RealClimate logo


Sealevelgate

Filed under: — stefan @ 11 March 2010 - (Italian)

Imagine this. In its latest report, the IPCC has predicted up to 3 meters of sea level rise by the end of this century. But “climate sceptics” websites were quick to reveal a few problems (or “tricks”, as they called it).

First, although the temperature scenarios of IPCC project a maximum warming of 6.4 ºC (Table SPM3), the upper limit of sea level rise has been computed assuming a warming of 7.6 ºC. Second, the IPCC chose to compute sea level rise up to the year 2105 rather than 2100 – just to add that extra bit of alarmism. Worse, the IPCC report shows that over the past 40 years, sea level has in fact risen 50% less than predicted by its models – yet these same models are used uncorrected to predict the future! And finally, the future projections assume a massive ice sheet decay which is rather at odds with past ice sheet behaviour.

Some scientists within IPCC warned early that all this could lead to a credibility problem, but the IPCC decided to go ahead anyway.

Now, the blogosphere and their great media amplifiers are up in arms. Heads must roll!

Unthinkable? Indeed. I am convinced that IPCC would never have done this.


The North Sea (see Stefan’s photostream on Flickr)

But here is what actually did happen.

In its latest report, the IPCC has predicted up to 59 cm of sea level rise by the end of this century. But realclimate soon revealed a few problems.

First, although the temperature scenarios of IPCC project a maximum warming of 6.4 ºC (Table SPM3), the upper limit of sea level rise has been computed for a warming of only 5.2 ºC – which reduced the estimate by about 15 cm. Second, the IPCC chose to compute sea level rise up to the year 2095 rather than 2100 – just to cut off another 5 cm. Worse, the IPCC report shows that over the past 40 years, sea level has in fact risen 50% more than predicted by its models – yet these same models are used uncorrected to predict the future! And finally, the future projections assume that the Antarctic ice sheet gains mass, thus lowering sea level, rather at odds with past ice sheet behaviour.**

Some scientists within IPCC warned early that all this could lead to a credibility problem, but the IPCC decided to go ahead anyway.

Nobody cared about this.

I mention this because there is a lesson in it. IPCC would never have published an implausibly high 3 meter upper limit like this, but it did not hesitate with the implausibly low 59 cm. That is because within the IPCC culture, being “alarmist” is bad and being “conservative” (i.e. underestimating the potential severity of things) is good.

Note that this culture is the opposite of “erring on the safe side” (assuming it is better to have overestimated the problem and made the transition to a low-carbon society a little earlier than needed, rather than to have underestimated it and sunk coastal cities and entire island nations). Just to avoid any misunderstandings here: I am squarely against exaggerating climate change to “err on the safe side”. I am deeply convinced that scientists must avoid erring on any side, they must always give the most balanced assessment they are capable of (and that is why I have often spoken up against “alarmist” exaggeration of climate science, see e.g. here and here).

Why do I find this IPCC problem far worse than the Himalaya error? Because it is not a slip-up by a Working Group 2 author who failed to properly follow procedures and cited an unreliable source. Rather, this is the result of intensive deliberations by Working Group 1 climate experts. Unlike the Himalaya mistake, this is one of the central predictions of IPCC, prominently discussed in the Summary for Policy Makers. What went wrong in this case needs to be carefully looked at when considering future improvements to the IPCC process.

And let’s see whether we learn another lesson here, this time about society and the media. Will this evidence for an underestimation of the climate problem by IPCC, presented by an IPCC lead author who studies sea level, be just as widely reported and discussed as, say, faulty claims by a blogger about “Amazongate”?

p.s. Recent sea level results. A number of broadly based assessments have appeared since the last IPCC report, which all conclude that global sea level rise by the year 2100 could exceed one meter: The assessment of the Dutch Delta Commission, the Synthesis Report of the Copenhagen Climate Congress, the Copenhagen Diagnosis report as well as the SCAR report on Antarctic Climate Change. This is also the conclusion of a number of recent peer-reviewed papers: Rahmstorf 2007, Horton et al. 2008, Pfeffer et al. 2008, Grinsted et al. 2009, Vermeer and Rahmstorf 2009, Jevrejeva et al. 2010 (in press with GRL). The notable exception – Siddall et al. 2009 – was withdrawn by its authors after we revealed numerical errors on Realclimate. This is a good example of self-correction in science (in stark contrast with the climate sceptics’ practice of endlessly perpetuating false information). Rather bizarrely, Fox News managed to turn this into the headline “More Questions About Validity of Global Warming Theory“.

** About the numbers stated above. Regarding the actual IPCC AR4 numbers, adjust the IPCC upper estimate of 59 cm by adding 15 cm to make it apply to 6.4 ºC warming (not just 5.2 ºC) and 5 cm to make it go up to 2100 (not just 2095). That gives you 79 cm. Add 50% to adjust for the underestimation of past sea level rise and you get 119 cm.
For the hypothetical case at the start of this post, just introduce similar errors in the other direction. Let’s add 31 cm by going up to 7.6 ºC and the year 2105 (in fact that is “conservative” but it gives a nice round number, 150 cm). Now assume you have a model compared to which actual sea level is rising 50% slower (rather 50% faster): now you’re at the 3 meters mentioned above. For details, see The IPCC sea level numbers.

305 Responses to “Sealevelgate”

  1. 251
    Hunt Janin says:

    As a newcomer to global warming and related issues, and living abroad as I do (in the Netherlands and in France), I’m struck by the fact that passions among highly educated people seem to run so high on these subjects. I can easily understand such feelings on other issues, e.g., gun control, abortion, terrorism, but WHY global warming, etc?

    Please reply to me at huntjanin@aol.com if you prefer.

  2. 252
    Hank Roberts says:

    > why
    Suppose someone were doing something that would flood the Netherlands.
    Would it worry you? Would you feel strongly about people denying it?
    Just as a thought experiment, if a large PR campaign were devoted to convincing people — falsely — that the Netherlands was at no risk of sea level rise, would you have any strong feelings about that happening?

    What if you knew the same kind of thing was routinely done, e.g.
    http://ajph.aphapublications.org/cgi/content/abstract/91/11/1749/
    http://ajph.aphapublications.org/cgi/content/abstract/88/12/1871
    http://www.scielosp.org/scielo.php?pid=S0042-96862000000700007&script=sci_arttext&tlng=en

    What if you then found out it was the same people and organizations using those same tactics? Would you have any strong feelings?

    What if you had grandchildren; would that change anything for you?

  3. 253
    Hank Roberts says:

    PS for Hunt, you might also read these two (one requires paid subscription, the other showed up online though you’d usually purchase a book to read it).
    See if the two together ring any bells for you personally.
    They may not. I know people who feel nothing when they read these.
    People differ in how/if they feel about what happens to others.

    http://heinonline.org/HOL/LandingPage?collection=journals&handle=hein.journals/glj96&div=17&id=&page=
    http://www-rohan.sdsu.edu/faculty/dunnweb/rprnts.omelas.pdf

  4. 254
    David Jordan says:

    Very chivalrous Eric but CFU can scratch his itch if he wants. I will ask my geologist colleagues to stop making contributions to climate science right away. We might miss them, however.

    CFUs comment about funding for Geology Majors is valid but it overstates the case. I am in daily contact with Geoscience students and postdocs of whom not one is funded by the oil industry and several are paid to site windfarms and find geothermal prospects. Ah those insidious insiders corrupting our debate!

  5. 255
    Hank Roberts says:

    > David Jordan

    Erik’s asking folks to quit biting. Could you quit chumming? It’s distracting.

    Erik’s right about that letter (not an article); others at the same site look like good science from geologists. It’s a _letters_ page, remember! http://www.geolsoc.org.uk/gsl/site/GSL/

    Sea level. What about that?

  6. 256
    Brian Dodge says:

    http://maps.google.com/?ie=UTF8&ll=17.702249,-64.75153&spn=0.047506,0.071239&t=h&z=14
    from wikipedia – “Hovensa is a petroleum refinery located on the island of St. Croix in the U.S. Virgin Islands. The refinery is a joint venture between Hess Corporation and Petroleos de Venezuela that mostly supplies heating oil and gasoline to the U.S Gulf Coast and the eastern seaboard with the crude mainly sourced from Venezuela. At a capacity of about 500,000 barrels per day it is in the top 10 largest refineries in the world.” which is where most of the “per capita” oil is consumed – population ~110k people – wow, almost 5 barrels per person per day!!!! &;>) BTW, the Coast Guard strongly recommends that anybody who isn’t driving an oil tanker avoid the sea lanes south of the refinery.

  7. 257
    Gilles says:

    “I would not go as far as you in stating that 10 meters are inevitable, though. Mind you that is centuries down the line – after we’ve achieved the zero-emissions society later in this century, we may actually find ways to achieve significant negative emissions (eg by using bioenergy with carbon sequestration) or even geoengineering schemes to lower temperature or sea level – who knows what is possible in a hundred or two hundred years? I’d say it is unlikely that humanity will let ten meters of sea level rise happen. That is why the key issue to me is doing what our generation can do now to avoid the worst happening within this century, and then see what subsequent generations can do further. -stefan”

    Sorry Stefan, but for me you’re changing your logics. If you are confident that future generations will be able to avoid a 10 meter rise, there is absolutely no reason to fear that they won’t be able to cope with 20 or 30 meters – that’s the same order of magnitude. And you show yourself that what happens in this century is not very sensitive to scenarios – for the exact same reason of long inertia. So if inertia is very long, I would say just the opposite : what we do in the near future is mainly immaterial. Either we will be able to fight the consequences of what has already been burnt – and also what we will burn in the future. Or not – in both cases.

  8. 258
    Gilles says:

    Nicks :”But you have been arguing that fossil fuel supplies are very limited, and industrial society is bound to collapse when they run out – so by your own logic, we should reduce their use as fast as possible so we still have some left for the big move. It is clear you will say anything that suits your argument of the moment, irrespective of whether it is consistent with what you have said before. That is a clear mark of someone who is not arguing in good faith. (And no, I have no interest in betting against someone who is clearly acting in bad faith, and does not give their full name. I leave you to guess why.)”

    Nicks , there is some confusion in what I said. I don’t really think we have the choice , I just explore your logics, assuming you’re right. And for the bet , it’s enough to propose an idea of a bet just to clarify where you think I’m wrong (and my real name can be found somewhere in this forum).

  9. 259
    Completely Fed Up says:

    “254
    David Jordan says:
    17 March 2010 at 3:09 PM

    Very chivalrous Eric but CFU can scratch his itch if he wants. I will ask my geologist colleagues to stop making contributions to climate science right away”

    Cut the histrionics, David. They’re not cute. I didn’t say that they couldn’t make contributions, but that you cannot cite geology expertise as equivalent to climatology expertise.

    But if you want to play the martyr, go ahead.

    Knock yourself out.

    [edit]

  10. 260
    Completely Fed Up says:

    “I can easily understand such feelings on other issues, e.g., gun control, abortion, terrorism, but WHY global warming, etc? ”

    What do you understand about gun control or terrorism?

    I do not see why people care so much about them.

    The armed populace has NO CHANCE against a corrupt government, not if they are allowed heavy weapons and armour and you are allowed a rifle.

    Gun ownership is pointless for that.

    Terrorism kill fewer people each year than in spoon-related deaths.

    Why be afraid of it?

    But what SOMEONE ELSE wants to do (burn CO2) affects ME. Just like dumping sewage into the river I walk past affects me because someone else didn’t want to pay for treatment.

  11. 261
    wilt says:

    Hunt Janin (#251), I think you deserve a better answer than Hank Roberts is giving you, with references to the tobacco industry (#252) that seem to be rather far off-topic.
    In my opinion, the main reason for the increased intensity (to put it mildly) in the climate debate in recent months is the fact that many people feel betrayed and lied to by the scientists associated with the IPCC panel. This distrust is reflected in the strong decline in public support for the AGW hypothesis (see recent polls in UK and USA). I am not going to discuss here all the errors and exaggerations in the IPCC report and in many alarming press releases from scientists and scientific institutes in the months before the Kopenhagen climate congress. But since the issue of global warming is very serious (both in possible consequences of climate changes, and in the unbelievable amounts of money involved in reducing CO2), the scientific basis for political decisions should be pretty strong. Therefore many people are starting to ask questions, and some of these questions are not so easy to answer (I think the present debate about projected sea level rise is a good example). As a consequence, several climate scientists feel attacked, and this often leads to a heated debate. Nothing wrong with that, as long as opponents in the debate respect each other and use scientific arguments rather than insinuations and personal attacks.

  12. 262
    Completely Fed Up says:

    wilt: “This distrust is reflected in the strong decline in public support for the AGW hypothesis”

    Some evidence that this is not true:

    http://www.desmogblog.com/stanford-study-confirms-“balanced”-media-stories-quoting-skeptics-mislead-public

    and some evidence that being let down is not the reason either, else this:

    http://www.desmogblog.com/mythical-tuvalu-pineapple

    would have killed off support of the denial of AGW.

  13. 263
    Hunt Janin says:

    For Wilt, re 261: Thanks very much the good and calm answer. I hope that others will follow your mature lead.

  14. 264
    David Kidd says:

    http://www.youtube.com/user/greenman3610

    I feel that Mr Sinclair should be encouraged to continue.This is the sort of stuff we need to help the confused and hurt the guilty.
    David Kidd

  15. 265
    Hunt Janin says:

    Does anyone know whether the US defense establishment (or any defense establishment) is studying the possible military impacts of sea level rise in the distant future?

  16. 266
    flxible says:

    Wilt@261 “In my opinion, the main reason for the increased intensity (to put it mildly) in the climate debate in recent months is the fact that many people feel betrayed and lied to by the scientists associated with the IPCC panel. (….) (see recent polls in UK and USA) (….).”

    Has waaaay more to do with the upcoming elections in the UK and the legislation in progress in the US, the IPPC meme is the handle contrarians have stumbled upon. The scientific basis for making necessary political decisions IS quite strong and clear, it’s the exact form of those decisions that’s causing the stir, not the science.

  17. 267
    Completely Fed Up says:

    “265
    Hunt Janin says:
    18 March 2010 at 9:42 AM

    Does anyone know whether the US defense establishment (or any defense establishment) is studying the possible military impacts of sea level rise in the distant future?”

    I believe DeSmogBlog had something on that. The US DoD does have a policy document on just that sort of thing and is down as a risk for the military security of the USA.

  18. 268
    Hunt Janin says:

    My thanks to Completely Fed Up re comment no. 267. I tried a couple of weeks ago to find, via the web, the DOD policy document referred to but failed entirely. Can anyone give me a lead?

  19. 269
  20. 270
    wilt says:

    Completely Fed Up (#262) responded to my remark (#261): “This distrust is reflected in the strong decline in public support for the AGW hypothesis”. He wrote:

    “Some evidence that this is not true: http://www.desmogblog.com/stanford-study-confirms-“balanced”-media-stories-quoting-skeptics-mislead-public

    I quote from the link he provided:
    “The Stanford researchers probed the impact on public understanding of climate change when media coverage features a climate skeptic alongside a climate scientist. Media stories featuring only a mainstream climate scientist “increased the number of people who believed that global warming has been happening and that humans have caused global warming.”

    However, when media stories also include a climate skeptic, ostensibly to add “balance” to the story, the result is a “significantly reduced” number of people who understand the issue and endorse government action to address the problem. “

    I think this exactly proves my point. Many people are not really convinced that ‘mainstream climate science’ is telling the truth, the whole truth and nothing but the truth. Otherwise they would not start to doubt so easily when a ‘skeptic’ is given the opportunity to express his views.

    I wonder what Completely Fed Up has in mind to change that situation. Exile for all skeptics? One cannot keep away the skeptical questions forever. There is only one choice: have an open discussion, without exaggerations, and try to convince people rather than just scare them.

  21. 271
    Hunt Janin says:

    Having what I term “a good second rate mind,” I’m always very, very careful, when reading up on a topic that is new to me (e.g., sea level rise), to make sure that I understand it pretty well before I begin to write about it. Alas, I’m now quite confused about the best and most responsible estimates for sea level rise by 2100. Some say the IPCC estimates are too low; others use either higher or lower figures. Is there a party line on this issue I can take comfort in and use in the introductory survey that I’m working on now?

  22. 272
    wilt says:

    Hunt Janin (#271), perhaps you are underestimating yourself when you say you only have a good second rate mind. Anyway, when you ask for a party line: the problem indeed is that every party has its own line, for virtually every consequence of increasing CO2, based on the rate of temperature increase that they think is associated with for instance a doubling of CO2. As for sea level rise, it seems that Rahmtorf and I agree that a reasonable ‘sea level sensitivity’ is about 20 cm for each degree celsius of temperature rise (see #230 and related previous posts). So if one believes that temperature rise by 2100 would be 5 or 6 degrees (as Rahmstorf does) then the result would be abaout 1 meter or slightly above. If you think that 2 degrees is more likely, then you end up with about 40 cm. If you take the median value (2.6 degrees) of the six different IPCC scenario’s then it’s about 50 cm. So the basic difference of opinion is about the rate of temperature increase, all other projections for climate changes are related to that estimate.

  23. 273
    Hank Roberts says:

    Hunt, you have to look at the number for _your_location_.
    Your local government will probably have made an assessment.
    As pointed out repeatedly, it’s not simply temperature as wilt keeps saying.
    That’s the notion from the people who think this is a debate.

    It’s a science question. Climatologists talk about global averages, it’s the place to start for dealing with global change.

    The life you live and the plans you make and the questions you ask locally are not the average. If you want to know what people think, it depends on where they live and what’s projected to affect them. There are global effects as on fisheries and spawning areas (predicted to be devastating on the short term). Yes, at the level that affects everyone, the oceans have already _been_ devastated. Ask any marine biologist, otherwise you’d never have a clue what’s been lost. Few give a damn about that. Your survey isn’t about that, is it?

    What’s happening and projected to happen depends on the material and the slope of the shoreline (Galveston? Maine?) and the other water flows in the area and the shoreline ecosystem (riprap? salt marsh? coral?); buried pipes (sewage outfalls? power plant cooling intake and outflow?); buried toxics in sediment and dumps; shoreline infrastructure.

  24. 274
    Completely Fed Up says:

    “However, when media stories also include a climate skeptic, ostensibly to add “balance” to the story, the result is a “significantly reduced” number of people who understand the issue and endorse government action to address the problem. “

    I wonder what Completely Fed Up has in mind to change that situation. Exile for all skeptics?”

    Uh, they’re not skeptics.

    And why would Exile fix the problem?

    just because you consider me a boogeyman doesn’t mean I am one.

    The solution here is investigative journalists being INVESTIGATIVE JOURNALISTS.

    And that requires that the partisan boss be hands-off. Since many media agency bosses don’t seem to be able to do this under their own steam, what we need is the companies and the bosses held responsible for failures of their media empire.

    When Fox News can argue AND WIN in court a defence against false statements by saying that they are entertainment and there’s no requirement to tell the truth, THAT is the problem that needs to be fixed.

  25. 275
    Hunt Janin says:

    Thanks, Wilt, for your clear, concise answer (#272). Maybe I’m not so dumb after all…

  26. 276
    Hunt Janin says:

    In my beginner’s-level book on sea level rise, I’d like to define — for the educated general reader — the role of the IPCC is one VERY SHORT paragraph that MOST scientists would subscribe to as being an accurate statement. I hesitate to try writing this myself. If you are bold enough to do so, have at it! Send your draft to me at huntjanin@aol.com. If I use it, you’ll get attribution in an endnote.

  27. 277
    wilt says:

    Completely Fed Up (#274), I don’t consider you or anyone who disagrees with me a boogeyman – until proven otherwise ;-)
    I did not seriously think that you would propose exile for all skeptics.
    And as for Fox News, I don’t think that they are the real problem. Very few people who use their brains will let themselves be guided by Fox. But many people (and I think their number is increasing) have serious questions relating to the projected temperature change and climate change. Those questions are usually not coming from Fox, because bluntly said Fox is not intelligent enough for such questions, or not interested in the answers.

  28. 278
    Completely Fed Up says:

    wilt, why did you think that I would chose Exile for denialists, then?

    If you’re going to talk about dumb actions, put them in your mouth, not mine, OK?

    And you’re wrong: Fox news IS a problem. Along with lots of other wannabees.

  29. 279
    Adrian O says:

    The satellite measured ocean level trends are at

    http://tidesandcurrents.noaa.gov/sltrends/sltrends.html

    The levels are rising about 1ft/century as they always did, except in the NW US and Canada, where the sea levels go down about  3ft/century.

    So the current CO2 emissions had no influence on ocean level growth. How exactly would they grow 10 times faster than now, 3 meters in a century?

    This is measured data – I am a mathematical physicist, so I believe in data rather than models or opinions.

    [Response: You need to look at more data. The graph you show is interesting but it is showing tide gauge data, not satellite data. That is available instead at http://sealevel.colorado.edu . If you put these sources together (which is not trivial), you get an acceleration from around 1 mm/yr in the 19th C, to 3 mm/year currently. Combined with observations of ocean warming and observations of ocean mass change (from melting ice and depleting groundwater), people conclude that they can indeed attribute the rise in sea level to the warming over the last 50 years or so (Domingues et al, 2008; Cazenave et al 2009). – gavin]

  30. 280
    Dave Burton says:

    Didactylos wrote (in #220), 15 March 2010:
    > Dave Burton…. you [are] a crank.

    Hey, I’m not they guy who accused NOAA of “…stooping to that most contemptible trick of graphing fraudsters: expand the Y axis enough, and magically any trend will disappear…” because of the “Y axis scaled in metres…” That was you, Didactylos. But if you think name-calling strengthens your case, go for it.

    Didactylos continued:
    > I do apologise for assuming you had generated the graphs yourself.
    > Instead, you just rescaled them so that the trend is very difficult
    > to see.

    No, Didactylos, I did not “rescale” them. Those are NOAA’s graphs, and it was NOAA who chose the scale for the Y axis, which so distressed you.

    Also, the trend is not difficult to see. In fact, it is perfectly clear: at most tide stations, including all of those with the longest, most complete and reliable records, the Local Mean Sea Level trend is a straight lines + noise, with no apparent acceleration in rate of MSL rise, at all, since the 19th century.

    BTW, you can tell those are NOAA’s graphs by the “noaa.gov” part of the URLs:

    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=120-012 (Warnemunde)
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=130-021 (Copenhagen)
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=680-140 (Sydney)

    GlenFergus wrote (in #222), 15 March 2010:

    #212 Dave Burton

    > > The obvious conclusion is that anthropogenic CO2 does not appear to
    > > cause a significant increase in sea level.
    >
    > Sweeping, unsupported and absurd. This greatly weakens your whole effort.

    It only sounds unsupported because you omitted the rest of of the paragraph. The part you quoted was just the concluding sentence. Here’s the entire paragraph:

    “If the global MSL trend had actually accelerated by about +1.3 mm/year since 1993, as the IPCC claims, that fact would be apparent at these tide stations, as a doubling or tripling of the measured rate of MSL rise. But there is no evidence of any such acceleration. The global average Mean Sea Level has been rising at a slow, steady rate of less than 1.2 mm/year for ~120 years — i.e., since long before there was any major human contribution to atmospheric CO2 levels. The obvious conclusion is that anthropogenic CO2 does not appear to cause a significant increase in sea level.”

    The conclusion is well-supported by the tide records. If anthropogenic CO2 actually caused sea levels to rise, then we should expect to see the rate of sea level rise increasing at the tide stations. We don’t. Instead, at the vast majority of tide stations we see exactly the same rate of LMSL rise now, when humanity is churning out CO2 at the highest rate in history, as 100 years ago, when humanity was producing little CO2. Thus the logical conclusion is that anthropogenic CO2 does not cause a significant rise in sea level.

    There are other possibilities, of course, such as the possibility that other unknown factors are canceling out the acceleration in MSL trend caused by anthropogenic CO2, but Occam’s razor supports my conclusion: that anthropogenic CO2 does not appear to cause a significant increase in sea level.

    Dave

  31. 281
    Hunt Janin says:

    For my beginner’s-level book on sea level rise, I feel obliged give a very short burst on global warming, especially on greenhouse gases. I have a short draft now and will be happy to send it to anyone who has time to read it very critically and to suggest improvements. If interested, please give me your email address.

  32. 282

    wilt (270): There is only one choice: have an open discussion, without exaggerations, and try to convince people rather than just scare them.

    BPL: Exaggerations are not needed, and people need to be scared, since not dealing with AGW means losing human civilization and a vast amount of life. If you see a kid in the street, facing away from a ’68 Camaro bearing down on him at 75 mph, and you can’t reach him/her in time, you don’t calmly say, “Child, a car is approaching from behind you. I recommend changing your position.” You say, “Hey! Get out of the street NOW! MOVE!

  33. 283

    wilt (277): as for Fox News, I don’t think that they are the real problem.

    BPL: No, but they sure are part of it. A huge news apparatus steadily lying to the public and succeeding at it is a very big problem.

  34. 284
    Hank Roberts says:

    > 281, Hunt
    Hunt, whoever volunteers to review your book for errors — make sure you check their references and make sure you’re not getting bad advice. We have lots more opinions around than expertise, and the experts are generally quite busy as it is. You’re very likely to get offers. You should evaluate them carefully, look at their publications and the footnotes and cites.

    You probably know that. But you’ve been asking some naive questions so — careful!

  35. 285
    Mark A. York says:

    RE: 279: faculty at Penn State, not a fan of MM,( to put it politely), and he has a scurrilous history at DotEarth. Scary. Based on his own assertions, he indoctrinates his students into climate change skepticism, or attempts to via extra curricula assignments.

  36. 286
    wilt says:

    Barton Paul Levenson (#282), your comparison with the kid in the street and the high-speed car would make sense if indeed the effects of AGW and climate change would be approaching so fast that one even has to worry about ‘losing human civilization and a vast amount of life’. As for the warming, it seems to me that even several IPCC-linked scientists agree that for the most recent decade there is a flattening and no statistical proof of ongoing warming. As for the present topic, sea level rise, if indeed there is a sea level sensitivity of about 20 cm for each degree Celsius of temperature rise (see #230 and related posts) then the median value of 2.6 degrees from the IPCC projections suggests an increase in sea level by 2100 of about 52 cm, or 5 mm per year. Not quite as scaring as a ’68 Camarro at 75 mph – apart from the fact that I am not sure whether such an old car would still reach such a speed ;-)

  37. 287
    Martin Vermeer says:

    Dave Burton #280: there is just no way you can draw any such conclusion from individual tide gauge records — they are way too noisy. The only reason you see a linear trend is because that’s what being fitted — and I would guess by simple least squares regression, not even taken the autocorrelation of the monthly values into account.

    The non-linearity is in there, but you have to globally combine tide gauge data to get rid of the noise first. Otherwise you’re just looking at the sea-level equivalent of local weather.

  38. 288
    don says:

    So I gather Focault’s Pendalum is really not too noisy to provide an empirical demonstration of the earth’s rotation, but a singular tide guage over time can’t demonstrate sea level rise? Maybe there was no statistically significant sea level rise. And isn’t all rotation on the globe local?

  39. 289
    Martin Vermeer says:

    Mark A. York #285: thanks, I missed that. Ah well. I see that he quotes Daly as an authority — cute.

  40. 290
    Hunt Janin says:

    As a newcomer, I’ve read a fair amount about the bad things that may happen to some countries of the world due to sea level rise by 2100. What countries, or regions, if any, may profit from higher sea levels?

  41. 291

    wilt (286): even several IPCC-linked scientists agree that for the most recent decade there is a flattening and no statistical proof of ongoing warming.

    BPL: Crap!

    http://BartonPaulLevenson.com/Ball.html

    http://BartonPaulLevenson.com/Reber.html

    http://BartonPaulLevenson.com/VV.html

    http://BartonPaulLevenson.com/Correlation.html

    wilt: As for the present topic, sea level rise, if indeed there is a sea level sensitivity of about 20 cm for each degree Celsius of temperature rise (see #230 and related posts) then the median value of 2.6 degrees from the IPCC projections suggests an increase in sea level by 2100 of about 52 cm, or 5 mm per year.

    BPL:

    1. A foot and a half of sea level rise is enough to cause massive infrastructure damage worldwide.

    2. IPCC estimates have consistently underestimated the rise of sea level, and do not account for possible catastrophic ice events.

    3. Sea level rise was never the main problem. Do the words “complete collapse of human agriculture some time in the next 40 years” mean anything to you?

  42. 292
    Martin Vermeer says:

    Hunt Janin #290: perhaps countries in areas of rapid post-glacial uplift, like Fennoscandia. Sea level rise will compensate the uplift, so they don’t have to move their harbours quite as often, as they have in the past. But the advantage is lost again if sea level rise outpaces the uplift…

  43. 293
    Hank Roberts says:

    > 290, 292
    Remember, Hunt’s trying to write a simple beginner-level book on sea level rise. I expect he’s looking for countries that will $$PROFIT$$, not just those less damaged by a rapid sea level rise.

    Jeremy Jackson would suggest that it’d be countries as far from the ocean as possible. http://scrippsnews.ucsd.edu/Releases/?releaseID=920
    http://symposia.cbc.amnh.org/archives/expandingthearc/speakers/transcripts/jackson-text.html
    “… as the ocean becomes harmful to your health, and as the wind blowing off the ocean carries the cholera and the E. coli to you, the only people who will live in Malibu are the poor people who can’t afford to live anywhere else. Rich people will live in Montana or Wyoming, as far from the ocean as possible.”

    This isn’t wild speculation. This is mainstream ecology, changes that have already happened. You won’t hear it from sources like the New York Times that are still publishing recipes for endangered species like tuna, though.

    Northern Paraguay, for example, has reportedly been quite popular with very rich, very reclusive folks. This was a decade ago: http://www.landcover.org/services/landcoverchange/paraguay.shtml

  44. 294
    Hunt Janin says:

    Thanks, Martin Vermeer, for your good reply (#292)to my question #290.

    I’m now thinking that in my introductory survey book on sea level rise, the educated general reader might well be interested in two or three case studies of how different kinds of countries may cope (or not cope) with sea level rise by 2100.

    Three case studies occur to me off-hand: (1) a developing country likely to fail entirely (e.g, Nigeria?); (2) a developed country which will probably be able to handle localized problems as they occur (e.g., the US?); and (a very highly developed country likely to be successful due to its small size and its early focus on this isseu (e.g., the Netherlands?).

    Constructive comments from all readers are invited.

  45. 295
    JD says:

    The entire premise of this article (and Sharon Begley’s plagiarism for Newsweek) is flawed. The premise is that there should be as much outrage over this error as there is over errors overstating AGW. No. This error is not an error in AGW projection. This is an error in projecting a consequence of the worst case of AGW. AGW skeptics do not deny that IF AGW happens, it will have consequences like this. They deny that it will happen at all. An error in the controversial subject matter is scandalous. An error here is just an error. The biggest scandal is that it is more proof of general sloppiness in the whole area.

  46. 296
    Hunt Janin says:

    Let me play devil’s advocate, if I may.

    It appears to me as a newcomer to this field that a reasonable, responsible guess about sea level rise is that, barring unforseen ice events, the rise likely be be only about 1 m by 2100.

    Excluding the obvious problems of the relatively small numbers of people living on atolls, what’s so terrible about this?

  47. 297
    Anonymous Coward says:

    Hunt (#296),

    People are expecting less than 1m actually. Sea level is more likely to become a big deal *after* 2100. But 2100 is not that far off. Put yourself in the shoes of people planning to build long-lived infrastructure.

    Anyhow… you ask about the consequences of +1m. As you’ve already been told, you need to think about local sea level rather than the global average for the short-term effects. +0m would already be a problem for places like New Orleans and Venice (Italy). Adding 1m on top of that is a big deal.
    Agriculture as well as wild ecosystems will also be affected obviously.
    But why are you asking about such basic stuff here? And why should I waste my time giving you detailed, non-authoritative answers? This is the intertubes. You’ve got authoritative answers at your fingertips such as: http://www.epa.gov/climatechange/effects/coastal/

  48. 298

    It really is somewhat disingenuous to list the Dutch Delta Commission, SCAR, Horton 2008, and The Copenhagen Diagnosis since all rely on Rahmstorf 2007.

    Pfeffer predicts .8M which is on the higher side, but not so far from IPCC.

    I agree that Rahmstorf, Rahsmstof and Vermeer, and Grinsted come up with higher estimates than the IPCC using similar empirical methodologies. Although Rahmstorf and Vermeer is a significant improvement in modeling from Rahmstorf both papers use a questionable methodology of applying regression to smoothed data which will tend to find correlation where none exists, and at the minimum will understate confidence limits.

    At the end of the day the people that the IPCC chose as experts on this topic have not weighed in.

  49. 299

    Sorry if this has already been mentioned, but this is a long comment thread. It is true that IPCC 2007 used an observed rate of 1.8 +- .5 for 1961-2003. You comment that this is 50% higher than the models, which is sort of true ignoring the error bars. But the updated figure from Domingues 2008 is 1.5 +- .4 which overlaps nicely with the IPCC figure of 1.2 +- .5 from models.

  50. 300
    Hunt Janin says:

    Has anything been written yet about the possible impacts of sea level rise by 2200?