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  1. The weak point is not in the sea level estimates, it is in the scenario estimates. There is no estimate of “plausibility” in the SRES. It’s just “what if” scenarios. If 5°C is already unlikely, then 6.4 °C is still more.
    Now how do the scenarios compare with reality? coal and gas are still far from their peak, but peak oil is close. There are numerous signs that the oil production will never exceed 100 Mbl/d, and even 90 may not be reached. How many scenarios are compatible with this value? none. So IF oil production peaks below 100 Mbl/d, THEN all scenarios are wrong about oil. IF all scenarios are wrong, THEN methodology is flawed. IF methodology is flawed, THEN nothing can be trusted. The bias is obvious : all scenarios are based on the hypothesis of continuous economic growth during the XXI century, which is nothing but wishful thinking. None has been validated by anything except politically biased governmental agencies reports, whose predictions have been definitely disproved in the recent years.. So you can extrapolate unlikely values , they will only be still more unlikely.
    Current sea level rise is about 3mm/yr, and if fossil production is close to peak, there is no reason for acceleration. This gives about 30 cm in the century, about one foot…

    [Response: Your logic is flawed, because data of the past century show how the rate of sea level rise increases in proportion with temperature - that is the point of our papers linked above. So if temperature does not rise any further, then your scenario of a constant rate and thus about a foot of sea level rise is reasonable. But the most optimistic scenarios have warming stopped at about 2 ºC above preindustrial, i.e. two to three times the current warming, which would imply roughly that the rate of sea level rise also doubles or triples. And then continues into the next century, and the next... -stefan]

    Comment by Gilles — 11 Mar 2010 @ 10:43 AM

  2. OT, but I need help from those of you with research grant experience.

    I just posted a new thread on my blog titled Taking the Money for Grant(ed) – Part I that responds to the following two claims:


    1) Scientists are getting rich from research grants!
    2) Scientists holding an anti-AGW viewpoint cannot get funding!

    I used my own recent grant experience to debunk claim #1. In a future post called Part II, I want to show examples of how grant money is spent at other institutions, especially the larger research institutions. Essentially, show me why you are also not getting rich from your grants. (I recall a comment here at RC during the CRU hack that accused Gavin of being a millionaire! Ugh!)

    My email address is mandias@sunysuffolk.edu

    You can give me as much or as little detail as you think it necessary to dispel claim #1. Before I post Part II, I will send a draft copy to any person whose information is being used and you will have carte blanche to edit what I had planned to post. Nothing will appear in my post that you do not confirm.

    I appreciate all the help you can offer!

    Comment by Scott A. Mandia — 11 Mar 2010 @ 10:49 AM

  3. Gilles: If you want probabilities assigned to your future scenarios, then I recommend to you the MIT Joint Program on the Science & Policy of Global Change studies: http://globalchange.mit.edu/pubs/abstract.php?publication_id=2003, for example. These contain within them best estimates (and uncertainty ranges) of available fossil fuel reserves, economic growth, cost and reserves of unconventional fuels, improvements in efficiency, and so forth.

    No study is perfect, and the MIT study certainly isn’t, but it is a good starting point for thinking about the future probabilistically, and I’d be curious as to why you might think that your opinions should hold more weight than those of the energy economists on the MIT team?

    Comment by Marcus — 11 Mar 2010 @ 10:52 AM

  4. BTW there is some inconsistency here : “Second, the IPCC chose to compute sea level rise up to the year 2095 rather than 2100 – just to cut off another 5 cm.” It means that the sea level rise in 2100 would be around 10 mm/yr, but that limits the global rise over 90 years below 10*90 = 900 mm, and more probably with a linear increase of the rate (constant acceleration) to (10+3)/2 * 90 = 540 mm. On the other hand, reaching 3 m in 2100 would require an acceleration a such that vt+at^2/2 = 3*90 + a*(90)^2/2 = 3000, giving a=0,67 mm/yr^2, meaning that the rate should increase by +6,7 mm/yr every decade ! where is it to see ???

    [Response: So where is the inconsistency? The 5 cm are for the actual IPCC number, which is 59 cm, which is indeed below those 900 mm as you rightly conclude. -stefan]

    Comment by Gilles — 11 Mar 2010 @ 10:55 AM

  5. As I have followed the sea level science, its sophistication seems to rise along with the predictions. Yet like the toad in the allegorical warming pot of water, public officials and journalists seem to focus on the here and now: – “still here, still alive.”

    I am willing to bet $1.89 that someone will come out and claim that you have predicted 3 meters of sea level rise by 2105.

    [Response: Sorry, I'm not taking this bet. -stefan]

    Comment by John D. Wilson — 11 Mar 2010 @ 10:56 AM

  6. Regarding the IPCC and its methods, practices, and standards – is there any other institution or organization in another scientific discipline whose mission and scope is close to the IPCC that a comparison can be made?

    Comment by Dean — 11 Mar 2010 @ 10:58 AM

  7. Gilles: “how do the scenarios compare with reality?”

    Everytime I see current measurements compared with the range of predictions from previous IPCC scenarios, the measurements are at or above the IPCC’s worst-case. The scandal is that estimation errors in this direction are not a scandal.

    Comment by Daniel C. Goodwin — 11 Mar 2010 @ 11:10 AM

  8. Thanks, Stefan. This really demonstrates the point that the media response to questions about the IPCC reports is asymmetric. People have complained that the AR4 SLR figures were misleadingly low ever since AR4 first appeared, but somehow that got exactly zero traction in the media.

    Here in the US, as far as I can tell, the conceptual dynamic runs thusly:

    “IPCC says that 21st century SLR could be 18-59 cm. But IPCC is on one extreme end of the spectrum, and all those skeptical scientists out there are on the other extreme, so reality is probably somewhere in between and sea levels will probably rise but by less than 18 cm”.

    Now, that’s a completely ridiculous line of reasoning, but that’s how things work over here, unfortunately.

    Comment by J — 11 Mar 2010 @ 11:11 AM

  9. Giles, your assumption that there will be no carbon-based energy to replace oil consumption is an interesting one. And by “interesting” I mean “naive” or “possibly deceptive”.

    We won’t burn anything once the oil is gone? No coal? No tar sands? No oil shale? Who sez?

    After the oil embargo of Japan in the summer of 1941, some Japanese turned to burning coal to power civilian vehicles. People do like to not walk.

    Comment by Jeffrey Davis — 11 Mar 2010 @ 11:14 AM

  10. Gilles,
    Why do you persistently elide the distinction between peak oil, and peak emissions from all fossil fuel combustion? You have done it again here, without the ghost of an excuse since you note yourself that “coal and gas are far from their peak” in the same paragraph as you say “if fossil production is close to peak, there is no reason for acceleration”? Why do you ignore the fact that there are reasons for sea level rise to accelerate even if emissions are lower than the SRES scenarios, given the unexpectedly rapid changes in both sea ice (raising arctic albedo) and ice sheets (raising the rate of ice flow)? Why do you insist both that fossil fuel use can raise the entire world to the wealth of France, and that continuous economic growth during the 21st century is nothing but wishful thinking?

    Comment by Nick Gotts — 11 Mar 2010 @ 11:16 AM

  11. Maybe this is a bit rude, and I’d be the first to admit that I don’t know a whole lot about the science, but comment #1 looks sorta nutty to me.

    As in, “just blather something about peak oil and scenarios and things and yada yada yada and maybe someone will believe it.”

    That’s sort of the problem, I think. Amateurs like myself have a hard time distinguishing legitimate science and sciency-sounding words and things.

    I do happen to know a *tiny* bit about the SRES assumptions, and my understanding is that they have been pretty well scrutinized, and that the IPCC has addressed a variety of different criticisms (although it would be useful perhaps to hear some of those rebuttals re-hashed, if anyone has the time and the patience).

    But I also know that for those looking to confirm their ignorance and their prejudices that the whole thing is rubbish, then they can look at our first comment and say, “hell yeah! The peak oil and the thing and the whatever! (burp)”

    Ah well.

    Comment by Steve315 — 11 Mar 2010 @ 11:26 AM

  12. The reason why it got through is that it was “wrong” in the way that the most vocal would never promote as being wrong.

    In fact, one poster recently demanded “Where in the IPCC reports are there any underestimating prediction” as “proof” that the IPCC is alarmist.

    They were given several examples.

    And here’s another one.

    But this hasn’t stopped the IPCC being labelled “alarmist”.

    A skeptic would have, though.

    I guess Stefan is a skeptic.

    Monkcton et al, not so much.

    Comment by Completely Fed Up — 11 Mar 2010 @ 11:38 AM

  13. Gilles, there is a large discrepancy in carbon reserves and how teh could be extracted. There is not much conventional left, but there still a lot of tar sand which can be tracted if we are really desesperate. Same thing for shale gas. Coal is lest obvious but there is still pleanty of it. Final heating depends essentialy on the total CO2 emited. To avoid 2C we must cut of CO2 dramatically NOW, which we know that will not happen. Therefore, we are commited to more than that.

    Neverthless, latest model gave a range of 1 more than 2 meters based on the range of IPCC scenario and the sea level model. A key aspect here is the thermal inertia of the ocean that introduce some buffer baring a collapse of the iceshelves.

    Comment by Yvan Dutil — 11 Mar 2010 @ 11:40 AM

  14. Nonsense, Gilles. Please don’t divert attention from the thread. The energy arguments are made over and over in every thread if not throttled early on. And there are far better places to argue them.
    http://www.salon.com/news/feature/2008/03/28/peak_oil_solutions/

    Comment by Hank Roberts — 11 Mar 2010 @ 11:42 AM

  15. Stefan, you have correctly pointed out the one sided concerns of AGW sceptics (self-sescribed). And I certainly acknowledge your expertise with regard to sea level rise. However, I wonder if even your corrections are not a bit optimistic?

    For example you assume a constant 50% underestimate of sea level rise. I understand that this is just for purposes of illustration and is not anything like a projection. But are there not indications of a nonlinear acceleration in Greenland mass loss?

    http://www.skepticalscience.com/Why-is-Greenlands-ice-loss-accelerating.html

    And are there not similar indications for Antarctica, with the possible (likely?) destabilization of the grounding lines of the Pine Island and Thwaites Glaciers?

    http://climatecodered.blogspot.com/2010/01/pine-island-glacier-loss-must-force.html

    I realize these threats may be somewhat tentative and not that well understood at this point, but if they have reasonable probablilities, then they should be taken into account in policy development.

    [Response: The destabilization of West Antarctica is possibly, perhaps even likely, over some time frame. My own view (not shared by everyone) is that it is extremely unlikely for Greenland. In either case the prediction is really difficult. If the air over Antarctica gets warm enough, Pine Island Glacier will certainly collapse, as your link discusses. And currently, warm ocean temperatures are leading to thinning, but it is far from clear that this is anything but short-term variability. There is good evidence that rapid loss of Pine Island means the loss of most of West Antarctica. But the time frame for that is not likely to be hundreds of years (giving ~50 cm/century) but thousands of years, and so it adds only another 5 cm or so per century to sea level rise. The bottom line is that it is hard to say if uncertainties in ice dynamics make Stefan's calculations are overly optimistic or not.--eric]

    Comment by Ron Taylor — 11 Mar 2010 @ 12:01 PM

  16. Steve315, no you understood it well enough.

    Comment by Completely Fed Up — 11 Mar 2010 @ 12:09 PM

  17. The Oil Drum is perhaps the best place to learn about peak oil

    http://www.theoildrum.com/

    Comment by Eli Rabett — 11 Mar 2010 @ 12:15 PM

  18. Is the fact that the models predict 50% less sea level rise correlated with the apparently incorrect expectation that Antarctica would gain mass? ie. is this number being added twice?

    [Response: No on two counts. First of all I didn't add any numbers above for Antarctica, just mentioned it. But more importantly, the finding that sea level rose 50% faster in the observations than in the models comes from Table 9.2 of the report, where you see that the models (with all forcings) give an average rise of 1.2 mm/year for the period 1961-2003, while the observations give 1.8 mm/year. When you look at this table you find the contribution of ice sheets was added in from observations even in the model estimate. Not sure why. -stefan]

    Comment by Steve Milesworthy — 11 Mar 2010 @ 12:18 PM

  19. YvanDutil@6 “(….) but there still a lot of tar sand which can be extracted if we are really desperate”
    No “desperate” involved Yvan, Canada has been full steam mining the tar sands to supply the largest percentage of US needs, with full support of the current denialist/obstructionist Conservative govt – combined with Venezuelas reserves, Gilles should have no employment concerns in his lifetime, especially with his willingness to migrate ;)

    Comment by flxible — 11 Mar 2010 @ 12:22 PM

  20. “Gilles,
    Why do you persistently elide the distinction between peak oil, and peak emissions from all fossil fuel combustion?

    because I didn’t. I didn’t say that peak oil IS the peak of fossil emissions, neither that it proves that peak fossils will occur sooner than the scenarios expect. I said that it proves that the methodology followed to establish the scenarios was flawed, which is not the same. It proves that the scenarios do not encompass the whole range of possibilities.

    Now the question of what will be the real amount of fossils extracted in the future is not a matter of scientific proof (there isn’t any), but a matter of reasonable guess, and use of available information. IF peak oil happens now or within a few years, it brings information : it brings the information that unconventional resources of oil cannot be extracted at a pace high enough to counterbalance the depletion of conventional ones, and that the economy can not bear too high a price of fossil fuels. They may be here, but nobody (or too few people) can afford them. That is very simple indeed. And if it happens to be true for oil, I wonder why it wouldn’t be true for other fossils, including coal. Expensive and bad quality coal cannot ALSO not be extracted at the pace of easy and good quality one, no matter the amount we have.

    You have done it again here, without the ghost of an excuse since you note yourself that “coal and gas are far from their peak” in the same paragraph as you say “if fossil production is close to peak, there is no reason for acceleration”? Why do you ignore the fact that there are reasons for sea level rise to accelerate even if emissions are lower than the SRES scenarios, given the unexpectedly rapid changes in both sea ice (raising arctic albedo) and ice sheets (raising the rate of ice flow)?

    I added a post concerning “acceleration” of sea level rise, which mysteriously disappeared (although it fitted more in the thread ;) ). In the opening post, Stefan said “Second, the IPCC chose to compute sea level rise up to the year 2095 rather than 2100 – just to cut off another 5 cm.” It implies that he thinks that the rising rate at the end of the century will be around 10 mm/yr (a threefold increase of the current rate). But wait .. if the rate is only 10 mm/yr, it implies that the overall rise of sea lever during the XXIth century would be only at most 90 * 10 = 900 mm, and most probably with a linear acceleration only the average (3+10)/2 * 90 = 585 mm. To reach 3 m (3000 mm), we would need an acceleration rate A such that
    v0.t+A t^2/2 = 3 * 90 + A *90^2/2 = 3000 giving A = 0,67 mm/yr^2 , meaning that the rate should increase linearly by +6.7 mm.yr-1 /decade. And more rapidly if it waits some time.

    Aheemm… I should say that I have seldom seen anything varying more smoothly than the sea level rise throughout the XXth century.

    http://www.skepticalscience.com/Visual-depictions-of-Sea-Level-Rise.html

    This damned thing seems VERY heavy to move , even the 70′s that are supposed to be the beginning of “real” anthropogenic warming don’t show any clear acceleration… and in any case very very far from + 6.7 mm/yr /decade !

    “Why do you insist both that fossil fuel use can raise the entire world to the wealth of France”

    I don’t think they will actually, I said it was included in the SRES scenarios ! (which I don’t believe of course…)

    “, and that continuous economic growth during the 21st century is nothing but wishful thinking?”
    because of the non availability of enough easy-to-extract fossil fuels.

    “There is not much conventional left, but there still a lot of tar sand which can be tracted if we are really desesperate. Same thing for shale gas.”
    You know, Yvan, the world economy is currently in a desperate state, but it doesn’t rush onto tar sands and oil shales, quite the opposite. Depletion of conventional resources doesn’t mean that we will miss energy – it means that the economy will crash and that we won’t need it anymore, simply because people will become poorer and poorer – that’s happening just now, all consumptions including electricity are decreasing. We don’t miss energy, we miss CHEAP energy, and expensive energy won’t help us.

    [Response: Ok, enough on this - Everyone, peak oil etc. has been discussed in dozens of threads - it is now OT on this one. - gavin]

    Comment by Gilles — 11 Mar 2010 @ 12:43 PM

  21. “I do happen to know a *tiny* bit about the SRES assumptions, and my understanding is that they have been pretty well scrutinized, and that the IPCC has addressed a variety of different criticisms (although it would be useful perhaps to hear some of those rebuttals re-hashed, if anyone has the time and the patience).”

    “perhaps”..yes :). I’d like too. Seriously.

    Comment by Gilles — 11 Mar 2010 @ 12:46 PM

  22. If the temperature is 5-6C warmer in 2100 I think sea level rise will be completely irrelevant. The vast majority of people on the planet will long since have starved and most species will be endangered or extinct.

    6 degrees is game over – new azolla event time.

    Comment by David Miller — 11 Mar 2010 @ 12:50 PM

  23. Giles, have you ever heard about latent heat? http://en.wikipedia.org/wiki/Latent_heat

    While the ice in the North Pole melts, the temperature around it barely increases, because the latent heat of fusion prevents the heat from increasing while the ice absorbs the energy necessary to melt the ice.

    [Response: Almost negligible - IPCC has an analysis of this somewhere, and in terms of heat absorption only the ocean counts. The ice melts slowly not for lack of available heat energy but because it is a poor heat conductor.]

    During this process sea levels barely rise because the ice floating actually tends to decrease sea levels as it melts, partially balancing glaciers melting that tend increases sea levels.

    [Response: Huh?]

    Once North Pole the ice is gone, temperatures are free to rise again. With ripple effects around the earth, melting glaciers faster, then Antarctic ice. The later rising sea levels sharply.

    Antarctic ice will be much slower to melt because it will first need to rise in temperature from subzero temperatures before it starts melting. This will also trigger another plateau.

    Combined with other positive feedback effects such as the change in albedo mentioned above, and the release of increasing quantities of methane gas, this more than explains why there WILL be an accelerated temperature and sea level rise even if we stopped adding CO2 into the atmosphere. The later hypothesis being very unlikely because of the deceptive political climate of science deniers.

    Comment by Jean — 11 Mar 2010 @ 12:56 PM

  24. All due respect to Stefan, but where does your “hypothetical” case come from? Is there a “denier” blog that actually indicated this or is it a complete fabrication?

    Unless the “hypothetical” case has some foundation in reality, this is nothing more than a classic strawman argument.

    Why include it at all? You have presented your critisim of the IPCC’s reluctance to be alarmist. Well done. What is the need to include some completely fabricated “denier” scenario, which says the opposite?

    Comment by David Smith — 11 Mar 2010 @ 1:00 PM

  25. Very interesting. The comment about not erring on either side, but giving the most balanced viewpoint possible is especially important in today’s incredibly polarized environment. The safe approach is to give ranges and probabilities within that range…but be sure you include the full range and the full time span!

    Comment by R. Gates — 11 Mar 2010 @ 1:03 PM

  26. Let’s see…..Sea Levels have increased on average 1.7-1.8mm/yr over the last 150 years….Next 100…..let’s see…..heavy math here…..

    I predict 17.5cm sea level rise by 2110.

    I’m taking bets.

    Comment by HarryDinPT — 11 Mar 2010 @ 1:10 PM

  27. From a policy view it would appear that the politicians expect the 2100 sea level rise to be the end of the matter. Yet all I see of scientific papers is that sea levels will continue to increase for centuries to come. So if we prepare for a, say, 3 meter rise then we may be a little early. But it will get there.

    Perhaps we should be expressing the error as time. That we expect a x meter rise by 2100 plus or minus y years. Emphasise that we know it will go up way over 5 meters but we are not sure how fast.

    Also in what order and at what rate do scientists expect things to happen. That way if it does happen faster than expected, we can be early warned. A Pine Island Glacier collapse would have implications on the stability of other glacier systems.

    You may be telling us that there is a degree of uncertainty on the upper limit of the rate of sea level rise, but we are not listening. You can hear the “no one told us” cries coming.

    Comment by Tony O'Brien — 11 Mar 2010 @ 1:16 PM

  28. I’m no scholar, but my understanding is–

    a) Most of the carbon dioxide we emit goes into the oceans.
    b) A large part of the added heat retained by an increase in greenhouse gases also ends up in the oceans.

    Both of these processes would seem to have a limit– that is, the more carbon dioxide is in the oceans already, the less good the oceans are at absorbing increased CO2. Does anyone know to what degree these factors are incorporated into existing models forecasting temperature and sea level? Thanks!

    Comment by Jacob — 11 Mar 2010 @ 1:25 PM

  29. Gavin understandably doesn’t want to be taken OT by having it pointed out yet another dozen times that there is easily enough carbon left underground to cause terrible trouble.

    Yet I would be sorry if we lost the other point, which is made far too seldom: changes in oil usage will cause huge feedbacks into the rest of the economy, plausibly affecting carbon emissions in a big way, and bringing the choice of scenario back On Topic later. (This doesn’t redeem all the other sins of “Gilles” though.)

    Comment by Ric Merritt — 11 Mar 2010 @ 1:42 PM

  30. David Miller wrote: “If the temperature is 5-6C warmer in 2100 I think sea level rise will be completely irrelevant. The vast majority of people on the planet will long since have starved and most species will be endangered or extinct.”

    You beat me to it.

    On the bright side, coastal cities that have been mostly depopulated by global famine will be easier to evacuate.

    And of course from the point of view of the people who are ultimately behind the campaign of deceit, denial, delay and obstruction, it matters little if the vast majority of human beings starve, as long as there remain sufficient resources to support “the top one percent”.

    I would like to see more articles here focusing on what the science can tell us about the likelihood, timing, and geographic distribution of AGW-driven, widespread, intense and prolonged drought.

    Today, Australia — tomorrow, the world?

    Comment by SecularAnimist — 11 Mar 2010 @ 1:47 PM

  31. Giles:

    Assuming you’re serious, one reason your analysis is wrong is that declining oil will affect mostly transportation, and not power generation. You’re making oil the number one CO2 contributor when it’s simply not. Also, it’s a non sequiter that if one analysis by one study in one are is wrong about one detail, then “nothing can be trusted.”

    The larger error is the belief that Stern, the IPC WG3, etc. have not considered the economics and scarcity of various fuels (fossil, nuclear, agricultural, etc.). That’s usually the larger flaw with these critiques.

    It’s clear to me, at least, Giles, that you have not read either the Stern report or any of the IPCC reports, or if you did so, you had to have been skimming through them looking for something to disagree with.

    Also, your comment looks like a printed rendition of an extended talk radio monologue. Most of your IFs are false, and where they aren’t, your IF THEN is invalid. Moreover, you repeat the word bias without giving any evidence of understanding what it means in a science context. Moreover, you confuse models, scenarios and methodology, and use the word flawed in a meaningless way. It’d be easy to respond to that with “everything’s flawed, to a degree” since you’re so unspecific about the flaws (and don’t give estimates of their magnitude).

    Also, in your terms, why you’re wrong is that the IPCC estimates so far have been undershooting actual sea level rise – that’s not a “model” or something you can call flawed or biased, that’s a comparison of observations to stated projections. Your estimate of about a foot is approximately the IPCC estimate, although you’re knocking it down a mm a year for no rational reason (Peak Oil, even for those convinced we’ve already reached a world Hubbard Peak, doesn’t mean oil production slows immediately or even stops increasing, initially it’s more a pricing matter, and we’d have to freeze ALL GHG emissions at current rates to justify your claim). The problem is, so far, the IPCC estimates are conservative. Put another way, again in your terms, all that has to happen even if oil declined is just a little extra coal production from India and China, say, let alone lots of other countries, and your confident assertion becomes wrong, and hence, biased and flawed, and you cannot be trusted.

    Comment by Marion Delgado — 11 Mar 2010 @ 1:49 PM

  32. Stefan,

    Thank you for the post. I agree with everything you said. IMHO, the fact that the IPCC has been extremely conservative on some fronts (Arctic sea ice) and sea level, is quite a big story. So much for alarmism.

    What the IPCC should strive for is that all the metrics for the biosphere are internally consistent. That is no easy task in such a complex system. But their job, and that of the scientists, is not to shelter us from inconvenient or distressing news. It is well documented that there has been immense pressure at times to play down the seriousness of consequences associated with a much warmer planet, and this is how such inconsistencies can arise. Alas, the media and those in denial refuse to report and recognize this fact.

    Unfortunately, one is damned if you do and damned if you don’t with the deniers. Just present the facts which the body of science suggests is the most likely.

    Thanks for all your hard work on the matter of sea level rise. I, for one, am very grateful to know that there are eminent scientists like you working on this problem, and trust that you will do your utmost to arrive at the most plausible answer.

    Comment by MapleLeaf — 11 Mar 2010 @ 2:01 PM

  33. You seem to be saying that the prediction of sea level rise to this point was made 40 years ago.
    And is spot on.

    Never happened.

    Comment by Larry Thiel — 11 Mar 2010 @ 2:31 PM

  34. I found this very informative.

    But I couldn’t help thinking that pretty soon we’ll find the fist few paragraphs of your piece cut and pasted and send around by denialists as an example of IPCC’s alarmism!

    Comment by calyptorhynchus — 11 Mar 2010 @ 2:50 PM

  35. In re, #1, “all scenarios are based on the hypothesis of continuous economic growth during the XXI century, which is nothing but wishful thinking.”

    There’s 6 billion people intensely interested in continuous economic growth. More on the way. I think we can count on relatively undiminished resource exploitation and continuing deforestation.

    Barring a complete collapse of civilization, world-wide, I think “CO2 levels will increase” is about the surest bet you can make.

    Comment by Charlie H — 11 Mar 2010 @ 2:55 PM

  36. “If the temperature is 5-6C warmer in 2100 I think sea level rise will be completely irrelevant. The vast majority of people on the planet will long since have starved and most species will be endangered or extinct.”

    OK but don’t forget that in order to reach 5-6 °C, we need a fossil fuel consumption continuously increasing up more to three times the current one, a energy per capita more than 5 times the current one, and an economic growth insuring an average GDP/capita about the current US one. So you’re really talking about a strange situation where all this energy would be burnt by people having starved for death for a long time ….


    Giles, have you ever heard about latent heat? http://en.wikipedia.org/wiki/Latent_heat
    eeeuh .. as a physics teacher… yes indeed !

    “While the ice in the North Pole melts, the temperature around it barely increases, because the latent heat of fusion prevents the heat from increasing while the ice absorbs the energy necessary to melt the ice.”
    yes, the temperature of water mixed with ice barely increase, I agree… actually it remains almost constant neglecting the variation of salinity.

    “During this process sea levels barely rise because the ice floating actually tends to decrease sea levels as it melts, partially balancing glaciers melting that tend increases sea levels.”

    Actually the melting of ice floating doesn’t decrease or increase anything if you neglect the variation of volume during the mixing of salt and fresh water… but since fresh water is somewhat less dense I would say it increases a little bit.

    “Once North Pole the ice is gone, temperatures are free to rise again. With ripple effects around the earth, melting glaciers faster, then Antarctic ice. The later rising sea levels sharply.”

    For me it’s starting to be kind of movie scenario at this point …

    “Antarctic ice will be much slower to melt because it will first need to rise in temperature from subzero temperatures before it starts melting. ”

    really? and the other ice doesn’t need that ?


    Combined with other positive feedback effects such as the change in albedo mentioned above, and the release of increasing quantities of methane gas, this more than explains why there WILL be an accelerated temperature and sea level rise even if we stopped adding CO2 into the atmosphere. The later hypothesis being very unlikely because of the deceptive political climate of science deniers.”

    I’m not a science denier : that’s my job…. I’m not a movie maker.

    Comment by Gilles — 11 Mar 2010 @ 3:17 PM

  37. #26 SecularAnimist says:
    “I would like to see more articles here focusing on what the science can tell us about the likelihood, timing, and geographic distribution of AGW-driven, widespread, intense and prolonged drought. ”

    It really is time to start looking into Doctor Strangelove-type end games.
    Is it just me or has the denialosphere blowhorn been turned up about 50 decibals as of late?

    Comment by Garrett — 11 Mar 2010 @ 3:30 PM

  38. Global sea level data based on satellite measurements are available from the University of Colorado. Link: http://sealevel.colorado.edu/

    Their most recent estimate is a rate of increase of 3.2 ± 0.4 mm per year.
    The data plotted (1992-2009) do not suggest an increasing rate in recent years. The trend value appears at best to remain the same. Of course one can not draw any conclusion about flattening based on only a few years, all that I am saying is that the curve certainly does not suggest an increasing rate.

    By extrapolation a value of 3.2 mm/year would imply a total global sea level rise of about 32 cm for the next century (till 2110). So how can you claim that a predicted value of 59 cm for the year 2095 would be implausibly low?

    [Response: The flaw in this logic is that you assume sea level rise is independent of temperature, i.e. does not accelerate as it gets warmer. But data show it does, and it makes physical sense too. Do you think ice melts faster when it is warmer? At the beginning of the 20th Century sea level rose at a rate of about 1 mm/yr, and after 0.8 ºC global warming this rate has roughly tripled, now standing at about 3 mm/year. -stefan]

    Comment by wilt — 11 Mar 2010 @ 3:32 PM

  39. [edit - OT means OT]

    “Also, in your terms, why you’re wrong is that the IPCC estimates so far have been undershooting actual sea level rise”
    That’s strange regarding the fact that sea level was ALREADY rising for a century or so, at 2mm.yr^-1, even without net warming : what the hell did they put in their calculations ?

    Comment by Gilles — 11 Mar 2010 @ 3:39 PM

  40. http://www.thegwpf.org/the-observatory/580-sea-level-shenanigans.html

    Comment by Ibrahim — 11 Mar 2010 @ 4:11 PM

  41. Great post. Thanks very much for this.

    I have to ask, though–is any of this SLR curiosity due to political influence, ala the infamous case of the “embers diagram” being pulled from the report? (http://dotearth.blogs.nytimes.com/2009/02/26/why-2007-ipcc-report-lacked-embers/)

    Comment by Lou Grinzo — 11 Mar 2010 @ 4:21 PM

  42. Tks Stefan R.- and Gavin S. et al. ça va sans dire – for your 2007 post as well. Some journalists did care, asked local scientists to check your figures (nothing personal, just standard practice), and tried to explain why research was pointing to higher sea-levels.

    [Response: Sure - many media reports have covered the evidence for a larger sea level rise than projected by IPCC. That was not my point. The point is in the asymmetry: that evidence was discussed in sober and factual terms, as we did in our RC piece at the time and as it should be. But if the IPCC made a mistake that overstates a climate impact, like the Himalaya glacier mistake, then it is hugely scandalised. Imagine the Himalaya statement in the IPCC report would have read that by the year 2350 80% of Himalaya glacier area would likely be gone. That would have been equally implausible and ill-founded as the year 2035, but as it understates the actual glacier melt problem, I am sure that the scandalising-machine would not have picked it up. -stefan]

    @Dean
    WHO assessments of epidemiological models for AIDS-TB-malaria perhaps?

    @Daniel Goodwin – 7
    “Current measurements”: quite so. The main exception was CH4 concentrations staying flat. It made for good copy while it lasted.

    Comment by oca sapiens — 11 Mar 2010 @ 4:31 PM

  43. There seems to be a repeat of the errors of Malthus and Ehrlich running through this thread.

    Comment by J — 11 Mar 2010 @ 4:49 PM

  44. What I see is the begining of an S-shaped curve in sea level. I don’t know what the eventual sea highstand will be, except that the maximum possible is around 80 meters. As for the rate of the S-shaped curve, dunno.

    Comment by David B. Benson — 11 Mar 2010 @ 5:14 PM

  45. I find all this sea level talk by skeptics quite wearisome. I live in Florida and have spent decades walking along Florida’s coastline. The sea level has risen and the coastline has retreated in a perceptible manner and this process of rise & retreat is accelerating.

    It is easy to perceive changes in the sea level, too, since ecological zones move inland.

    You can see what I observed today in Safety Harbor:

    http://www.flickr.com/dmathew1

    It is well known that Florida was completely covered by the ocean recently from a geological standpoint. Yet conservative newspapers and politicians continue to deny the threat of global warming. The great cause of Florida’s political class at the present moment is oil drilling.

    Comment by David Mathews — 11 Mar 2010 @ 5:29 PM

  46. Nice counter to the argument that the IPCC is alarmist and all the errors are on the side of making things sound more alarming (Himalayan glaciers…)

    On the CRU “fraud” accusations, I gave an accuser space on my blog. Anyone who wants join in, feel free. I thought it would make for a useful change to have the denialist slant up front and argued with. In the interests of science, though I am not confident that the experiment will be useful …

    Comment by Philip Machanick — 11 Mar 2010 @ 5:31 PM

  47. #11 Steve315

    “Amateurs like myself have a hard time distinguishing legitimate science and sciency-sounding words and things.”

    The remedy: Read the posts for science; read the comments for entertainment!

    Comment by Jerry Steffens — 11 Mar 2010 @ 5:41 PM

  48. > wilt
    > University of Colorado …
    > Their most recent estimate is a rate of increase of 3.2 ± 0.4 mm per year.

    wilt, you’re pointing to fairly old information, on a page that hasn’t been updated recently. Are you aware of how much new information has come out?

    Compare for example
    http://www.skepticalscience.com/Visual-depictions-of-Sea-Level-Rise.html

    — brief excerpt follows; the original has links to the papers on which the description is based, and much more info, which I’ve omitted here —–

    Recent reviews … show that the most up to date estimates of mean rate of sea level rise for the 20th century are converging on around 1.7 to 1.8mm/year, with uncertainties of around 0.2 to 0.3mm. …. the “slowing down” reported by some observers (around 2008) has proved short lived (judging from 2009/2010 data)…. Again refinements and corrections of recent datasets from GRACE (with GPS) and ARGO resolve previous and relatively recent difficulties, so that the sum of these climate-related contributions (2.85 ± 0.35 mm per year) is now comparable with the altimetry-based sea level rise (3.3 ± 0.4 mm per year) over the 1993 to 2007 period …. while the steady and gradually accelerating increase since pre-industrial times of around 30cm or a foot may appear manageable, if the recent trend of accelerating mass loss from Greenland and Antarctic Ice caps, as well as the world’s glaciers continues, then the potential sea level rises will have significant impact …. The weight of peer-reviewed evidence for this acceleration in sea level rise is robust….

    Comment by Hank Roberts — 11 Mar 2010 @ 7:28 PM

  49. PS, question for the scientists — we often hear people remark about the charts of temperature apparently not changing much from say 1940 to 1970 or so, but I haven’t seen anyone note that during the same period, this chart

    http://www.skepticalscience.com/images/sea-level-tidal-satellite.jpg
    (from the same skepticalscience page) _looks_like_ sea level changing faster.

    I’d guess this kind of eyeballing evaluation is getting the kind of study that Tamino takes on, findint a statistic suitable for asking whether we can distinguish a linear trend from an acceleration in rate of change.

    [Response: Have a look at Rahmstorf (2007) or Vermeer and Rahmstorf (2009) (linked in above) for the connection between global temperature and sea level. -stefan]

    Comment by Hank Roberts — 11 Mar 2010 @ 7:35 PM

  50. Re Gilles @36: “OK but don’t forget that in order to reach 5-6 °C, we need a fossil fuel consumption continuously increasing up more to three times the current…”

    Or for the current and committed warming to cause the release of just a portion of the methane currently locked in clathrate ices and the CO2 currently locked in permafrost tundra and bogs.

    Just ask yourself what the mean surface temp was the last time atmospheric CO2 was at 387 ppmv, oh, about 15 mya in the middle miocene.

    Comment by Jim Eager — 11 Mar 2010 @ 7:41 PM

  51. Man the dykes: the general theory of the blogoshere predicts that within 24 hours, talk radiologists will shamelessly chop off this article’s first two words , and tell the world :

    “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” :

    First, although the temperature scenarios of IPCC project a maximum warming of 6.4 ºC ( just to add that extra bit of alarmism… 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! …

    Some scientists within IPCC warned early that all this could lead to a credibility problem”

    To disinformation artistes disposed to declare misplaced commas ” fatal flaws” any attempt at irony is a godsend.

    For a reality check on this dismal hypothesis, just turn the dial to talk radio next week

    Comment by Russell Seitz — 11 Mar 2010 @ 8:49 PM

  52. Sorry if this is not on the exact topic of the present blogpost, but I was wondering if someone here could recommend a clear, point-by-point critique of the climate chapter in Levitt & Dubner’s “Superfreakonomics”?

    Raymond Pierrehumbert mentions in his blogpost from 29 Oct. 2009 that “there have been many detailed dissections of everything that is wrong with the treatment of climate” there, so I thought someone with a competent background here might recommend one or two in particular…

    Comment by orangejuice — 11 Mar 2010 @ 8:52 PM

  53. Of course IPCC underestimation for sea level rise won’t be widely reported and disseminated within the media. The very idea of accurate reporting in the media is a joke. We actually have to depend on first sources to be able to actually get any reliable information about climate change. When we go to second or third sources (third being the media reporting on bloggers, etc), we find ourselves lost, torn, completely misled. But first sources are extremely difficult to digest for the regular public, very few will spend hours of their free time reading scientific reports, and verifying what they say is true. People would prefer to sit back and listen to those whose disinformation fits within their ideology.

    Comment by Josh Cryer — 11 Mar 2010 @ 9:07 PM

  54. orangejuice (52) — Joe Romm, on his ClimateProgress (listed on the sidebar), did a thorough disection, in several parts.

    Comment by David B. Benson — 11 Mar 2010 @ 9:16 PM

  55. Target Atmospheric CO2: Where Should Humanity Aim? by Hansen et al. (2008) provides a sobering look at sea level and CO2 concentrations. The last time Antarctica was ice-free, sea levels were 120m (~400 feet) higher than today. CO2 concentrations were estimated to be 425±75 ppm at that time. Today’s values are already “in the zone”.

    Comment by Scott A Mandia — 11 Mar 2010 @ 9:20 PM

  56. Stefan or Gavin,

    When you are talking about a sea level rise of one meter, are you speaking of world oceans? The volume of ice needed to create a one meter rise would be quite high.

    If the area of the oceans is 361×10^6 km^2 and it rose 1 meter, the volume of water would be 3.61 × 10^14 m^3.
    Change the units to miles, and we have 86,609 cubic miles of water.

    86 thousand cubic miles is a lot of water. I’m not saying it couldn’t happen, but we are talking about a LOT of extra water.

    Comment by EL — 11 Mar 2010 @ 9:49 PM

  57. Does ice melt linearly? I wish you guys would post more formulas.

    Comment by EL — 11 Mar 2010 @ 9:50 PM

  58. David Benson, thank you for the pointer.

    Comment by orangejuice — 11 Mar 2010 @ 9:53 PM

  59. “Most of the current global land ice mass is located in the Antarctic and Greenland ice sheets (table 1). Complete melting of these ice sheets could lead to a sea-level rise of about 80 meters, whereas melting of all other glaciers could lead to a sea-level rise of only one-half meter.” from
    http://pubs.usgs.gov/fs/fs2-00/

    Comment by David B. Benson — 11 Mar 2010 @ 9:56 PM

  60. RE- Comment by EL — 11 March 2010 @ 9:49 PM:

    Water expands when it warms.

    Steve

    Comment by Steve Fish — 11 Mar 2010 @ 10:05 PM

  61. Mr. EL wrote on the 11th of March 2010 at 9:49 PM:

    1 meter SLR=86,609 cubic miles of water by 2100

    this is 870 cu mi per year

    we already have on the order of 122 cu. mi. coming off Greenland/Antarctica per year

    currently the political class is betting that it not increase before they get diselected, and the financial class is betting the same does not happen before they retire

    do you feel lucky ? i dont

    sidd

    Comment by sidd — 11 Mar 2010 @ 10:10 PM

  62. You’d think policy-makers and people concerned about life on planet earth would be focused like a razor on the high end predictions, and consider the IPCC rather conservative in its claims. They’d be shrugging off the “it isn’t as bad as the IPCC claims on the Himalayan glaciers,” and honing in on “the IPCC isn’t giving a full account of sea rise because of uncertainties regarding the mechanics and other factors; what might it really be?”

    Like when they’re planning a bridge, do they figure building it to tolerate the weight (a) during light traffic conditions, (b) during average traffic conditions, or (c) for a rush hour when a caravan of tractor-trailers carrying full loads of lead are bumper-to-bumper on the bridge?

    Or, confronted with a sign that says “bridge out” re a broken bridge over a very deep canyon, does one (assuming a non-sucidal person), (a) accelerate (which is what we’re doing by increasing our GHG emissions), (b) maintain the same speed, or (c) come to a stop and find another route?

    However, even the low range figures of projected harms from AGW, even earlier IPCC reports, even what science knew back in 1990, before studies had reached .05 on AGW, even then the indication was that we should do everything possible as quickly as possible to reduce our GHGs down by at least 60 or 70% within 10 to 20 years, and then use the savings from that for possible future adaptations.

    What’s going to get people off their behinds, or rather keep them on their behinds so they don’t go around emitting GHGs?

    Comment by Lynn Vincentnathan — 11 Mar 2010 @ 10:15 PM

  63. #56 EL

    Yes, a lot of extra water. 361,000 Km^3 in fact.

    Currently it is estimated that the Antarctic is losing about 246 Km^3 per year, and Greenland about 286 Km^3 per year. A total of about 532 Km^3 per year.

    http://www.agu.org/pubs/crossref/2009/2009GL040222.shtml

    Still a long way to go but the evidence is that the process has sped up over the last few years and fits a quadratic trend better than a linear trend.

    Comment by Andrew Hobbs — 11 Mar 2010 @ 10:18 PM

  64. Charlie H wrote: “There’s 6 billion people intensely interested in continuous economic growth”

    And if wishes were horses we’d all be knee-deep in horse manure.

    There are a lot of people intensely interested in achieving continuous bliss through continuous heroin use.

    They probably have a better shot at success than people who imagine that we can sustain “continuous economic growth” for a population of 6 billion humans through continuous business-as-usual consumption of fossil fuels.

    Of course, what continued business-as-usual consumption of fossil fuels can achieve is trillions of dollars in profits for the fossil fuel corporations in the decades until (1) economically recoverable reserves are exhausted and (2) the resulting unmitigated anthropogenic global warming brings a rather gruesome end to the lives of the vast majority of those six billion people.

    But that’s a small price to pay for “continuous economic growth” for the “top one percent”, who expect to command the wealth, power and resources needed to survive the AGW catastrophe, and who, after all, have no real need for the surplus population anyway.

    Comment by SecularAnimist — 11 Mar 2010 @ 10:23 PM

  65. 55
    Scott A Mandia says: “The last time Antarctica was ice-free, sea levels were 120m (~400 feet) higher than today. CO2 concentrations were estimated to be 425±75 ppm at that time.”

    But wasnt that pre the continent drifting over the pole? As i understand it ice started accumulating on Antarctica 45million years ago(approx, top o head figure) With this ice age(not talking interglacial/glacial.. but ice house/hot house) began 2.5 million years ago… but basically the ice sheet was caused by the location of the continents. Rather than atmospheric make up at the time.

    Comment by Mike — 11 Mar 2010 @ 10:51 PM

  66. The timing of sea level rise is the hardest thing to predict and it isn’t really that important. When Greenland melts, sea level will go up 7 meters. Does it matter if it is 100, 200 or 300 years? Is putting most of Florida under water ok if it is 200 years in the future?

    Comment by daedalus2u — 11 Mar 2010 @ 10:53 PM

  67. David B. Benson – I never realized there was that much ice.

    Comment by EL — 11 Mar 2010 @ 10:55 PM

  68. “Man the dykes: the general theory of the blogoshere predicts that within 24 hours, talk radiologists will shamelessly chop off this article’s first two words , and tell the world : …

    If Russell Seitz is a skeptic, he’s the only one I like. That is so accurate!

    And David Benson, great work over at Dot Earth. Alas, anything there is a wasted effort. Revkin has the people, and the view, he wants dominating his blog. As with most papers these days, it has an active conservative action program firmly in place for comment threads.

    Comment by Mark A. York — 11 Mar 2010 @ 11:05 PM

  69. Re David Benson’s USGS link @ http://pubs.usgs.gov/fs/fs2-00/ , keep in mind that the last time atmospheric CO2 was at 387 ppmv there was virtually no permanent ice in the Arctic and there was less ice in the Antarctic than there currently is. So that’s virtually all 6.55 meters from Greenland, plus virtually all .46 meters from the Antarctic Peninsula, plus most of the 8.06 meters from the West Antarctic ice sheet.

    Not by 2100, maybe not by 2200 or even 2300, but if we stay at the current level, let alone go higher, it will happen.

    Count on it.

    Comment by Jim Eager — 11 Mar 2010 @ 11:07 PM

  70. 56: Yes it is a lot of water/ice, but it represents slightly over 1% of the glacial ice in the world. Losing 1% of the ice in a century does not sound like a very extraordinary thing.

    Comment by Thomas — 11 Mar 2010 @ 11:09 PM

  71. Yet another “gate” is about to make the rounds.

    He seems to think that GISTemp uses CRU data in its temperature analysis. AFIAK, it uses GHCN.v2_mean, USHCN.v2 and SCART to cover Antartica. I would like to see what Jim Doyle’s original question was. It seems from the answers to have been something about US regional temps, but I can’t really tell and don’t want to wade through 200+ pages of email to see what it was, if indeed it is even in there.

    Just a heads up.

    Comment by Rattus Norvegicus — 11 Mar 2010 @ 11:19 PM

  72. “Who controls the past controls the future. Who controls the present controls the past.” (George Orwell.) So perhaps a historical perspective is justified.

    The 10-year rate of rise estimated by the Jason/Topex satellites has been around 3.3 mm/year, almost the double the 20th century average. On the other hand the global warming from 1910 to 1945 was almost identical to the 1975 to 2005 warming in both rate and magnitude. It also was followed by a period of higher than average rates of sea level rise. The 10-year rate of rise in the 1950s (average of Church et al and Jerejeva et al estimates) was around 3.2 mm/year, sensibly identical to the present level rise. (http://www.climatedata.info/Impacts/Impacts/sealevels.html)

    The fact that current rates of rise have been experienced in the past after similar temperature increases does not of course invalidate the predictions for the future perhaps it does justify the caution shown by the IPCC.

    Comment by Ron — 11 Mar 2010 @ 11:20 PM

  73. EL says: 11 March 2010 at 9:49 PM

    Don’t forget about thermal expansion.

    Comment by Doug Bostrom — 11 Mar 2010 @ 11:29 PM

  74. Scott A Mandia re:#55

    Two questions!

    When did sea level rise to 120 meters above today’s stand?

    [Response: Above? It was 120 meters below today at the Last Glacial Maximum, about 20,000 years ago, and about 70 meters above today in the high-CO2 greenhouse climate before continental ice sheets started to form about 40 million years ago.]

    Is there a correlation between sea level and atmospheric CO2 concentration in the recent past(latest Quaternary) other than over the last century?

    [Response: Sure, a very close correlation over the Quaternary because of the well-known correlation of CO2 concentration with the glacial cycles that dominated the Quaternary, and which come with about 120 m amplitude in sea level due to the waxing and waning of huge ice sheets. -stefan]

    Comment by FHSIV — 12 Mar 2010 @ 12:41 AM

  75. I find it hard to understand why it is OT to mention that some of the IPCC scenarios are unrealistic (like Giles did in #1)? Have a look at this
    http://www.tsl.uu.se/uhdsg/Publications/IPCC_article.pdf
    very fresh article about Peak Oil/Coal. It has everything to do with sea level rise (as well as other climate projection for this century)!

    Comment by Bengt A — 12 Mar 2010 @ 12:46 AM

  76. Any discussion of sea level changes should take into account local subsidence and emergence of the land mass. Very often apparent rises in sea level are in fact due to land subsidence, often due to extraction of water from underlying aquifers.

    If rises in sea level were really global, and land subsidence and emergence were not a factor, then we would see the same rate and degree of sea level rise at all coastal points. The fact that we see quite wide variations is surely telling us something.

    [Response: This effect is of course taken into account in sea level studies. Your latter point is not correct. Even sea level proper can show regional variations, regardless of land movement. You see this in the satellite data; it is pictured and discussed in the IPCC report and a host of papers. -stefan]

    Comment by mondo — 12 Mar 2010 @ 1:31 AM

  77. “Re Gilles @36: “OK but don’t forget that in order to reach 5-6 °C, we need a fossil fuel consumption continuously increasing up more to three times the current…”Or for the current and committed warming to cause the release of just a portion of the methane currently locked in clathrate ices and the CO2 currently locked in permafrost tundra and bogs.”
    Yes, another scene in the movie. Read the previous thread about methane.
    “Just ask yourself what the mean surface temp was the last time atmospheric CO2 was at 387 ppmv, oh, about 15 mya in the middle miocene.”
    Several degrees higher , which only proves that the average temperature is by no means a single valued function of CO2 concentration, which is not surprising since the average temperature is not a meaningful measurement of anything physical (it is neither the enthalpy, nor the effective temperature, nor anything else than an average temperature). The radiative balance of Earth can be influenced by other things than the average temperature : ocean and atmosphere circulation, fraction of deserts, forests, ice coverage, influencing cloud coverage, and so on… so basically the comparison with numerical values in the distant past is not accurate enough to draw any conclusion.

    Comment by Gilles — 12 Mar 2010 @ 1:54 AM

  78. Sorry back to my first post and the comment :
    “Your logic is flawed, because data of the past century show how the rate of sea level rise increases in proportion with temperature ….But the most optimistic scenarios have warming stopped at about 2 ºC above preindustrial, i.e. two to three times the current warming, which would imply roughly that the rate of sea level rise also doubles or triples.”
    Maybe I don’t understand correctly, but the equation of your paper : dH/dt = a(T-To) is obviously non physical since it describes a indefinitely rising sea level even if temperature has stabilized above To ! (and adding a dT/dt term doesn’t help of course). The only meaningful linear equation I can imagine is a relaxation one dH/dt = -a(H-Ho(T)) where Ho(T) is some equilibrium sea level at the temperature T. Of course if H and Ho(T) rises with a approximate linear rate , in first approximation, you will find an approximate linear law comparable to yours , but extrapolation of this law is spurious since the real relaxation equation produces a plateauing of H to the equilibrium value , which is not the case of your equation (there is obviously no equilibrium value in yours !).

    [Response: How about reading my paper? It explains all this and even illustrates it with a graph (Fig. 1). -stefan]

    Comment by Gilles — 12 Mar 2010 @ 2:11 AM

  79. EL #57: the rate at which ice melts in big ice sheets is pretty complex as it depends on effects like whether the ice is likely to break up, whether it can move a short distance and land on water and what it is grounded on. The latent heat of melting ice is a well known formula, as is the energy needed to raise its temperature to melting point. I don’t recall exact numbers but on that basis simply increasing energy flows by a few W/m2 would take thousands of years to melt the bigger ice sheets. But the fact that for example the West Antarctic Ice Sheet has a large fraction grounded below sea level means that this is not necessarily a relevant calculation. All it would take to lose much of this grounded below sea level ice sheet much faster than the rate of melting would imply is for water to find its way in substantial quantity under the ice and speed its flow to sea.

    So short answer: there isn’t a short answer.

    Comment by Philip Machanick — 12 Mar 2010 @ 3:36 AM

  80. If you’re interested in seeing what the ice in the Southern Ocean and the Weddell Sea near the Antarctic Peninsula looked like in 2009, I’ve put up some 56 shots of icebergs, sea ice and their inhabitants here.

    Antarctic Icebergs
    http://earthlightimagery.com/gallery.php?gid=49

    Even if you looked before I guarantee you’ll find new images.
    Tim

    Comment by Tim Jones — 12 Mar 2010 @ 3:52 AM

  81. Stefan, If I understand you correctly you seem to consider 59cm SLR implausibly low, for 2095, where can we find a more plalusibly proyection, and a global index to compare both?

    [Response: Read the p.s. of the post. ]

    Comment by Sordnay — 12 Mar 2010 @ 3:58 AM

  82. Re Gilles @36: “OK but don’t forget that in order to reach 5-6 °C, we need a fossil fuel consumption continuously increasing up more to three times the current…”

    Nope. We could have various other things that achieve similar effects, including unexpected positive feedbacks, large increases in non-fossil-fuel based emissions (more then 50% of my country’s emissions are not from fossil fuels – and our per-capita emissions are among the highest in the world), spikes in fossil fuel usage followed by declines rather than constant increase, etc.

    But I certainly agree that 6 degrees of global warming isn’t an immediate civilisation killer. It probably only means 3 degrees of warming in some areas. Of course, it also probably means average temperatures 9 degrees higher in some areas – but I never much liked the US’s Southern States anyway.

    Comment by sean — 12 Mar 2010 @ 4:18 AM

  83. Hey Guys, take a look at the wilkins ice shelf..it’s about to completely break up. I’ve been following http://www.esa.int/esaEO/SEMWZS5DHNF_index_0.html
    every day for the last year..and since the ice bridge collapsed last year it’s been pretty stable until now. Deep fissures are now apprearing to the bottom left and right of the time lapse images.

    Comment by Lawrence Coleman — 12 Mar 2010 @ 4:50 AM

  84. Take a look specifically at frame three of the animation and tell me what you think.

    Comment by Lawrence Coleman — 12 Mar 2010 @ 4:53 AM

  85. “Response: How about reading my paper? It explains all this and even illustrates it with a graph (Fig. 1). -stefan”
    If I hadn’t read it, I would not know your equation. I repeat : your equation is a linear approximation that will be always correct at the beginning, because almost any differential equation can be expanded and cut at first order linear approximation, but is obviously spurious and doesn’t give the correct behavior on the long term. So “calibrating” it in the current period and extrapolating it will produce spurious behavior.

    [Response: Hint: the paper introduces the equation with the sentence [emphasis added]: “The initial rate of rise is expected to be proportional to the temperature increase” and then shortly afterwards states: “The equilibration time scale is expected to be on the order of millennia. Even if the exact shape of the time evolution H(t) is not known, we can approximate it by assuming a linear increase in the early phase; the long time scales of the relevant processes give us hope that this linear approximation may be valid for a few centuries.” I was cautious in applying it only to one century, after calibrating it for a 120-year period. I also tested how well this holds up using climate model output. We have a paper submitted looking at longer time scales (multi-century), where of course we do take into account that there is a finite equilibration time scale involved. -stefan]

    Comment by Gilles — 12 Mar 2010 @ 5:06 AM

  86. Did anyone see yesterday’s MacPaper? USA Today repeated all the lies about how the CRU hack revealed that scientists had concealed data and conspired to keep out skeptics.

    Comment by Barton Paul Levenson — 12 Mar 2010 @ 5:48 AM

  87. Gilles, read the 2009 paper. Your complaint above in #78 is about the equation from the earlier paper–the very issue the 2009 paper addresses. I had to reread the 2009 a few times myself just now. Recommended.

    Comment by Hank Roberts — 12 Mar 2010 @ 6:05 AM

  88. Reahrding #74 FHSIV:

    Stefan, thanks for the correction. I should have looked out my window here on Long Island and realized that I was not under a huge ice sheet! Doh!

    Obviously, the 120m is the amplitude and not the “above today” value.

    Comment by Scott A Mandia — 12 Mar 2010 @ 6:26 AM

  89. Sean :”Nope. We could have various other things that achieve similar effects, including unexpected positive feedbacks, large increases in non-fossil-fuel based emissions (more then 50% of my country’s emissions are not from fossil fuels – and our per-capita emissions are among the highest in the world), spikes in fossil fuel usage followed by declines rather than constant increase, etc.”
    Sean, either you believe in scenarios from the SRES, or not. I just remind the hypothesis at the basis of these scenarios. If you imagine things very different from what is described in AR4, then you agree with me, that they do not encompass the whole possible stories, but then we should discuss their plausibility from the beginning. Taking numbers computed by these scenarios is then worthless, you can also imagine 10 or 20°C degrees as well.

    Comment by Gilles — 12 Mar 2010 @ 6:45 AM

  90. 86 Hank

    I read the 2009 paper, and I already addressed that adding a dT/dt term (eq 2 : dH/dt = a(T-To)+bdT/dt ) does not help removing the spurious behavior of a linear increase of sea level toward infinity even if the temperature has stabilized, which is obviously impossible. That’s pretty simple to see on the equation, isn’t it ?

    Comment by Gilles — 12 Mar 2010 @ 7:00 AM

  91. Comment from Stefan at my previous contribution (#38)
    “At the beginning of the 20th Century sea level rose at a rate of about 1 mm/yr, and after 0.8 ºC global warming this rate has roughly tripled, now standing at about 3 mm/year. –stefan “

    Stefan, you are right that around 1900 the rate of increase in sea level was very low (there was even a short episode of decreasing sea level), but briefly afterwards it increased rapidly, and around 1915 the highest rate of the last century was observed. For a broader perspective see the discussion on Climatedata (especially Fig.1). Link: http://www.climatedata.info/Impacts/Impacts/sealevels.html

    Remarkably, there was also a strong increase of sea level around 1950, AFTER the 1910-1940 period when temperature increased at a similar rate as in 1975-1998. Over the last century or so the rate of rise has fluctuated from -20 mm/decade up to 40 mm/decade. The total increase since 1880 has been around 250 mm. And overall the yearly trend has remained about the same during the last century, despite the occurrence of periods when temperature increased strongly and a long period in between when temperature remained the same. So the evidence since around 1890 does not at all support a direct (or even linear) relationship between temperature and sea level.

    [Response: You are looking at different time scales. If you look at short periods, the rate of sea level rise does indeed fluctuate wildly up and down, as you say. That happens with any noisy time series that you take a derivative of. I thus doubt whether these fluctuations are real or just artifacts of imperfect data coverage. This noise then drowns out the relationship between sea level and temperature that is clearly demonstrated in our papers for longer periods. Have you even looked at the papers before criticising? -stefan]

    Comment by wilt — 12 Mar 2010 @ 8:12 AM

  92. “70
    Thomas says:
    11 March 2010 at 11:09 PM
    Losing 1% of the ice in a century does not sound like a very extraordinary thing.”

    Really?

    Because that would indicate that you expect the Greenland Ice Sheet to be only 10,000 years old…

    (oops, typo…)

    Comment by Completely Fed Up — 12 Mar 2010 @ 8:58 AM

  93. [edit - PO is OT]

    Comment by Jeffrey Davis — 12 Mar 2010 @ 8:59 AM

  94. Gilles, please. Gavin’s asked you nicely to stop with the peak oil stuff.

    If you’ll make the time to read Stefan’s paper here, the 2009 one, you’ll get a clue why your hobbyhorse is way inappropriate here: even if your group is right, much of the problem is at _this_ end of the time span.

    Good ideas: putting off burning fossil fuel and possibly finding there isn’t that much to burn later
    Bad idea: burning what we have as fast as we are regardless of the future, and that’s a bad idea even if we run out sooner than expected _because_ problem is rate of change. It’s _early_fast_burning_ we need to stop now.

    Rate of change and timing of change.

    Comment by Hank Roberts — 12 Mar 2010 @ 9:31 AM

  95. Re Gilles @77: “Read the previous thread about methane.”

    I did, perhaps you missed the words “just a portion of”?

    “which only proves that the average temperature is by no means a single valued function of CO2 concentration”

    Which no one has asserted. Never the less, continued paleoclimate research shows that the correlation between atmospheric CO2 and global average temperature continues to get stronger. The miocene is no longer the exception it once was, and now even the ordovician is not looking so anomalous.

    The past can never be an exact analogue for the present and future because not all factors and conditions will be duplicated, but Richard Alley’s assertion that CO2 is the control knob is looking stronger and stronger.

    Comment by Jim Eager — 12 Mar 2010 @ 9:31 AM

  96. Jim: ““which only proves that the average temperature is by no means a single valued function of CO2 concentration”

    Which no one has asserted. ”

    Ergo:

    http://en.wikipedia.org/wiki/Straw_man

    Comment by Completely Fed Up — 12 Mar 2010 @ 10:16 AM

  97. Scott A Mandia #88

    So, sea level was 70 meters higher than today at a point 40 mya. 70 meters relative to what? The shape and positions of the continents are a little different than in the Eocene. Have you considered tectonic changes to the volume of the oceanic basins over this time? or have you assumed that this variable has remained constant. This would be a defensible assumption for the Late Quaternary, but not as far back as the Eocene. And, how is this relevant to a discussion of possible changes of a fraction of a meter over the next century?
    The approximatley 6 meter higher stand above today’s level during latest Pleistocene is a more credible basis for discussion and comparison.

    Can you give me a reference or a link for the “well-known correlation of CO2 concentration with the glacial cycles that dominated the Quaternary”. What came first, the chicken or the egg? Are you suggesting that the glaciation in the Quaternary has been contolled by CO2 concentration?

    [Response: Quaternary glaciations are driven by orbital cycles; CO2 acts as an amplifying feedback and "globaliser" (without it you can't get such cold glacials, nor would the northern and southern hemispheres freeze in sync). A detailed discussion of the lead/lag relationship between CO2 and temperature in Antarctica (which I presume is what you are referring to) is provided by Ganopolski and Roche 2009. -Stefan]

    Comment by FHSIV — 12 Mar 2010 @ 10:32 AM

  98. “The equilibration time scale is expected to be on the order of millennia.”
    OK, then do you agree that the linear problem is degenerated following the ratio of sensitivity (dHeq/dT) to equilibrium timescale, since only the ratio of the two determines the initial growth rate. So your hypothesis that the equilibration timescale is “very long” (on the order of millennia) is only useful to justify the linear acceleration rate. However, this has a strong consequence on the asymptotic value, because the actual value at a given time t is of the order of the equilibrium value multiplied by t / teq (hence the quadratic time evolution). So what you’re claiming is that the 1 m sea level rise observed in 100 years is actually a 10 m equilibrium value (which is perfectly compatible of course with the fact that your curves keep growing in 2100 without any sign of slowing, and will continue during a millenium or so).
    If you’re right, I would say that we’re heading anyway to a several meters sea level rise in the next millenium whatever we do, even by cutting completely our emissions just now, since the 0.7 °C (and hence a 3 meter rise) is already there, the sea will rise during one millenium in any case. So we’d better start to move away from the coasts , or at least to plan a gradual move , and we could as well use as much fossil fuels we want to do that – it’s just a question of how high we should rebuilt our cities !

    Comment by Gilles — 12 Mar 2010 @ 10:41 AM

  99. “Gilles, please. Gavin’s asked you nicely to stop with the peak oil stuff.
    Good ideas: putting off burning fossil fuel and possibly finding there isn’t that much to burn later
    Bad idea: burning what we have as fast as we are regardless of the future, and that’s a bad idea even if we run out sooner than expected _because_ problem is rate of change. It’s _early_fast_burning_ we need to stop now.

    You’re right, peak oil is immaterial with Stefan’s hypothesis. Actually the amount of fossil fuels we burn is immaterial as well, since the sea will continue to rise at some mm/yr during one millenium, inexorably and whatever we burn. So don’t care about fossil fuels : just move high enough , while house on heights are still cheap !

    Comment by Gilles — 12 Mar 2010 @ 10:45 AM

  100. “So, sea level was 70 meters higher than today at a point 40 mya. 70 meters relative to what? ”

    Than today.

    You even said so in that section.

    Comment by Completely Fed Up — 12 Mar 2010 @ 10:50 AM

  101. Gilles, Stefan’s been answering you inline (adding to your response). Are you missing these answers? You keep restating your problem and he’s several times now pointed out the words in the actual paper that answer the question, and suggesting you read the paper.

    Most recently quoting in response to your problem the paper where it says “we can approximate it by assuming a linear increase in the early phase; the long time scales of the relevant processes give us hope that this linear approximation may be valid for a few centuries.”

    Check the right sidebar to see where there’s a recent inline response, but also back up and look at your earlier posts for inline replies. Otherwise you may feel you’re being ignored and repeat yourself unnecessarily.

    Comment by Hank Roberts — 12 Mar 2010 @ 10:59 AM

  102. Re FHSIV @97,

    Tectonic changes to the volume of the oceanic basins would alter the potential change in sea level from melting ice sheets, but not the [em]volume[/em] of water resulting from the melt.

    The glacial cycles that dominated the Quaternary were initiated by northern hemisphere summer insolation levels, which were driven by the Milankovitch cycles. Changes in CO2 levels in turn [em]amplified[/em] those glacial cycles.

    Fast forward to present: global mean temp had been declining since the peak of the Holocene Climate Optimum 7000-8000 years ago….until now. The sun didn’t get hotter, the orbital configuration yields [em]less[/em] northern hemisphere summer insolation, yet it is or nearly is as warm as the Holocene Climate Optimum. What changed?

    CO2 increased by ~38%, CH4 by ~150%. Greenhouse gases are no longer acting as an amplifying feedback, they are acting as a direct [em]forcing[/em].

    Comment by Jim Eager — 12 Mar 2010 @ 11:03 AM

  103. “Which no one has asserted. Never the less, continued paleoclimate research shows that the correlation between atmospheric CO2 and global average temperature continues to get stronger. The miocene is no longer the exception it once was, and now even the ordovician is not looking so anomalous.
    The past can never be an exact analogue for the present and future because not all factors and conditions will be duplicated, but Richard Alley’s assertion that CO2 is the control knob is looking stronger and stronger.”

    sorry, but then what was the point of your question about Miocene? and I can’t see how a correlation between A and B can show that A is the cause of B or B the cause of A ??

    Comment by Gilles — 12 Mar 2010 @ 11:07 AM

  104. Hi,
    about errors in SRES, you should definitely check out the amount of fossil fuel reserves they are using, which is total nonsense.

    For example all scenarios range between 11ZJ an 50ZJ of oil (with 17ZJ to 30ZJ for median scenarios), when ultimate exploitable reserves are estimated to be at most 14ZJ (best estimate : 11ZJ).
    How can you ever get 50ZJ ?!!

    Same for natural gas : between 15ZJ and 55ZJ in SRES, but only 11ZJ of ultimate reserves.

    And for coal : between 3.3ZJ and 68ZJ in SRES (median scenarios between 13ZJ and 47ZJ) when ultimated reserves are 15ZJ.

    You can see those data graphed for oil, natural gas and coal here starting page 70 against all 40 SRES scenarios here :
    http://www.tsl.uu.se/uhdsg/Publications/Sivertsson_Thesis.pdf

    All datas can be found here:

    IPCC SRES scenarios, column “hydrocarbon use”:
    http://www.grida.no/climate/ipcc/emission/097.htm

    Data for oil (p7):
    http://www.ifp.fr/content/download/69134/1492238/version/2/file/Panorama2010_11-VF_Produits-petroliers.pdf
    or this page for proven reserves :
    http://tonto.eia.doe.gov/cfapps/ipdbproject/iedindex3.cfm?tid=5&pid=57&aid=6&cid=ww,&syid=2008&eyid=2009&unit=BB

    Data for natural gas (last page) :
    http://www.ifp.fr/content/download/69135/1492244/version/2/file/Panorama2010_12-VF_Ressources-gas-naturel.pdf
    or this page for proven reserves:
    http://en.wikipedia.org/wiki/List_of_countries_by_natural_gas_proven_reserves

    Data for coal :
    http://www.ifp.fr/content/download/69133/1492232/version/4/file/Panorama2010_10-VF_Charbon.pdf

    Now you just have to find the conversion rates to Joules to find the numbers cited above.

    By the way, this information is also confirmed by one of the climategate e-mails:
    http://eastangliaemails.com/emails.php?eid=112&filename=926947295.txt
    “We ARE NOT supposed to be working with the assumption that these scenarios are realistic.”

    Cheers,

    Comment by Jean B. — 12 Mar 2010 @ 11:19 AM

  105. “and I can’t see how a correlation between A and B can show that A is the cause of B or B the cause of A ??”

    Because you need causation. If A can cause B but B cannot cause A, then you can tell the difference.

    Comment by Completely Fed Up — 12 Mar 2010 @ 11:23 AM

  106. orangejuice says: 11 March 2010 at 8:52 PM

    Pretty comprehensive treatment of “Superfreakonomics” in the following series of posts at Climate Progress but you’ll need to wade through a lot of Dr. Romm’s prolific ink to tease ‘em out. :

    http://climateprogress.org/2009/10/12/superfreakonomics-errors-levitt-caldeira-myhrvold/

    http://climateprogress.org/2009/10/14/superfreakonomics-errors-nathan-myhrvold-intellectual-ventures-bill-gates-warren-buffet/

    http://climateprogress.org/2009/10/16/science-error-superfreakonomics-why-stop-amazon-search/

    http://climateprogress.org/2009/10/17/error-superfreakonomics-krugman-economics-dead-wrong/

    http://climateprogress.org/2009/10/26/global-cooling-myth-statisticians-caldeira-superfreakonomics/

    http://climateprogress.org/2009/11/17/superfreakonomics-authors-charlie-rose-levitt-dubner-abandon-climate-science/

    Comment by Doug Bostrom — 12 Mar 2010 @ 11:46 AM

  107. > Gilles
    > the amount of fossil fuels we burn is immaterial … whatever we burn.

    Wrong, if you’d read the 2009 paper you’d probably see where he points out why emission _now_ early in the century causes more sea level rise faster.
    At least read the paper, don’t just state your beliefs without any cite.

    Comment by Hank Roberts — 12 Mar 2010 @ 11:58 AM

  108. What is happening is that because of a couple of errors, the nay-sayers have introduced a new whipping boy, madly spinning this into a credibility issue, blanketing any and all issues connected to climate change. A classic trick of debate…paint your opponent as inept or lying, and then no matter what they say, the audience is finished with listening. And, typically, the people on the right side of the issue are clueless as to how to deal with this. I’m afraid academics and scientists are good at the book-larnin’ and science, but dreadful at hand to hand combat. Someone needs to have a Paladin to come and clean out the bad guys.

    Comment by greyfox — 12 Mar 2010 @ 12:10 PM

  109. Re Gilles @102: “I can’t see how a correlation between A and B can show that A is the cause of B or B the cause of A ??”

    Correlation can’t show causation, but the known radiative physics of CO2 can.

    Comment by Jim Eager — 12 Mar 2010 @ 12:30 PM

  110. #7 exactly what are you referring to as my humble opnion differs 180 degrees from yours?..

    Comment by Jan Lindström — 12 Mar 2010 @ 12:36 PM

  111. 6 degrees C of warming is the for-sure extinction point for humans. At 5.2 degrees C of warming, there will be few, if any, humans left. Civilization will have long since collapsed due to famine and other factors. Any people still alive in 2100 will have no competition for space on higher ground. Indeed, they will be lonely and searching for other people. What this article really tells us is that 2100 is the cutoff date. Thanks, RC, for giving us this definitive date.

    [Response: I appreciate your point, but overly definitive statements about the future simply serve as targets for the inactivists. Truly, you cannot know such things and suggesting that RC has told you this will happen is not appropriate. - gavin]

    Comment by Edward Greisch — 12 Mar 2010 @ 12:42 PM

  112. Reminder: scientists are the “skeptics” – at least the good scientists. Denialists ARE NOT skeptics, and it is wrong to give them that much credit. Anyone who has reached a conclusion such as “global warming is a hoax” is making an untenable, illogical, scientifically unsupportable conclusion.
    Alarmists, on the other hand, can still be skeptics; it is easy to be alarmed by some of the projections that are made by climatologists, even when one still continues to question the data, analyses, models, and projections.

    Comment by Geno Canto del Halcon — 12 Mar 2010 @ 12:42 PM

  113. Comment from Stefan at #91:
    ‘If you look at short periods, the rate of sea level rise does indeed fluctuate wildly up and down, as you say.’

    Thank you for your response.
    But if you realize that on a short term basis there is so much fluctuation, why then did you write at my previous contribution (#38): “At the beginning of the 20th Century sea level rose at a rate of about 1 mm/yr, and after 0.8 ºC global warming this rate has roughly tripled, now standing at about 3 mm/year. –stefan “
    Such a formulation suggests that from the start of the century till the end there had been a 3-fold increase in the rate of sea level rise. Whereas the data that I have referred to before
    (http://sealevel.colorado.edu/) clearly indicate that there was no consistent increase in trendvalue per decade for the whole period since 1880, in other words the rate has remained almost the same and certainly has not “roughly tripled”.
    The other thing that I would be worried about if I would have to defend your hypothesis, is that the trendvalue was virtually the same in the period 1940-1975 as in the two warm periods before and after those years.

    [Response: Fig. 3 of Rahmstorf (2007). -stefan]

    Comment by wilt — 12 Mar 2010 @ 12:47 PM

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

    You should drop that style of writing, here at Real Climate, and focus on science. All science, all the time: data, models, estimation, precision and uncertainty. Science is your expertise. Rebut errors, fix your own errors when they are disclosed (checking first, of course, to see if they really are errors.)

    “If a donkey bray at a donkey, who can tell the difference?” Cut out all braying, and leave it to those to whom you feel a superiority. You’ll win in the long run and gain (perhaps regain) the respect of scientists and non-scientists.

    Comment by Septic Matthew — 12 Mar 2010 @ 1:11 PM

  115. Sorry if this has been asked before, but:

    “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.”

    I take it that this does not include the “rapid dynamic changes” in continental glaciers (e.g. due to lubrication by meltwater) that were excluded from the original calculation in AR4, right? Or does some of the 50% fit into that pattern? If not: how much could this add to the rise, based on current best estimates?

    [Response: I gave those numbers just to illustrate that one could have equally plausibly come up with very different values, erring in the other direction. I did not mean to imply that you could simply "correct" the IPCC projections by adding 50% if they've been off by 50% in the past - that wouldn't be sound science for a number of reasons. I do think that other approaches to estimate future sea level rise, like the papers I linked in the p.s., are a valid alternative to the IPCC approach. -stefan]

    Comment by werecow — 12 Mar 2010 @ 1:21 PM

  116. Mr. Gilles writes on the 12th of March, 2010 at 10:45 AM:

    “since the sea will continue to rise at some mm/yr during one millenium, inexorably and whatever we burn. ”

    The last part, ‘whatever we burn,’ is not yet established.

    But do allow me to explore your thought a little further, for you have touched upon a nagging concern of mine.

    There is an instability sometimes called the ‘Weertman instability.’ Consider an iceshelf, grounded submarine. If the seabed below the ice deepens landward, the configuration is not stable, see for example, Schoof,Journal of Geophysical Research,v112,F03S28,2007. The situation we are in is depicted in Panel 3g in the following figure and we are set to proceed to 3h. The time progression goes down the left hand column, across and up the right hand column.

    http://membrane.com/sidd/longthaw/schoof-3.png

    In short, consider the West Antarctic Ice Sheet, 7 meter of sea level rise. How fast can it collapse? Bindschadler commented on the ANDRILL results that a millenium ought to be regarded as an upper limit. You will find a discussion of the ANDRILL results on this site.

    If we have indeed destabilized the WAIS, your sentence above would be literally true, together with the last clause. ‘Inexorable’ is quite apposite, for we shall have begun the long retreat from the coasts. There will be no stable coastline for centuries.

    In another life, I used to indulge in a game of bridge, now and then. I seem to recall that sometimes, a contract could only succeed for a small set of card distributions, and one played the hand assuming that were indeed the case.

    I prefer to imagine that the outcome may yet be in doubt, and although these may be the last throws of a losing hand, I shall play as though I meant to win.

    sidd

    Comment by sidd — 12 Mar 2010 @ 1:25 PM

  117. Bengt A @ 12 March 2010 at 12:46 AM

    Thank you, that paper is a valuable contribution.

    Comment by Ric Merritt — 12 Mar 2010 @ 1:49 PM

  118. 86 Barton Paul Levenson says:
    “Did anyone see yesterday’s MacPaper? USA Today repeated all the lies about how the CRU hack revealed that scientists had concealed data and conspired to keep out skeptics.”

    BPL, check out physicsworld.com’s story on the IOP sumission to the Parliamentary inquiry.
    http://physicsworld.com/cws/article/news/41965

    The level of knowledge on climate science in the comments makes me feel like a rocket scientist, which is both incredulous and especially alarming given that it’s a website of the IOP itself.

    (cough) it takes a minute to sign up… (cough)

    Comment by J Bowers — 12 Mar 2010 @ 2:09 PM

  119. Stefan claims in his response to the first comment “data of the past century show how the rate of sea level rise increases in proportion with temperature”.

    But the graph of sea-level rise over the past century, as given in Wikipedia based on long-term tide gauge measurements, is almost perfectly linear! You can place a straight-edge along the period from 1910-2010. If the temperature has been rising, and if increased temperature increases the rate of rise, it should curve upwards. But any such upward curvature is negligible to the point of invisibility. How come?

    [Response: Don't know what Wikipedia shows, but the main two global sea level data sets that I know, those of Church and White (2006) and Jevrejeva et al. (2006), give a similar acceleration of sea level rise, as we discussed in "Ups and downs...". Full references given there. -stefan ]

    Comment by Gerry Quinn — 12 Mar 2010 @ 2:42 PM

  120. I recognize the estimate in the P.S. is a back-of-the-envelope estimate, but is there a particular reason for assuming that the 1.8 mm/yr observed vs. the 1.2 mm/yr modeled represents a multiplicative bias rather than an additive bias or a random error?

    Assuming a multiplicative bias gets you from 79 cm in 2100 to 119 cm in 2100, while assuming an additive bias gets you from 79 cm in 2100 to 85 cm in 2100, and assuming a random error keeps you at 79 cm.

    I suppose sea level rise is sufficiently like a deterministic system that random error can be plausibly discounted, but how do you choose between the other two possibilities?

    [Response: See response to #115]

    Comment by John N-G — 12 Mar 2010 @ 2:42 PM

  121. > Edward G

    Realclimate contributors and other scientists have been trying to get you to stop making this false claim for years now.

    For example, you were told the same thing at RC and at Tamino’s in 2007:

    http://initforthegold.blogspot.com/2007/12/theres-no-ulitmate-tipping-point.html

    “Thursday, December 20, 2007
    There’s No Ultimate Tipping Point
    Ray on a response on RealClimate says nicely something I have been trying to say to the doomsayers: Edward Greisch: …’”

    You don’t actually cite an actual link to an RC source when you’ve made this claim. You can’t — checking it would show you were wrong.

    Google on your own name and a few words you regularly use and you’ll find a
    lot of blogs you might want to revisit to correct this misstatement, either posted by you or by someone using _you_ as the source.

    No wonder people think RC is full of alarmists, with this kind of nonsense being widely posted elsewhere.

    Remember, kids — check the source. Don’t believe some guy on a blog.

    Comment by Hank Roberts — 12 Mar 2010 @ 2:42 PM

  122. Regarding my posting #111 on sea level data, I supplied the wrong link, sorry about that. The data on sea level since about 1880 can be found here: http://www.climatedata.info/Impacts/Impacts/sealevels.html
    The Colorado site mentioned earlier only deals with the recent (satellite-based) measurements.

    Comment by wilt — 12 Mar 2010 @ 2:49 PM

  123. Completely Fed Up #99

    Sorry to be unclear. I meant what geographic location is your reference point, not what point in time.

    Comment by FHSIV — 12 Mar 2010 @ 2:59 PM

  124. Jim Eager Re #101

    You said “Tectonic changes to the volume of the oceanic basins would alter the potential change in sea level from melting ice sheets, but not the [em]volume[/em] of water resulting from the melt.”

    That’s my point. Have the changes in the volume of the ocean basins over the last 40my been assessed and factored into the comparisons of documented/observed sea level stands over the same period. It seems like an apples and oranges comparison if the ocean basin volume changes are not considered.

    You said “The glacial cycles that dominated the Quaternary were initiated by northern hemisphere summer insolation levels, which were driven by the Milankovitch cycles. Changes in CO2 levels in turn [em]amplified[/em] those glacial cycles.”

    I agree regarding Milankovitch cycles, but I am not convinced regarding CO2 amplification. Can you provide me with a reference so that I can get up to speed on this?

    You said “Fast forward to present: global mean temp had been declining since the peak of the Holocene Climate Optimum 7000-8000 years ago….until now. The sun didn’t get hotter, the orbital configuration yields [em]less[/em] northern hemisphere summer insolation, yet it is or nearly is as warm as the Holocene Climate Optimum. What changed?”

    Well if it is only “nearly is as warm” than nothing needs to have changed!

    You said “CO2 increased by ~38%, CH4 by ~150%. Greenhouse gases are no longer acting as an amplifying feedback, they are acting as a direct [em]forcing[/em].”

    Then I’ll ask what changed? Did we pass a tipping point?

    Comment by FHSIV — 12 Mar 2010 @ 3:23 PM

  125. I would suggest the location is the same location as the one millions of years ago.

    You know.

    Since the only thing you’ve changed is the date and said that the difference between them is 70m.

    It’s only a shot in the dark, but seems fairly clear and reasonable.

    Doesn’t it?

    Comment by Completely Fed Up — 12 Mar 2010 @ 3:38 PM

  126. NASA: Feb 2010 was 2nd hottest ever globally, for land+ocean (http://bit.ly/GISlandoc) as well as for land only (http://bit.ly/GISland)

    Comment by Kees van der Leun — 12 Mar 2010 @ 4:07 PM

  127. Slower feedbacks such as the albedo feedback due to the melting of large ice sheets in Greenland and Antarctica were not considered by the IPCC. (Hanson, et al., 2008) When these feedbacks are included, the sensitivity value increases to approximately 6 oC. Hanson et al. explain:

    Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6 oC for doubled CO2 for the range of climate states between glacial conditions and icefree Antarctica. Decreasing CO2 was the main cause of a cooling trend that began 50 million years ago, large scale glaciation occurring when CO2 fell to 425±75 ppm, a level that will be exceeded within decades, barring prompt policy changes. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm. The largest uncertainty in the target arises from possible changes of non-CO2 forcings. An initial 350 ppm CO2 target may be achievable by phasing out coal use except where CO2 is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO2 is not brief, there is a possibility of seeding irreversible catastrophic effects.

    and

    Humanity today, collectively, must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate. If we stay our present course, using fossil fuels to feed a growing appetite for energy-intensive life styles, we will soon leave the climate of the Holocene, the world of prior human history. The eventual response to doubling preindustrial atmospheric CO2 likely would be a nearly ice-free planet.

    Humanity’s task of moderating human-caused global climate change is urgent. Ocean and ice sheet inertias provide a buffer delaying full response by centuries, but there is a danger that human-made forcings could drive the climate system beyond tipping points such that change proceeds out of our control. The time available to reduce the human-made forcing is uncertain, because models of the global system and critical components such as ice sheets are inadequate. However, climate response time is surely less than the atmospheric lifetime of the human-caused perturbation of CO2. Thus remaining fossil fuel reserves should not be exploited without a plan for retrieval and disposal of resulting atmospheric CO2.

    Paleoclimate evidence and ongoing global changes imply that today’s CO2, about 385 ppm, is already too high to maintain the climate to which humanity, wildlife, and the rest of the biosphere are adapted. Realization that we must reduce the current CO2 amount has a bright side: effects that had begun to seem inevitable, including impacts of ocean acidification, loss of fresh water supplies, and shifting of climatic zones, may be averted by the necessity of finding an energy course beyond fossil fuels sooner than would otherwise have occurred.

    To summarize, Hanson et al. believe that it is quite possible Earth could end up ice free with CO2 levels of 350 ppm which is well below where we currently are. Because the melting of Antarctic ice takes centuries there is time to lower the “tipping point” level of CO2 before it is too late.

    As Forrest Gump would say, “and that’s all I have to say about that.” :)

    Comment by Scott A Mandia — 12 Mar 2010 @ 4:30 PM

  128. > FHSIV
    > what changed? Did we pass a tipping point?

    Yes, in evolution.
    Primates started burning fossil fuels.

    In all previous events, the planet warmed naturally (look up Milankovich for example). With that warming, CO2 started to go up. That’s a feedback.

    This time, the CO2 increase–very fast– started artificially, happening while the planet was otherwise in a long slow cooling period. That’s a forcing.

    Now, as the planet warms up again, due to the forcing from fossil carbon being burned, _that_ warming is causing CO2 to increase; that increase is a feedback.

    Comment by Hank Roberts — 12 Mar 2010 @ 4:49 PM

  129. Completely Fed Up #123

    Eschew obfuscation!

    Comment by FHSIV — 12 Mar 2010 @ 4:52 PM

  130. Re rate of ice sheet melting. These pictures from Discover magazine show researchers kayaking on a river of melt water atop Greenland. I’m no scientist, but seeing a literal river of surface melt water gives me no confidence that future melting will be linear with temperature. Also, I haven’t noticed mention on this thread of the fact that the Western Antarctic ice sheet is grounded many meters below sea level.

    http://blogs.discovery.com/earth/2009/07/a-river-runs-along-the-top-of-it.html

    Comment by RoySV — 12 Mar 2010 @ 4:53 PM

  131. FHSIV (122) — Please read “The Discovery of Global Warming” by Spencer Weart, first link in the science section of the sidebar. Then you may care to read the Chareny et al. 1979 NRC report:
    http://books.nap.edu/openbook.php?record_id=12181&page=R1

    Comment by David B. Benson — 12 Mar 2010 @ 5:14 PM


  132. These pictures from Discover magazine show researchers kayaking on a river of melt water atop Greenland.

    Given that some of those meltwater rivers disappear down moulins, just the thought of kayaking down one of those gives me the heebee-jeebees!

    Comment by caerbannog — 12 Mar 2010 @ 5:14 PM

  133. The temperature has just gone from 31.9999 to 32.0001.

    I’m standing in front of the glacier screaming,”Run, run, run!”

    “These scientests…”, say the deniers. “They get so excited over the littlest things.”

    Comment by Ken Peterson — 12 Mar 2010 @ 5:22 PM

  134. 125
    Scott A Mandia says
    “To summarize, Hanson et al. believe that it is quite possible Earth could end up ice free with CO2 levels of 350 ppm which is well below where we currently are. Because the melting of Antarctic ice takes centuries there is time to lower the “tipping point” level of CO2 before it is too late.”

    Youve gotta ask what caused the co2 drop? 50million years ago is when the continents came to be where they are, and the gradual decrease in co2 began, 35million years ago is when full blown ice sheets formed over Antarctica(depends who yah source, but generally between 700-900ppm co2) and 20-15 million years ago co2 dropped too around current levels, and glaciations commenced in the northern hemisphere with the continuing decline in co2 til full blown glaciation around 2.5mybp.

    During glaciations co2 levels drop, through increased oceanic absorption and burial. But id put it to you, that when Antarctica came to be where it is, and prevented ocean transport of heat over the pole, and the circumpolar ocean current came into being, it lead to the gradual burial o co2, and the climate we have today(obviously over millions o years) But i just find it very hard to swallow in light of this, that 350ppm could cause Antarctica to be ice free. Change the dynamics for sure, but ice free?

    Comment by Mike — 12 Mar 2010 @ 5:59 PM

  135. “Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6 oC for doubled CO2 for the range of climate states between glacial conditions and icefree Antarctica”

    A large long term climate sensitivity to present forcings indicate that previous forcings should also have a large long term climate sensitivity and that the long term reaction to forcings would have to be attributed for today’s climate. In other words, how much of the warming of the latter part of the 20th century would you attribute to the warming that occurred in the early portion of the 20th century? If little or none then why would today’s forcings behave any differently?

    Comment by stevenc — 12 Mar 2010 @ 6:15 PM

  136. Hank :> Gilles
    > the amount of fossil fuels we burn is immaterial … whatever we burn.
    Wrong, if you’d read the 2009 paper you’d probably see where he points out why emission _now_ early in the century causes more sea level rise faster.
    At least read the paper, don’t just state your beliefs without any cite.”

    No, YOU’re wrong (again, after your stating that stratosphere is warmed by the long wavelength IR radiation from below…). The paper states (correctly within its hypothesis) that all scenarios are more or less the same until the mid 20′s, which contribute most to the sea level rise, so the result in 2100 is rather insensitive to the scenario. Which is quite understandable if the equlibration timescale is about one millenia, the sea level is a very strong low-pass filter and rather insensitive to the last years. If the timescale is really much longer than one century, it means also that the current rise is only a small part of the asymptotic one (which will be neared only after one millenium or so), and so it means that the sea level rise will continue inexorably throughout centuries whatever we do. It’s true that the asymptotic value will depend on the final temperature, but the 3 meter rise is already in the pipe, sorry , guys. Now of course it’s only IF the paper is right. If you’re not convinces, I can write you a more mathematical demonstration.

    That’s a very general statement : if the reaction timescale is much larger than a century , then we can’t do much to avoid it before 2100 since it has already started and will last for a long time, and if not, then the sea level will saturate at rather modest values. Choose your preferred scenario.

    Comment by Gilles — 12 Mar 2010 @ 6:31 PM

  137. It is my impression that Stefan, author of article here, represents the best of the IPCC thinking and correctly represents that process.

    It is not a criticism of the science, rather it is recognition of how difficult the problem is. But I find it “unsettling” that the IPCC related sea level rise to surface temperature as a linear relationship. ((6.4/5.2) = ((59 + 15)/ 15) shows this linearity based on the numbers from the article above.) By this thinking, the 50% unexpected increase in sea level rise would indicate a 50% unexpected increase in “warming” which really means surface temperature only.

    It sort of looks like the 50% unexpected increase in sea level rise is in lieu of some of the expected temperature increase, thus there would not be a linear relationship between these changes. Correcting the atmospheric temperature model would not necessarily result in an indicated increase in the surface temperature, as it seems that Stefan here seems to be suggesting.

    How the extra heat is apportioned between sea ice “heat of fusion (melting really)” and deeper ocean heat content is not clear in data I have seen. It seems this would be known for the present circumstances if the radiative imbalance were known, and the measured ocean heat content down to 700 meters was the whole story on ocean heat content.

    Comment by Jim Bullis, Miastrada Co. — 12 Mar 2010 @ 6:36 PM

  138. > stratosphere is warmed by the long wavelength IR radiation from below
    http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/earth_atmosph_radiation_budget.html

    Comment by Hank Roberts — 12 Mar 2010 @ 7:05 PM

  139. Re FHSIV @122: I agree regarding Milankovitch cycles, but I am not convinced regarding CO2 amplification

    Then with respect, you do not understand the Milankovitch cycles and how a relatively small change in insolation over only a relatively small part of Earth’s surface during only part of the year could lead to continent-wide glaciation or deglaciation. The change in watts per square meter is simply not great enough by itself. Only when you add in the amplifying feedbacks is there a large enough change in energy.

    Can you provide me with a reference so that I can get up to speed on this?

    I’ll second Spencer Weart’s The Discover of Global Warming, but it sounds like a basic earth science text would help as well.

    Well if it is only “nearly is as warm” than nothing needs to have changed!

    Yet another indication that you do not understand the Milankovitch cycles. Hint: we should be cooling. We are not. Why not?

    And don’t forget that because of the thermal inertia of the ocean we have not yet seen the full warming that the increase in greenhouse gases will produce.

    Then I’ll ask what changed? Did we pass a tipping point?

    Yes, humans invented agriculture and domesticated rice (methane) and started burning fossil carbon based fuels on an industrial scale (CO2), releasing carbon into the atmosphere and active carbon cycle that had been locked out of that cycle for hundreds of millions of years.

    Comment by Jim Eager — 12 Mar 2010 @ 8:19 PM

  140. Thanks Stefan, really good stuff.

    “Just to avoid any misunderstandings here: I am squarely against exaggerating climate change to ‘err on the safe side’.”

    I’m not so sure. An old collegue runs flood forecasting in this state; has done for decades. He had to do his stuff again last week as a record flood approached a western town. He said 14 m, but I knew what the peak would really be, because I’ve watched him for a long time. It came in at about 13.5. Fact is, he’s always wrong. Not because he can’t run a flood model. Because, unlike most in his scientific organisation, he’s an engineer.

    The object isn’t to be right. It’s to give the most useful answer, especially for those who won’t grasp the uncertainty.

    [Response: There is a difference between doing science (as we do) and running operational flood warnings. I don't know much about the latter, but probably there is a case here for adding a safety margin to account for the fact that there is uncertainty and the warning should cover the worst case. If that's so, of course this should be a transparent and previously agreed procedure. -stefan]

    Comment by GlenFergus — 12 Mar 2010 @ 9:30 PM

  141. Could someone please tell me whether or not carbon sequestration from increase in humus on farms [which is going on worldwide and at the moment unquantifiable]has been taken into account in any of these scenario/climate models.

    Comment by donald moore — 12 Mar 2010 @ 9:48 PM

  142. 111 response: Sorry Gavin. Oh! You mean some people will just give up and say: “Since it’s inevitable, there is nothing I can do.”? I have a neighbor like that, but I find that stance impossible to understand. Many other people say: “It won’t happen for centuries”; and “Let the grand kids solve their own problems.” For them, you have to have a hard date and it has to be right now. Neither type of person can be moved by anything I say. They leave me wanting to move to Mars.
    How do you deal with them?

    Comment by Edward Greisch — 13 Mar 2010 @ 1:19 AM

  143. “Then with respect, you do not understand the Milankovitch cycles and how a relatively small change in insolation over only a relatively small part of Earth’s surface during only part of the year could lead to continent-wide glaciation or deglaciation.”
    Sorry, something bothers me (again); I understood that the main feedback that amplifies anthropogenic CO2 action is water vapor, not CO2 it self (the gamma value is rather low, so the retroaction to raise the CO2 concentration can be neglected with regards to the H20 average concentration). But this should be true for any cause of variation of the forcing, including the Milankovitch cycles, so the main amplifier should be the water vapor, and not the CO2 which is only a (almost passive) tracker when it’s not the primary cause of change ?

    Comment by Gilles — 13 Mar 2010 @ 2:46 AM

  144. 104 Jean B

    The paper is severely flawed. It only deals with proved reserves. Proved reserves are a small fraction of the projected technically and economically recoverable reserves.

    A simple example that everyone should understand: ANWR. There are ZERO proved oil and natural gas reserves in ANWR. NOT ONE DROP or cubic foot has been discovered or proved. Does that mean that if ANWR were opened to production that no oil or natural gas would be produced?

    The thesis also understates the potential for unonventional resources. Another example: US proved reserves – esp of conventional oil – have declined signifantly. Yet, US oil production is projected to INCREASE by 25% by 2027 and continue at a rate 20% higher than current production. The projected increase is due almost exclusively to the production of unconventional reserves. US production from unconventional natural gas reserved is projected to increase by 50% by 2030. NOTE: The unconventional oil reserves considered do NOT include oil sands or shale oil.

    http://www.eia.doe.gov/oiaf/aeo/overview.html#production

    Comment by JiminMpls — 13 Mar 2010 @ 2:46 AM

  145. Actually, the best and longest coastal tide gauge records indicate that:

    1) global average mean sea level has been rising at a rate of less than 1.2 mm/year; and

    2) it was rising at that rate long before there was a major anthropogenic contribution to atmospheric CO2; and

    3) there has been no sign of acceleration in the rate of sea level rise either recently or at any other time in the last 120 years. The graphs of Mean Sea Level are essentially straight lines + noise.

    The fact that the rate of sea level rise now is about the same as it was when anthropogenic CO2 emissions were very low, before there were any automobiles or coal-fired electric power plants, leads to the obvious conclusion that anthropogenic CO2 does NOT appear to cause a significant increase in sea level.

    See:
    http://www.burtonsys.com/climategate/distance_weighted_MSL_avg.html

    Dave Burton
    Cary, NC

    Comment by Dave Burton — 13 Mar 2010 @ 3:13 AM

  146. Concerning again the estimate of relaxation time, I am also perplex on the accuracy of its determination. In , there are several estimates based on different reconstructions and satellite measurements, and they all differ by more than their error bars ! I prefer not commenting the validity of pre 1900 temperature reconstructions, this has been the subject of a number of discussions here and elsewhere. But I’m puzzled by this kind of result : ” Mediterranean archaeological data (Sivan et al., 2004), and salt-marsh records from New England (Gehrels et al., 2005) suggest variations in sea level have not exceeded ±0.25 m from 2,000 to 100 yr be- fore present.”
    If the relaxation time is really around 1000 yrs, it means that the current 0.3 m for 0.6 °C is actually a 5 m/°C sensitivity, because we have felt still only one tenth or so of the real change. Limiting the past variations to 0.25 m over two millenia would mean that the temperature averaged over one relaxation time (hence close to the equilibrium situation) wouldn’t have changed by more than 0.25/5 = 0.05 °C throughout two millenia …??? strange, I thought there was multisecular warm periods during Roman Empire and Middle age… why was the sea level insensitive to these variations ?

    Satellite and historical estimated do not agree very well, and if the whole “acceleration” story is just due to the difference between two experimentally different ways of measuring sea level, ahemmm… I think one should be VERY cautious before taking that as proven facts. Even the “one relaxation time” or “two relaxation times” can obviously be a very crude approximation : what about possible multidecadal cycles that could have been unnoticed before, for instance ? satellite measurements are much too recent to be really constraining. I don’t have the impression that all this stuff can be considered as solid science at all, it’s only possibilities… and as I said IF the equilibration time is very long, there is nothing much we can do to change the evolution throughout the century anyway. If I lived on a coast , I would wait after all before moving… after acceleration is really confirmed :). But anyway I live at 200 m above sea level.

    Comment by Gilles — 13 Mar 2010 @ 3:27 AM

  147. JiminMpls : I understood peak oil wasn’t the preferred subject here, but the situation is very simple : if you’re right, peak oil is far away. If peak oil is close, you’re wrong (because unconventional resources are simply too expensive to allow a large demand). We’ll know that within 5 or ten years, much before climate models will have been really validated and the climate sensitivity fixed. BTW I maintained on a French forum a thread monitoring short term EIA forecasts for 4 years, which shows they have been constantly wrong and deceiving (they were constantly predicting since 2005 a rise in oil production that never really happened, even before the crisis, and even despite a very high price of the barrel), if you’re interested on the subject.

    Comment by Gilles — 13 Mar 2010 @ 3:36 AM

  148. oops sorry for the misuse of html flags… unfortunately no editing is possible here !

    Comment by Gilles — 13 Mar 2010 @ 5:58 AM

  149. FHSIV, #139, you can chew what the hell you like.

    Got anything substantive?

    Comment by Completely Fed Up — 13 Mar 2010 @ 7:09 AM

  150. As long as we are beating up on the IPCC why not ding them for not including an estimate of how increased erosion owing to stronger precipitation events mentioned elsewhere in the report lead to a faster filling in of the ocean bottom and an increase in sea level as measured from the coasts. A small effect to be sure, but since the report fails to be logically consistent by not including the estimate we can surly conclude that it is trying to cover up climate risks and is in the pay of Saudi Arabia.

    This is kind of fun. There must be a few more things on the silly side in this direction that compensate for silliness in the other direction.

    Comment by Chris Dudley — 13 Mar 2010 @ 7:34 AM

  151. GlenFergus,
    There is a “right way” to err on the side of caution (or “bound”) and estimate–and that is to specify a confidence interval. Most engineers do not do this. The bad ones take their estimates as gospel and the good ones add a fudge factor based on years of experience.

    Bounding is crucial to risk management in part because it allows risk avoidance. However, because mitigation is costly, bounding allows us to ensure that the cost of mitigation does not exceed the risk posed by the threat and to balance risk and mitigation between competing threats.

    Comment by Ray Ladbury — 13 Mar 2010 @ 8:43 AM

  152. @144
    “. Yet, US oil production is projected to INCREASE by 25% by 2027 and continue at a rate 20% higher than current production. ”
    Assuming this goes as predicted (which is very unlikely, the data already being vastly revised to lower values every year, as you can see from AEO09 to AEO10), going from 5 to 6 million barrels (i.e +1 million barrel) over 20years is PEANUTS ! It’s decreased 4 million barrels/day over the past 40years !
    How is demand going to increase ?
    Why has Saudi Arabia & Iran production DECREASED over 2005-2008 while price was going UP ?

    Unconventional resources are taken into account in IFP documents.

    Comment by Jean B — 13 Mar 2010 @ 8:44 AM

  153. GlenFergus,
    There is a right way to “err on the side of caution” (or “bound”) an estimate, and that is to specify a confidence interval. In my experience, most engineers don’t do this. The bad ones take their estimates as “gospel,” and the good ones add a fudge factor based on long experience (that often began with taking their estimates as gospel). The problem with this approach is that the fudge factor is subjective–depending on the tolerance of risk for the individual engineer–and we have no way of estimating how conservative it is.

    A confidence interval–even if it is Bayesian–at least gives some estimate of conservatism, especially if it is clear how it was determined. It also allows mitigation resources to be balanced among different risks in a way that minimizes overall risk.

    Comment by Ray Ladbury — 13 Mar 2010 @ 9:03 AM

  154. #145 Dave Burton.

    Your analysis of sea level rises is full of holes. In your analysis you highlight Vaasa and Galveston. A quick check of just these two stations show that the whole area around Vaasa is rapidly uplifting at the rate of about 8 mm per year (Due to the loss of the ice sheet from the last ice age) and Galveston was sinking rapidly due in part to ground water extraction. I am sure there must be many other stations with problems. Yet clearly you have not adjusted any of the station data to take such effects into account. So all your conclusions are nonsense and bear little relation to reality.

    Didn’t it occur to you that there might have been a bit of a problem with the raw data when you had sea level decreasing by 8 mm per year in one area and increasing by similar amounts in another area, over a period of a century or so?

    Comment by Andrew Hobbs — 13 Mar 2010 @ 9:38 AM

  155. Stefan commented on only one of the two remarks I made in a previous post on sea level rise (# 113).

    In the other remark that remained unanswered, I wrote that we apparently agreed that the rate of sea level rise since 1880 does indeed fluctuate wildly up and down, and that I therefore found it strange that he did not consider the mean yearly (or decadal) sea level rise over the period since 1880, but just took two values (from around 1900 and around 2000) to claim that since those values happened to be 1 and 3 mm/ year respectively, the rate would have ‘roughly tripled’ during the century whereas this clearly is not the case when you look at the whole set of data (http://www.climatedata.info/Impacts/Impacts/sealevels.html)

    Now, I dislike the use of words like cherry picking. Shall we call it ‘selective citation’?

    [Response: I think I made it clear already that one needs to look at longer time scales, not those short-term fluctuations. I was referring to the fact that in the early part of the record - say, 1870-1920 - sea level was rising on average at about 1 mm/year, while in the latter part of the record - say the past 20 years - it's been rising at over 3 mm/year. Before you accuse scientists of 'selective citation', why don't you just look at the scientific papers they actually wrote? The long-term changes in the rate of sea level rise are the very basis of Rahmstorf (2007) and Vermeer and Rahmstorf (2009) and are pictured there, and they have nothing to do with picking particular points in time. They are based on the entire record. Note, by the way, that the Church and White (2006) paper, where the sea level record was originally published, is titled: "A 20th century acceleration in global sea-level rise". -stefan]

    Comment by wilt — 13 Mar 2010 @ 10:17 AM

  156. I’m new to this game and may be doing this wrong but I’m writing an introductory survey (for a U.S. publisher) on sea level rise and would very much value any comments on the adverse consequences of a sea level rise of 2 m by 2100. Please reply to me directly, if convenient.

    Thanks.

    Hunt Janin (huntjanin – at – aol.com)

    Comment by Hunt Janin — 13 Mar 2010 @ 10:21 AM

  157. Mr. Hobbs,

    Obviously you did you even bother to read it. I did not “highlight” Vaasa and Galveston, other than by pointing out that they are the GLOSS-LTT tide gauges with the lowest and highest MSL trend, respectively. I am obviously aware of the fact that local factors such as crustal rebound and local subsidence due to groundwater pumping are predominate in both cases. In fact, if you’d bothered to read any further you’d have read the following:

    “…much (probably at least half) of the MSL trend at most sites is due to local conditions, rather than the global MSL trend.”
    It is right here:
    http://www.burtonsys.com/climategate/global_msl_trend_analysis.html#insight2

    A simple average of the GLOSS-LTT tide stations Local Mean Sea Level trends yields an average annual MSL Trend of 0.6 mm/year. Weighting the stations by length of operation yields 0.5 mm/year. The median LMSL trend is 1.1 mm/year.

    A more sophisticated distance-weighted average, in which stations are weighted according to their proximity other stations (i.e., weighted less if they are near other stations, to prevent distortion of the global average due to disparate weighting the impact of local conditions) also results in a global average MSL trend of 1.1 mm/year.

    If varying numbers of “outliers” (like Vaasa and Houston) are discarded, the resulting averages still never exceed about 1.2 mm/year (see the “example6″ script). Likewise, if the parameters used for distance-weighted averaging are adjusted over a wide range, the resulting averages still never exceed about 1.2 mm/year. There is no way of torturing the data into supporting a global average MSL trend of more than about +1.2 mm/year.

    What’s more, if you look at the MSL graph for the longest and most reliable tide gauge records, you cannot fail to notice that, even as CO2 levels have taken off, there has been no corresponding acceleration in MSL trend since the late 19th century — in direct contradiction of AR4′s false claim that “coastal tide gauge measurements confirm” an accelerating rate MSL rise.

    All the code and data is available for download, along with simple instructions to make it easy for you to duplicate and verify the results:
    http://www.burtonsys.com/climate/whatif.html
    Your criticism is most welcome, Mr. Hobbs, but please do me the courtesy of READING it first:
    http://www.burtonsys.com/global_msl_trend_analysis.html

    Dave Burton

    Comment by Dave Burton — 13 Mar 2010 @ 10:29 AM

  158. 136 Gilles wrote: “That’s a very general statement : if the reaction timescale is much larger than a century , then we can’t do much to avoid it before 2100 since it has already started and will last for a long time, and if not, then the sea level will saturate at rather modest values. Choose your preferred scenario.”

    I don’t buy this. I know that people routinely discuss inertia with regard to climate but there isn’t actual physical inertia. You are arguing as if there is.
    It takes a long time for the oceans to absorb the heat due to a change in forcing because the changes in forcing are small and the oceans are big. If the forcing increases for a while and then drops back to its initial value all in less than an equilibration time the oceans simply won’t equilibrate to the maximal forcing. If the forcing goes up and stays up for millennia then the oceans will equilibrate. What we do matters.

    Comment by John E. Pearson — 13 Mar 2010 @ 10:47 AM

  159. > he’s always wrong…. Because … he’s an engineer. (Flood warnings)

    Sullenberger, who landed that plane safely in the Hudson, was interviewed on NPR a month or two ago. I recall he said much the same thing about the airlines — that they used to be owned and managed by professionals who did their very best on everything, going far beyond the minimum.

    He said now, airlines are managed by beancounters who hire the cheapest maintenance people in the world, and direct them to do the work legally required but take no extra effort or expense whatsoever. And that quality control is one of those excess costs the beancounters have eliminated.

    He said where under the old procedure a pilot in an emergency might have had a 2x or 3x margin of safety doing something beyond the design spec, presently a pilot would be lucky taking the aircraft to the design spec limit.

    He’s retired now.

    Comment by Hank Roberts — 13 Mar 2010 @ 10:56 AM

  160. > the best and longest coastal tide gauge records
    > Dave Burton.

    Opining that one (tide gauge) data set is “the best and longest” isn’t convincing, without reasons, when it’s so easy to look up sources. The uplift and subsidence information is, as Andrew Hobbs points out, used in doing this kind of analysis — except by you. Why?

    Comment by Hank Roberts — 13 Mar 2010 @ 11:19 AM

  161. John :I don’t buy this. I know that people routinely discuss inertia with regard to climate but there isn’t actual physical inertia. You are arguing as if there is.
    It takes a long time for the oceans to absorb the heat due to a change in forcing because the changes in forcing are small and the oceans are big. If the forcing increases for a while and then drops back to its initial value all in less than an equilibration time the oceans simply won’t equilibrate to the maximal forcing. If the forcing goes up and stays up for millennia then the oceans will equilibrate. What we do matters.”

    But the forcing can NOT drop, since even if we stopped just now any emission of fossils fuels, the temperature would remain constant, and it IS the forcing for sea level. According to Stefan, the 0.3 current rise would only be a small part of the asymptotic level which would be only reached in 1000 years, giving 3 meters. That’s the absolute minimum. But it is very unlikely that we could avoid + 2°C, so we’re heading to a + 10 meters rise whatever the reasonable efforts we could do. The difference between being very active just now to limit the amount of fossil fuels, and burning two or 3 times this quantity ; would result in an asymptotic value from 10 to 20 or 30 meters – the coast lines are doomed anyway (reached only after one millenium of course). So I wonder if it is not better to keep fossil fuels to rebuild the countries at higher altitudes than to give them up and fight a 10 meter rise with our hands. That’s an interesting debate – if Stefan is right of course.

    [Response: What is your argument: that 10 meter rise is not worse than 3 meter rise, because in either case we are "doomed"? That may be true if you live on the Maldives, but not in most other parts of the world. It would seem a rather far-fetched justification for a do-nothing attitude. -stefan]

    Comment by Gilles — 13 Mar 2010 @ 12:42 PM

  162. #155 wilt

    Try relevant citation.


    The Climate Lobby
    Understand the Issue
    http://www.climatelobby.com/fee-and-dividend/
    Sign the Petition!
    http://www.climatelobby.com

    Comment by John P. Reisman (OSS Foundation) — 13 Mar 2010 @ 12:48 PM

  163. For Dave Burton, just an example of how uplift and subsidence are discussed, here is a rather good recent geology blogger’s post on recent science:

    http://dynamic-earth.blogspot.com/2009/11/cyclic-subsidence-and-uplift-in.html

    — excerpt follows —-

    … Interpreting how these forcers interacted with the Mississippi delta system makes up a fair component of the literature, and has provided some interesting insights and entertaining arguments for many years. A recent paper by Blum et al (2008) has revealed a previously unknown driver of change within the deltaic system: cyclic uplift and subsidence driven by changing sediment volumes in the lower Mississippi valley.

    Blum et al (2008) point out that the subsidence recorded along the Gulf Coast is different, depending on where you measure it. The figure below is from Blum et al (20088, their Figure 1 on p. 676). Notice how the Alabama and Texas coasts are pretty different from the Valley edge subsidence patterns. Of course, this has been recognized before. Tornqvist et al (2004) interpreted this signal as a result of ongoing glacio-isostaic adjustments. Using marshland peats as baselines, and correcting for the subsidence pattern, Tornqvist et al (2004) reconstructed a sea-level curve for the Mississippi delta.

    However, an unexpected result of the Tornqvist model was a phase of “unacceptably high” rate of uplift in the peat benchmarks during the mid-holocene, corresponding to a mid-Holocene sea-level high. Tornqvist et al (2004) did not think that a phase of such large-scale uplift was very realistic, and discounted it.

    However, Blum et al (2008) may have identified a viable mechanism for rapid uplift and subsequent subsidence in the Mississippi Delta. Using the same data points and subsidence curves as Tornqvist et al (2004), Blum et al (2008) preformed a series of 1-D and 3-D isostatic modelling exercises that explain the observed uplift pattern (shown below is their Figure 3, on p. 677)….”

    Comment by Hank Roberts — 13 Mar 2010 @ 12:58 PM

  164. Hunt Janin (#156), you wrote that you would very much value any comments on the adverse consequences of a sea level rise of 2 m by 2100, because of an introductory survey you want to write. Now anyone is free to write whatever he or she wants, but before you start shouldn’t you put things in perspective? The IPCC report (2007) has several scenarios. B1 based on 1.8 degree Celsius increase yields a projection of 18-38 cm sea level rise for the 21st century, A1F1 (based on 4 degrees) gives 26-59 cm. Many if not most people, even when they believe in AGW, think that 4 degrees temperature increase in 2100 is very unlikely. Very few experts (Rahmsdorf being one of them) predict a sea level rise above 1 m. So a story about 2 m sea level rise by 2100 may sound very scary, but its credibility is so low that few people would even start reading it, and my humble advice would be to think again. If you are really dedicated to the cause of informing the public about AGW and climate change, then more exaggerations are really not helpful.

    Comment by wilt — 13 Mar 2010 @ 1:23 PM

  165. Speaking of ‘wrong … because he’s an engineer’ and margins of safety, I just happened on this, found at a wonderful blog by a meteorologist:
    http://www.flame.org/~cdoswell/ServiceAss/Challenger&Feynman.pdf

    No, that’s not about the “safety margins” on the O-rings. It’s another problem discovered later, _also_ “managed” by relaxing the safety margin.
    Gad.

    Comment by Hank Roberts — 13 Mar 2010 @ 1:32 PM

  166. “But this should be true for any cause of variation of the forcing, including the Milankovitch cycles, so the main amplifier should be the water vapor, and not the CO2 which is only a (almost passive) tracker when it’s not the primary cause of change?” Comment by Gilles — 13 March 2010 @ 2:46 AM

    No, because water vapor doesn’t work as a linear feedback over ice age cycles because of the energy balance of phase change. More energy going into wet ice melts the ice faster, but the temperature and water vapor stay the same. Much of the additional water vapor that goes into the atmosphere as the SST rises gets quickly sucked out as precipitation; the precipitation falling on ice sheets acts as a rapid sink for atmospheric water vapor. This results in a non-linear global average water vapor gamma, whose value is proportional to the percentage of permanent ice coverage. If the gamma for water vapor were high enough to kick start the end of an ice age with Milankovic forcing, when the ice coverage is largest, then the response to currently observed forcings (Pinatubo, solar cycles) would have to be larger. I expect that the transition of the Arctic Ocean from perennial to annually ice covered will increase the water vapor feedback – we’ve already lost 4 million km^2 of perennial ice covered water vapor sink. Some of the water vapor that used to be deposited on the ice cover as precipitation or direct condensation at temperatures of zero Celsius or lower are now transporting latent heat to the Greenland Ice Sheet, contributing to its rising mass loss and sea level rise. (Ta-da! Brought the discussion back on topic &;;>)

    Comment by Brian Dodge — 13 Mar 2010 @ 2:29 PM

  167. This is a nice presentation I went to at JPL last fall. The sea level session is by Lee Fu.

    Present day sea level rise = 1/3 thermal expansion +
    1/3 melting of mountain glaciers +
    1/3 melting of ice on Greenland and Antarctica

    Recent rates of sea level rise are 10 times larger than historic rates. 3.2 mm per year.

    http://climate.nasa.gov/files/Fu_Oct24_09.ppt

    http://climate.nasa.gov/ClimateSymposium/

    Comment by Mark A. York — 13 Mar 2010 @ 2:29 PM

  168. Gilles, #161: “even if we stopped just now any emission of fossils fuels, the temperature would remain constant”

    Apparently not. Remember?
    http://www.realclimate.org/index.php/archives/2010/03/climate-change-commitments/

    Comment by CM — 13 Mar 2010 @ 2:51 PM

  169. 165, Hank Roberts

    What in your opinion is the best reference for sea level change, complete with data, graphs and code?

    Comment by Septic Matthew — 13 Mar 2010 @ 4:19 PM

  170. Re #119. Stefan claims that the work of Church and White, and Jerevana, show acceleration of sea level rise during the past century. Quite simply, they don’t.

    [Response: Hmmm. The Church and White (2006) paper is titled: "A 20th century acceleration in global sea-level rise". If you think that paper does not show an acceleration, why don't you submit a comment to the peer-reviewed literature? -stefan]

    Jerejeva is essentially about paleo-temperatures, and is complex to understand and seems relatively irrelevant anyway.

    Church and White take data from the last 140 years, and fit various curves to it. But the raw data used by both Church and White, and Jerejeva, and shown in graphs on both, is derived from tide-gauge measurements. So is the Wikipedia graph (this comes from the work of Douglas, which I’m sure Stefan will be familiar with), simply does not show the claimed acceleration over this period.

    From the graphs in all three sources, it is quite obvious that the actual measured sea level rise has been approximately linear for the last century. Prior to 1910 or thereabouts, sea level appears to have been rising more slowly (though on the other hand the tide gauge measurements before that period are less plentiful and soon peter out).

    In short, forget the projections and equations, and look at the data! No significant acceleration over the past century. The apparent acceleration took place a century ago, and since then sea level rise has been approximately constant.

    Comment by Gerry Quinn — 13 Mar 2010 @ 5:30 PM

  171. > Gerry Quinn
    > … but the raw data … derived from tide gauge measurements … does not

    Have you met Dave? This has already been discussed once in recent days here.

    Comment by Hank Roberts — 13 Mar 2010 @ 5:57 PM

  172. Gerry Quinn:

    You are seriously reaching, given that the title of Church and White is “A 20th century acceleration in global sea-level rise”.

    So, if you are contending that you know enough about this subject to be able to challenge these results – where is your own paper on the subject?

    I think you are confusing the term “acceleration” with the idea of “perfectly quadratic”. Obviously we don’t expect a perfect fit from noisy data like this – but the acceleration is undeniable. Look at the residuals! In your denial, you even have to make a little exception “prior to 1910 or thereabouts, sea level appears to have been rising more slowly” in order to pretend that the acceleration isn’t there. Clue: you can’t delete the acceleration then claim it isn’t there.

    Your argument boils down to “it looks linear, except where it isn’t”.

    If you want to challenge the statistics, then you will have to provide a statistical argument, instead of handwaving and appealing to eyeballing graphs.

    Your post is particularly disingenuous given that Church and White directly address the change in rate around 1930:

    Another approach, given the clear change of slope at 1930, is to do linear regressions on the two halves (1870–1935 and 1936–2001) of the record. The slopes are 0.71 ± 0.40 and 1.84 ± 0.19 mm/yr respectively, implying an acceleration of 0.017 ± 0.007 mm/yr/yr (95%).

    They have you coming and going.

    Comment by Didactylos — 13 Mar 2010 @ 6:40 PM

  173. “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:”

    Obviously, global sea level rise by the year 2100 “could” exceed one meter. What was the most probable sea level rise in each of the assessments?

    Comment by Mark Bahner — 13 Mar 2010 @ 6:49 PM

  174. #140 : On floods, uncertainty, and the engineering response

    “…should be a transparent and previously agreed procedure.”

    Of course Stefan. It’ll all be there in the manual, fully argued and justified. We’re not talking some cavalier or arbitrary fudge. And that “most useful answer” obviously depends on the sophistication of the target audience. (I guess you’d want to know what his best estimate was, and what his error distribution is in that basin, and how he got to that.)

    The AGW discussion desperately needs to move beyond mere understanding and on to more of what to do about it. Science does the understanding; engineering is about doing – efficiently (time and money) and with justifiable confidence (manage the risks, allow a margin). There’s a huge peer reviewed literature on that second bit, little of which seems to be ref’d in AR4 (WG2 bugger all, WG3 some).

    [Response: I completely agree. Risk assessment and risk management are the key words for dealing with climate change, and there is a lot of experience on those topics in other fields like engineering. Now that a review of the approach and procedures of IPCC has been announced, I'd argue that this should be one of the key issues: the IPCC needs to provide a proper risk assessment, based on those established procedures adopted in other areas of public risk. -stefan]

    I don’t know what I’m suggesting, but it’s sure not to keep underestimating impacts because some d’head denier might complain.

    Comment by GlenFergus — 13 Mar 2010 @ 7:02 PM

  175. #157 Dave Burton

    I have reread all the pages you indicate and your current conclusions are still unsupportable.

    I only looked at Vaasa and Galveston because you yourself named them in your analysis. I didn’t looked at any others though I suspect many of the stations would need adjusting. As you said most stations are likely to be affected by local conditions. Yet you still go ahead and use the basic data without corrections.

    It is not sufficient to simply cull stations on the basis of sea level rise you don’t like. You should not just cull the outliers, or even cull all the negative values. In fact it is not appropriate to cull stations in any way, on the basis of values of sea level rise alone. The only acceptable process is to go through each and every station and find out using knowledge and data independent of the sea level data, whether there are any anomolies associated with that station. Glacial Isostatic Adjustment would be the major effect causing uplifting, but there could also be sinking (eg for Galveston) or even whether tidal stations have been moved etc. You then need to apply those corrections to the data.

    Once you have done that, collated the information and its sources, then perhaps you might have a decent basis for an analysis. If your results are still different from the published values then one can start looking at the reasons. It doesn’t mean that you would be correct or incorrect, but it would provide a reasonable basis for comparison and making some decisions about who is correct, and why.

    As for your other conclusions

    Your conclusion #2 “Because of the large variation in rate of sea level change between different seaside locations, changes in the global average rate of sea level increase have much less effect on seaside communities than one might guess.”

    (Not technically correct since the values are tidal gauge readings rather than actual changes in sea levels – which in this context does make a difference)

    This conclusion may be currently correct but it has little to do with global changes in sea level, but rather in many cases, the local effects that were mentioned. However such local effects could well be swamped by global sea level rise in the future.

    Your conclusion #3 “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.”

    All you did was to look at a few of the records; no analysis in any way. Your eyeball just says it doesn’t look like it has increased. Since you haven’t used good data anyway, and with no analysis, such a conclusion is nonsense.

    For those that want a pointer to the results of a reasonable analysis of sea level data try


    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.

    Comment by Andrew Hobbs — 13 Mar 2010 @ 8:19 PM

  176. 121 Hank Roberts: Don’t believe me. It isn’t my thesis. Just read:
    “Six Degrees” by Mark Lynas
    “Under a Green Sky” by Peter D. Ward
    “The Long Summer” by Brian Fagan
    “Collapse” by Jared Diamond.
    “Climate Code Red” by David Spratt and Philip Sutton
    “The Vanishing Face of Gaia” by James Lovelock

    http://www.sciam.com/article.cfm?articleID=00037A5D-A938-150E-A93883414B7F0000&sc=I100322

    http://www.geosociety.org/meetings/2003/prPennStateKump.htm
    http://www.astrobio.net is a NASA web zine. See:

    http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=672

    http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=1535

    http://www.astrobio.net/news/article2509.html

    http://astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2429&mode=thread&order=0&thold=0

    Yes, I know that there are people who will just give up and die. There is no way to get them to do anything else.

    But MOST PEOPLE AND MOST GOVERNMENTS ARE MOTIVATED BY FEAR AND LITTLE ELSE.

    IF we take strong action immediately, WE CAN AVOID THE BAD CONSEQUENCES! If you continue to tell them that GW is nothing to be afraid of, they will do nothing.

    FEAR MOTIVATES GOVERNMENTS. Why else would our defense budget be 1/2 TRILLION dollars/year? Our government should fear GW at least as much, and in dollars. If it did, GW would soon be over.

    I am NOT a doomsayer. I am an advocate of strong GW legislation. The stronger the better. The sooner the better. RC should do likewise.

    Comment by Edward Greisch — 13 Mar 2010 @ 9:21 PM

  177. > Mark Bahner
    http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/428.htm — and look at various answers for specific assumptions and scenarios. There’s no simple answer.

    Edward, your thesis isn’t RC’s thesis.
    Drill down past the news article or press release, find the actual science paper, read it, and quote from the actual science. Provide a cite and link.

    Same advice for anyone making claims about what science says.

    Comment by Hank Roberts — 13 Mar 2010 @ 10:26 PM

  178. 175, Andrew Hobbs.

    I have selected the following from the Church and White article that you linked:

    [11] If this acceleration was maintained through the 21st
    century, sea level in 2100 would be 310 ± 30 mm higher
    than in 1990, overlapping with the central range of projections
    in the Intergovernmental Panel on Climate Change
    Third Assessment Report (IPCC TAR) [Church et al.,
    2001]. For 1910 to 1990, the acceleration in ocean thermal
    expansion (only) in these climate models range from 0.005 ±
    0.003 mm yr2 to 0.014 ± 0.004 mm yr2 (Table 11.2 of the
    IPCC TAR), consistent with the present estimates of
    0.013 mm yr2 and 0.017 mm yr2 for the 132 year period
    and the 0.008 mm yr2 for the 20th century.
    [12] Between 1930 and 1960, GMSL rises faster than the
    quadratic curve at a rate of about 2.5 mm yr1 (Figure 2c),
    following (with about a 20 year lag) the 1910 to 1940
    period of more rapid global temperature rise [Folland et al.,
    2001]. Variability in GMSL trends prior to 1930 are not
    significant. After 1960, there are minima in the rates of rise
    in the 1960s and 1980s, each followed by more rapid rates
    of rise (peaking at over 3 mm yr1), consistent with Holgate
    and Woodworth [2004].

    Are these considered to be reliable results by most supporters of AGW? They posit that fluctuations in sea level rate of increase are concordant with earlier changes in temperature (seeming to imply a belief that temperature has not changed at a constant rate); have there been follow-on analyses of this via vector autoregressive or other multivariate time series methods?

    Comment by Septic Matthew — 13 Mar 2010 @ 10:41 PM

  179. RE: 178 The Le Fu JPL sea level presentation cites this paper for the graphic. You would have to look at the slide to see it though.

    Comment by Mark A. York — 13 Mar 2010 @ 11:23 PM

  180. #178 Septic Matthew

    I pointed out the paper as an example of the type of data corrections and analysis that has been used. ie a simple averaging of raw culled station data as used by Dave Burton is not appropriate.

    As for their actual results, they are out of date now, with rather larger values calculated from more recent data, including satellite data. In addition, the predictions from this study are purely extrapolation of historical values. They obviously cannot take into account any ‘sudden’ qualitative changes such as ice sheet collapse and increased glacier movement which seems to have become a feature over the last few years. For the latter reason many researchers now appear to consider a rather greater rate of sea level rise more likely.

    Comment by Andrew Hobbs — 13 Mar 2010 @ 11:56 PM

  181. Hank Roberts(177) “http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/428.htm — and look at various answers for specific assumptions and scenarios. There’s no simple answer.”

    The source you reference (the TAR) contains no “most likely” estimate for sea level rise in the 21st century. It’s also obviously not something published after AR4.

    Comment by Mark Bahner — 14 Mar 2010 @ 12:05 AM

  182. You asked for all of them. The first is on paper; the second and third are in the link I gave. As I said, there’s no single simple answer; there are various scenarios, ‘what if’ situations, not predictions. You mistake — oh, you’re that Bahner. You know all this.

    Sorry I took the bait.

    Comment by Hank Roberts — 14 Mar 2010 @ 12:37 AM

  183. 177 Hank Roberts: “find the actual science paper, read it, and quote from the actual science. Provide a cite and link.”:
    I have done that as much as I can. I do not have access to most of those papers. They are in journals that cost $ way too much/year each. I am a federal retiree, not a professor at a major university. No, I can’t just drive 50 miles, then walk a few blocks, then spend all day in the library. I can’t walk that far, among other things. I do what I can at the library that is accessible to me.

    Since you are so young and well endowed, why don’t you do it for me?

    Notice that I am not complaining about the journals not being free on line. They are not free on line, so don’t complain that I am not reading them. The local public library is free, and the book authors have summarized the journals for me.

    Comment by Edward Greisch — 14 Mar 2010 @ 1:22 AM

  184. The bait being that Mark Bahner knows there’s no single “most likely” estimate in the material so far; they’re consistently discussing probabilities in ranges higher than came out of the assessment in the fourth IPCC publication.

    E.g. for California — various scenarios from more recent assessments:

    “Over the past several decades, sea level measured at tide gages along the California coast has risen at a rate of about 17–20 centimeters (cm) per century, a rate that is nearly the same as that from global sea level rise estimates (Church and White 2006). A paper authored by Rahmstorf (2007) demonstrated that over the last century observed global sea level rise can be linked to global mean surface air temperature. This provides a methodology to estimate global sea level using the surface air temperature projected by the global climate model simulations, and it leads to larger rates of sea level rise than those produced by other recent estimates (Cayan et al. 2008). The present estimates include those of Rahmstorf’s method, assuming that sea level rise along the Southern California coast will be the same as the global estimates. Also, the projections here include a second set of estimates that are a modification of Rahmstorf’s method that attempts to account for the global growth of dams and reservoirs, which have artificially changed surface runoff into the oceans (Chao et al. 2008), in addition to the effects of climate change. Using the global surface air temperature from the GCMs included in this assessment, the resulting estimates in Figures 17 and 18 indicate that potential sea level rise over the next century will increase over its historical rate by a considerable amount. Each model has a different rendition of global surface air temperature within the historical period within its “20C3M” historical simulation,1 so that simulated historical sea levels vary between models. But in the experiments run here, the sea level estimates were adjusted so that for year 2000 their value was constrained to the same, zero value—this allows for comparison across the simulations of the amount of projected sea level rise over the twenty-first century. By 2050, sea level rise, relative to the 2000 level, ranges from 30 cm to 45 cm. As sea level rises, there will be an increased rate of extreme high sea level events (Figure 19 and Table 7), which occur during high tides, often when accompanied by winter storms and sometimes exacerbated by El Niño occurrences (Cayan et al. 2008c). Importantly, as decades proceed, these simulations also contain an increasing tendency for heightened sea level events to persist for more hours, which would seem to imply a greater threat of coastal erosion and other damage. Virtually all of the increase in frequency and magnitude of sea level exceedances can be ascribed to the underlying secular increase in mean sea level….”
    http://water.usgs.gov/nrp/proj.bib/Publications/2009/cayan_tyree_etal_2009.pdf
    CLIMATE CHANGE SCENARIOS AND SEA LEVEL RISE ESTIMATES FOR THE CALIFORNIA 2009 CLIMATE CHANGE SCENARIOS ASSESSMENT, section 8, at p.30

    Comment by Hank Roberts — 14 Mar 2010 @ 1:45 AM

  185. An interesting article which very clearly illustrates how the conclusions depend on your prejudices. Again, I am baffled that no one else seems to see the obvious.

    What you are saying is that current models of sea level change which, when applied to the last 40 years, a period for which we have good climate data, predict a sea level rise which is only 2/3 of the one that actually happened. Correct?

    OK, we have a model and we have data. Fine! The model underestimates the change in the measured variable by 50%. We can then draw the following conclusions:

    1) The model gets the right sign of the effect.
    2) The model gets the incorrect result

    When we have a model that fails to reproduce the observed results but doesn’t give a crazy result we can choose between two conclusions:

    a) Either the model is seriously wrong (which it could be even if it got the right result)

    or

    b) The model is reasonable but some other extra effect(s) is at play which is not accounted for in the model

    Depending on the exact details on the model we can choose to try to “correct” it to make it account for the observed values. This kind of “fine tuning” may sometimes be useful in an engineering context but is shunned in all real science. What you do is simply throw away important scientific information – the discrepancy between the model and the data clearly shows that you have missed some understanding of the physics. If you “correct” that without understanding what you are doing the model will essentially loose all of its predictable power except perhaps in the very nearest future.

    If current models of sea level rise are 50% percent wrong in the estimate of the current sea level change we thus have an unknown factor, certainly not necessarily linear, which is important. If this unknown factor reverses (which it of course may well do – remember it is unknown – it could well be e.g. cyclic) and the rest of the model is right the resulting sea level rise in the next 100 years will probably only be about half of what is predicted or about 30 cm. Given the large uncertainties in the forecasted temperatures [which, apart from physics, also depend on politics – the “scenarios”] for the future I would say that it is safe to say the current sea level models aren’t really useful to predict anything reliable in a 100 years perspective.

    Finally, it might be interesting to discuss the size and relevance of these values. Living in a country (Sweden) where post-glacial rebound makes the sea level fall at up to 1 m per century (and has done so for many centuries) it is quite safe to conclude that sea level changes of this order and probably much larger, isn’t much of problem. We live in a dynamic world where change is the most important factor. The idea of a static world is simply a flawed model.

    Comment by Steven Jörsäter — 14 Mar 2010 @ 2:22 AM

  186. Hank Roberts wrote:
    > Opining that one (tide gauge) data set is “the best and longest” isn’t convincing, without reasons, when it’s so easy to look up sources.

    They are the GLOSS-LTT stations. Google it:
    http://www.google.com/search?q=“GLOSS-LTT”
    The first link result should convince you.

    Hank continued:
    > The uplift and subsidence information is, as Andrew Hobbs points out, used in doing this kind of analysis — except by you. Why?

    Not just “except by me.” E.g., Nakiboglu and Lambeck (1991) used a spatial decomposition approach.

    The problem to be solved is separating the global average isostatic MSL trend from local effects. If we actually had trustworthy uplift and subsidence measurements, we could just add the uplift or subtract the subsidence. But we don’t. What we have is not actual measured data for uplift and subsidence. Rather, it is the result of computer modeling of very poorly understood systems.

    You’ve heard “garbage in, garbage out?” Well, adding garbage to data is like adding root beer to lemon-lime soda. What you get is garbage, not data. Like root beer, garbage has the dominant flavor.

    Fully 2/3 of the GLOSS-LTT tide gauges have recorded local MSL trends of less than the Church/IPCC claimed 1.8 mm/year, most of them MUCH less than that. That should make it obvious that there is something wrong with their method.

    Rather than adding untrustworthy model-based “corrections” (garbage) to actual measured data, it is much better to work with the real, measured data we have, and eliminate the local effects from the global averages by weighting the tide stations according to whether or not they are close enough to other tide stations to be affected by the same local factors.

    We have good tide gauge data going back to the 1800s, some of it from tide stations which are not significantly affected by crustal rebound (the main factor which the models attempt to account for). If you want real, trustworthy answers, you should use real, trustworthy data.

    Mark A. York wrote:
    > This is a nice presentation I went to at JPL last fall. The sea level session is by Lee Fu.
    > …Recent rates of sea level rise are 10 times larger than historic rates. 3.2 mm per year.
    > http://climate.nasa.gov/files/Fu_Oct24_09.ppt
    > http://climate.nasa.gov/ClimateSymposium/

    Thanks for the links, Mark, but fooey on Mr. Fu.

    On the basis of “23 Annual Tide Gauge Records” (which ones are unspecified) he claims that the rate of sea level rise increased around approximately 1910 (or 1925, depending on which of his graphs you look at) to 2.0 mm/year, a rate which his first tide gauge line shows holding steady through the end of the 20th century, but the second one purports to show increasing to 3.2 mm/year around 1985.

    He’s completely wrong.

    Worse, much of his error is INTENTIONAL.

    Take a look at his 2nd graph, labeled “Church and White, 2006″ (open the powerpoint and hit PgDn 11 times). That’s the graph which shows rates of 0.8 mm/yr to 1925, then 2.0 mm/yr to 1985, then 3.2 mm/yr to 2000. Do you see the chicanery? HE RESET THE STARTING POINTS DOWNWARD for the trend lines! For both the 2.0mm/yr and 3.2 mm/yr line segments, he intentionally skewed the slopes higher by starting with a negative noise spike, and for the 3.2 mm/yr segment he also ended it on a positive noise spike (and had to stop the segment prematurely to find the highest one)!

    That is obvious, shameless, intentional biasing of the results. Is it any wonder that Hansen/NASA are in such ill repute?

    In the second place, why do you suppose that Fu/NASA chose to look at just 23 tide gauges? There are 159 in the GLOSS-LTT set, chosen specifically for monitoring long term sea level trends, because of the quality of their records and their good geographical distribution. 70% of them have recorded local MSL trends of less than Fu’s claimed 2.0 mm/yr. 44 of the 159 GLOSS-LTT tide stations have tide records dating from the 1800s, though two ceased operation in the 1930s, leaving 42. 36 of the 42 (86%) show MSL trends of less than 2.0 mm/yr.

    In the third place, look at Fu’s first tide gauge graph, labeled “Historic Sea Level Rise / 120 years” (open the powerpoint & press PgDn 6 times). It shows NO increase in MSL trend at any time since 1910. But anthropogenic CO2 emissions were a tiny trickle in 1910, compared to today. So where’s the effect on sea level from CO2? The answer, from coastal tide gauge measurements, is THERE IS NONE.

    In the fourth place, if you actually look at the graphed local MSLs for the tide station which have been in operation since the late 1800s, you will not find ANY evidence of an uptick in MSL trend around 1910 or 1925 — nor, for most stations, at any other date. But don’t take my word for it, see for yourself. Go to the spreadsheet:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    and look at the 44 GLOSS-LTT tide stations which have been in operation since the 1800s. Click on the tide station names to view the graph (at noaa.gov) of Local Mean Sea Level at that tide station. There are 44 of them (though two of them ceased operation during the Depression.) I defy you to find even one which shows the 1910 or 1925 uptick that Fu claims.

    For a nice example of a good tide gauge record, take a look at Warnemunde, Germany:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=120-012
    It records a continuous MSL record from 1855 to 2005, with an absolutely flat mean sea level trend of 1.20 millimeters/year for the entire 160 year period. (Some others tide stations show a slight increase somewhere between 1860 and 1880.)

    Or, ironically, consider Copenhagen, Denmark. It records a continuous, straight local MSL trend of 0.49 millimeters/year from 1889 to 2006, with no sustained uptick in rate at any date:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=130-021

    Or consider Sydney, Australia. It records a continuous, straight local MSL trend of 0.59 mm/yr from 1886 to 2003, with no sustained uptick in rate at any date:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=680-140

    The fact is that the best available tide gauge data shows that the global average MSL trend has been steady at less than 1.2 mm/year for at least 120 years, with no sign of acceleration in 1910 or 1925 (Fu) or 1993 (IPCC) or any other date.

    See: http://www.burtonsys.com/climate/global_msl_trend_analysis.html

    Comment by Dave Burton — 14 Mar 2010 @ 4:14 AM

  187. “illes, #161: “even if we stopped just now any emission of fossils fuels, the temperature would remain constant”

    Apparently not. Remember?
    http://www.realclimate.org/index.php/archives/2010/03/climate-change-commitments/“”

    the blue curve corresponding to zero emission IS constant ! not with Bern model, but I understand with the model presented here. Now as I said zero emission is anyway unrealistic, and I think 2 degrees are hardly avoidable (and hence a +10 m sea level rise whatever we’ll do – if Stefan is right, of course).

    Comment by Gilles — 14 Mar 2010 @ 7:04 AM

  188. Septic Matthew:

    Church and White (2006) don’t attempt any attribution of the acceleration they calculate. They do discuss probable causes and reference the appropriate literature.

    I suggest that if you are genuinely interested, you read the papers that are cited as actually addressing attribution for sea level rise.

    You say “seeming to imply a belief that temperature has not changed at a constant rate” – but I am hopeful that you are aware that global temperature has not changed at a constant rate through the period discussed in the paper. If you are unaware of this, then I can direct you to products such as GISTEMP and HADCRUT….. but you can’t possibly be ignorant of this. You are just kicking up dust.

    Comment by Didactylos — 14 Mar 2010 @ 7:52 AM

  189. Dave Burton:

    You complain an awful lot about corrections, but seriously demanding that uncorrected data be used leads to complete nonsense – such as that produced by Beck for CO2.

    You also complain about cherrypicking end-points! Given that the conclusion is not dependant on endpoints, but is merely an illustration of the acceleration, your complaints are completely spurious.

    You complain a lot, but your substance is curiously lacking.

    When it comes to concrete evidence, you suddenly decide to cherry pick yourself – not an endpoint, but singling out individual tide records, in the vain hope that we would forget about the rest. I like to believe that RC readers are not that stupid.

    If your “source” (which seems to be mainly yourself) had any genuine evidence, they would have published it by now, would they not?

    I see you also stoop to that most contemptible trick of graphing fraudsters: expand the Y axis enough, and magically any trend will disappear. “Look! It’s flat!” you cry. Well, of course it is. You scaled the data inappropriately. When you are interested in mm/year, a Y axis scaled in metres is a pretty big clue that you are Doing It Wrong.

    Comment by Didactylos — 14 Mar 2010 @ 8:41 AM

  190. Gilles says:
    14 March 2010 at 7:04 AM
    “illes, #161: “even if we stopped just now any emission of fossils fuels, the temperature would remain constant”

    Apparently not. Remember?

    The blue curve wasn’t the only curve. There was another one with a negative slope. Capitalizing a false assertion doesn’t make it correct. There is no physical reason that the excess forcing can’t drop. There is a range of temperatures associated with any scenario. Perhaps the most likely scenario is the one presented in that letter. More likely, further study is required to nail it down.
    WIth your do-nothing approach you advocate pushing the temperatures as high as possible. In fact there is a range of temperatures not “2 degrees” that “you think” but more like “2-4″ degrees. Focusing on the bottom temperature of the range is disingenuous. It is plausible that we can quit coal by mid century and there is no reason at all to not aim for that.

    Comment by John E. Pearson — 14 Mar 2010 @ 9:39 AM

  191. Here’s what I think is a useful lecture on sea levels. It’s the third one down in the video gallery.

    Rising Sea Levels Demystified
    Mr John Englander,
    Chief Executive Officer, The International SeaKeepers Society

    http://www.imarest.org/Events.aspx/EventGallery.aspx

    http://www.imarest.org/Events.aspx/IMarESTEvents/StanleyGray/24thMarch2009Completed.aspx

    Comment by Mike Donald — 14 Mar 2010 @ 10:19 AM

  192. > Edward G
    > why don’t you do it for me

    Google Scholar finds the science papers behind the links you’re posting. You can use that right from your chair.

    I’m as busy and as retired as you are, and without a pension. We all have all the work we can do about these issues, and I’m sincerely trying to be helpful — by urging you to be careful and cite your sources correctly.

    I’m giving you the same advice I give anyone posting claims, whatever their political goals — you can cite them yourself. Don’t stop at the first Scholar link if it gets only the abstract; check the other versions Scholar suggests.

    And recheck what you couldn’t find.
    More papers are becoming available every day at the authors’ websites.

    Interlibrary L o a n is your friend. If you’re unable to go to the library, your library will bring or send material to you. Ask at your local library.

    Comment by Hank Roberts — 14 Mar 2010 @ 11:28 AM

  193. Stefan commented on my contribution #155, and clarified his previous comment (#38). He now states that he meant to refer to the 1870-1920 period instead of ‘at the beginning of the 20th century’ which I thought was implying only a single observation point. I therefore withdraw my suggestion of selective citation.
    In the same comment, he points my attention to the Church & White article (GRL 2006). This is remarkable, because Church & White conclude that during the 20th century there was only a very small acceleration of sea level rise (0.013 mm/year per year). If the accelaration remained constant the 1990 to 2100 sea level rise would be between 280 and 340 mm. Here is the complete abstract of their article:
    “Multi-century sea-level records and climate models indicate an acceleration of sea-level rise, but no 20th century acceleration has previously been detected. A reconstruction of global sea level using tide-gauge data from 1950 to 2000 indicates a larger rate of rise after 1993 and other periods of rapid sea-level rise but no significant acceleration over this period. Here, we extend the reconstruction of global mean sea level back to 1870 and find a sea-level rise from January 1870 to December 2004 of 195 mm, a 20th century rate of sea-level rise of 1.7 ± 0.3 mm yr−1 and a significant acceleration of sea-level rise of 0.013 ± 0.006 mm yr−2. This acceleration is an important confirmation of climate change simulations which show an acceleration not previously observed. If this acceleration remained constant then the 1990 to 2100 rise would range from 280 to 340 mm, consistent with projections in the IPCC TAR.”. Link:
    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.

    [Response: That you call the acceleration found by Church and White (0.013 mm/year per year) "very small" is your value judgement. It applies to a 130-year period, so it means that in their quadratic fit, the rate of rise in the year 2001 is 1.7 mm/year larger than in 1870 (namely 0.013 * 130).

    In addition, I cannot quite reproduce their result. Letting matlab do a quadratic fit (with function polyfit) on their data gives me an acceleration of 0.016 mm/year per year. The rate of rise in 1870 in this quadratic is 0.8 mm/year, in 2001 it is 2.9 mm/year, with the difference being 2.1 mm/year and not only 1.7 mm/year. (Note that this is a 3.6-fold increase in the rate of sea level rise since 1870.) Be that as it may, if you attribute those additional 2.1 mm/year to 0.8 ºC warming (as is done in the semi-empirical models) you get a "sea level sensitivity" of 2.1/0.8= 2.6 mm/year/degree, a bit less than the 3.4 mm/year/degree which I found in my 2007 paper. The difference is due to the fact that the actual sea level data deviate from a quadratic curve. However, the bottom line is that there is no fundamental disagreement between the acceleration found by fitting a quadratic and that used in the semi-empirical models, although there is some difference in exact numbers.

    Your second point, that future sea level rise would be quite small if the rate of acceleration remained constant, is correct - but in the semi-empirical approach, a constant acceleration rate would imply that in the next 130 years, global temperature will again rise by only 0.8 ºC as it did in the last 130 years. This is well below any realistic temperature scenario. -stefan]

    Comment by wilt — 14 Mar 2010 @ 11:42 AM

  194. Insist the old data is the most reliable while ignoring new work?

    The old data is known inadequate to show sea level change, according to the references I find.

    Look, I’m just an ordinary reader with a penchant for looking stuff up, but in a few minutes, I find that GLOSS-LTT is old data known lacking and there has been a worldwide effort to improve on it. You can look this up yourself.

    Scholar finds three hits for “GLOSS-LTT” since 1994.
    http://scholar.google.com/scholar?hl=en&q=GLOSS-LTT&as_sdt=2000&as_ylo=1994&as_vis=0

    Look at all three.

    A review of sea-level research from tide gauges during the World Ocean …
    PL Woodworth, C Le Provost, LJ 2002 – books.google.com
    (you can read and search it)
    This mentions what’s lacking in the GLOSS-LTT system — a way to handle uplift and subsidence — and discusses the additions being made to address that lack of information in the old data. References include the Fu (2001) paper mentioned above.

    The Permanent Service for Mean Sea Level: An Update to the 21stCentury
    P. L. Woodworth and R. Player
    Journal of Coastal Research, Vol. 19, No. 2 (Spring, 2003), pp. 287-295
    (first of 9 pages available as a PDF) also mentions
    http://www.jstor.org/stable/4299170

    Comment by Hank Roberts — 14 Mar 2010 @ 12:10 PM

  195. Hank Roberts (182) writes:

    “You asked for all of them. The first is on paper; the second and third are in the link I gave.”

    No, what I asked for were the “most likely” values from the studies Stefan referenced when he wrote, “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:…”

    You linked to the THIRD assessment report, which can not possibly be relevant to the studies Stefan was referring to, which occurred after the FOURTH assessment report.

    Why not save us all a lot of trouble, and let Stefan answer the question (since he’s the one who made the orginal statement)?

    Comment by Mark Bahner — 14 Mar 2010 @ 12:25 PM

  196. RE: Le Fu “He’s completely wrong.”

    No he isn’t. This is how much sea level rise has increased. Your problem seems to be the credibility of NASA. You start with that proposition and then claim to prove it. You’ve been called on it by knowledgeable people here. Certainly you know that sea level rise is not uniform, right?

    Comment by Mark A. York — 14 Mar 2010 @ 1:25 PM

  197. My thanks to Wilt and to any others who have commented on my first-ever post, asking about the bad effects of a 2 m rise in sea level (for an introductory survey I’m writing now). Wilt, please rest assured that I don’t plan to tell my readers to get ready for a 2 m rise. As a mere generalist, I just want to know what a relatively worst-case scenario might involve.

    [Response: The key issue is: 2 meters by when? Highly unlikely to get there by the year 2100, but getting quite likely by 2200. -stefan]

    Comment by Hunt Janin — 14 Mar 2010 @ 1:57 PM

  198. 188, Didactylos: Church and White (2006) don’t attempt any attribution of the acceleration they calculate. They do discuss probable causes and reference the appropriate literature.

    That’s not different from what I wrote.

    but I am hopeful that you are aware that global temperature has not changed at a constant rate through the period discussed in the paper.

    I have written that myself, but there has been some disputation as to the nature of the “nonconstancy”.

    You are just kicking up dust.

    No, I asked whether someone had used a particular method (VAR analysis) to test a particular hypothesis (increases and decreases in rate of sea level rise related to increases and non-increases in global mean temp.)

    I suggest that if you are genuinely interested, you read the papers that are cited as actually addressing attribution for sea level rise.

    Lead me to one (your “favorite”) and I’ll read it, with or without genuine interest.

    180, Andrew Hobbs,
    Thank you. Would you like to provide a link or citation of one of the more recent papers that you mention? One including satellite data through 2009 would be best, but might not yet be peer-reviewed.

    Comment by Septic Matthew — 14 Mar 2010 @ 2:26 PM

  199. RC: Is it the Hatch Act?

    Comment by Edward Greisch — 14 Mar 2010 @ 3:06 PM

  200. Gilles #187, my bad. Got my graphs mixed up. So I have no issue with your statement about temperatures remaining constant after zero emissions, though as you and John Pearson both noted it’s not the only possibility.

    Comment by CM — 14 Mar 2010 @ 3:10 PM

  201. RE 185: I also happen to live in Sweden and while post-glacial rebound is clearly still strong in northern Sweden, it is essentially zero in the southern part. Thus, rising sea levels will definitively be a problem also in our country. Also, I have my own 45 year anecdotal record of sea level at my summer house, where beach erosion is a very real problem

    Comment by Pagodroma — 14 Mar 2010 @ 5:13 PM

  202. Interesting statistic just out: China’s oil consumption is 28% greater than at the same time last year. This is a startling rise. I’d be very curious to see the same info from India. Perhaps it won’t take as long as we thought for the ‘upping’ of fossil fuel consumption.

    Comment by Steve Missal — 14 Mar 2010 @ 5:41 PM

  203. 174 Response stefan: Where will we see the engineering part? Will it be in another blog or a new part of RC?

    Comment by Edward Greisch — 15 Mar 2010 @ 2:20 AM

  204. Re: #170, 172, regarding the timing of sea level rise and accelerations thereof:

    Much is being made by Stefan and a poster called Didactylos about the title of Church and White’s paper referring to acceleration during the twentieth century. Church and White themselves observe that the data appears to have a clear change in slope somewhere around 1930. They found that two linear regressions (splitting at 1935, half-way through their dataset) actually fit the sea level data *better* than their quadratic.

    “The rms residual to the linear fits is lower at 5.8mm (cf 7.5mm) consistent with much of the acceleration occurring in the first half of the 20th century rather than a smooth acceleration over the whole period” [Church and White] (The 7.5 mm refers to the rms for their quadratic fit.)

    In my original post I referred to the data I was familiar with, that of Douglas, as given in Wikipedia under ‘Current sea level rise’, and widely cited in the literature. The curve is much the same anyway, i.e. it is linear from 1930 to the present date. I would not disagree with 1930 as a break point, although one could arguably place it earlier.

    Either way, the best-fitting model of Church and White indicates that sea level has been rising at a constant rate for at least 80 years, which is pretty much what I posted initially in #119.

    So I ask once again: where does this leave Stefan’s contention in #1 that “data of the past century show how the rate of sea level rise increases in proportion with temperature”. Has temperature been approximately constant since 1930? Because, quite clearly, annual sea level rise has! I would appreciate if future responses addressed temperature and sea level data, rather than titles of reports, or ad hominems a la Didactylos.

    [Response: Did I mention that if you want to know how we got our results, it is an option to read our papers (freely accessible, linked above in the post)? They deal in sea level and temperature data and the connection between the two in some detail. -stefan]

    Comment by Gerry Quinn — 15 Mar 2010 @ 8:28 AM

  205. “202
    Steve Missal says:
    14 March 2010 at 5:41 PM

    Interesting statistic just out: China’s oil consumption is 28% greater than at the same time last year. This is a startling rise. I’d be very curious to see the same info from India.”

    How about the US? I’d be interested in that.

    Comment by Completely Fed Up — 15 Mar 2010 @ 9:59 AM

  206. I hope mr Robbert Dijkgraaf will read this post.

    Comment by Elmar Veerman — 15 Mar 2010 @ 11:45 AM

  207. IEA: “But the agency said that demand in the area covered by the Organization for Economic Cooperation and Development remained “persistently weak” and would fall by 0.3 per cent this year.”

    “The OECD group’s 30 developed economies including Britain, France, Germany, Japan and the U.S., which account for most of global economic output.

    “This year’s global oildemand growth will be driven entirely by non-OECD countries, with non-OECD Asia alone representing over half of total growth,” it said.”

    Comment by J — 15 Mar 2010 @ 12:27 PM

  208. CFU@205

    U.S. Liquid Fuels Consumption. U.S. liquid fuels consumption declined by 810,000 bbl/d (4.2 percent) to 18.7 million bbl/d in 2009, the fourth consecutive annual decline. Motor gasoline was the only major petroleum product whose annual consumption did not decline. Distillate fuel consumption declined by 310,000 bbl/d (8.0 percent) in 2009, led by a sharp economy-related decline in transportation usage.

    The economic recovery contributes to projected growth in total liquid fuels consumption of 200,000 bbl/d in 2010 and 210,000 bbl/d in 2011. Nevertheless, expected U.S. consumption in 2011 is lower than total consumption was in 1999 and is 1.7 million bbl/d lower than the highest level of annual consumption reached in 2005.

    from here

    & Steve@202
    Isn’t per capita use more relevant? [~2008 ranks]:
    # 1 Virgin Islands: 845 bbl/day per 1,000
    # 10 Saudi Arabia: 83 bbl/day per 1,000
    # 19 Canada: 71 bbl/day per 1,000
    # 23 United States: 68.6 bbl/day per 1,000
    # 62 United Kingdom: 29 bbl/day per 1,000
    # 144 China: 5.7 bbl/day per 1,000
    # 165 India: 2.4 bbl/day per 1,000

    Comment by flxible — 15 Mar 2010 @ 1:20 PM

  209. flxible, maybe Gilles will use that as proof that CO2 is the lifeblood of economic recovery, then…!

    Comment by Completely Fed Up — 15 Mar 2010 @ 1:55 PM

  210. Yes, energy usage and economic activity vary proportionately.

    Comment by J — 15 Mar 2010 @ 2:34 PM

  211. There’s always lots of good information being exchanged here at Realclimate, which is why I continuously come to the site. The criticism of the IPCC, however, is unfounded.
    The IPCC is not narrow-minded, nor are they politically motivated or getting big grant dollars from whomever. It represents a collaborative of respected scientists from across the world, from numerous countries and biomes, with, I’m sure, unique concerns for their home nations.
    This is good. It ensures that no one personal bias dominates their studies, and that all views get consideration. What some people don’t like to hear is that all views basically agree that human activity is altering the climate, making it warmer, and that there is a positive feedback.
    Aye, there’s the rub. Positive feedback. Permafrost defrosting, methane emission, loss of the ocean’s ability to sequester carbon. Not to mention thermal expansion and inundation of low-lying areas, which creates marshes and swamps- which in turn release more methane and CO2.
    All this while the human population is expected to keep ballooning. Has the IPCC taken this into account? absolutely. If different areas of the scientific community- biologists, geologists, meterologists, etc. each do their own studies, based only on information from their field, there will be different results. Only the IPCC addresses information gathered from across the scientific spectrum, and with that, they have added credibility.

    Comment by Tgorle — 15 Mar 2010 @ 2:35 PM

  212. Didactylos wrote on 14 March 2010 at 8:41 AM:
    > …you stoop to that most contemptible trick of graphing fraudsters: expand
    > the Y axis enough, and magically any trend will disappear. “Look! It’s
    > flat!” you cry. Well, of course it is. You scaled the data inappropriately.
    > When you are interested in mm/year, a Y axis scaled in metres is a pretty
    > big clue that you are Doing It Wrong.

    Dear Didactylos,

    I assume that you are complaining about these graphs, to which I linked in my previous message:

    Warnemunde, Germany:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=120-012

    Copenhagen, Denmark:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=130-021

    Sydney, Australia:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=680-140

    (You can find links to the other 156 GLOSS-LTT tide station LMLS graphs here: http://www.burtonsys.com/climate/MSL_global_trendtable1.html )

    Didactylos, may I suggest that you direct your criticism of the graphs to the good folks at NOAA. The graphs are theirs, not mine, as you can see from the URLs. At the bottom of each graph page is a link to NOAA’s contact information:
    http://tidesandcurrents.noaa.gov/contact.html

    For the record, I think NOAA a good job on this. The Local MSL trend analyses and graphs appears to be carefully and competently done. But if you disagree, please take it up with them, not me.

    The fact is that the longest and best quality tide gauge records of local mean sea level graph out as essentially straight lines + noise. They show that the global average MSL trend has been steady at less than 1.2 mm/year for at least 120 years, with no sign of acceleration in 1910 or 1925 or 1985 (Fu) or 1993 (IPCC) or any other date.

    Didactylos also wrote:
    > You also complain about cherrypicking end-points! Given that the conclusion is not dependant
    > on endpoints, but is merely an illustration of the acceleration, your complaints are
    > completely spurious.

    Wrong. I am disturbed that you dismiss fraud as “merely an illustration,” as if it were harmless. The fact is that the conclusions (the 2.0 and 3.2 mm/yr slopes of the lines) obviously ARE dependent on the cherry-picked endpoints.

    The fact is that the longest and most reliable tide station local mean sea level measurement records graph as essentially straight lines + noise. They show that there has been NO measurable acceleration in mean sea level rise on the world’s coasts since the mid-to-late 1800s.

    Didactylos also wrote:
    > When it comes to concrete evidence, you suddenly decide to cherry pick yourself – not an
    > endpoint, but singling out individual tide records, in the vain hope that we would forget
    > about the rest.

    Wrong. I gave you links to the graphs of ALL the GLOSS-LTT tide station records, and I challenged you to “find even one which shows” Fu’s claimed uptick in rate of MSL rise.

    I wrote, “don’t take my word for it, see for yourself. Go to the spreadsheet:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    …look at the 44 GLOSS-LTT tide stations which have been in operation since the 1800s. Click on the tide station names to view the graph (at noaa.gov) of Local Mean Sea Level at that tide station.”

    (Did you notice that I wrote “at noaa.gov?” I really wish you guys would bother to READ before you criticize!)

    Hank Roberts wrote on 14 March 2010:
    > Insist the old data is the most reliable while ignoring new work?
    > The old data is known inadequate to show sea level change, according to the references I find.

    At issue is whether there has been any acceleration in the rate of Mean Sea Level rise since the late 1800s. I’ve seen claims of accelerations occurring at about 1910, 1925, 1985, and 1993.

    None of those dates are recent, which is why we have to rely on old data.

    Fortunately, we have actual measurements of sea level at coastal tide stations from back then. Yes that data is “old,” but it is the only reliable data we have, and it is unquestionably more reliable than computer modeling results, where the models are modeling processes that aren’t well understood.

    Andrew Hobbs wrote on 13 March 2010 to Septic Matthew:
    > simple averaging of raw culled station data as used by Dave Burton is not appropriate.

    Andrew, I obviously did not do just “simple averaging of raw culled station data.”

    For the second time I ask you, please do me the courtesy of READING it before criticizing it. Here’s the link:
    http://www.burtonsys.com/global_msl_trend_analysis.html

    Andrew Hobbs wrote on 13 March 2010:
    > The only acceptable process is to go through each and every station and find out
    > using knowledge and data independent of the sea level data, whether there are
    > any anomolies associated with that station. … or even whether tidal stations
    > have been moved etc.

    If you look at the data, Andrew, you will see that NOAA has already done this. See, for example, the graph for Goteborg, Sweden:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=050-032

    Note how NOAA handled the discontinuity in 1969, when the station was relocated.

    Andrew also wrote:
    > Glacial Isostatic Adjustment would be the major effect

    We can only RELIABLY correct for things that we can measure. We have no historical measurements of glacial rebound or subsidence due to groundwater pumping, so adding dubious fudge factors based on questionable computer models just corrupts the data.

    What we do have, fortunately, is long running reliable measurements of sea level at locations unaffected by glacial rebound. Nearly all of them show the same thing: a straight line (plus noise), with no sustained acceleration in the rate of MSL rise at all since at least the late 1800s.

    Andrew wrote:
    > All you did was to look at a few of the records; no analysis in any way.

    If you’d actually READ it you’d know that’s nonsense.

    I’ve personally looked at all 159 of the GLOSS-LTT tide station MSL graphs. I found just ONE station (with a much shorter than typical LMSL record) which seems to show an uptick around 1975 (but no subsequent increase). I found one other (with rough, sporadic data), where there was a large nearby earthquake in 1993, which hints at a coincident uptick. Also, Brest & Aberdeen (two of the longest records) show slight upticks in the late 1800s.

    But the great, great majority of tide gauge locations have recorded NO sustained increase in MSL trend, ever. See for yourself:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    (click on the location names to see NOAA’s graphs)

    If you look at the MSL graphs for the longest and most reliable tide gauge records, you cannot fail to notice that, even as CO2 emissions have soared, there has been no corresponding acceleration in MSL trend since the late 19th century — in direct contradiction of the IPCC’s claim that “coastal tide gauge measurements confirm” an accelerating rate MSL rise.

    All my code and data is available for download, along with simple instructions to make it easy for you to duplicate and verify the results:
    http://www.burtonsys.com/climate/whatif.html

    Andrew, you wrote, “you did… no analysis in any way” even after I’d already given you access to the code and spreadsheets which show how I analyzed the data! How can you just write nonsense like that when even a cursory skim of the material would tell you that it was nonsense??

    Here’s a brief summary of what I did to analyze the GLOSS-LTT tide station data:

    First, of course, I calculated the simple average. It is only about 0.6 mm/year, which is 1/3 of the IPCC’s claimed rate.

    Then I calculated the median. It is only about 1.1 mm/year — still less than 2/3 the IPCC’s claimed rate.

    So then I calculated a time-weighted average. In other words, suppose that, instead of weighting each tide station equally, we weight each tide station-year equally. That means we weight a tide station which was in operation for 100 years with twice the weight of a tide station that was in operation for just 50 years.

    Calculated that way, the average is just 0.5 mm/year.

    Next, I weighted the observations according to their distances from other stations, so that areas with larger numbers of stations would not over-influence the calculated global average.

    Note that Church & White (2006) apparently made some attempt at this. They wrote, “Where there are multiple records near a single satellite grid point, the changes in height at each time step were averaged.” But they gave no details of how this was done or what they considered “near.”

    To know what SHOULD be considered “near” it is necessary to know something about the granularity of the local effects which affect local mean sea level. First, I had to find the latitude/longitude data for all the GLOSS-LTT tide stations (which NOAA doesn’t list). Then I wrote a program to calculate the distances between tide stations, from their latitudes & longitudes. Then I analyzed the correlations between sea level trends and geographical distances between tide stations.

    I found that beyond a distance of about 800 km there is no discernable correlation, beyond about 400 km the correlation is slight, and below 400 km the correlation is approximately linear, approaching 1.0 at short distances.

    The distance-based weighting is based on a piecewise-linear approximation of the observed correlation. vs. distance.

    The distance-weighted average mean sea level trend turned out to be about the same as the median: 1.1 mm/year.

    I also combined the distance-weighted averaging with time-weighted averaging. The result was 1.1 mm/year.

    I also repeated the calculations after discarding varying numbers of outliers (the stations with the highest and lowest sea level trends). Every result was between 0.4 mm/year and 1.2 mm/year, and the distance-weighted averages were all between about 0.9 mm/year and 1.2 mm/year.

    I even tested a very broad range of different distance-weighting functions. The results varied from 0.6 mm/year to 1.2 mm/year, with all the reasonable and semi-reasonable weighting functions resulting in about 1.1 mm/year.

    Note that the code to enable you to easily reproduce all these calculations is all available for download on my web site. It has been tested under both Linux and Windows.

    The bottom line is that there simply is no avoiding the conclusion that the IPCC’s claimed 1.7 or 1.8 mm/year rate of MSL increase exaggerates the true global average rate of sea level increase by at least 50%.

    Comment by Dave Burton — 15 Mar 2010 @ 2:51 PM

  213. “Yes, energy usage and economic activity vary proportionately.”

    Really?

    So Virgin Islands is the most prosperous country in the world?

    Cool.

    Comment by Completely Fed Up — 15 Mar 2010 @ 3:00 PM

  214. Malthus would not have predicted the decline in birth rates in the developed countries either.

    Comment by J — 15 Mar 2010 @ 3:10 PM

  215. “Didactylos, may I suggest that you direct your criticism of the graphs to the good folks at NOAA.”

    If that were so, why did you not use their graph in your paper? Why did you go and use your own graphing?

    The NOAA graph shows a trend. You take the data and throw it about until it looks a mess and they proclaim that the data doesn’t show anything because it’s a mess.

    Comment by Completely Fed Up — 15 Mar 2010 @ 3:12 PM

  216. >>>>”So Virgin Islands is the most prosperous country in the world?”

    Perhaps they’re on the leading edge of figuring out how to increase economic activity dramatically without energy.

    Or perhaps that’s just silly.

    Comment by J — 15 Mar 2010 @ 3:23 PM

  217. Completely Fed Up wrote on 15 March 2010:

    >> “Didactylos, may I suggest that you direct your criticism of the graphs
    >> to the good folks at NOAA.”
    >
    > If that were so, why did you not use their graph in your paper? Why did
    > you go and use your own graphing?
    >
    > The NOAA graph shows a trend. You take the data and throw it about until
    > it looks a mess and they proclaim that the data doesn’t show anything
    > because it’s a mess.

    I have no idea what you’re talking about. I used NOAA’s graphs exclusively for the LMSL trends. The graphs I made were for things NOAA didn’t graph.

    I don’t know what “throw it about” means, either, but I certainly didn’t “proclaim that the data doesn’t show anything because it’s a mess.”

    Rather, what the data does very clearly DOES show is that global average mean sea level has been rising at less than 1.2 mm/year since the 1800′s, and shows no sign of accelerating.

    If there’s something you don’t understand, then just ask, and I’ll try to explain or clarify it.

    Dave Burton
    Cary, NC

    Comment by Dave Burton — 15 Mar 2010 @ 4:09 PM

  218. > Virgin Islands
    > energy use per capita

    Something grossly skews that — I vaguely recall this from something I read years ago.

    I think it’s so high because the Virgin Islands is the place a great many ocean shipping companies register their vessels, a “flag of convenience — so all the fuel consumed by their business is credited to the Virgin Islands (although the ships never stop there, and neither does the income from burning the fuel).

    It’s another argument for tracking carbon benefits, not just carbon burned.

    Comment by Hank Roberts — 15 Mar 2010 @ 4:14 PM

  219. 208, flxible: Isn’t per capita use more relevant? [~2008 ranks]:

    Relevant to what? Certainly Americans can cut petroleum use with little effect on total health and wealth, but the Chinese govt. will from now on dominate the international government-level discussions of policy, such as, What to do about AGW? What to do about Darfur? What to do about Iran? In discussions of civil liberties in Saudi Arabia, the US never had much influence, and now has none; Saudis will go to college in China, and buy their flying toys from China.

    Comment by Septic Matthew — 15 Mar 2010 @ 5:35 PM

  220. Sorry, Dave Burton. Further study of your site reveals you as a crank, and I know better than to waste time with cranks.

    I find it amusing, though, how you simply repeat yourself (using twice as many words) when any error is pointed out to you. Saying things all over again doesn’t add any weight to your argument, it just makes us conclude that you failed to understand the criticism.

    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.

    And with that, we must say goodbye.

    Comment by Didactylos — 15 Mar 2010 @ 6:46 PM

  221. Matthew – Relevent to the previous poster that reported that Chinese petro use had increased 28% …. not sure what the Saudis education has to do with the climate, but your apparent concern over the growing Chinese influence on the shape of your future is interesting – aren’t the Chinese also increasing non-fossil energy use rapidly?

    Hank@218 – Someone must stop there, because the US Virgins import AND export very large volumes of oil, producing none and using no other form of energy domestically.

    Comment by flxible — 15 Mar 2010 @ 8:03 PM

  222. #212 Dave Burton:

    Congratulations for actually doing the work, unlike many. You might even have spotted something important (the correlation distance; do you know some geostatistics?). But you’ll need to watch those sweeping statements (and confirmation bias?) if you want to be taken seriously.

    The bottom line is that there simply is no avoiding the conclusion that the IPCC’s claimed 1.7 or 1.8 mm/year rate of MSL increase exaggerates the true global average rate of sea level increase by at least 50%.

    No. What you actually found is that IPCC’s rate is inconsistent with your average of the NOAA tide gauge data. You found nothing about its consistency or otherwise with a “true global average”, which tide gauges cannot measure. (That is without model-based interpretation, which you disdain … rather foolishly, I think.)

    And on your website:

    The IPCC’s claim that “coastal tide gauge measurements confirm” an accelerating rate of MSL rise is nonsense.

    Yes, you did find that; possibly correctly. But “nonsense” seems unnecessarily loaded.

    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.

    Comment by GlenFergus — 15 Mar 2010 @ 8:49 PM

  223. Really Dave, anyone who couches criticism with this red flag: “How did the IPCC’s AGW alarmists get it so wildly wrong?”

    is not the sort of scientist where new revelations in science come from.

    Comment by Mark A. York — 15 Mar 2010 @ 10:26 PM

  224. From Flxable:

    “Isn’t per capita use [of fossil fuels] more relevant?”

    Absolutely not!

    This is the worst sort of statistical mumbo-jumbo one can come up with in regards to climate change. The atmosphere and oceans do not care one whit about per capita additions of GHG’s – they only respond to totals.

    If one person (group A) pours a ten gallon bucket of oil in a pond: per capita is ten gallons, total of ten gallons.

    If ten people (group B) each pour one gallon of oil into it: per capita is one gallon of oil, total of ten gallons.

    Hurray for group B! Or, maybe not. The pond isn’t effected by how many people put the ten gallons of oil in it, only the total.

    Now we can make this even more insidious, once we’ve established that per capita is the norm of measurement. Let’s get group C, which has 100 people in it. They pour only one half of a gallon of oil into the pond per person, making them much less polluting than either group A or B usign the per capita measurement.

    Except it’s 50 gallons in total.

    Who’s the worst polluter?

    Comment by Frank Giger — 16 Mar 2010 @ 12:35 AM

  225. “Response: What is your argument: that 10 meter rise is not worse than 3 meter rise, because in either case we are “doomed”? That may be true if you live on the Maldives, but not in most other parts of the world. It would seem a rather far-fetched justification for a do-nothing attitude. -stefan”

    First I understand that you recognize I’m right (which is not obvious for all readers of this thread) : if inertia is very long, then we cannot avoid a several meters rise of the sea level, whatever we do, even if we stopped now any carbon emission. I first think that it is must be clearly stated by people like you, who understand what a relaxation time is, which may not be the case of a general audience.

    So it should be clearly understood that, if your model is right, strongly reducing the amount of carbon we burn would NOT avoid a 10 meter rise, it would just limit it to 10 meters instead 20 or 30 meters. Now much obviously with a 10 meter rise there will be in any case a considerable change on coast lines and we’ll have to move anyway billions and people and hundred of cities. So one could really ask : since we have to move anyway, is it better to keep fossil fuels to do the move and go simply higher and farther in the land, or to stop using them and fight water with our hands? I have no easy answer, I think the debate is interesting.

    [Response: From my 2007 paper:

    Paleoclimatic data suggest that changes
    in the final equilibrium level may be very large:
    Sea level at the Last Glacial Maximum, about
    20,000 years ago, was 120 m lower than the
    current level, whereas global mean temperature
    was 4° to 7°C lower (5, 6). Three million years
    ago, during the Pliocene, the average climate
    was about 2° to 3°C warmer and sea level was
    25 to 35 m higher (7) than today’s values. These
    data suggest changes in sea level on the order of
    10 to 30 m per °C.

    I've stated many times in public (eg in most of my talks and in the book "Our threatened Oceans") that we're heading for many meters of sea level rise in the very long run. 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]

    Comment by Gilles — 16 Mar 2010 @ 2:33 AM

  226. This may be a foolish question, but I’ll risk asking it anyway. If you want to reply, please do so to me directly at huntjanin@aol.com to avoid troubling the experts.

    The question is this: at what point will developed nations REALLY BE FORCED TO DO SOMETHING about sea level rise? At l.5 meters, 2 meters, 3 meters, or what? In other words, at what point will the danger of doing nothing become so great that it overcome political inertia?

    [Response: A cynic might respond: never. We'll just switch from "not sure whether it is serious enough to do something" to "now it's too late to do something". -stefan]

    Comment by Hunt Janin — 16 Mar 2010 @ 4:21 AM

  227. “224
    Frank Giger says:
    16 March 2010 at 12:35 AM

    From Flxable:

    “Isn’t per capita use [of fossil fuels] more relevant?”

    Absolutely not!”

    Why then do you not explain why not?

    “The atmosphere and oceans do not care one whit about per capita additions of GHG’s – they only respond to totals.”

    But the totals come more from each USian than each Chinese. Therefore the greatest “bang for the buck” comes from the US changing their use.

    The bang-for-the-buck DOES depend on per capita.

    You just don’t want to think of that. Better to leave the US ahead, yes?

    “If one person (group A) pours a ten gallon bucket of oil in a pond: per capita is ten gallons, total of ten gallons.

    If ten people (group B) each pour one gallon of oil into it: per capita is one gallon of oil, total of ten gallons.”

    But if you arrest group A you fix the problem ten times easier than if you arrest group B.

    Comment by Completely Fed Up — 16 Mar 2010 @ 5:36 AM

  228. Thanks, Stefan.

    You may possibly remember that in the book (an introductory survey) I’m now writing on sea level rise, I want to speculate on the political, economic, military, and social effects such a rise may have in the distant future.

    I do realize that these topics are off-limits for this website but hereby invite anybody who has views on these effects to contact me directly at huntjanin@aol.com.

    Comment by Hunt Janin — 16 Mar 2010 @ 7:37 AM

  229. Fed up, I explained why per capita is a bad measurement quite well, I thought.

    Per capita has no bearing on totals to the environment. And it is total emissions that matter.

    Arresting Group A won’t save the pond. Groups B and C will see that the fish are all dead.

    But it will fit a political agenda.

    Comment by Frank Giger — 16 Mar 2010 @ 8:37 AM

  230. Stefan, thank you for your comment at my #193 post. The ‘sea level sensitivity’ that you introduce here has a value of 2.1 mm/year/degree when one uses the Church&White calculation, and 2.6 in your calculation. Now for a period of 90 years (2010-2100) this would mean for each degree of temperature rise a sea level rise of 19 or 23 cm, respectively. As you well know, the best estimates for temperature rise by 2100 in five of the six IPCC scenario’s are below or slightly above 3 degrees (the values are 1.8, 2.4, 2.4, 2.8, 3.4, 4.0). A 3 degree temperature increase by 2100 would then cause a total sea level rise of 57 cm (Church&White) or 69 cm. In this perspective, the 59 cm mentioned in the IPCC report is not implausibly low, in my opinion. Especially when you consider the trend values in temperature in the recent decades (approximately 0.16 degree per decade, by extrapolation this would yield only 1.4 degrees temperature rise by 2100).

    [Response: But now you're comparing the upper limit of the IPCC range to a central estimate for a moderate warming, based on a quadratic sea level fit rather than on the actual correlation with temperature ... what is the point? Just to justify a lower number? -stefan]

    Comment by wilt — 16 Mar 2010 @ 9:59 AM

  231. “229
    Frank Giger says:
    16 March 2010 at 8:37 AM

    Fed up, I explained why per capita is a bad measurement quite well, I thought.”

    “Absolutely not” is no explanation.

    “Per capita has no bearing on totals to the environment.”

    But it has everything to do with how to solve the totals to the environment.

    In no ways is it “absolutely not!”.

    Comment by Completely Fed Up — 16 Mar 2010 @ 10:28 AM

  232. Frank Giger,
    I agree that simple per capita measurement can be misleading and that total emissions are what matters. However, I think that in a country with high consumption per capita has more opportunity for reduction, and if that is successful, then high-population, low per capita countries could also adopt the strategies.

    For once, people are going to have to realize that everyone’s actions matter. China’s efficiency gain is ours and vice versa. It is quite the opposite of a zero sum game.

    Comment by Ray Ladbury — 16 Mar 2010 @ 11:07 AM

  233. Frank Giger@224 “Who’s the worst polluter?”
    The problem with your examples Frank, is that in the real world the “group oil dumped” is not equal. Fast math = the Chinese percapita [~0.006 bbls/person/day - total= ~7.5million bbls/day] would have to go up 10+ times to match that of the US [~0.07 bbls/person/day or ~21million bbls/day]. I entirely agree that the planet doesn’t care where it comes from, but your vehemence looks like the US cry “why should I cut back if they don’t”. We need to lean it out as much as possible as fast as possible, the highest percapita is where the most “fat” is, which also happens to be where the technology should be affordable and available, social circumstances do count.

    Note I was responding to the comment that China has recently had a 28% increase in oil consumption, which isn’t a good thing but, is that really more significant [0.006->0.008 or 7.5->9.5million] than say a 28% decrease in the US [0.07->0.05 or 21->15million]? We’re still dumping 10 times more into the pond. It seems to me their increase was as much due to their production of export goods as anything else – you’re right, global is global, but there are definitely some regions that can affect change faster than others and the fastest way to cut Chinas emissions is for the West to stop importing so much [disposable] production from them, meaning for the US to drastically cut consumption of all kinds.

    Also re the over the top consumption of the Virgin Islands, I haven’t explored that, but as that’s actually part of the US economy [US$ is the currency, even in the British Virgins], likely all the oil that gets imported there than moved on to elsewhere should actually be chalked up to the US [probably trans shipped to US refineries, but I think it’s being credited to “the Virgin Islands”.

    Comment by flxible — 16 Mar 2010 @ 11:12 AM

  234. So one could really ask : since we have to move anyway, is it better to keep fossil fuels to do the move and go simply higher and farther in the land, or to stop using them and fight water with our hands? – Gilles

    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.)

    Comment by Nick Gotts — 16 Mar 2010 @ 11:24 AM

  235. If everyone hasn’t seen it already, read the Feb. 12th Item, in Science, about the study of Calcite Formations in Mallorcan Sea-Caves.
    They have convincing proof that, at ~ 82 kya, the Seas were at least a Meter higher then, than they are now; though Atmospheric CO2 was not even close to the levels it is now.
    I’ve tried to plot the Milankovich Cycles for that date – as the Authors did not care to address the why of their findings – but I don’t have a good enough graph to plot the time period accurately enough.
    Oh! I bet Real Climate has, don’t you? I’ll look!
    BTW: I think the Toba Eruption may be responsible for the subsequent return to Ice Age Conditions, after this MIS 5a Sea Level Peak.

    [Response: What makes one local paleo data point "convincing proof" to you? -stefan]

    Comment by James Staples — 16 Mar 2010 @ 1:40 PM

  236. The truth is that the Chinese are putting more GHG’s into the atmosphere as a total than the USA is.

    Per capita matters little when one is talking about climate change threats; only the totals matter to the system.

    Similarly, growth in Chinese emissions isn’t just oil use. Like in the USA, its coal fired power plants that represent the bulk. And they’re building them like there is no tomorrow.

    That is mutually exclusive from saying the USA shouldn’t reduce emissions. There’s no whiney “but they’re doing it, too!” in pointing out the fact that per capita emissions is a false indicator of “greenish” behavior.

    Indeed, the argument has been turned on its head; those countries with high populations and emerging industrialization have used it as cover to mask total emissions for political (and financial) gain.

    The disturbing trend is that the outsourcing of emissions and pollution to the Chinese by way of manufacturing relocation from the USA is just about at the maximum level; globalization has worked in that the domestic Chinese market is now producing for its own consumers, and will increasingly do so. They’re even outsourcing their own manufacturing to Vietnam and other countries.

    On the Virgin Islands – it’s outsourcing of GHG’s by way of a humongerous oil refinery there that’s skewing the numbers. Puerto Rico, for example, gets zero GHG credit (or debit, depending on outlook) for refining crude into gasoline and diesel, since its done for them on St. Croix.

    The sad thing is we know how to do targeted, regionalized cap-and-trade; heck, we did it within the largest single CO2 emitting industry within the USA with regards to mercury and sulfur to mitigate acid rain. Even as one of those evil Republicans I can get behind making the industry responsible for some 40% of the nation’s CO2 emissions more efficient and less polluting. Bushels full of carrots by way of tax credits to go with it as well – and fat bonuses to execs be damned, what matters is cleaner (or even phased out) plants.

    Comment by Frank Giger — 16 Mar 2010 @ 1:51 PM

  237. 232, Ray Ladbury: China’s efficiency gain is ours and vice versa. It is quite the opposite of a zero sum game.

    That’s worth repeating and remembering. Economics is usually a positive sum game, and war is usually a negative sum game (first side to 0 loses to the side that remains positive, though there may be tremendous productivity at some points during the war, as with US, Germany and USSR in WWII.)

    China is worth thinking about in detail as they simultaneously work on: increasing CO2 output, increase CO2 sequestration, increase efficiency, and increase generation from renewable and nuclear sources.

    Comment by Septic Matthew — 16 Mar 2010 @ 2:25 PM

  238. 221, flxible: Matthew – Relevent to the previous poster that reported that Chinese petro use had increased 28% …. not sure what the Saudis education has to do with the climate, but your apparent concern over the growing Chinese influence on the shape of your future is interesting – aren’t the Chinese also increasing non-fossil energy use rapidly?

    The bit about Saudi education is off on a tangent, but the point about diminished US influence in the oil markets is relevant to any discussion about what the US and EU might attempt to achieve by any international energy/climate/other settlements that might require Chinese cooperation.

    As to your question, the totality and complexity of current Chinese development is astonishing, and not easy to address in a few short notes. Forecasts vary, but China will probably start to reduce its CO2 emission in the era of 2030 – 2060. That’s if “the present trends” continue. And if those same “present trends” continue, China will be producing more CO2 per year by the time of the decline than the whole anthropogenic world does now.

    And ironically, the carbon-intensive industries in China have been financed in part by CO2 offsets paid by EU companies. Another irony is that 500,000 Chinese work in Africa, but they leave the local governments in power so they are not stigmatized by the label “colonists”, so no one objects.

    These considerations are far afield of the science of AGW, but once we venture into politics and policy (e.g. the Copenhagen meetings and other meetings; “risk management”) they become important.

    Comment by Septic Matthew — 16 Mar 2010 @ 2:45 PM

  239. You know, I went to the Virgin Islands, but I couldn’t find any…
    Okay, I’ll shut up.

    Comment by Barton Paul Levenson — 16 Mar 2010 @ 3:01 PM

  240. What’s the math?

    If China and India continue their CO2 growth, what percentage decrease would be required of the US to cause a valuable decrease in temps?

    Or, if the CO2 production of the US went to zero what would be the temp decrease over say 50-100 years?

    Comment by J — 16 Mar 2010 @ 3:16 PM

  241. Total CO2 emissions from China, with 5 times the population, are about 1% higher than those of the US. In order for China to decline to the global per capita level they would have to reduce by under 5% – in order for the US to decline to that same average, it will have to reduce per capita by 78%, how many are willing to do their share? [and I notice on the list that the US Virgin Islands are included in the US figure]. Denying the inordinately large contribution of the developed world to the problem is where the political and financial gain is being covered up, lets look at getting our house in order, capping and trading will only shovel more money under the CO2 blanket.

    Comment by flxible — 16 Mar 2010 @ 7:09 PM

  242. Cliff Ollier has published a strongly worded critique of the view that rapid ice-sheet movement is occuring or will occur in response to a warming climate. I have no expertise in this field, nor a strong commitment to any view here – except that good science is paramount and intemperate language (which Ollier uses) unhelpful. It is particularly striking because it is published in Geoscientist – the magazine of the Geological Society of London – and thus carries considerable weight.

    Would anyone care to comment? Yo will find the piece here http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/page7209.html

    [Response: "Strongly worded critique" indeed. I would have said "Snarkily-worded diatribe". Isn't it obvious from the tone of the article that Chris Ollier has more words than wisdom? In any case, however much of an idiot Ollier may or may not be, his essay stands (or rather, falls) by itself.

    Here's a typical phrase: "glaciers do not slide on their bellies, lubricated by meltwater." Umm. No. Basal sliding is well observed phenomenon, if not completely well understood. Ollier seems to think old references carry more weight, so he might try reading Weertman, 1957, On the sliding of glaciers. Journal of Glaciology, 3(21), 33–38.

    Here's another 'scientific-sounding' phrase from Ollier: "glaciers are pushed by the weight of the glacier, not sucked by the calving at the ice front." Sounds good, doesn't it? My response to this is F=Ma. Try reading this: Evolving Force Balance at Columbia Glacier, Alaska, During it Rapid Retreat, by S. O'Neel, W.T. Pfeffer, R.M. Krimmel, and M.F. Meier (JGR Earth Surface, Vol 110, F03012, doi:10.1029/2005JF000292, 2005), which is available on line here.

    Bottom line: Ollier's article is complete and total B.S.

    --eric ]

    Comment by David Jordan — 17 Mar 2010 @ 8:51 AM

  243. “It is particularly striking because it is published in Geoscientist – the magazine of the Geological Society of London – and thus carries considerable weight.”

    Geology isn’t climatology.

    Don’t assume. Check.

    Comment by Completely Fed Up — 17 Mar 2010 @ 9:04 AM

  244. “The truth is that the Chinese are putting more GHG’s into the atmosphere as a total than the USA is.”

    The truth is that the US can easily reduce CO2 production by 40%. China would find it much more difficult.

    The truth is that the US is the low-hanging-fruit in mitigation.

    The truth is that the US now has the opportunity of putting their money where their mouth is on their aspiration to “Leader of the Free World”.

    So Lead, already.

    Comment by Completely Fed Up — 17 Mar 2010 @ 9:07 AM

  245. I’m pleased to see that the online Letters page ( http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/letters ) contains two replies which take issue with Olliers’ view. But it does seem surprising that a body as significant as the GeolSoc would publish such a piece without caveats.

    Comment by David Jordan — 17 Mar 2010 @ 9:53 AM

  246. I’m aware that Geology isn’t Climatology, CFU, and I don’t really understand what you think I’m assuming or what I should be checking. Given that the GeolSoc is one of the principal voices of Geologists in the UK (including Quaternary Geologists who often do know something about glaciers) and that its views carry weight across the environmental sciences, I am simply expressing concern that such an article would have got through its editors.

    Comment by David Jordan — 17 Mar 2010 @ 9:58 AM

  247. David Jordan:

    The piece is aptly named, though. Quite how or why such nonsense got published, I cannot divine. I lost count of the times it used the term “alarmist”. No doubt they think it’s okay to publish opinion in the interest of selling more subscriptions to outraged readers…. I hope it backfires.

    “Glaciers – science and nonsense”. Lots of nonsense, very little science. I’m not an expert, and even I can detect the nonsense. Such condescending tripe about Archimedes’ principle, and that idiotic strawman about Vostok.

    Why is a soil scientist and volcanologist spouting off about glaciers, and exhibiting painful ignorance while doing so?

    Comment by Didactylos — 17 Mar 2010 @ 11:25 AM

  248. “246
    David Jordan says:
    17 March 2010 at 9:58 AM

    I’m aware that Geology isn’t Climatology, CFU, and I don’t really understand what you think I’m assuming or what I should be checking”

    You’re positing that that discussion was in a geology journal and therefore important for climate science.

    This indicates that you consider geology to be climate science.

    You posit that just because it appears in a presigious place for geology (guess where most of the money for geology majors comes from, by the way), that this gives gravitas to the discussion.

    This indicates that you consider prestige in geology equates to prestige in climate science.

    You assert that the discussion is a killer argument.

    But that is based on your misapprehension that geology is the same as climate science.

    You didn’t check.

    [Response: Give the guy a break. He was just asking about an article. I gave him a solid and helpful answer. Can't we leave it at that, folks?--eric]

    Comment by Completely Fed Up — 17 Mar 2010 @ 11:27 AM

  249. Use that “edit” tool, Eric!
    http://www.cartoonstock.com/newscartoons/cartoonists/amc/lowres/amcn39l.jpg

    There are some good thoughtful letters at the geology site; one writes:

    — excerpt follows —
    As geoscientists, I think we owe it to ourselves, and to those we interact with, to be well-informed about humanity’s ability to influence the global climate. However, I suspect that many non-academic geoscientists like myself, who do not have the time or resources to read deeply into the literature, are at little advantage over journalists and others who seek to interpret climate science to the public and our elected representatives. I wish I could sustain an informed critique of those who criticise the ‘consensus’ predictions of the Intergovernmental Panel on Climate Change (IPCC) as being either exaggerated or too conservative, but I cannot (not in detail, anyway; and it’s the details that some of the ‘sceptics’ tend to focus on)…. So what is to be done?

    … I think the Geological Society should remind Fellows of their ethical duties as scientists to avoid making deliberately misleading statements about climate science (or indeed any other type of science), driven by non-scientific (e.g. political) agendas. The Society has, after all, seen it necessary to produce a Position Statement repudiating “Creation Science (attempts by Young Earth Creationists to gain acceptance for what they misrepresent in public as corroborative empirical evidence for their view)” as “a trespass upon the domain of science”. I do not think it is stretching a point to see the tactics of some seemingly scientific deniers of anthropogenic climate change as being akin to (albeit more sophisticated than) those of ‘creation scientists’.
    — end excerpt —

    Comment by Hank Roberts — 17 Mar 2010 @ 12:12 PM

  250. Stefan, thanks again for your comment, this time relating to my #230 post. You wrote: “But now you’re comparing the upper limit of the IPCC range to a central estimate for a moderate warming, based on a quadratic sea level fit rather than on the actual correlation with temperature … what is the point? Just to justify a lower number?“

    I am not searching for low numbers, but I am trying to find out what projection would be fitting best to the observations from say the last 150 years.
    I have used the quadratic sea level fit following the remarks that you made earlier (#155 and #193) about the Church&White article, and the ‘sea level sensitivity’ based upon their conclusions. I then assumed a 3 degrees temperature rise by 2100. The result would then be approximately 60 cm sea level rise in total.
    Now you call the chosen value of 3 degrees ‘moderate warming’, but I may remind you that 3 degrees is well above the median value (2.6) of best estimates from all six IPCC scenario’s. In my terminology a modest warming would be 1 to 2 degrees. Using the approach described here one can only project a sea level rise of 1 meter or more during this century by supposing that the temperature increase by 2100 will be 5 or 6 degrees Celsius. One can have different opinions on whether that is a realistic temperature scenario. Such values are at the upper limit of the upper limit IPCC scenario’s.

    Comment by wilt — 17 Mar 2010 @ 1:20 PM

  251. 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.

    Comment by Hunt Janin — 17 Mar 2010 @ 2:05 PM

  252. > 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?

    Comment by Hank Roberts — 17 Mar 2010 @ 2:23 PM

  253. 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

    Comment by Hank Roberts — 17 Mar 2010 @ 2:29 PM

  254. 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!

    Comment by David Jordan — 17 Mar 2010 @ 3:09 PM

  255. > 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?

    Comment by Hank Roberts — 17 Mar 2010 @ 3:58 PM

  256. 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.

    Comment by Brian Dodge — 17 Mar 2010 @ 10:37 PM

  257. “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.

    Comment by Gilles — 18 Mar 2010 @ 1:00 AM

  258. 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).

    Comment by Gilles — 18 Mar 2010 @ 1:03 AM

  259. “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]

    Comment by Completely Fed Up — 18 Mar 2010 @ 3:45 AM

  260. “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.

    Comment by Completely Fed Up — 18 Mar 2010 @ 3:55 AM

  261. 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.

    Comment by wilt — 18 Mar 2010 @ 5:58 AM

  262. 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.

    Comment by Completely Fed Up — 18 Mar 2010 @ 6:53 AM

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

    Comment by Hunt Janin — 18 Mar 2010 @ 7:24 AM

  264. 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

    Comment by David Kidd — 18 Mar 2010 @ 8:44 AM

  265. 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?

    Comment by Hunt Janin — 18 Mar 2010 @ 9:42 AM

  266. 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.

    Comment by flxible — 18 Mar 2010 @ 10:33 AM

  267. “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.

    Comment by Completely Fed Up — 18 Mar 2010 @ 11:38 AM

  268. 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?

    Comment by Hunt Janin — 18 Mar 2010 @ 1:24 PM

  269. For Hunt Jain:
    http://www.google.com/search?q=US+Department+of+Defense+climate+change+sea+level
    Try the first hit the search gives you.

    Comment by Hank Roberts — 18 Mar 2010 @ 1:38 PM

  270. 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.

    Comment by wilt — 18 Mar 2010 @ 3:48 PM

  271. 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?

    Comment by Hunt Janin — 19 Mar 2010 @ 7:59 AM

  272. 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.

    Comment by wilt — 19 Mar 2010 @ 8:48 AM

  273. 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.

    Comment by Hank Roberts — 19 Mar 2010 @ 10:38 AM

  274. “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.

    Comment by Completely Fed Up — 19 Mar 2010 @ 10:44 AM

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

    Comment by Hunt Janin — 19 Mar 2010 @ 10:56 AM

  276. 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.

    Comment by Hunt Janin — 19 Mar 2010 @ 11:39 AM

  277. 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.

    Comment by wilt — 19 Mar 2010 @ 12:27 PM

  278. 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.

    Comment by Completely Fed Up — 19 Mar 2010 @ 1:06 PM

  279. 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]

    Comment by Adrian O — 19 Mar 2010 @ 9:15 PM

  280. 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

    Comment by Dave Burton — 20 Mar 2010 @ 2:38 AM

  281. 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.

    Comment by Hunt Janin — 20 Mar 2010 @ 4:27 AM

  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!

    Comment by Barton Paul Levenson — 20 Mar 2010 @ 4:59 AM

  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.

    Comment by Barton Paul Levenson — 20 Mar 2010 @ 5:01 AM

  284. > 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!

    Comment by Hank Roberts — 20 Mar 2010 @ 5:57 PM

  285. 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.

    Comment by Mark A. York — 20 Mar 2010 @ 10:31 PM

  286. 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 ;-)

    Comment by wilt — 21 Mar 2010 @ 7:57 AM

  287. 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.

    Comment by Martin Vermeer — 21 Mar 2010 @ 11:31 AM

  288. 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?

    Comment by don — 21 Mar 2010 @ 11:31 PM

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

    Comment by Martin Vermeer — 22 Mar 2010 @ 1:30 AM

  290. 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?

    Comment by Hunt Janin — 22 Mar 2010 @ 4:28 AM

  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?

    Comment by Barton Paul Levenson — 22 Mar 2010 @ 5:42 AM

  292. 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…

    Comment by Martin Vermeer — 22 Mar 2010 @ 8:56 AM

  293. > 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

    Comment by Hank Roberts — 22 Mar 2010 @ 9:29 AM

  294. 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.

    Comment by Hunt Janin — 22 Mar 2010 @ 10:38 AM

  295. 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.

    Comment by JD — 24 Mar 2010 @ 3:03 PM

  296. 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?

    Comment by Hunt Janin — 26 Mar 2010 @ 10:12 AM

  297. 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/

    Comment by Anonymous Coward — 26 Mar 2010 @ 3:11 PM

  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.

    Comment by Nicolas Nierenberg — 30 Mar 2010 @ 10:52 AM

  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.

    Comment by Nicolas Nierenberg — 30 Mar 2010 @ 5:13 PM

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

    Comment by Hunt Janin — 1 Apr 2010 @ 3:30 AM

  301. Martin Vermeer #287, from your confusion it sounds like you haven’t looked at the tide gauge records yourself. May I make a suggestion:

    1. Go to my augmented version of NOAA’s GLOSS-LTT tide gauge table, here:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html

    2. Click on the “Year Range” column header. That will sort the list of tide stations according to the number of years they’ve been in operation.

    3. PgDn to the bottom of the table, to view the tide gauges which have been in operation the longest. (Over 40 of them have been in operation for more then 100 years.)

    4. Click on the station names for these stations to view the Mean Sea Level trend graph for each station.

    5. For each graph, look at the X-axis, and find 1993. Now look at the graph, and see if you can see an uptick of at least +1.2 mm/year starting about then.

    It just isn’t there. The ONLY visible uptick in MSL trend was in the late 1800s. That is true even though CO2 emissions have really taken off, starting in the middle of the 20th century.

    Note that 1.2 mm/year from 1993 to 2006 would add up to 13 x 1.2 = 15.6 mm (1.56 cm, or 0.0156 m). That amount of change would be hard to see at a location like Cuxhaven, Germany, or Helsinki, Finland, where there’s a lot of apparently-random fluctuation in sea level (“noise”). But some other stations, like Sydney and Townsville, Australia, and Korsor, Denmark, have a little enough year-to-year fluctuation that an increase of that magnitude would be noticeable. It just isn’t there.

    Moreover, recall that atmospheric CO2 levels started increasing rather dramatically starting in the 1950s, and global temperatures rose significantly starting in the mid-1970s, and are still not far from their peak of a decade or so ago. So if anthropogenic CO2 causes sea level rise, sea levels should have been rising at an increased rate for quite some time — for at least 30 years, if not more — not just since 1993. So where is the increase?? It just isn’t there.

    I encourage you to take a half hour and just click on the station names, and view the graphs. Look for the uptick.

    In the oldest tide stations you can see an uptick in the late 19th century, but where is the uptick in the 20th? It’s just not there.

    Well, there is one station, with a short tide gauge record, which seems to show a (unique) uptick (perhaps due to well drilling). But the stations with the longest and best data don’t show any 20th century increase in rate of MSL rise.

    Remember, the eustatic (global average) sea level trend is added to local factors, worldwide. So if it changes, it should change everywhere, and be noticeable everywhere that the “noise” isn’t too high. It just isn’t.

    Even Church & White (2006), who claim to have detected a slight 20th century acceleration in rate of MSL rise (0.008 ± 0.008 mm yr-yr), admit that “no 20th century acceleration has previously been detected” by other researchers. What’s more, they claim that the bulk of the acceleration which they detected occurred around 1930(!!). That immediately brings to mind a few questions:

    1. Note that the low end of their Confidence Interval is exactly zero. In other words, even Church & White (the researchers who are most confident that there has actually been an acceleration in MSL rise, cannot quite say with 95% confidence that there has been any acceleration of MSL rise during the 20th century. So why is the RC crowd so confident that there has been? Could it be confirmation bias at work?

    2. Why 1930? Worldwide human CO2 emissions were still low then; they didn’t really take off for another 20 or 30 years. So, even if C&W are right, how would an acceleration which (might have) occurred around 1930 in any way confirmation that increased emissions of anthropogenic CO2 cause increased sea level rise?

    3. If there really was a substantial uptick in rate of MSL rise around 1930 (rather than 1993), then WHERE IS IT IN THE TIDE STATION GRAPHS? Surely in the subsequent 75 years we should be able to see it in the longest tide gauge records, if it were really there? 0.008 mm/yr^2 for 75 years would add up to a difference of 0.6 mm/yr. For many tide stations, that represents a doubling or more of their MSL trend. So look at the graphs. Which ones show a rate of MSL rise at the end of the graph which 0.6 mm/yr higher than in 1930? (Good luck finding them!)

    4. If the amount of acceleration in MSL trend during the 20th century, when CO2 emissions soared, was so low that we can’t see it in the graphs, even after 75 years, then why on earth would we fret that it might become catastrophically large over the next 90 years? Even using C&W’s acceleration figure of 0.008 mm/yr^2, that would only add 0.72 mm/yr to the rate of annual MSL rise by 2010 — a near negligible amount.

    Hunt Janin #296 wrote, “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.”

    A better guess is 5-20 cm. (10 cm if the current rate of 1.1 mm/yr continues; 20 cm if it doubles; 5 cm if it halves.)

    Of course, I’m talking about a global average. Some locations will see much larger increases, and others will see declines in sea level.

    -Dave

    Comment by Dave Burton — 2 Apr 2010 @ 7:06 PM

  302. “A better guess is 5-20 cm. (10 cm if the current rate of 1.1 mm/yr continues; 20 cm if it doubles; 5 cm if it halves.)”

    A better guess would be 80-200cm.

    Comment by Completely Fed Up — 7 Apr 2010 @ 5:10 AM

  303. First, I need to make a typo correction (#301):

    I wrote:
    “…over the next 90 years? Even using C&W’s acceleration figure of 0.008 mm/yr^2, that would only add 0.72 mm/yr to the rate of annual MSL rise by 2010 — a near negligible amount.”

    That should have been:
    “…over the next 90 years? Even using C&W’s acceleration figure of 0.008 mm/yr^2, that would only add 0.72 mm/yr to the rate of annual MSL rise by 2100 — a near negligible amount.”

    Please forgive the mistake!
     

    Second, despite the report of acceleration in Church & White (2006), there’s a very good reason to expect that sea level rise will not accelerate at 0.008 mm/yr^2 over the next 90 years. The reason is that (according to their latest data) it hasn’t done so over the last 90 years.

    In fact, according to Church & White’s latest data and methodology, the rate of sea level rise actually decelerated at 0.006 mm/yr^2 over the last 90 years for which they have data (1917 to 2007).

    C&W’s methodology for calculating the acceleration is simple. They plot the data, and fit a quadratic curve to it. The acceleration is twice the quadratic coefficient.

    Microsoft Excel can fit quadratics. So I downloaded C&W’s latest data, loaded it into Excel, selected the last 90 years, generated an Excel X-Y “chart,” and fitted a quadratic “trendline” to it. Here’s the graph; click on it to load the spreadsheet. As you can see, the quadratic term is negative, which indicates deceleration:

    Of course, -0.0062 mm/yr^2 is a very small deceleration. If continued for 90 years, it would amount to a decline in rate of global mean sea level rise of only about 0.56 mm/yr. (Likewise, C&W’s reported +0.008 mm/yr^2 20th century acceleration is also very small.)

    Now, I’m not claiming that the rate of sea level rise is actually decelerating. It is possible to cherry-pick starting points to show either acceleration or deceleration of sea level rise during the last century, using Church & White’s data and method. For instance, using 1940 as the starting year shows deceleration, and using 1950 as the starting year shows acceleration. Likewise, choosing the last 100 years (1907 to 2007) yields a very small acceleration, and choosing the last 95 years (1912 to 2007) yields a very small deceleration (though in both cases the amount is so tiny that the quadratic curve appears to be perfectly straight).

    The truth is that the tide gauge data for mean sea level for the last century is simply a straight line plus noise. There simply has been no measurable sustained acceleration or deceleration, regardless of whether you analyze the GMSL-LTT tide gauges (individually or averaged), or Church & White’s latest data.

    However, I have real concerns about the reliability of C&W’s “corrected” data. It indicates a linear trend which is substantially higher than that which the GLOSS-LTT tide gauges show. The reason is probably given in this remarkable admission in paragraph 5 of their paper:

    “An additional spatially uniform field is included in the reconstruction to represent changes in GMSL. Omitting this field results in a much smaller rate of GMSL rise…”

    In other words, they added an ad hoc fudge factor! They didn’t directly say whether that “correction” in rate of GMSL rise was temporally uniform, but if so then it would affect only the linear trend, not the quadratic coefficient. Still, I’d like to know exactly how they processed the data before I completely trust it, even for calculating acceleration & deceleration.

    Dave

    Comment by Dave Burton — 9 Apr 2010 @ 10:33 PM

  304. Well, it appears that I can’t embed images in my comments. So to see the graph of Church & White’s last 90 years of Global Mean Sea Levels, with the Excel-generated quadratic curve fit to it showing deceleration, click here:
    http://i831.photobucket.com/albums/zz231/ncdave4life/church_white_1917-2007_trimmed-1.gif

    To download the spreadsheet, click here:
    http://www.burtonsys.com/climate/church_white_2009_gmsl_90yr.xls

    Dave

    Comment by Dave Burton — 9 Apr 2010 @ 10:39 PM

  305. Another typo correction:

    “GMSL-LTT” should be “GLOSS-LTT” (of course).

    Dave

    Comment by Dave Burton — 9 Apr 2010 @ 10:53 PM

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