predictable bag of tricks – you have used this logic again and again. You take a limited data set, with no analysis as to what is happening or why (usually you just deny attribution), and then extrapolate a linear rate of acceleration based on 19 years of data, finally arriving at: “What – me worry?”. Mitrovica puts SLR into perspective. He shows that the recent SLR is anomalous since the last ice age; that SLR accelerated since tide gage data have been available, and that SLR has acceleration has increased again since satellite data has been available. This is not a linear rate of acceleration. He discusses the potential of glacier and icecap melt. Given his evidence, why would SLR NOT continue to accelerate? There are very good reasons why it will. You, however, assume that the present rate of increase, based on 19 years of data, is linear and will continue to be linear. Why? Because, I dunno, it just will?
There seems to be two, at least, problems here. One is the media failing to educate the public about science. The second is that a great many Americans are frightened by the word science. What is the solution? You cannot teach a person how to use a wrench if they do not understand what a nub and bold does for them.
Re- Comment by Everette L. Wampler — 11 Nov 2012 @ 4:00 PM:
You missed the biggest one. Three- The propaganda by the monied interests that are successfully creating confusion and fear in the uneducated public, just like they did for tobacco, lead pollution, ozone, asbestos, and more. If you don’t recognize this you have been taken in. Steve