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  1. By how much would sea levels need to rise before coastal dwellers are adversley effected I wonder?

    Incidently even with large scale warming it is doubtful that Greenland and Antartica will disapperar completeley, come 2150 or 2200 we may see 2 to 3 meters of sea level rise?

    Comment by pete best — 27 Mar 2007 @ 12:53 PM

  2. Since this is in centimetres could you juxtapose these figures with any level of uncertainty with the 20 feet rise should Greenland and the WAIS both melt? I watched Lomborg testify in Congress and this was the one point he made of Gore’s film where he claimed it was false beyond any doubt.

    [Response: Greenland ice is good for 7 metres and the WAIS for 6 metres of sea level rise. 20 feet is about 6 metres so either ice sheet alone, or half of each, could lead to a 20 feet rise. -stefan]

    Comment by Mark A. York — 27 Mar 2007 @ 1:02 PM

  3. [The main conclusion of this analysis is that sea level uncertainty is not smaller now than it was at the time of the TAR, and that quoting the 18-59 cm range of sea level rise, as many media articles have done, is not telling the full story. 59 cm is unfortunately not the "worst case".]

    Worse case, in my view, is not the high range of sea level rise….it is merely the fact the rise will continue rising and there is no possibility for the sea rise to retreat….not in centuries or longer.

    Comment by John L. McCormick — 27 Mar 2007 @ 1:02 PM

  4. Yesterday afternoon (3/26/07) I attended a public workshop on “Rapid Changes in Ice Sheet Mass Balance” organized by the US Climate Change Science Program. The people giving presentations, who know ice as well as anyone, made a clear case not only that we have little understanding of ice dynamics, but that (as one of them put it) the main sources of uncertainty in the models are all in the direction of underestimation of the sensitivity of ice sheets to a temperature rise. But then the IPCC didn’t model ice dynamics anyway, they just assumed that nothing different could happen. I think it would be hard to find anyone familiar with the subject who thinks the IPCC upper bounds are a good guide for policy makers… What were they thinking of?

    [Response: One of the reasons this stuff wasn't included in detail in the IPCC report is that it is all pretty new. Anythinig included in the report has to have stood the test of time, at least a bit. The rule was anything cited had to be in press by May 2006. Many of the important papers postdate that. All this goes to show that IPCC is for the most part, conservative. That's how science works, contrary to what the "skeptics" claim.--eric]

    Comment by Spencer Weart — 27 Mar 2007 @ 1:24 PM

  5. C’mon you guys! This is funny.
    Nobody can even predict who will win the NCAA B-Ball tournament with any reasonable certainty!
    And now some number crunchers with dubious models and no real understanding yet as to how the climate really works are telling us what the climate will be like in a 100 years? There are so many events that could happen between now and then to change everything.
    But hey, if we’re going to play this game, then here’s my prediction: global temperature will be 0.28°C colder than today and sea levels will be 93.7 mm higher. I’ll spare you my 5 other scenarios. Michael Crichton is right, an informed guess is just a guess.

    Comment by Pierre Gosselin — 27 Mar 2007 @ 1:57 PM

  6. Thank you very much Stefan for this clarification! I think the point you mentioned about the riskassessment ist very importand for people who have to decide about the security of costal homelands for the next centuries. They should always take into consideration the worst case scenario and not only what is allowed for policymakers to read. The next point I appreciate are the graphs you presented. If the measured data are really at the upper end of the past predictions – this should alert everybody who has to deal with these issues.

    Comment by Andreas Mueller — 27 Mar 2007 @ 2:15 PM

  7. Nice article.

    George Kukla states, that increasing temperature will lead to increased snow precipitation and snow gains will offset the sea level rise – he warns of coming ice age ;-). He apparently did not change his mind since 1970-ties…

    Considering the carbon-cycle feedback, some models (e.g. Cox et al.) estimate large positive vegetation feedback (increased soil respiration, lower photosynthesis due to increased vegetation stress, increased fire frequency…) and some of the most extreme scenarios predict the CO2 concentration to be up to 980 ppm. This is what I call catastrophe…

    Hmm – 6C rise in global temperature – i think we are in trouble even with the rise of 3C…

    Mark Serreze in his latest article in Journal Science states, that complete summer ice melt in Arctica is increasingly probable – in fact it is only matter of time, when it will happen. We know, that Arctic is melting quite rapidly. Antarctica is melting much slower, if at all. My question is:

    Do we know from from paleoclimatology, that we can have a climate state, in which there is *no* summer ice in the North pole, while the South pole “is ok”?

    I think this would create a bit of thermal imbalance in the climate and also would mean large changes in the weather pattern, which would *not* be limited only in the arctic region…

    I just wonder, what we tell our children, if they will ask what were we doing, when we were aware of this possibility…

    Comment by Alexander Ac — 27 Mar 2007 @ 2:23 PM

  8. Off topic comment, but I do not know where else to have this question asnswred (if anyone could kindly direct me, I would appreciate it). I’ve been chatting with a denialist, who insists that a big reason he does not “believe” in anthropogenic climate change is because “ice cores going back thousands of years cannot tell temperatures or CO2 levels when the temperature was too warm for ice formation.” ie. Perhaps a sudden, rapid spike in CO2 levels and global temperature like we are now experiencing hashappened in the past, naturally, but we are not aware of it because no ice cores exist to tell us. Now I know this is a stupid argument anyway (“a 30% increase in human CO2 and a corresponding rise in temperature are not linked, because we don’t know that it can’t happen naturally”) but I was wondering if he was at least right about the ice core data. Thanks!

    Comment by Mike — 27 Mar 2007 @ 2:24 PM

  9. Re#1
    Dear Andreas,

    I think, that the upper limit of sea level rise should alert *everybody*, because in the end, we *all* deal with this planet ;-)
    Or where do You think the people from coastal ares will go? :-)

    Comment by Alexander Ac — 27 Mar 2007 @ 2:27 PM

  10. Can anyone shed any more light on this press release from last June which claims that Arctic average sea level appears to be falling?

    http://www.nerc.ac.uk/press/briefings/2006/arctic.asp

    Comment by Nick Riley — 27 Mar 2007 @ 2:30 PM

  11. For what it’s worth, I’ve had an insightful flash into how to stop global warming. According to Lilo, Pudge, a fish off the coast of Kauai, controls the weather. If we can keep him in peanut butter sandwiches, everything will be under control.

    Comment by Barton Paul Levenson — 27 Mar 2007 @ 2:31 PM

  12. Re 3 (Nick Riley). What’s interesting is that this is presented as ‘something strange that needs explaining’ – both by NERC and the BBC (as linked). There is no suggestion that it could indicate global warming scares are exagerated. If this study had shown that the Arctic sea level was rising more rapidly than elsewhere, this would have been headlined as further dramatic proof of impending doom. Its true that id does not disprove AGW. But it supports the case that all pieces of ‘evidence’ need to be considered with caution.

    Comment by PHE — 27 Mar 2007 @ 2:43 PM

  13. Nick, you can read the abstract. It’s a first effort at digging info out of data, making corrections, and modeling what they think may be happening:

    http://www.agu.org/cgi-bin/wais?ff=G21A-02

    “… to determine Arctic sea level change …. is not an easy feat, as the ice cover obstructs the view of part of the sea surface and affects the measurements in mixed ocean/sea-ice conditions. Thus considerable effort has been put in the separation of the radar returns from leads and from sea ice. Moreover, microwave radiometer measurements of wet tropospheric delay can not be used since those measurements are also affected by sea ice. The Arctic altimeter data were retracked using an OCOG retracking algorithm, and the diffuse returns from the leads and open ocean were combined with a host of instrumental corrections and geophysical models to determine instantaneous mean sea level….”

    Comment by Hank Roberts — 27 Mar 2007 @ 2:47 PM

  14. Re#2
    Yes you are right!
    I would like to know the “weight” of each decimeter sea level rise regarding the consequences for people living near or far from costal regions? I suppose the first decimeter will be within current safety margins (at least I hope so!) but what will happen if the sea level will rise to the next decimeter and so far? What are the critical margins for whom? Are there any assumptions about the ability of mankind to adapt to theses changes? Are there projections what each decimeter will cost? So if 10 cm will cost nothing, 20 cm will cost 1 billion and 30 cm will cost 100 billion then we should know something more about the weight of these measures and not only look at a scalar value.

    Comment by Andreas Mueller — 27 Mar 2007 @ 2:49 PM

  15. Hi folks: I found this article at MSNBC and am wondering if the opinions expressed in it have been taken into account…

    “But with ever more omens foretelling the death of the ice capsâ��possibly, in some models, by the year 2040â��researchers are launching a major effort to make such a prediction.”

    http://www.msnbc.msn.com/id/17770832/site/newsweek/

    Comment by Franklin Shinley — 27 Mar 2007 @ 2:54 PM

  16. Thanks for clearing up some of the confusion. This point actually came up at my defense last week, as some of my committee was not aware that the new sea-level estimates did not include dynamic effects from the ice sheets, and therefore could not be considered ‘lower’ than previous estimates. It points to the importance of future dynamical modeling of ice flow.

    Comment by Todd — 27 Mar 2007 @ 3:00 PM

  17. Thanks for diving into this topic. The clear danger in issuing an SPM document is that nobody ends up reading the full report, nor incorporating the subtle complexities of the science into policy planning (which sadly is still likely to be the case even after the full report is issued.)

    One of the ironies of all this is that we almost daily discover the limits of our knowledge regarding these processes, and find that we have erred in our thinking always on the lower end of the range of possibilities; nature seems generally to move faster and further than we guess at first. And I’m not the first to notice this. In fairness, our science has little ground proofing of theory on climate change because this is our first time having actual field observations. That said, if our predictive science is somehow missing the trajectory of the changes then that failure ought to become a topic of discussion in itself at some point.

    Though I know it is entirely nonsense, in the back of my mind I imagine waking up one morning and catching a headline in the paper stating that Greenland has experienced a sharp increase in icequakes, and getting to work and checking CNN and finding out that half the ice sheet is currently in motion and accelerating, heading for the sea, and the UN Security Council is sitting in emergency session, and Wall Street is in a panic, and then looking out the office window at San Francisco Bay and realizing, once again, that our science was behind nature, not ahead of it, and we didn’t know how far behind we’d fallen.

    Like I said, it’s all nonsense. But I would be comforted if someone could explain to me exactly what is nonsensical about it.

    Comment by cat black — 27 Mar 2007 @ 3:11 PM

  18. [[Michael Crichton is right, an informed guess is just a guess. ]]

    Michael Crichton doesn’t know his guess from a hole in the ground. If the CO2 goes up as in a given scenario, and all else is equal, and the known feedbacks are in place, then the temperature will rise by so much with error bars. What is so hard about that?

    Comment by Barton Paul Levenson — 27 Mar 2007 @ 3:13 PM

  19. [["ice cores going back thousands of years cannot tell temperatures or CO2 levels when the temperature was too warm for ice formation." ]]

    The ice cores are from places where there is snow deposition every year. We don’t measure temperatures from the layers directly, we calculate it from proxies like the level of carbon dioxide in bubbles and the O16/O18 ratio.

    [Response: Correcton: the level of carbon dioxide in bubbles is never used to infer temperature. But yes, the 18O/16O ratio is one of several methods that is used to infer temperature. And yes, snow falls even in "warm" years on the Greenland summit, and the Antarctic plateau.-eric]

    Comment by Barton Paul Levenson — 27 Mar 2007 @ 3:15 PM

  20. “In terms of a risk assessment, the uncertainty range that one needs to consider is in my view substantially larger than 18-59 cm…[T]his discussion has all been about sea level rise until the year 2095. Sea level rise does not end there…”

    I think these sum up the important points.

    Here’s a site for trends by state, and it doesn’t look good for mine, Texas: http://tidesandcurrents.noaa.gov/sltrends/sltrends_states.shtml?region=tx

    Then if you add in enhanced hurricanes & floods (there was a hurricane-looking downpour over Houston on March 14th, the rain going round & round, & not moving eastward very fast)….then the situation is bad indeed.

    I wonder if our state planners are aware of global warming & its impacts (I know the water planners are not, according to a recent news article).

    Comment by Lynn Vincentnathan — 27 Mar 2007 @ 3:16 PM

  21. Great post. But did you see that Roger Pielke on 7 February attacked you guys for “adding to the confusion” for stating that the new 59 cm should not be compared to the old 88 cm? Clearly he was wrong and just trying to score some cheap points at your expense, without bothering to check the facts properly. His strategy seems to be to attack others so that he can then present himself as “honest broker”.

    Comment by Alexander Hill — 27 Mar 2007 @ 3:30 PM

  22. Why do the folks talking about ice sheet melt, talk about “global temperature”, when what affects the ice melt/ice dynamics is the temperature adjacent to the ice? Why do we talk about a global temperature increase of 1.4 or 1.6 degrees when Greenland ice pokes up into a region where the temperature has increased much more, and the ice sheets on the Antarctic Peninsula are in an area where the temperature changes over the last few years are even greater? What is the effect of a warmer North Atlantic Drift current on Greenland? What is the effect of warmer Antarctic waters on Antarctic ice that is in direct contact with that warmer water?

    My point is that seawater at -0.5C has a very different effect on fresh water ice than seawater at +0.5C, and yet that is only 1 degree of warming. Not all degrees of warming are equal, and therefore averages do not mean much. The real question is, “What is the heat content of the water in contact with the ice sheets of concern?” This is where we can get some real near term excitement in the field of ice dynamics.

    Comment by Aaron Lewis — 27 Mar 2007 @ 3:42 PM

  23. Re #14: Andreas Mueller — The first decimeter is not free for anyone living along a flat coast. The low countries, England, Germany and especially Bangladesh come to mind, but this is hardly a complete list.

    The obvious problems are storm surges and salt water intrusion into wells, but there may well be others I haven’t learned about…

    Comment by David B. Benson — 27 Mar 2007 @ 4:05 PM

  24. >MSNBC, Newsweek article claims:
    “scientists have never found this phenomenon worrisome. Until this year, when Ronald Kwok of NASA’s Jet Propulsion Laboratory rang the alarm. He’d noticed that in 2005….”

    Yeah, right. People had been trying to tell us about this for a long time before 2005. Al Gore got the Navy’s archive declassified to let this info be studied in public — in the previous millenium.

    I refute Newsweek with a couple of easily found examples, there’s plenty more — thus:
    http://www.nsf.gov/od/oia/activities/cov/opp/2001/GPRA_Rpt.doc.
    and thus:
    http://research.nps.navy.mil/cgi-bin/vita.cgi?p=display_more&id=1023568034&field=pubs&title=PUBLICATIONS

    Comment by Hank Roberts — 27 Mar 2007 @ 4:08 PM

  25. It is wrong to blame the journalists for getting the story wrong when it took Stefan eight screenfuls of text and diagrams to explain what the IPCC really means! It was stupid of the IPCC to combine projections of sea level with temperature when they knew that the two were not directly linked. Did they really think that the public, journalists, and sceptics would read (or even understand) the small print in the sea level column stating “Model-based range excluding future rapid dynamical changes in ice flow”? Or was this obfustication done deliberately at the request of the Bush Administration?

    Of course, most IPCC scientists don’t believe that rapid dynamical changes in ice flow can happen! They believe in the 19th century uniformitarian paradigm of Charles Lyell, where geological change is slow and steady and all is right with the world. But that is wrong. Geology changes abruptly using eruptions, earthquakes and tsunamis, not to mention anoxic events and mass extinctions.

    Climate too is a dynamical system, in which positive feedbacks can dominate. When they do, they are short lived, because the system will continue to change until negative feedbacks take over, and the system is again stable. Once stable it will remain there, until a new shock knocks it into another abrupt change with positive feedbacks again dominating.

    We think the climate is stable because we have lived in the Holocene, which is one of those stable states. Like all other interglacials it will end abruptly, but rather than returning to an ice age, this one will switch into a hothouse world because of anthropogenic greenhouse gases.

    Re #10 where Nick Riley asks about http://www.nerc.ac.uk/press/briefings/2006/arctic.asp , the answer is that the Arctic sea ice is thinning and the fresh water from the melting ice is being replaced by denser saline sea water. This causes the small fall in sea level in the Arctic where it is happening. It means that the Arctic sea ice has continued to thin by 0.1 m per year since Rothrock et al. reported in 1999. Since it was 2 m thick in 1997, simple arithmetic shows it will all be gone by 2017 if not sooner.

    Of course this conflicts with the estimates for an ice free Arctic in 2040, 2050, and 2060 quoted by the scientists. For writing this, will I recieve another ad hominem attack, where I am accused of arrogance for daring to criticise them, and of stating the obvious? For instance – [Response: I don't usually resort to sarcasm in my original response, above, but Alastair McDonald's comment must surely rank as one of the most impressive displays of know-it-all-ness I've seen yet on RealClimate. He not only knows the cause, but he knows the solution to all our global warming concerns. -eric]

    Or will I be ignored? That is their normal technique when they have no answer, but they know that they are right!

    Comment by Alastair McDonald — 27 Mar 2007 @ 4:31 PM

  26. Re #8: [...ice cores going back thousands of years cannot tell temperatures or CO2 levels when the temperature was too warm for ice formation.]

    That seems pretty easy. If you’re measuring CO2 levels in the ice, you have some carbon, so you can apply C14 dating to it, no? If you do that (or use other dating techniques, the explanation of which I’ll leave to those more knowledgeable), and you find that you don’t have any gaps in the record, then his objection is answered.

    Comment by James — 27 Mar 2007 @ 4:48 PM

  27. Re #5. Pierre, As is clear from his books, Michael Crichton does not see the value in being informed. As such, I do not trust his assessment (or that of any other anti-science hysteric) for much of anything.
    And actually, in many cases, an informed expert on basketball can indeed pick the winner more often than not. What is more, start with the opinion of experts and let a large number of “fans” weigh in (by betting), and that is how Vegas makes much of its money. (And it’s also not too dissimilar from scientific consensus, although the “fans” being scientists themselves are more professionally trained.)
    In any case, these are scientific predictions–and scientific predictions have a pretty good track record of being true. You really ought to learn about the process.
    By quoting Crichton as an authority, all you do is diminish your own.

    Comment by Ray Ladbury — 27 Mar 2007 @ 5:13 PM

  28. Re #8 and #26

    I see the problem now, and it is partly true that we cannot tell the temperture beyond 150,000 years ago in Greenland because there is no ice before that date. However, we have been able to go back 700,000 years in Antarctica. Since carbon dioxide is a well mixed gas, then the CO2 in the Antarctic cores tells us about the CO2 worldwide as far back as 700,000 years ago. And we can extrapolate the temperature from the Antarctic ice core to the rest of the world.

    There is other evidence that can be used to calculate the temperatures and CO2 levels before the times recorded in the ice cores, and also during the times of the ice cores. It was ocean sediment cores that proved Milankovitch was right, and fossil beaches that supported that idea. The ice cores are used because they have been proved right by other supporting evidence, and they show that the supporting evidence can be used for times before that recorded by the ice cores.

    HTH,

    Cheers, Alastair.

    Comment by Alastair McDonald — 27 Mar 2007 @ 5:18 PM

  29. Re #s 10 and 13: This BBC article has a bit more explanation on falling Arctic sea level.

    Comment by Steve Bloom — 27 Mar 2007 @ 5:31 PM

  30. Steve, the AGU abstract I linked in #13 is the study on which that BBC article is based.

    All — when a news article gives a few clues (AGU, author’s names) Google Scholar will almost always find you the actual abstract, at least.

    I quoted about half the abstract in #13 — it’s a _very_ tentative conclusion for the reasons they state there. Good, difficult work trying to tease useful information out of that sort of data set. An exercise.

    Comment by Hank Roberts — 27 Mar 2007 @ 6:23 PM

  31. Re. 10, there’s also this article about it on realclimate; and this one is also good.

    Comment by Dave Rado — 27 Mar 2007 @ 6:38 PM

  32. How certain are we that Greenland and Antarctica will take many hundreds or thousands of years to melt, even under heavy (5C+) global warming? My intuition is that the abnormal warming of the poles will continue, so a 5C rise in global temperature would mean perhaps a 15C rise in polar temperatures, and that should be able to melt Greenland in short order. Ice sheets have strong positive feedbacks, so I wouldn’t be surprised if they melt faster and faster as time passes.

    Comment by yartrebo — 27 Mar 2007 @ 8:03 PM

  33. >4, Spencer
    I see David Archer listed as a presenter; I hope you all will have more to say about this, here or at Stoat’s ‘Antarctic’ thread or somewhere else.

    Does anyone know where the current/daily ‘ice quake’ data shows up? The standard earthquake reports pick up smaller shakes but the online maps show Greenland as silent, which puzzles me.

    Comment by Hank Roberts — 27 Mar 2007 @ 8:12 PM

  34. Hmm, I didn’t know this:
    http://geohazards.cr.usgs.gov/staffweb/mcnamara/Pubs/papers_pdf/Columbia_IRIS.pdf

    “Alaskan and immediately adjacent Canadian glaciers supply one of the largest measured glaciological contributions to global sea level rise (~0.14 mm yr-1, equivalent to new estimates from Greenland). Retreating tidewater glaciers dominate the Alaskan sea level
    contribution due to their ability to efficiently transfer mass via iceberg calving [Arendt et al., 2002]. During retreat phase, a tidewater glacier may retreat on the order of 1-2 km yr-1 concurrent with dramatic increases in ice velocity…”

    Comment by Hank Roberts — 27 Mar 2007 @ 8:17 PM

  35. RE #5 “And now some number crunchers with dubious models and no real understanding yet as to how the climate really works are telling us what the climate will be like in a 100 years? There are so many events that could happen between now and then to change everything.”

    And one event between now and 100 years from now is that people might start reducing their GHGs, unlikely as that may seem. So, what d’ya say, let’s all reduce our GHGs by 70+% and end GW. That’ll show them arrogant, money-grubbing science types whose right.

    And BTW, who needs models to tell us that heat melts ice, though my Sunfrost frig seems to take forever to defrost. But once that ice gets to a certain point, big chunks just start dropping down, one after another, kaboom! kaboom!

    This brings me to catastrophe theory, which might fit those rather sudden changes in ice. I don’t know anything about CT, except that some functions look like potato chips….discontinuous, abrupt shifts.

    Comment by Lynn Vincentnathan — 27 Mar 2007 @ 9:28 PM

  36. Since the first IPCC report in 1990 confidence expressed in the validity of the AGW hypothesis has increased with each successive report. The 1990 report stated that: “the observed (20th century temperature) increase could be largely due to… natural variability”. The 1995 report said: “the balance of the evidence suggests a discernible human influence on climate”. In 2001 it was claimed “there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” and the current report concludes says it is: “90% probable” that the recent warming is “due to the observed increase in anthropogenic greenhouse gas concentrations”. During this time global expenditure on climate change research has been estimated to exceed $50 billion. It is now claimed that the science is settled,the evidence for AGW is overwhelming and the debate is over. . Unfortunately, few people, including most scientists other than climatologists, seem to have any clear or consistent idea of what this powerful new evidence actually is.

    It would be of great value to public understanding if a short list of perhaps five to ten of the most important new findings (since 1990) in support of AGW was available. I am not suggesting a detailed report, just an annotated list with a few links to key references. In view of overwhelming scientific evidence and consensus such a list should be a trivial task for the experts on this forum. Certainly it would provide a valuable clarification to the fog of claims and counterclaims in the public perception.

    Comment by Walter Starck — 27 Mar 2007 @ 11:40 PM

  37. It seems to me that when one has strong reason to suspect that one does not understand the most important factor in a situation (ice dynamics here), then quoting a quantitative value and a quantitative error range for all the second order effects which one does understand is singularly pointless. The reality is that climatologists currently have no adequate basis for quantitative projections of 21st century sea level, and they should say so as the main conclusion of the sea level section, not in hard-to-follow footnotes. The real story for the change from the TAR to AR4 is that “ice dynamics turned out to be much more important and rapid than we realized, and now we don’t know what to tell you” That should have been said in some reasonably clear manner.

    Comment by Stuart Staniford — 27 Mar 2007 @ 11:41 PM

  38. Stefan:
    You say you couldn’t get your suggested changes made to the summary. Why was this? Was it due to “political” pressures or time constraints, were you out-voted in some way, outgunned by more senior scientists, etc? Any further explanation of how the IPCC comes to a final document would be greatly appreciated by many of us outsiders!

    Comment by Ian K — 28 Mar 2007 @ 12:49 AM

  39. Re #32: Have you checked the average temperatures at the South Pole and on top of the Greenland Ice Sheet? I think that you will find that even a 5deg C increase in annual average temperature will still see average temperature way below zero at the South Pole, and probably the same in Greenland.

    So tell me. If the average temperature is still below zero, how much ice will melt?

    [Response: Ice sheets are in equilibrium in a stable climate exactly because ablation (melt, in simple terms) balances accumulation (i.e. snowfall). In the center, where it is very cold, they gain mass, while around the edges they lose an equal amount. The problem with warming is not that it starts to melt the ice on the summit of Greenland or at the south pole, but around the edges of the ice sheets.]

    Second. Surely the issue relating to the mass of the ice sheet in the case of on-land ice sheets is precipitation as well as temperature. If temperatures are below zero, any precipitation will increase the ice volume. So precipitation must be a key factor. How much do we know about precipitation/temperature inter-relationships?

    [Response: As stated in my article, precipitation changes used in the projections are taken from a high-resolution atmospheric model. This is what leads to the assumption that Antarctica will gain mass overall, due to increased precipitation. However, this has not happened so far - until now, Antarctica seems to be losing mass.]

    Third. To assess the issue of rising sea levels, why not go to the coast when a spring high tide is acting. That will show you at least some of the effect.

    [Response: The problem of sea level rise does not arise on a calm day, even at spring tide. It arises during severe storm surges, which become a lot more frequent. For example, a study for New York showed that what is a once-in-a-century flooding event (submerging subway stations etc.) now, whould occur every 3 years if sea level were just 1 meter higher. -stefan]

    Comment by trevor — 28 Mar 2007 @ 1:35 AM

  40. James Hansen is even more “alarmistic” – the sea level rise of more than a 1 meter is quite well possible, read here:

    http://arxiv.org/ftp/physics/papers/0703/0703220.pdf

    Though I don’t know, if he attributes higher probability to +meter rise till 2100 than Stefan under BAU emmision scenario…

    Comment by Alexander Ac — 28 Mar 2007 @ 2:03 AM

  41. Also relevant:

    http://arxiv.org/abs/physics/0703220

    Comment by John Gribbin — 28 Mar 2007 @ 2:03 AM

  42. First, thanks for the article – sea level rise is quite a hot topic right now. Secondly this post was not generated by a scep-bot.

    It’s understandable that you should focus on the upside of potential sea-level rise as that is what your models predict. However, to those of us who continue to wonder at the appropriateness of using models to predict climate, two of your comments stand out:

    “We therefore see that sea level appears to be rising about 50% faster than models suggest..”

    “A second problem with the above range is that the models used to derive this projection significantly underestimate past sea level rise.”

    Models surely are of less value if they are not used to produce the most accurate prediction of a future event. If they are wrong or have not reflected past events then the relevant parameters should surely be adjusted so that future projections will be consistent with past reality. Are you saying that they are and weren’t? “Significant” and “50%” are pretty fancy amounts wrong.

    If a model runs with a known bias, what is the value of that model? Further, if that bias only exists for you while the model builder (believes she) has it right, then that makes your model wrong. If the amount wrong a model can be (whether yours or hers) is 50% then you don’t need too many wrong models before you have one 100% wrong.

    I will anticipate the response that model results lie within a range (the IPCC stated one of which you in fact dismiss as being useful). But you have stated that they are wrong by so large a factor that one has to query how they are used, what outputs are released and of course more crucially what recommendations in terms of public policy are made as a result.

    Comment by Alan K — 28 Mar 2007 @ 2:20 AM

  43. The whole point behind a summary is to – well, summarize. I accept that the IPCC has to be conservative and it is as well not to include very recent findings. However, we now seem to have a situation where the published worst case is actually not as bad as the true worst case. Politicians and journalists aren’t going to read the full report: the IPCC should update the summary when the report is published or risk an unwarranted degree of complacancy.

    Comment by Bill Tarver — 28 Mar 2007 @ 2:59 AM

  44. What is the maximum sea level rise before the ocean boils? I assume that there would be no ice anywhere at that time. The problem I have is that I don’t know the average slope of the shore. The shore is not vertical. What average shore slope is assumed in the IPCC computations? Please at least give me enough basic numbers to calculate backwards to get your assumed sea shore slope. Please send your answer to my email address.
    I conclude that I should not buy land within a few hundred feet of sea level. My very bad back of the envelope calculation says sea level cannot rise more than 800 feet before the ocean boils. If the ocean boils, we are all cooked anyway.

    [Response: If you melt all ice on Earth, sea level would rise about 70 metres. Last time this happened was in the Eocene, about 40 million years ago, when climate was about 4 ºC warmer than now (see Fig. 3.1-1 here).
    The IPCC does not assume an average shore slope, it gives vertical sea level rise. If you want to roughly see the effect on coastlines, you can do that interactively here. -stefan]

    Comment by Edward Greisch — 28 Mar 2007 @ 3:40 AM

  45. Due to the dynamics of ice being little understood why is it assumed by the IPCC (for one) that it is unlikely for Antartica or Greenland to melt significantly. Is it simply intertia or is there some other science such as thermodynamics telling us that they will not lose much ice between now and 2100?

    In additional how much ice would these places need to lose in order to weaken the oceans thermohaline/conveyor systems around the world ?

    The rate of ice decrease at these places is likely to stay relatively constant and hence not add to much to sea level rises because they are huge stores of ice that take millenia to weaken and wear down even with a large scale warming event taking place ?

    Comment by pete best — 28 Mar 2007 @ 3:48 AM

  46. For the past month or so, sea surface temperature anomalies in the areas between the Antarctic and New Zealand and, subsequently, the Pacific, have been strongly negative. This has happened before, recently. ‘Tracking’ the path of the anomalies indicates their source.
    In addition, I note this new paper in GRL: ‘Rapid Freshening of Antarctic Bottom Water from the Indian and Pacific Oceans’; Rintoul, March 2007.
    It seems clear that the SSTAs are a function of seasonal sea ice loss at the surface. Does the Rintoul paper suggest the possibility of large outflowing of freshwater from below the surface, perhaps from subglacial lakes or rivers?
    Can you tell me if either of these phenomena are unusual and, if so, whether such processes are accurately reflected in current estimates of ice mass balance, or whether they, too, suggest an underestimate. The Rintoul paper, in particular, may be indicative of a process which has not, afaik, previously been considered.
    Regards,

    Comment by Fergus Brown — 28 Mar 2007 @ 3:49 AM

  47. Re #40, #41 Hansen’s paper

    Stefan, would you care to comment on Hansen’s paper? It seems to me that he makes a good case for “more alarmism”, i.e. scientist must speak out and say that we should seriously consider a sea level rise >1 m on a century scale, because there is a non-negligible possibility of that happening. From your article I guess you would agree that there is a 1% possibility (say). Wouldn’t that justify raising the alarm?

    I think there is another reason why we should. The reaction I see in newspaper articles etc is: ‘Oh, IPCC says it’s just going to be 20-60 cm by 2100 [and Al Gore is an alarmist for bringing up the possibility of >5 m rise]. Like there will be some magical cut off in 2100! Of course history does not end in 2100, so if we’re not going to see large sea level rise in the 21st century, that’s no comfort at all for our grandchildren.

    I am aware of the “crying wolf problem”; this is a complicated issue, and I don’t want to advocate “all out alarmism” just now, but I would like to hear some opinions.

    [Response: I did not know Hansen's paper but read it just now. I fully agree with what he writes about "scientific reticence", his words echo my own experience very well. In many IPCC discussions I have noticed a strange asymmetry: people were very concerned about possibly erring on the high side (e.g., the upper bound of sea level rise possibly being criticised as "alarmist"), and not very concerned about erring on the low side (or some even regarding this as a virtue of being "cautious"). How likely is it actually that the rate of sea level rise in this century would on average be only half of the rate currently observed, despite further warming? But this is what would have to happen to reach the lower end of the IPCC range, namely 18 cm. (Current observed rate is 3.1 mm/year according to IPCC, or 3.3 mm/year using the satellite data 1993-2006.) Nobody was very concerned that 18 cm is a rather implausibly low value, possibly related to the fact that the models used to produce it already greatly underestimate the past sea level rise. Imagine the reverse had happened: models that greatly overestimate past sea level rise and come up with some implausibly high sea level rise number. Would IPCC have simply published that, as they did with the 18 cm value? I very much doubt it. Giving a low value is considered "safe", it requires no courage for sticking your neck out, while giving a high number is considered risky and alarmist. I don't think we are doing our job properly if we apply double standards to "low" and "high" estimates in this way. We need to dispassionately look at all the evidence, regardless of what is politically convenient or risky. -stefan]

    Comment by Dick Veldkamp — 28 Mar 2007 @ 5:25 AM

  48. Stefan: Very informative post, thank you. I wanted to ask if you could give a citation for the study you mentioned in your response to post No. 39 about frequency of subway flooding in New York.

    [Response: Rosenzweig, C and Solecki, W D (eds) (2001) Climate Change
    and a Global City: The Potential Consequences of Climate
    Variability and Change. Metro East Coast. Report for the US
    Global Change Research Program. National Assessment of the
    Potential Consequences of Climate Variability and Change for
    the United States. Columbia Earth Institute, New York. ]

    I find your figure comparing the IPCC 2001 SLR scenarios with observed SLR to be compelling. The question I hope the appropriate scientific community is addressing is why is sea level rising 50% faster than the modeling projected? What are the most likely reasons for this? Reading your post and following some of the literature on dynamical changes it is tempting to conclude that the difference may be due to acceleratded ice sheet flow in Greenland and Antarctica that is not accounted for in the models. But there could also be errors in the modeling of the melt rate of mountain glaciers, the rate of snowfall on Greenland and Antarctica, and the underdog, failure to account for significant net groundwater depletion.

    It might be interesting to show observed SLR in comparison to projections of the 1st and 2nd IPCC projections as well.

    Comment by Tom Huntington — 28 Mar 2007 @ 7:26 AM

  49. Per the IPCC comment noted above:

    “Contraction of the Greenland ice sheet is projected to continue to contribute to sea level rise after 2100. … The corresponding future temperatures in Greenland are comparable to those inferred for the last interglacial period 125,000 years ago, when paleoclimatic information suggests reductions of polar land ice extent and 4 to 6 m of sea level rise. {6.4, 10.7}”

    Further interglacial sea level rise is probably inevitable irrespective of anthropogenic warming contributions. Why should warming during the current Holocene Interglacial be significantly different/less than during the previous Eemian Interglacial (MIS5e), when sea levels were, per the IPCC’s own comments, above modern levels or for that matter above the purported mid-Holocene highstand?

    In fact, the literature is pretty clear that the better analog for the Holocene is actually MIS11 (Droxler), around 400 kya, when orbital eccentricity was quite low as it is today, resulting in a longer interglacial (Berger) with sea levels higher than during the Eemian.

    Note that during both the Eemian and MIS11, CO2 levels were lower than they are today, which strongly suggests a polar warming/melting mechanism other than CO2. Perhaps this anthropogenic warming debate is an unfortunate distraction from what we should be really focusing on – preparing for higher interglacial warming and rising sea levels, period.

    Comment by Dan Fregeau — 28 Mar 2007 @ 7:37 AM

  50. Let’s put some facts on the table:

    - The poles go through (nearly) 6 months of darkness each year. With no sunlight in the winter, and with the sun at a low angle in the sky in the summer, it is always going to be cold at the poles and any melting in the summer is going to freeze back in the winter;

    - The average annual temperature at the south pole is -49.5C. The average annual temperature at the north pole is -25.0C. 5.0C of warming leaves the poles very cold.

    - Sea level has been rising at 1mm to 3mm every since the large continental glaciers melted after the last ice age – ie for the last 9,000 years.

    - The interior of Greenland is below sea level. This is important if one is thinking of all of the ice melting or one is thinking of the glaciers “sliding off” into the sea.

    - The arctic is still experiencing “rebound” from the weight of the glaciers from the last ice age.

    - The Minimum Sea Ice Extent in the arctic was lower in 1990 than in 2006 – ie the arctic ice summer (September) minimum has been more-or-less stable for 16 years.

    [Response: I'm always suspicious when someone announces: now here come the facts! You'd have to give some references for some of your "facts". Sea level has been rising for 9,000 years at the rate of 1-3 mm/yr? So in the Middle Ages it was 1-3 meters lower than now? A number of studies (interestingly, some looking at where the Romans built fish ponds and other structures connected to the sea) and the IPCC rule this out, concluding just the opposite: in the preceding millennia, there was not even remotely the rate of sea level rise that is observed for the last century, it is a modern phenomenon. And on the September arctic sea ice cover, NASA has a very different story. -stefan]

    Comment by George K — 28 Mar 2007 @ 7:53 AM

  51. 18. Well, that’s a very confident view of the accuracy of predictive models. Not in any way justified,IMO , but confident.
    {see 2006 hurricane season}

    19. How accurate can we expect temperature recreations to be using proxies form 100,0000 years ago ??

    Comment by tom — 28 Mar 2007 @ 7:58 AM

  52. Too many faults in the ice core data, and the whole “it`s our fault” argument to know where to start.
    1) temperature jumps preceding co2 level jumps. I checked out the page on this site trying to explain the 800 year lag, except that they couldn`t explain it. They gave a circular argument saying that something kick started the temperature jump, which led to the co2 rise… but they don`t know what. Exactly, they don`t know.
    2) temperature drops often precede co2 drops as well. so if the co2 “feedback” is in effect, how does the temperature suddenly drop? and if the co2 did suddenly drop before the temperature, why in the heck would it when according to this site, co2 rise leads to runaway temperature and co2 rise due to this feedback effect.
    3) the dramatic rise in co2 levels started before the industrial revolution.
    4) the circular nature of the conclusions raised upon analysis of the data on this site, ie, the non-existence of any possible explanation for the initial lag between temperature and co2 rise before the alleged “feedback” effect comes into place, show that they are nothing more than pure assumptions based on the hypothesis that humans are at fault for the most recent rise, itself based on non-existent evidence. the conclusion that humans are at fault is just plain unsubstantiated, illogical and unscientific.

    If the sea rises, move. It will be gradual enough for most of the “developed” world to cope with. It`s strange I didn`t see any names on this thred even remotely Bangladeshi, and yet there are people who seem worried that they are going to wake up the next morning with their house submerged. Instead of wasting our time and effort saving the people who need it least, we should be spending it helping those who need it whether there`s indeed an ocean rise or not.

    Now, if this feedback effect is actually on the mark, and it`s runaway train from now on, it`s really too late for us to do anything except start the bidding on Mount Everest for the sake of our offspring 1000 years down the road. so let`s stop the arguments about how many decimeters and how much sloping will affect the rise. I appreciate the honest sentiments about saving the planet for our offspring, but if the earth says it`s time, it`s time. we should say so long, and thanks for the memories.

    Comment by mark — 28 Mar 2007 @ 8:19 AM

  53. Re #23 & 14, there is also the problem of trees dying near the coast, as the salt water underground seeps further inland — which has been happening at an accelerated rate in India, Florida, Caribbean islands & elsewhere (places that have been slightly sinking, even without sea rise compounding this). And I think (not sure) that the saltwater also is bad for underground cement structures near the coast.

    Comment by Lynn Vincentnathan — 28 Mar 2007 @ 8:52 AM

  54. RE # 50

    Thank you George for putting those facts on the table.

    Stefan had me worried there for a minute.

    Comment by John L. McCormick — 28 Mar 2007 @ 9:08 AM

  55. tom (51):

    18. Well, that’s a very confident view of the accuracy of predictive models. Not in any way justified,IMO , but confident.
    {see 2006 hurricane season}

    Global climate models are judged by testing how well they simulate the
    recent past – not by comparing them to the very different forecast
    models of peripherally related discipline (seasonal hurricane
    forecasting) . The AR4 SPM includes information on how well GCMs
    simulate the recent past – see page 11.

    In addition, although GCMs have improved greatly since 1988, Eli’s
    discussion of Jim Hansen’s 1988 GCM-based forecast, and comparison to
    how things actually turned out, is quite informative; even 19 years
    ago, NASA’s climate scientists were able to accurately forecast
    global temperatures up to the present.

    The methods used for seasonal hurricane forecasting are substantially different
    from those used for global climate models; they are very different
    problems. Your logic is akin to someone vacationing in Key West, who,
    upon hearing the NHC has forecast a major hurricane will pass nearby
    (or landfall) in 48 hours, insists that the NHC’s forecast should be
    ignored because the University of Florida has a lousy football
    team. Just as the association between UFL and NHC is not justification
    for judging the quality of NHC’s forecasts by the quality of UFL’s
    football team, the fact that seasonal hurricane forecasters and
    climate scientists attend some of the same conferences is not
    justification for judging global climate models by the success of
    William Gray’s (or TSR’s) statistical hurricane season forecasting.

    Comment by llewelly — 28 Mar 2007 @ 9:26 AM

  56. Yo, Tom, regular civilian readers of RC (yours truly fall into this catgory) would know that, as with many things, one must remeber all the pieces of the assumptions involved. The weak ENSO of 2006-07 altered the pattern of Northern Hemisphere mid-latitude westerlies, and *the models predict lower Atlantic hurricane intensity*, which is what was observed.

    Comment by David Graves — 28 Mar 2007 @ 9:37 AM

  57. Re #50:
    “- The poles go through (nearly) 6 months of darkness each year. With no sunlight in the winter, and with the sun at a low angle in the sky in the summer, it is always going to be cold at the poles and any melting in the summer is going to freeze back in the winter;”

    History and climate physics disagree with you on this one. Heat transport and a thick greenhouse gas blanket were enough to make the South Pole a temperate region at one point during the Mesozoic Era.

    Even if the average temperature is below 0C, ice sheets will still melt if there is any more than minimal melting in the summer, because the melt water does not stay on the surface but runs off, usually to the base of the ice sheet.

    “- The interior of Greenland is below sea level. This is important if one is thinking of all of the ice melting or one is thinking of the glaciers “sliding off” into the sea.”

    There is plenty of ice above sea level in Greenland, and isostatic rebound will work to bring most areas that are under sea level back above sea level.

    Comment by yartrebo — 28 Mar 2007 @ 9:37 AM

  58. Re #53:

    Salt water intrusion (at least around here, in NYC) is usually caused by humans pumping too much groundwater, though a sea level rise could only hurt.

    As far as concrete goes, it is unaffected by salt and actually strengthened by water.

    Comment by yartrebo — 28 Mar 2007 @ 9:41 AM

  59. I sure wish we had a parallel topic in which people had to provide cites and the cites were checked first, before posting their opinions and beliefs and asserting them as scientific fact.

    Even reading RC every day, it’s increasingly hard to know who’s making things up.

    The information’s getting awful thin compared to the pretend stuff, and we’re seeing more double-team (one person posts bogosity, another comes along and posts thanks and gratitude for the ‘facts’).

    Don’t let this site get taken over, please. Ask some new reader to go through a topic like this and naively rate each post for superficial credibility. See if I’m right.

    Comment by Hank Roberts — 28 Mar 2007 @ 10:04 AM

  60. RE #59

    Hank, my apology for posting #54.

    That was my snarky reply; not a note of gratitude. I will be more careful next time.

    And, I am in total agreement with your concern RC might be overtaken by trolls and diversionists.

    Comment by John L. McCormick — 28 Mar 2007 @ 10:19 AM

  61. Stefan: Are there groups of scientists coring around the edges of Greenland trying to determine the minimum extent and thickness of the ice sheet during the last interglacial? A reconstruction of Greenland’s minimum ice sheet thickness would spark a lot of intuitive questions and maybe some answers about ice sheet dynamics.

    Comment by Andrew Sipocz — 28 Mar 2007 @ 10:32 AM

  62. Re #60 (John McCormick)

    I thought your reply was quite funny actually – a little snarkiness should be OK.

    Comment by Dick Veldkamp — 28 Mar 2007 @ 11:02 AM

  63. [[ The poles go through (nearly) 6 months of darkness each year. With no sunlight in the winter, and with the sun at a low angle in the sky in the summer, it is always going to be cold at the poles and any melting in the summer is going to freeze back in the winter;]]

    That’s an elegant theory, but since the extent of the ice caps has indeed been shrinking (we can measure it from satellites), your theory doesn’t seem to match the evidence.

    Comment by Barton Paul Levenson — 28 Mar 2007 @ 11:17 AM

  64. [[1) temperature jumps preceding co2 level jumps. I checked out the page on this site trying to explain the 800 year lag, except that they couldn`t explain it. They gave a circular argument saying that something kick started the temperature jump, which led to the co2 rise... but they don`t know what. Exactly, they don`t know.]]

    But they do know. Do a Google search on “Milankovic cycles.”

    Comment by Barton Paul Levenson — 28 Mar 2007 @ 11:18 AM

  65. #59. Hank wrote:

    [[I sure wish we had a parallel topic in which people had to provide cites and the cites were checked first]]

    I agree Hank. Something needs to be done about this website. This website is being taken over by histrionics and questionable experts and is defeating its original purpose which is to inform the public.

    Now, the public must be more confused than ever by the postings on this website.

    I can’t tell who is trolling, who is legit and who is obfuscating the truth.

    Probably, I am partly responsible, as you pointed out, by responding to trolls and leading the posts off track myself as well…and who even knows if my background is legit… or anyone else’s for that matter?

    We certainly know that some posters and groups of posters, by their repeated rants, are trying to destroy the continutiy of the threads…sucessfully I might add.

    What is happening now, is defeating the original purpose of this website.

    I read that this website was designed to be a link between climate science and the public…right now it is turning into a link between pseudo science (from the wierd public posts) and idealogues.

    Personally, I almost never posted to this site until I read that Gavin posted something such as…”OK readers, help me out” for responding to the myriad of seemingly legit, endlessly repeated public questions.

    Moderators…please take this seriously. Let’s not destroy this hugely sucessful open link between legitimate scientists and the legitimate public.

    Do whatever you have to do…it seems the community does not have to ability to sucessfully control the disrupters.

    Comment by Richard Ordway — 28 Mar 2007 @ 11:26 AM

  66. Interesting article – particularly as a study by researchers at Columbia University, the City University of New York and the International Institute for Environment and Development has just found that around one-tenth of the world’s population lives within 10 metres of sea level. And in China and Bangladesh, the share of population in such zones is growing fast. See http://environmentalresearchweb.org/cws/article/futures/27436 for more details.

    Comment by Liz Kalaugher — 28 Mar 2007 @ 11:39 AM

  67. Measurements from Greenland are that between 2003 and 2005, 172 cubic kilometers (41 cubic miles) of ice was lost, three times as much as was added ( http://www.sciencedaily.com/releases/2007/03/070327122328.htm ). This kind of ice sheet response was not predicted by earlier models, and the direct gravity satellite observations (Grace) seem very reliable. (Previous studies were attacked by the likes of CO2science.org, who claimed that Greenland was actually gaining mass).

    This might not affect the equilibrium climate sensitivity, but will affect the transient climate sensitivity – the rate of response to forcing. It’s also a good example of how science can miss important variables, as well as of how a rapidly warming world might behave very differently than a world locked into a glacial/interglacial cycle will. A decade ago, it was widely agreed that the West Antarctic and Greenland ice sheets were stable and would melt slowly, like stationary ice cubes.

    With respect to the other missing variable in the IPCC reports, it seems that carbon cycle feedbacks will affect the equilibrium climate sensitivity to anthropogenic CO2 by increasing the ‘non-anthropogenic’ atmospheric CO2 levels. The IPCC, by not including the recent data, must be underestimating both the transient and equilibrium climate sensitivity. This raises the question: when does the IPCC plan to issue an updated report that does include ice sheet dynamics and carbon cycle feedbacks? Six years from now?

    The other issue is that the IPCC should extend their predictions to at least 2200, not just to 2100. If there are scientific reasons for not doing so, is it safe for observers to assume that the consensus among climate scientists is that there is little basis for trusting the models past 2100?

    Comment by Ike Solem — 28 Mar 2007 @ 12:23 PM

  68. The northern sea ice figures are available from The Cryosphere Today which has all the satellite pictures archived for every day back to 1979.

    Here is a graph of the daily sea ice area back to 1979.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    http://arctic.atmos.uiuc.edu/cryosphere/

    Comment by John Lang — 28 Mar 2007 @ 12:48 PM

  69. Re #44:
    “What is the maximum sea level rise before the ocean boils?”

    The entire ocean cannot boil away, at least in the short term. Heating the ocean and atmosphere to +374C/221atm would boil about 75% (by mass) of the ocean, at which point there would no longer be a distinction between liquid and gaseous water.

    As far as what temperature and corresponding pressure below +374C gives the highest water level, I got as follows (very approximate):
    temperature: +180C
    pressure: 11 atm (10 atm H20, 1 atm other gases)
    height: 380m above present sea level

    At higher temperatures, water evaporation outpaces thermal expansion, and at lower temperatures, thermal expansion is dominant. I calculated that the 70m rise from melting ice becomes about 80m because of thermal expansion, assumed that 70% of the Earth’s surface is ocean, and used 5.15 * 10^18 kg and 1.4 * 10^21 kg as the masses of the dry atmosphere and hydrosphere respectively. I also assumed that the entire atmosphere is saturated and the same temperature throughout. If it isn’t fully saturated (unlikely since that would cause the pressure to drop and more H20 to rise from lower parts of the atmosphere) or if it is cooler at higher altitudes (quite likely), the maximum sea level will be higher and attained at higher temperatures and pressures.

    Comment by yartrebo — 28 Mar 2007 @ 12:50 PM

  70. I agree with those expressing concern about the trends in some of the recent posts on RC. I suggest that it is not censorship to apply a little stronger filter. You could, for example, filter out posts like #52, which is simply a restatement of incorrect and misleading talking points that have already been addressed several times. It is not necessary to allow these statements to be repeated over and over until some begin to attach significance to them. (Any lie repeated often enough….)

    Comment by Ron Taylor — 28 Mar 2007 @ 1:01 PM

  71. Re #59 & #65

    Writing only as a layreader and infrequent commentor, I believe you may be overestimating the influence of the denier-trolls and underestimating the discernment of the average readers. This is a very credible and robust forum due, in my opinion, both to the excellent articles and to the excellent posts by folks such as yourselves. You provide good answers to the honest questions and needed rebuttals to the nonsense. And I’ve learned a lot from the additional links provided (Lynn’s link in #20 was great). I worry that too strong a reaction would hurt the forum more than it helps.

    My suggestion would be to add a metric next to each commentor’s name. The value would initialize at zero and any of the contributors could increment it by +1 for a good post and by -1 for a FUD post. I’d cap the values at +- 10 to keep people from frequent posting just to boost their numbers. I suspect that the trolls would drop off when their scores hits about -5 (though they may return under another name). Just a suggestion.

    Best Regards,

    Comment by Phillip Shaw — 28 Mar 2007 @ 1:04 PM

  72. Regarding my points at #50 about sea level rise over the past 8,000 years, this chart is from NASA – GISS from just this January.

    http://www.giss.nasa.gov/research/briefs/gornitz_09/slr.jpg

    http://www.giss.nasa.gov/research/briefs/gornitz_09/

    Comment by George K — 28 Mar 2007 @ 1:43 PM

  73. #59, Hank I disagree to a certain extent, let people write what they think so feedback may make them think some more.

    About Arctic ice sheet, it will likely never completely disappear during the long night, surely is on its way to vanish during summer time, the biggest factor accelerating its demise is not temperature but dominant winds, if they change in favour of dumping more old sea ice than usual on a continuous basis, then even with temperatures still quite cold, the ice sheet will appear semi-annually. There are a few obstacles to this, the biggest one being tidal effects, especially during full and new moons, which literally push the ice against the Canadian Archipelago, there is the Arctic Ocean Gyre which favours dumping of ice from the Russian side of the Pole to the North Atlantic, but equally favours packing the ice again on the Archipelago West Coast. The only way for it to disappear completely if for the winds to go off kilter, intead of a near permanent High pressure at the Pole during winter, the near permanent High pressure should stay year round, dumping more ice when it shouldn’t, during the summer. A near permanent high pressure during the summer would also allow more sunshine to add more heat to the open water of the Arctic Ocean. Its up to the models to come up with the possibility of such a scenario. I think it likely, having seen for myself the power of mere winds on the most huge ice packs.

    Comment by wayne davidson — 28 Mar 2007 @ 1:46 PM

  74. Re #s 59/65: The moderators already exercise some degree of control. Rants do tend to get removed. Posts like #50 that are composed of denialist talking points but are politely phrased should be let through IMHO so long as they get refuted. My impression is that they do get refuted, although that probably ceases to be done consistently in the latter portions of some of the longer comment sections. OTOH, I suspect the majority of readers, especially the less informed ones, tend to read just the main posts and don’t even get to the comments, and certainly not to the bitter end. (Does the software track whether people enter the comment sections?)

    I do think that the site could use some sort of short “caveat emptor” blurb at the top of the comments making it clear that the non-green comments should not be taken as the gospel truth. To increase the number of those green comments without creating an extra burden for the existing moderators, perhaps some of the regular climate scientist commenters could be given moderator privileges to the extent needed to highlight their own comments in green. Possibly that would also encourage such folks to make more comments, which would be helpful.

    Finally, I think it would be good to have a brief “RC User’s Guide” prominently linked just below the banner. This would help keep first-time readers from feeling so intimidated, which I think is the biggest drawback of the site. If there’s any interest, I would help put it together.

    Comment by Steve Bloom — 28 Mar 2007 @ 1:47 PM

  75. While we’re on the subject of user friendliness, I want to compliment Stefan on the structure of this post: A short “abstract” with a hyperlink to the conclusion (“bottom line”), making the material equally accessible to users with different levels of knowledge (or interest in this particular subject).

    [Response: That hyperlink was actually Gavin's idea, so he should be praised... -stefan]

    Comment by Steve Bloom — 28 Mar 2007 @ 1:54 PM

  76. Re 50,70: George, you should have read your source:

    “Twentieth century sea level trends, however, are substantially higher that those of the last few thousand years. The current phase of accelerated sea level rise appears to have begun in the mid/late 19th century to early 20th century, based on coastal sediments from a number of localities. Twentieth century global sea level, as determined from tide gauges in coastal harbors, has been increasing by 1.7-1.8 mm/yr, apparently related to the recent climatic warming trend. Most of this rise comes from warming of the world’s oceans and melting of mountain glaciers, which have receded dramatically in many places especially during the last few decades. Since 1993, an even higher sea level trend of about 2.8 mm/yr has been measured from the TOPEX/POSEIDON satellite altimeter. Analysis of longer tide-gauge records (1870-2004) also suggests a possible late 20th century acceleration in global sea level.

    Recent observations of Greenland and the West Antarctic Ice Sheet raise concerns for the future. Satellites detect a thinning of parts of the Greenland Ice Sheet at lower elevations, and glaciers are disgorging ice into the ocean more rapidly, adding 0.23 to 0.57 mm/yr to the sea within the last decade. The West Antarctic Ice Sheet is also showing some signs of thinning. Either ice sheet, if melted completely, contains enough ice to raise sea level by 5-7 m. A global temperature rise of 2-5°C might destabilize Greenland irreversibly. Such a temperature rise lies within the range of several future climate projections for the 21st century. However, any significant meltdown would take many centuries. Furthermore, even with possible future accelerated discharge from the West Antarctic Ice Sheet, it highly unlikely that annual rates of sea level rise would exceed those of the major post-glacial meltwater pulses.”

    The main point about the models’ predictions of sea-level rise are that they tend to underpredict what is actually seen. This raises the concern level rather than lowering it. Sea-level rise gets a lot of attention because it is a virtual certainty, and will have somewhat predictable consequences. It is far from the only possible effect, though, of climate change. Again, focusing on the uncertainties is not particularly profitable. The systematic errors all run only one way, and it is against those arguing for complacency.

    Comment by Ray Ladbury — 28 Mar 2007 @ 2:32 PM

  77. Thank you for this excellent summary, Stephan. Your last point is particularly well-taken: sea-level rise seems to be popularly expected to magically cease as of 2100. Discussions of adaptation strategies such as building sea-walls (where the concrete therein is a CO2 emissions source, of course) apparently originate from this statistical fantasy.

    A more important question than where the sea-level will be in x years is when we can reasonably expect thermal equilibrium to be achieved, when it stops rising. At what point are the ice sheets committed to total meltdown, when carbon-cycle feedbacks are properly taken into account? Have “scientific reticence” or an irrational faith our own viability as a species hindered our ability to contemplate and calculate through that “tipping point”?

    Comment by Daniel C. Goodwin — 28 Mar 2007 @ 2:37 PM

  78. Re #70 Re # 50 [sea level rise of 1 -3 mm(per year?) for last 8,000 years]

    The NASA-GISS article you provide a link to says: “Over the past few thousand years, the rate of sea level rise remained fairly low, probably not exceeding a few tenths of a millimeter per year.” And: “Twentieth century sea level trends, however, are substantially higher that those of the last few thousand years. “

    Comment by Rick Brown — 28 Mar 2007 @ 2:39 PM

  79. “- Sea level has been rising at 1mm to 3mm every since the large continental glaciers melted after the last ice age – ie for the last 9,000 years. …”

    Just guessing by eye, that graph shows sea level was around 39 meters lower 9,000 years ago, and that by 5,000 years ago sea level rise had erased all the seaside condos in that 39-meter range. From 5,000 years ago until now, there has been a significant slowdown in sea level rise versus the first 15,000 years graphed.

    I think maybe you left out a word. 1mm to 3mm every what and for how long?

    Comment by J.C.H — 28 Mar 2007 @ 2:40 PM

  80. >50, 70
    The confusion is that stating an overall “per year” rate doesn’t represent the data accurately.

    Rate of change is important.

    The article and chart linked in #70 point out that there were several large pulses; it’s not a steady rate of change so a “per year over 9000 years” hides the variability:

    “Twentieth century global sea level …. Since 1993, an even higher sea level trend of about 2.8 mm/yr has been measured from the TOPEX/POSEIDON satellite altimeter. Analysis of longer tide-gauge records (1870-2004) also suggests a possible late 20th century acceleration in global sea level.”

    Comment by Hank Roberts — 28 Mar 2007 @ 4:38 PM

  81. Re #58 Sea ice (John Lang)

    John, interesting links.

    Strangely enough the first graph (the sinusoidal one) is not showing much ice loss, while the other graphs are. I suppose it must be a visual illusion (after all, all graphs must be consistent). Doubtless teh real numbers are found with statistical procedures rather than from the graphs.

    Comment by Dick Veldkamp — 28 Mar 2007 @ 4:39 PM

  82. And BTW, who needs models to tell us that heat melts ice, though my Sunfrost frig seems to take forever to defrost. But once that ice gets to a certain point, big chunks just start dropping down, one after another, kaboom! kaboom!

    Comment by Lynn Vincentnathan � 27 Mar 2007

    Another common example: ice and snow on steeply pitched roof on a warming day will suddenly, without warning, come down in a rush. When certain undetectable thresholds are crossed gravity becomes stronger than what ever friction was holding the ice in place. No models necessary or even possible.

    Comment by tom root — 28 Mar 2007 @ 6:07 PM

  83. Re. #45, see Stefan’s response to #47. Contrary to popular belief, many climatologists – and especially the IPCC, because it has to get a consensus – play it safe much too much.

    Comment by Dave Rado — 28 Mar 2007 @ 6:30 PM

  84. Re. #36, it’s the rapidly increasing weight of evidence all pointing in the same direction, rather than any new theory, that is the reason for the increasing levels of certainty. This evidence is summarised quite well here and in the links from that page.

    Comment by Dave Rado — 28 Mar 2007 @ 6:44 PM

  85. Re 40, 86 and others wrt conservatism of scientists. This goes to show the absolute falsehood of Crichton’s assertions about scientific consensus. The need to reach consensus in science means that scientific conclusions are almost always conservative rather than alarmist. Not every threat considered by the IPCC will necessarily be realized, but many are virtual certainties, many will likely be much worse than the IPCC predicted.

    Comment by Ray Ladbury — 28 Mar 2007 @ 7:08 PM

  86. When one is discussing sea level rise, (as in other types of data) I believe one should discuss the entire record.

    The simple fact is that sea level has been generally rising since the ice age was over and even after the large continental glaciers completely melted. Maybe it only increased a few tenths of a mm for periods of time, maybe it was faster than that at other times.

    Sea level has risen by about 10 metres since 8,000 years ago. That translates into 1.25 mm per year.

    Sea level has risen about 2 metres over the last 5,000 years. That translates into 0.4 mm per year.

    Since 1900, sea level has risen about 20 cm. That translates into 2.0 mm per year.

    I think it is important to recognize that sea level rise is not a brand-new phenomenon.

    Here are two other charts showing sea level rise over the recent past.

    http://en.wikipedia.org/wiki/Image:Holocene_Sea_Level.png

    http://en.wikipedia.org/wiki/Image:Recent_Sea_Level_Rise.png

    Comment by George K — 28 Mar 2007 @ 7:36 PM

  87. RE # 88

    [I think it is important to recognize that sea level rise is not a brand-new phenomenon.]

    Agreed.

    Now, for the sake of good common sense, you should agree the topic relates to measured increasing deglaciation and thermal expansion of the oceans. Neither are brand new phenomena.

    But, this measured increasing rate of sea level in a world of 6.6 billion inhabitants (ten percent of whom reside on coastal plains) IS A BRAND NEW PHENOMENON.

    Give us some indication that has any meaning.

    Comment by John L. McCormick — 28 Mar 2007 @ 7:53 PM

  88. I’m curious what the predictions are like for beyond 2090-2099. While the time-scale for the predictions is “long-term” in comparison with a human lifetime (I’ll certainly be dead by 2090-2099), in many endeavors, people implicitely use much longer time frames.

    In Singapore, where I currently live, property is typically sold either on a 99 yr lease or freehold (i.e. in perpetuity). If people totally discounted anything beyond 2099, the sale price for a freehold property would be the same as for an equivalent 99-yr leasehold property. That’s not the case, however. Freehold property sells at a substantial premium over leasehold. Why? Because people expect that property to still be usable, and hence have value, 99 yrs from now.

    If there’s some non-negligible chance that the groundfloor of some beautiful new seafront freehold apartment is going to be underwater in, say, 125 yrs, the price of that apartment shouldn’t be substantially higher than that of an equivalent 99-yr leasehold apartment.

    After the IPCC FAR SPM was released, someone from the Singapore government (minister of the environment?) said something to the effect that Singaporeans shouldn’t worry because reclaimed land in Singapore is built up to 1.25m above sea level, way above the “worst case” sea level rise of 59cm. Hmm… perhaps worth the gamble for 99 yr leasehold property perhaps, but probably not for freehold, given that sea level rise is likely to continue long after 2099.

    Comment by Gerry Beauregard — 28 Mar 2007 @ 8:00 PM

  89. Re 86: George K, it is a bit disingenuous to look at average rates of sea-level rise. The rate was quite rapid during the early part of your 8000 year period, and we know why–the melting of continental glaciers. The rate then slowed to a crawl, and we know why–the continental glaciers were mostly melted and there existed a rough equilibrium between Winter snowfall and Summer melt and a relatively stable climate. Now the rate of rise is again rapid–and we know there must be a reason. Why? Because things do not just happen. The planet does not just cyclically warm and cool. There are drivers that force it to do so, and if the behavior of the planet changes, that means one or more of the drivers must also be changing.
    Now, as John points out: The situation during this rapid rise is different than in previous epochs of rapidly rising sea level. In the interim, all the infrastructure of civilization has been developed, and human population has increased to 6.6 billion. I would call this a not insignificant difference.

    Comment by Ray Ladbury — 28 Mar 2007 @ 8:19 PM

  90. I’m looking forward to the progress made in ice dynamics. The Greenland ice sheets are getting more and more cracks through which more and more liquid water flows, possibly creating lakes, or going to the bottom to lubricate the moving sheets. I can’t help to wonder what would be the results of a few accidents like what happened in the French Alps in 1892, but each multiplied by a 100 factor, taking place on each side of the globe. Antarctica is already harboring immense pockets of liquid water. In the St Gervais occurence, a 90000 cubic meters ice plug was pushed out by a 200000 cubic meters volume of liquid water. I just can’t help to wonder what potential exists in Greenland and Antarctica for similar, much larger events. I’m also wondering how we’re monitoring the amount of precipitation over the oceans and how that has changed.

    Comment by Philippe Chantreau — 28 Mar 2007 @ 8:57 PM

  91. In Douglas Preston’s fine novel Tyrannosaur Canyon he describes the American West in that time before the asteroid hit. There were no ice caps, the whole place was tropical and the coastline was over in New Mexico someplace. That should be the take home lesson, not Crichton’s modern Jurrasic Park concoction and subsequent disconnect.

    Comment by Mark A. York — 28 Mar 2007 @ 9:26 PM

  92. Re: Stefan’s response to #44:

    If you melt all ice on Earth, sea level would rise about 70 metres. Last time this happened was in the Eocene, about 40 million years ago, when climate was about 4 ºC warmer than now.

    I don’t think this is fully accurate. My understanding (from Wikipidia and other sources) is that 4º is the low end temperature of the Eocene, which ranged up to 6º warmer than today. Please correct me if I am wrong about this. Also, polar ice did not melt in the Eocene, instead ice sheets began to form at the end of it. Your statement implies that 4º of warming will (eventually) melt all the polar ice caps, while my understanding is it would take considerably more than this. Still, the 25 to 35 meters of sea level rise from the Pliocene (3 millin years ago) when temperatures were only about 3º is enough reason for concern.

    Comment by Blair Dowden — 28 Mar 2007 @ 9:40 PM

  93. Interesting blog post on consensus at Scientific American. This is my answer.

    “god help you if you walk into a pub and act full of yourself, as many climate scientists do.”

    Really? Because the climate scientists I deal with have the patience of Job. They explain the same things over and over while fending off the same barrage of insults from people so ignorant of the facts they can’t accept any scientific explanation. And they won’t. No, I think you’re wrong. Mollycoddling the public, and let’s identify who they are: conservative or leaning that way politically is not the answer. The answer for them is education not geared to what they want to hear by a messagemaker.

    So far the Nicholson line applies. They can’t handle the truth.

    http://blog.sciam.com/index.php?title=please_stop_talking_about_the_global_war&more=1&c=1&tb=1&pb=1

    Comment by Mark A. York — 28 Mar 2007 @ 10:19 PM

  94. re: 93. Agreed. Unfortunately, there are a large number of skeptics or deniers who refuse to acknowledge or even want to be educated about the subject. These laymen actually think they know more than people who have spent decades studing climate science. And then they refuse to admit when they are wrong. It is quite astonishing and sad that people actually “think” that way.

    Comment by Dan — 29 Mar 2007 @ 4:28 AM

  95. Hansens speaks of the potential for “rapid non linear collapse” on his recent talks on fossil fuel depletion and climate change here in the UK. Apparantly the number of ice quakes on Greenland has escalated quite rapidly and could indicate something serious going on.

    Is there any scientific rationale behind Mr Hansen reasoning ?

    Comment by pete best — 29 Mar 2007 @ 4:36 AM

  96. An archived Webcast is now available of a presentation that took place yesterday (March 28th) at the University of Texas at Austin.

    Description from the site:

    Secrets of the West Antarctic Ice Sheet: A Panel Discussion
    About Global Warming, Climate Change and Rising Sea Levels

    Webcast panel of some of the world’s leading polar ice experts on area of major uncertainty facing climate scientists. Panel will take questions from the Web and a live audience.

    Presentation doesn’t start until about 13 minutes into the Webcast. If you haven’t a fast enough connection to receive this, here’s part of what Reuters has to say:

    A Texas-sized piece of the Antarctic ice sheet is thinning, possibly due to global warming, and could cause the world’s oceans to rise significantly, polar ice experts said on Wednesday.

    They said “surprisingly rapid changes” were occurring in Antarctica’s Amundsen Sea Embayment, which faces the southern Pacific Ocean, but that more study was needed to know how fast it was melting and how much it could cause the sea level to rise.

    The warning came in a joint statement issued at the end of a conference of U.S. and European polar ice experts at the University of Texas in Austin.

    The scientists blamed the melting ice on changing winds around Antarctica that they said were causing warmer waters to flow beneath ice shelves.

    Comment by AndrewM — 29 Mar 2007 @ 5:08 AM

  97. Hello Pete,

    “Is there any scientific rationale behind Mr Hansen reasoning ? ”

    I’ve not read the Hansen paper linked to above on this page, but don’t see how fossil fuel depletion is an issue that can limit emissions. We’ve used but a fraction of the available extractable reserves so far and there’s massive reserves of coal left.

    Re Greenland:
    You do worse than looking at Luckman et al “Rapid and synchronous ice-dynamic changes in East Greenland” http://geography.swan.ac.uk/glaciology/adrian/luckman_GRL_feb06.pdf

    Or google “basal lubrication”.

    Comment by CobblyWorlds — 29 Mar 2007 @ 6:24 AM

  98. There is a documentary about some guys who went to Greenland and recovered a WW2 fighter plane that was resting on the ice where it made its emergency landing in 1942. After 50 years, they had to burrow down through 268 feet of new ice to reach the fighter on the surface of the 1942 ice cap.

    Few structures can just continue to get taller and taller forever, but especially not one in which the edges are being eroded by melting and erosion. It’s no different than the snowmen and snow forts and snow dams we built as kids. Snow is a wonderful building material, but it has its limits. In the 3rd grade we backed up an astonishing amount of water during recess by blocking a stream of melt water on our playground with a hastilly made snowbank. We watched in amazement from our classroom window when our engineering feat experienced a sudden and catastrophic failure – a huge wave of water swept out into the street. No adult saw it, but after school we rushed out and looked at the water line on the sides of the parked cars.

    So yeah, the 3rd grader in me thinks Hansen’s reasoning has a future.

    Comment by J.C.H — 29 Mar 2007 @ 6:36 AM

  99. Re 97, Dr Hanson has been talking in the USA recently with an article called “Lets call the coal thing off” in which he advocates just like he did in the UK talk that we can use all of the remaining Oil and Gas reserves but existing coal fired power stations and technology must not be built and old power stations phased out by 2050. Fortunately for the world (and Dr Hansen) Sen Kerry seems to think along the same lines, however getting this into legislation is another matter as the USA’s fossil fuel companies are powerful and unless clean coal technology can come along soon then the 159 new coal fired power plants that the USA intends to build will not have this technology fitted or retrofitted. This is a major issue for climate change, if the USA builds these power stations as they last for 60 years then the world would be committing itself to the 1 more degree rise that Dr Hansen seems very worried about.

    http://www.energybulletin.net/22996.html
    http://www.salon.com/news/feature/2007/03/12/muckraker/ (choose enter site to skip the advertising to get to the article)

    Dr Hansen not only thinks that the issue of climate change is urgent he wants soemthing done about it sharpish. I believe that Dr Hansen also is attributed to have said 1 more degree celsius and we are done for.

    On ice dynamics etc I await consensus on the issues of rapid non linear climate change or other related system change. Back in 2005 the UK held an meeting on abrupt climate change and many thought that this material would make it onto the new IPCC report, however it appears to not have made it so I was just asking what RC thought of this possibility? However in the main I would suggest that RC in the main agrees with the IPCC assessment.

    Comment by pete best — 29 Mar 2007 @ 7:37 AM

  100. Irony in 93 and 94.
    As a “laymen” who has worked very hard on understanding the subject, you two come across as smug, condescending know-it-alls.
    I enjoy reading this blog, it’s very informative and I have changed my views based on what I read. But I do not believe the science on AGW is anywhere close to being as conclusive as you two imply.

    Comment by tom — 29 Mar 2007 @ 8:14 AM

  101. One sixth of the worlds population lies below 25 meters. The four countries most at risk: China, India, Bangladesh, and the US. In the US, 50 million people live below 25 meters, or 1/6 of our population. If you use the first order assumption that economic contribution is proportional to population, this would mean that $2 trillion of our economy is at risk.

    Comment by Mike Burnett — 29 Mar 2007 @ 8:58 AM

  102. So could what you are saying be boiled down to this:
    Sea level had been rising 1 mm per year with out increased co2 but is now rising at 3 mm per year?
    So what was going to happen in 300 years will happen in 100 years.

    No wonder most economists say treat GW as a natural occurring phenomenon. People are extremely adaptable and we get more capable of adapting as technology increases. The longer we wait the easier the reaction.

    Comment by Floccina — 29 Mar 2007 @ 9:01 AM

  103. [[There is a documentary about some guys who went to Greenland and recovered a WW2 fighter plane that was resting on the ice where it made its emergency landing in 1942. After 50 years, they had to burrow down through 268 feet of new ice to reach the fighter on the surface of the 1942 ice cap.]]

    If 268 feet of ice was deposited in that time, wouldn’t ice depths fairly recently in geological time have extended to astronomical sizes? Is it possible the plane sank in the ice?

    Comment by Barton Paul Levenson — 29 Mar 2007 @ 9:21 AM

  104. [[No wonder most economists say treat GW as a natural occurring phenomenon.]]

    Who cares what economists have to say about climatology? Do climatologists go around researching markets?

    Comment by Barton Paul Levenson — 29 Mar 2007 @ 9:22 AM

  105. Re99: Ah, spoken like somebody who doesn’t understand the problem. I recommend checking out post 88 for a mild example of the economic implications of climate change. Much of humanity lives in regions less than a meter above sea level. And the real worry is not the 3 mm per year rise, but the fact that the rate of rise is accelerating–and we don’t fully understand why. In a world where population is expected to increase by ~50% before it stabilizes, a shrinking land mass is a concern.
    And sea level rise gets so much attention only because it is the most certain consequence of climate change. Others–failure of agriculture infrastructure, spread of tropical diseases, etc., while less certain, could have a greater impact.
    The science here is settled. It is well understood by the experts–even if not by the general public–and there is no controversy. What is needed now is a risk management and mitigation approach, where cost and probability of occurrence are both considered.

    Comment by Ray Ladbury — 29 Mar 2007 @ 9:34 AM

  106. Re #99:

    Flocinna, you wrote “People are extremely adaptable and we get more capable of adapting as technology increases. The longer we wait the easier the reaction.”. You seem to be an advocate of the “Don’t Worry, Be Happy” approach to dealing with AGW.

    The fallacy of that approach is that new technology doesn’t just happen. As an engineer with decades of technology development experience I know that new technology only comes into existence when countries, corporations, and individuals invest the necessary resources to develop and implement it. Identifying a need for a particular technology, such as carbon-neutral electrical generation, is easy. Turning it into a reality can be very difficult, and often take years longer than the initial planning.

    A good example of this is commercial nuclear fusion power generation. Billions of dollars, and thousands of man-years, have been spent since the mid-1960s trying to make the theory a reality. We’ve been “25 years” away from practical fusion power for the past 40 years. Anyone care to bet when the first fusion power plant will go on-line?

    The engineering challenges we face with AGW are mind-boggling. Even considering only the problems associated with sea level rise, it quickly becomes apparent that the sooner we get started, the less expensive and less disruptive the mitigation efforts will be. Take just one city, say Los Angeles, for example. How much money and time will it take to upgrade its airport, LAX, for a 4 – 6 meter sea level rise? How about its port facilities, water treatment plants, power plants, roads, wastewater plants, and so on? If Los Angeles spent $100,000,000 a year, every year, starting today, it would still take more than a generation to do all of the needed work.

    The sea level rise is coming. Ignoring it until it is lapping around your ankles makes no sense.

    Comment by Phillip Shaw — 29 Mar 2007 @ 10:08 AM

  107. Humans may be adaptable, but I don’t agree with “the longer we wait, the easier the reaction.” Whether we are able to adjust to the changes global warming is bringing or not, basically we are messing with a system whose components and feedbacks we don’t fully understand. Not to mention, I don’t believe anyone in the world has the right to damage climate which is being shared by the whole world. And worse, we don’t have the right to damage climate for our children. We need to act now by reducing emissions and reversing the damage as quickly as possible.

    Comment by Figen Mekik — 29 Mar 2007 @ 11:16 AM

  108. RE the West Antarctic Ice Sheet (#96, AndrewM), there’s a discussion of that at Thinning of West Antarctic Ice Sheet

    The consensus view of the workshop: Satellite observations show that both the grounded ice sheet and the floating ice shelves of the Amundsen Sea Embayment have thinned over the last decades. Ongoing thinning in the grounded ice sheet is already contributing to sea-level rise. The thinning of the ice has occurred because melting beneath the ice shelves has increased, reducing the friction holding back the grounded ice sheet and causing faster flow.

    Oceanic changes have caused the increased ice-shelf melting. The observed average warming of the global ocean has not yet notably affected the waters reaching the base of the ice shelves. However, recent changes in winds around Antarctica caused by human influence and/or natural variability may be changing ocean currents, moving warmer waters under the ice shelves.

    Our understanding of ice-sheet flow suggests the possibility that too much melting beneath ice shelves will lead to “runaway” thinning of the grounded ice sheet. Current understanding is too limited to know whether, when, or how rapidly this might happen, but discussions at the meeting included the possibility of several feet of sea-level rise over a few centuries from changes in this region.

    The evidence is in; the contrarians can’t explain the simultaneous warming of both poles as well as the melting of glaciers all over the world using ‘natural variability’ arguments. It’s time for the media who report on global warming to put the contrarian viewpoint in the category of ‘discredited science’.

    Comment by Ike Solem — 29 Mar 2007 @ 11:42 AM

  109. About Topex/Poseidon/Jason and tide gauge data : its seems strange that a new instrument (satellite) just coincide with a new trend (3-3,2 mm / y for 1993-2006 rather than 1,7-1,8 mm/yr for 1900-1992), even if there’s a well-known decadal variability (Cazenave 2005), with a low centennal acceleration (Church and White 2006). Should ancient measurements of sea-level be reevaluated, and if so, what would be the real present anomaly when compared to previous decades? Was there already an accelerating trend prior 1992, in the 1980s? Or is there a clear shift in the 1990s explaining the acceleration of the satellite-era?

    Thanks for information.

    Comment by Charles Muller — 29 Mar 2007 @ 11:42 AM

  110. An interesting graph from New Scientist showing CO2 emissions in perspective:

    http://www.newscientist.com/data/images/ns/cms/dn10507/dn10507-1_600.jpg

    it seems, that we have troubles to stabilize the CO2 concentrations at 550 ppm…

    at the moment, I don’t see any convenient solution…
    Still, if the developed world is not able to reduce it’s co2 output meaningfully , HOW could we await this from developing nations in the future, which from historical point of view have emmited much less carbon than we did…

    Comment by Alexander Ac — 29 Mar 2007 @ 11:45 AM

  111. Just how good are the measurements? You are talking about mm/year.

    1. How do you account for thermal expansion, is it regionalized?
    2. How are you accounting for tectonic plate shift? Is it not likely that the shape of the basins are changing at rates that are significant given the time scale and the mm/yr change rates?
    3. Is there a global calculation for H2O that accounts for ground absorbtion, evaporation cycles, and ice mass?

    If I have missed some links where the workup to this is shown, I would be grateful if you could share them.

    Thanks,

    James Williams

    Comment by jdwill — 29 Mar 2007 @ 11:52 AM

  112. Re #100
    I’ve always found that doing preventive maintenance on my house and car is less expensive than repairing the damage after the roof leaks because I was too cheap to replace some loose shingles, or the engine freezes up because I was too lazy to add oil. I don’t recall any exact figures, but I think some economists have estimated that a bit of preventive maintenance for our planet with regard to AGW (i.e., reducing GHG emission) will be less expensive than, say, rebuilding or relocating entire cities flooded by the rising sea level (and storm surges that go along with elevated sea level); I’ll pit these economists against your laissez faire economists any day.

    Comment by Chuck Booth — 29 Mar 2007 @ 11:53 AM

  113. Re: 101

    Who cares what economists have to say about climatology? Do climatologists go around researching markets?

    I think your comment typefies the relative vacuum that the climate sciences are sometimes percieved to operate in. Some have argued that climate scientists could learn a lot from the statisitcal data analysis methods of economists:
    http://www.dmi.dk/dmi/tr03-37.pdf

    Advanced statistical methods take into account the failure of standard assumptions and their effects on results, and offer new techniques to overcome the problems. However, these up-to-date methods have not been widely embraced in climate research. Development of advanced statistical methods in the fields of econometrics and geostatistics has now surpassed the methods still used in climate research.

    Comment by cbone — 29 Mar 2007 @ 11:57 AM

  114. Re #100: [People are extremely adaptable...]

    In this case, an appropriate adaptation would be to alter lifestyles so as not to cause further AGW and its related problems. But if you dare to suggest actually doing that, you’d better have ear protection ready, else you’ll be deafened by the squawking from the denialist camp.

    Hey, you suppose maybe some humans aren’t so adaptable after all?

    Comment by James — 29 Mar 2007 @ 12:01 PM

  115. Re #104: James Williams — Tectonic plate shift is interesting in regard to ocean basin size. The main change is due to the Australio-indian plate shoving into Asia at a considerable rate. This means that the Indian Ocean becomes larger at about that rate. Despite this extra capacity, the oceans are rising…

    Comment by David B. Benson — 29 Mar 2007 @ 12:16 PM

  116. Re 104: Uh, James, it’s not all that complicated. To a first approximation, a certain amount of land is above sea level, and a certain amount below. The fastest plate moves at about 15 cm per year–and that’s in the pacific basin and so not going to have much effect. In brief answer to you questions
    1)Yes, they can take thermal expansion into account. That is only going to increase the sea level rise in any case.
    2)Not significant. There’s not a lot orogenesis going on these days, while arrangements of the continents will change over HUNDREDS OF MILLIONS of years, you won’t see a lot of change in elevations.
    3)Sorry, other than ice mass, I don’t see the relevance of this. There’s virtually no soil in Greenland or Antarctica under the glaciers, so not much ground absorption.

    What you are asking is what the models do.

    Comment by Ray Ladbury — 29 Mar 2007 @ 12:17 PM

  117. Re 105: David

    Right, but how are these shifts being measured? Are we able to use something like radar/sonar from satellites to map the ocean bottoms accurately and calculate volume?

    Thanks,

    Comment by jdwill — 29 Mar 2007 @ 12:26 PM

  118. >100, “most economists say”
    >101, “who cares what most economists say”

    A thought — rather than argue about the statement, how about providing a source for it? If it’s true that any economist says this, show us who and where by providing a cite or a link to the page.

    Here’s a good short discussion about that kind of claim.
    It’s often not useful to make, or respond to: http://en.wikipedia.org/wiki/Weasel_words

    Comment by Hank Roberts — 29 Mar 2007 @ 12:30 PM

  119. Re 105: David

    Thanks. But, how is the volume calculated? Do we have the ability to map the ocean bottoms accurately using Sonar or some type of radar from satellites? Is there a link to a global project or series of projects that have done such a mapping?

    Thanks,

    James Williams

    Comment by jdwill — 29 Mar 2007 @ 12:35 PM

  120. Re #100
    So could what you are saying be boiled down to this:
    Sea level had been rising 1 mm per year with out increased co2 but is now rising at 3 mm per year?

    I think you misread, or didn’t follow the links. For the last two millennia, sea level has been rising at a few _tenths_ of a millimeter per year. This century, the sea will rise more than it has, cumulatively, since the time of Christ.

    Comment by Tim McDermott — 29 Mar 2007 @ 12:43 PM

  121. Re 110: I have read that article and yes it is going to be difficult with a world population of 9 billion come 2050 for us to stabalise a t550 ppm, however way before 2050 PEAK OIL and GAS would have occured and that means plenty of other issues for us to mull over such as where to get our energy from in the first place.

    Fossil fuels might be responsible for AGW but they are also responsible for nearly everything that modern humans have come to expect of life, progress and prosperity for all at least in principle.

    I await the cohesive energy strategy for a sustainable future myself and until I see it in print for thr entire world then I doubt that we will mitigate CO2 levels below 550 ppmv.

    Scary aint it

    Comment by pete best — 29 Mar 2007 @ 1:30 PM

  122. BTW the site for some reason held and then later reposted one of my posts. Sorry for any repeats or misnumberings.

    #116. OK and thanks for as much as you answered, but how is this known? I am looking for some links to detail. Plus, are the plates limited to planar movement?; could they not be raising and lowering on the mantle? My essential question: is the 3D shape of the ocean floor being measured or studied? If so, where and how?

    The reason I am bringing this up is to help me understand what the level of uncertainty in sea level measurements might be.

    Comment by jdwill — 29 Mar 2007 @ 1:32 PM

  123. There is post-glacial bounce, which appears to be in the model.

    NASA, NOAA, etc. – these guys have toys on top of toys on top of toys. They’ve measured this stuff ten ways to Sunday, and they will keep adding measurements and new measurement toys. NOAA has been doing this stuff almost since the American Revolution. When the 28th Marines and my father planted a flag on top of Mt. Suribachi, Iwo Jima, a crew of science guys from the NOAA were right there with them.

    NASA, NOAA, etc. are staffed by dedicated people and they’re exceptional scientists.

    In the news today:

    http://www.sciencedaily.com/releases/2007/03/070327122328.htm

    Comment by J.C.H — 29 Mar 2007 @ 1:51 PM

  124. James Williams — The Indian plate is disappearing under Asia at 4 mm/yr, according to Wikipedia. I’ll leave you to find a suitable depth for the Indian Ocean, say about 200 km south of the continental shelf. But if it is 1 km deep there is a volume increase of 1 m/yr. Clearly not enough to matter…

    Wikipedia is always a good place to start. There are often links to more authoritative sources.

    Comment by David B. Benson — 29 Mar 2007 @ 1:55 PM

  125. Something that always bugs me about this stuff, is when it is supposed to start to happen.

    Correct me if I’m wrong but wasn’t the average sea level rise for the past century 3mm a year? And isn’t that what we are measuring now?

    If data is in that contradicts my assumptions, please mention it.

    But if drastic changes are in store, or happening now as the news suggests to me, when are you going to see 10mm a year or higher in sea level rise, which is the bottom line? I’m aware sea level can “differ” depending where on the globe you are, but if Greenland or Anarctica is going to lose dramatic amounts of ice, it has to show up sometime.

    Comment by sunbeam — 29 Mar 2007 @ 1:58 PM

  126. Oops!

    4 m^2/yr per meter along an east-west axis the width of the Indian portion of the plate.

    Still doesn’t matter.

    Comment by David B. Benson — 29 Mar 2007 @ 1:59 PM

  127. Just want to add, since there doesn’t seem to be an edit button, that there is nothing special about the 10mm. I simply want to know when the sea level rise figure is going to have a dramatic rise. Also if my impression of the current rate is wrong, I’d like to know.

    Comment by sunbeam — 29 Mar 2007 @ 2:00 PM

  128. #122 JCH

    Thanks, that article is exactly the sort of starting point I was looking for.

    James Williams

    Comment by jdwill — 29 Mar 2007 @ 2:05 PM

  129. Here is another article in the news today:

    http://www.sciencedaily.com/releases/2007/03/070328170704.htm

    Comment by J.C.H — 29 Mar 2007 @ 2:46 PM

  130. Re 103:

    BPL,

    The plane that was recovered from the Greenland glacier is one of six P-38Fs, plus a B-17, that crash landed on the snow in July 1942 after encountering bad weather while being ferried to Iceland on their way to England. All of the crews were recovered safely. The account of the location and recovery of the P-38 is told in the book The Lost Squadron.

    I believe that the present depth of the remaining wrecks of 268 feet is simply snow and ice accumulation since 1942. If I remember the story correctly the firn layer is about forty feet down. Since the snow was firm enough to land on I can’t think of any mechanism for the planes to sink into it. And consider that the 268 feet of ice and snow represent 300 feet or so of snowfall. Over the fifty years between the crash and the recovery that’s only six or seven feet of snow a year.

    The recover took fifteen years of dedicated work, 1977 – 1992. The recovered plane has been restored and is now flying on the airshow circuit as Glacier Girl. It is the only P-38 flying with its original engines. If you’d like to learn more just google Glacier Girl.

    Comment by Phillip Shaw — 29 Mar 2007 @ 2:53 PM

  131. Increase in ocean volume — According to Wikipedia, the ocean area in 362 million km. At an increase of 3 mm/yr, that is 1.086 billion m^3/yr. Suggested sources include

    melting in Alaska
    melting in Greenland
    melting of other glcaiers and ice caps, such as in Patagonia
    groundwater depletion
    thermal expansion

    Comment by David B. Benson — 29 Mar 2007 @ 3:31 PM

  132. >depth
    Search for “bathymetry” and urge your national government to fund it!

    Best done from space, e.g.:
    https://darchive.mblwhoilibrary.org/handle/1912/1413

    Don’t take this plan for more accurate measurement as a reason to imagine there might be some sudden and unnoticed change happening at the base of the ocean that’s raising water levels worldwide without anyone noticing any earthquake or other effect, please.

    Comment by Hank Roberts — 29 Mar 2007 @ 4:08 PM

  133. Re #96:

    A statement from the panelists at the University of Texas meeting regarding the potential for severe effects from relatively rapid melting of the West Antarctic Ice Sheet is here:

    http://www.jsg.utexas.edu/walse/statement.html

    (Tech note: The webcast referred to in #96 unfortunately doesn’t seem to work on an Intel Macintosh. My old P4 powerbook seems to handle it.)

    Comment by Michael Tobis — 29 Mar 2007 @ 8:47 PM

  134. Re #57. Yartrebo, I guess the down-side of isostatic rebound of Greenland (and presumably the Antarctic too) is that it will increase the gradient towards the sea, which will of course speed up the loss of the remaining ice. Another positive feedback?

    Comment by Nigel Williams — 29 Mar 2007 @ 9:35 PM

  135. critique and bottom line links don’t work

    Comment by Regina — 29 Mar 2007 @ 10:24 PM

  136. So, to clarify my earlier question, the antarctic ice cores provide uninterrupted CO2 data for the past 700,000 years? There are no gaps in the record? I think the fellow I was debating with claimed the Vostok ice cores contained large gaps of thousands of years where all sorts of crazy stuff could have happened, ergo the past 150 years might be a natural phenomenon we have no record for. Is it possible to date the carbon reliably, to verify the record? And do ocean sediment samples verify the ice core data by comparing CO2 levels, or another method? Thanks!

    Comment by Mike — 30 Mar 2007 @ 3:24 AM

  137. Whoah! Who else besides Dr. Hansen is talking about this?
    Where’s the info from, anyone recognize it?
    http://europe.theoildrum.com/uploads/465/cv_hansen_fig4.png

    found here: http://www.energybulletin.net/22996.html

    Comment by Hank Roberts — 30 Mar 2007 @ 3:31 AM

  138. I know you’ll appreciate this because the Bush administration has done so much to keep science information from getting out–

    Re: prosecutor-purgegate

    http://www.thecarpetbaggerreport.com/archives/10349.html

    What explains the failure of the mainstream media to cover the purge scandal for so long, and so many other scandals? Do you think somebody just set up newspaper editors to cheat on their wives, and threatened to tell if the editors wouldn�t play ball when they come back some day and ask for something?

    It wouldn�t be that hard to do, when you think about it. People wouldn�t talk about it.

    Comment by Swan — 30 Mar 2007 @ 6:52 AM

  139. re: 136

    Natural variability is an abstraction. It refers to natural variability of the forces that produce this or that phenomenon. Things don’t happen randomly. If there’s a fluctuation, there’s something that caused the fluctuation. In climate, there are known vectors — sun, greenhouse gases, clouds, etc. We’ve currently got a huge spike in the greenhouse gas CO2. Unless you’ve got something else in mind, that’ll do it.

    Comment by Jeffrey Davis — 30 Mar 2007 @ 7:01 AM

  140. [[I think the fellow I was debating with claimed the Vostok ice cores contained large gaps of thousands of years where all sorts of crazy stuff could have happened, ergo the past 150 years might be a natural phenomenon we have no record for.]]

    Driven by what?

    Comment by Barton Paul Levenson — 30 Mar 2007 @ 7:06 AM

  141. Re: 130

    Actually, the butial of objects like this is quite interesting..

    Aircraft like this are usually found much further down than normal accumulation would suggest – this is because of a couple of effects -

    (a) The aircraft is dark and so likely to warm up more in the sun, melting ice around and underneath it, and
    (b) The pressure of the aircraft will also lead to pressure-melting and gradual sinking of the aircraft.

    Comment by Andrew Dodds — 30 Mar 2007 @ 7:20 AM

  142. Sea level rise, etc.

    See http://users.aol.com/hmolvar/index.html for one of the many possible consequences.

    Comment by Henry Molvar — 30 Mar 2007 @ 8:29 AM

  143. Re 137 ankh:

    http://www.climatecrisiscoalition.org/hansen/vermont_14aug20061_textwfigs.pdf

    Says it’s from:

    http://adsabs.harvard.edu/abs/2006Sci…311.1756E

    Comment by Adam — 30 Mar 2007 @ 9:04 AM

  144. Re #88 (my own earlier post)

    http://www.wildsingapore.com/news/20070304/070307-10.htm

    “Singapore has already put measures in place in response to earlier studies by the IPCC, which was set up by the United Nations Environment Programme and the World Meteorological Organisation. All reclaimed land, for example, are [sic] currently designed to be about 125cm above the highest recorded tide. This is well above the sea-level rise of 59cm projected by the IPCC report.”

    Some people in Singapore (which has lots of reclaimed land) apparently believe that 59 cm is the upper limit for sea level rise, but in fact it could go up a bit more than that even this century – and of course still more after that. It’s pretty hard to raise the height of reclaimed land after roads and buildings have been built on it! And this is just one relatively minor example of the economic impact of climate change…

    Comment by Gerry Beauregard — 30 Mar 2007 @ 9:25 AM

  145. Re 137, I posted about it on post 99, he wants a moratorium on new coal fired power stations until clean coal technology is developed proven it would seem. Europe is also using more coal these days and we all know about China. Clean coal technology is vital to mitigate AGW, however I am doubtful that this will be met within the 10 year period that Dr Hansen required before we allegedly reach that 1 Degree tipping point he has talked about.

    Look at http://www.321energy.com for information on energy services. It is all very interesting there and lots of articles speak of peak oil and gas, new vehicles and alternatives to assist us in our sustainable brave new world.

    Comment by pete best — 30 Mar 2007 @ 9:46 AM

  146. #136 Mike wrote: “ergo the past 150 years might be a natural phenomenon we have no record for…”

    This is a wierd comment. Please read this website. No serious scientist would just use one line of evidence…or their peers would destroy his or her career (maybe not… since Richard Lindzen, Fred Singer, Michaels and other frauds are doing this..just not in peer-reviewed literature).

    Many other lines of corroborating evidence exist…ocean bed cores, Carbon 12 to 13 ratios in rock, lake bed sample cores, fossil tea leaves (sorry, joke…tree leaves’ stomata (fossil holes that breathed in CO2), amber holes, precipitates that correspond to CO2, other leaf fossils vs animal fossils, and others (its too early in the morning).

    What do you take the scientific communtity for? Only idiots or political rantists would claim that the scientific community would use only one line of evidence.

    For instance, for tree rings, easily 40 tree cores from one area would be used to confirm the data.

    For ancient rock sample Uranium series dating…easily four independent labs would analyze ten or more samples using different techniques to date or do carbon 12/13 anlysis and test the results against each other.

    It is a pretty tough business and you are eventually scutinized pretty closely.

    If you have holes in your arguments, you will eventually be torn to shreds in the peer reviewed journals…if you are honest enough to do it…

    This ice core data body of evidence has been used, examined, refined and built up since the 1950s.

    Jeees.

    Comment by Richard Ordway — 30 Mar 2007 @ 9:49 AM

  147. Re 134. The gradient might be reduced as isostatic adjustment will have the greatest effect where the ice thins most….near the edges of the ice sheet.

    Comment by stephan harrison — 30 Mar 2007 @ 10:13 AM

  148. During WW2 my uncle worked as a physicist under G.R. Irwin at the Naval Research Laboratory:

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

    Comment by J.C.H — 30 Mar 2007 @ 11:12 AM

  149. RE #93, thanks for the link ( http://blog.sciam.com/index.php?title=please_stop_talking_about_the_global_war&more=1&c=1&tb=1&pb=1
    ). I skimmed over the entry.

    It’s good scientists are looking to the social & behavior aspects re global warming. As mentioned in my (not yet released) post, we need a holistic perspective (re all the problems involved with GW & with the measures that cause GW & a host of other problems, as well).

    And, here, I’ll mention that we need a holistic approach to the study of GW, which includes not only the physical sciences, but the social/behavioral sciences, & even the humanities, since people are causing the problem & people are being affected by the problem.

    My field, anthropology, is the only one I know of (except gerontology) that is simultaneously a physical science, social/behavioral science, and humanities, and it has a subfield in the subfield of sociocultural anthropology called environmental anthropology. So it is well positioned to get involved with GW studies, but to my knowledge it’s not been very involved (a few studies here & there). In fact, it was when I was working on a lecture for Intro to Anthro in 1990, on the final chapter, “The Future of Humanity,” that I seriously got into looking at GW, both for my students and for myself.

    In that lecture I would chalk in a chart (based on rough ideas, not stats) about human adaptibility — sort of an exponential (hocky-stick) curve — a long near-flat line of minor advances over a couple million years, then a slight upswing for the intro of agriculture 12K years ago, and a big upswing at the very end for the industrial revolution, which has even allowed us to go into many new environments (the sky, outer space & under the water), & have a rich lifestyle, etc.

    Then as I finish chalking in the exponential-like curve, I mention that there’s nothing inherent in this that means we’ll automatically keep progressing. In fact, we could cause ourselves so many problems (e.g., environmental, resource depletion), that we crash. And I draw a sharp broken downswing to the end of the curve.

    I’m gonna try harder to push GW in anthropology. If this is not one of the great human (anthro) issues, then what is?

    Comment by Lynn Vincentnathan — 30 Mar 2007 @ 11:43 AM

  150. Ah, now this is something that’s been nagging at me for some time.

    …this discussion has all been about sea level rise until the year 2095. Sea level rise does not end there, as the quotes from the SPM at the beginning of this article show. Over several centuries, without serious mitigation efforts we may expect several meters of sea level rise.

    Clearly the difference between the outputs of different models and different scenarios diverges over the period of time being modeled. Clearly at some point, merely extrapolating the best, worst, and average trend lines (for both global mean temperatures and for sea-levels) stops being at all useful. For starters, off the top of my very lay layperson’s head, non-linearities and feedbacks that may not be apparent at decadal timescales will emerge. Secondly noise in the system and minor differences between models will be amplified to the point that they drown useful outputs. The scenarios seem likely to become increasingly inaccurate over time, as well — for instance, there are plenty of events beloved by catastrophists that could greatly reduce human population and/or CO2 emissions in a very short period (a new influenza pandemic for instance, or some sort of major earthquake or volcanic event that causes significant economic disruption, or… pick your favourite Horizon episode…

    So, I understand that there are good reasons for the IPCC charts to stop at 2100 (or 2090, or thereabouts)… but surely I’m not the only one to wonder what happens to those plots if the x axis is extended out another century or two? Even if they’re artificially restricted scenarios such as “CO2 emissions stabilise at 1990 levels for the next 300 years”? If anyone’s got pointers to vaguely credible sources such data, I’d love to know…

    Comment by Andrew Simmons — 30 Mar 2007 @ 1:05 PM

  151. Re #44 (Edward Greisch):

    It might be worth pointing out something that I think you might be confused about: Note that with the earth being like 70% ocean, the average sea shore slope is a very small correction to any calculation of sea level rise. For example, even if the sea levels rose enough to increase the area of the oceans to 74% of the earth’s surface (which is, of course, I think a large overestimate of anything that is going to happen), you would get less than a 6% error in the predicted sea level rise by not accounting for this (i.e., because the surface area of ocean has increased by ~6%…In the area where the ocean already was, the increased volume is given by the surface area times the increase in sea level. In the new area, it is some fraction of this since the depth of the ocean in this new area ranges from a value of 0 to a value of the sea level increase).

    Comment by Joel Shore — 30 Mar 2007 @ 1:12 PM

  152. Geography is another such field.

    Comment by t.r. — 30 Mar 2007 @ 3:43 PM

  153. re 96 108

    It seems funny that what seems to be happening in Minnesota seems to be happening in Antarctica’s Amundsen Sea Embayment and other places.

    They said “surprisingly rapid changes” were occurring in Antarctica’s Amundsen Sea Embayment,

    For example, ice fisherman are often surprised by patches of thin or open water that they drop into on occasion even after some seemingly Minnesota style cold spells.

    They’re caught off guard by huge blocks of ice jamming and flooding their homes as rapid thaw of snow on frozen ground occurs even though the winter has been milder than a Minnesota style normal.

    They don’t seem to know or care much about the interactions between snow cover, albedo, ice thickness and how their lake surfaces freeze and thaws.

    The winter of 2006-2007 was a tricky one ya know. Little or no snow cover until early in March. Air temperatures in February were below averages but with sunny skies. The ice got thick in some parts but not others. The sun penetrated the snow free lake surfaces until the snow came. Warm mid March weather got rid of the snow on top allowing the sun back in to warm the water beneath the ice and eliminate it. Thus much of the lake ice was elimated by waters below the ice that didn’t really get very cold, Minnesota style.

    The seemingly funny part is Minnesotans need to be told about the unpredictable danger in driving or snowmobiling out on the lakes, over and over again every year, yet they go out anyway (rarely catch anything worthwhile – mostly bottle bass).

    It seems most humans needs to be told again and again about the consequences of greenhouse gas emissions but global warming doesn’t seem to bother them much so they won’t change. They’ll take their chances which are not as good as they used to be.

    March, 2007 daily high and low temperature plots at Minneapolis are at:

    http://new.photos.yahoo.com/patneuman2000/albums

    Plots showing surprisingly abrupt jumps in the frequency of record high low air temperatures and abrupt falls in the frequency of record minimum low temperatures at Minneapolis and Park Falls 2 South, Minnesoa are at:

    http://npat1.newsvine.com/

    Comment by pat neuman — 30 Mar 2007 @ 4:08 PM

  154. Re 145: Would just like to clarify, I personally am not using these arguments; I am quoting the arguments of someone else, and am trying to address his criticisms. I have looked at the data on this site, but have only recently begun educating myself on the topic, so I’m seeking some clarification. For example, I understand that the ice core data from antartica extends back 700,000 years; my question was, is it 700,000 years of data altogether, or are there gaps? Now I know that there are no gaps. Your comments regarding corroborating lines of evidence are very interesting; I have read about tree rings and carbon dating, but tend to find more about WHAT the results say, rather than HOW they were done. If I tell him “uranium dating provides evidence” I expect he will reply “those tests can be wrong.” But now I can argue that the process involves multiple labs, samples, and different kinds of tests; the results are simply much more reliable. So thanks for the info!

    Comment by Mike — 30 Mar 2007 @ 5:12 PM

  155. Lynn, that’s a great approach. After all, the rise of human civilization over the past six thousand years relied on a fairly stable climate for agricultural production, as I understand it. This is a very rich topic for making the link between human civilization and climate – there are the cultures that lived in the Sahara before it dried out, there are the Anasazi ruins of the American Southwest, the collapse of Mayan civilization due to drought, and the southward expansion of the Scandinavians due to regional cooling.

    However, the contrarian claim is that such climatic fluctuations are ‘normal’ and thus the current warming trend is also ‘normal’. The counter to this is to explain that climate is sensitive to many different variables, from orbital solar forcing over long timescales to volcanic eruptions over short timescales. By focusing on the fact that climate is sensitive to forcings, you can show students how the climate is also sensitive to anthropogenic CO2 forcing, which is greater than any current ‘natural’ forcing.

    Thirty second soundbite: “Our climate is sensitive and variable, as the paleoclimate record and the record of human civilization shows. Human civilization is very dependent on a stable climate regime, as history shows. By adding CO2 to the atmosphere, we are creating a strong influence that will (and is) having a stong effect on the sensitive climate system; the effects are sure to impact human civilization and we therefore have to take action to slow the rate of global warming, and that means drastically reducing fossil fuel use.”

    Comment by Ike Solem — 30 Mar 2007 @ 5:25 PM

  156. I think the denialist trolls on these threads are quite valuable. I read one of the denialists and try to phrase my response, then I can scroll down and see if I got it right.

    My own feeling is that we need to be able to refute, civilly, courteously, and briefly, the denialist arguments. To be able to do that you need to be aware of the argument you’re hearing and have an answer ready, and have a high degree of confidence that your answer is right. Practicing on the troll comments in the threads is a good way to be ready.

    Comment by serial catowner — 30 Mar 2007 @ 5:51 PM

  157. Re 113. It is not obvious that one discipline is more advanced in its use of tools than the other. It seems to me that all disciplines have trouble in describing, simulating and modelling systems which are far-from-equilibrium. Specifically, there are numerous systems that appear, for example, to exhibit self-organised criticality (SOC) and yet very little is understood about SOC. It is not surprising, for example, that the IPCC does not venture to properly describe the melting of the poles because that would be well beyond current methodologies and theoretical frameworks. How, for example, would one be able to describe the formation and dynamics of the large-scale vortices that are bouncing around the antarctic circulatory system and their (resonant) interaction with, for example, the west antarctic ice sheet. Such an example fits within the scope of the nonlinear dynamical processes, dominated by ice sheet disintegration, which James Hansen refers to in the above-linked paper Scientific Reticence and sea level rise. Turning to economics, similar issues apply. If economies are to deliver carbon downsizing on the scale required over the timescales required (eg 90% reduction over about 20 years), the process is nothing other than an economic phase transition. It is hard enough describing simple phase transitions in physics, let alone the phase transitions in process and triggering on the global economic scale. Is the global economy about to enter a state of SOC as it responds to the challenge of climate change? Perhaps. Will global corporations go through a process of SOC as they carbon downsize, synchronise, transition, and accelerate to the carbon lock-down phases? Perhaps. Will antarctica, and specifically the west ice sheet, enter a state of SOC? Perhaps … the climatological experts on RC could provide some comment on the third term which is at the heart of James Hansens paper on Scientific Reticence and his suggestion that paleoclimate ice sheet models do not generally contain the physics of ice streams … or realistic interactions with the ocean … and that sea level rises during this century may be an order of magnitude greater than the IPCC story.

    Comment by Michael — 30 Mar 2007 @ 6:48 PM

  158. Re #137 (Hank Roberts, according to the current number scheme): Who else is talking about it? Why, RealClimate, that’s who. I’m also talking about it, but that fact seems not to impress people for some obscure reason.

    Comment by S. Molnar — 30 Mar 2007 @ 7:06 PM

  159. Serial catowner, I’m not sure that trying to reply to denialists is necessarily a worthy undertaking. If you’re the same serialcatowner who posts in Seattle PI, I share a lot of your concerns, but some denialists are so entrenched in their opinions and so irrational, you’ll never have them acknowledge even the hardest facts. RC is best to actually foster your understanding of the underlying science. Rather than trying to oppose denialists, it is best if you can disseminate that understanding to whatever portion of the general public you have access to, where there is often no established opinion and a limited comprehension of the issues/underlying science.

    Comment by Philippe Chantreau — 30 Mar 2007 @ 7:23 PM

  160. This report of findings from Antarctica just yesterday indicates that a huge ice sheet is thinning much quicker than predicted. If it melts, or slips into the ocean(could that happen?), the seas would rise 20 ft. The question is, when could this happen?

    Comment by Jack Roesler — 30 Mar 2007 @ 9:11 PM

  161. >137, 144
    thank you Adam for the pointer. I’ve also found mention at Eli Rabett’s blog of Hansen’s presentations.

    Comment by Hank Roberts — 30 Mar 2007 @ 10:21 PM

  162. Lynn thanks. Ike Solem makes a great point following up. Thefatc we cam into exoesuence in one of these geological and orbital blips should give anyone pause. Of course the Crichton crowd still thinks Dinoasaurs and humans lived together so…

    Comment by Mark A. York — 30 Mar 2007 @ 11:18 PM

  163. RE #102, “Sea level … now rising at 3 mm per year? … No wonder most economists say treat GW as a natural occurring phenomenon. People are extremely adaptable and we get more capable of adapting as technology increases. The longer we wait the easier the reaction.”

    [My post on this failed, so here goes again.]

    The problem with this thinking is that there are many other harms from GW, not just sea rise, which seems not to be the worst of the problems. Severe drought, heat killing the crops, & loss of glaciers on which a large chunk of humanity depend for irrigation & drinking water are perhaps more serious problems from GW.

    So even if sea rise does not seem to be a serious problem (and others have pointed out it is a serious problem), there are plenty of other serious problems in store.

    We need a holistic approach. While analyzing a narrow aspect of GW, such as sea rise, we need to keep in the back of our minds all the other effects of GW, and all the other problems arising from the same measures that cause GW (e.g., energy production), such as acid rain and local pollution, to name a few.

    And the non-environmental problems relating to failure to mitigate GW, such as wealth loss due to inefficiency & lack of conservation.

    There are health issues related to our inactive lifestyle. When feasible it is good for the health and spirits to offset a bit of our driving by walking or cycling. Eating low on the food chain is also good for our health, as well as mitigating GW & many other environmental problems.

    Of course there are benefits from measures that cause GW, such as a high lifestyle, but either we choose to tighten our belts in wise ways now — which would be good for our health & pocketbooks — or we (mainly our descendents) may be thrust into a harmful, debilitating type of poverty. Perhaps we need to think about what we really want. Is it money & things, or is it happiness, love, health, & comfort, which we think those things will buy — but we get so caught up in the shopping spree that we forget our original goals.

    I know people who live far from work and drive many miles each day, only because the realtor showed them homes far away (there were comparable, even better homes closer). If feasible (& other requirements can be met), there are many benefits to living closer to work/shops/schools, aside from reduced environmental harms — more time with family, less stress, less health problems from car fumes.

    Mitigating GW is a win-win-win-win situation, v. failing to mitigate, a lose-lose-lose-BIG LOSE situation.

    We cannot simply focus on one narrow aspect of GW, such as sea rise, figure we can get out of the way in time not to get our feet wet, then dismiss the problem of GW altogether.

    Comment by Lynn Vincentnathan — 31 Mar 2007 @ 9:16 AM

  164. [[1) temperature jumps preceding co2 level jumps. I checked out the page on this site trying to explain the 800 year lag, except that they couldn`t explain it. They gave a circular argument saying that something kick started the temperature jump, which led to the co2 rise... but they don`t know what. Exactly, they don`t know.]]

    But they do know. Do a Google search on “Milankovic cycles.”

    You know why they keep repeating that “cause unknown”? because Jeff Severinghaus of Scripps Institution of Oceanography did a completely crappy job of explaining the 800-year lag issue, and RealClimate compounded its error in not cleaning it up and explaining it by linking to it off its analysis of tGGWS. It doesn’t mention Milankovich cycles by name, nor explain C02 absorption by colder vs. warmer water. It’s deeply confusing.

    For instance:

    Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later.Then CO2 further warms the whole planet, because of its heat-trapping properties.[My emphasis]

    A normal reader of that would conclude he was saying this:

    Gee, we have NO IDEA AT ALL why ice ages stop, however, we DO know that that same mysterious process we know absolutely nothing about increases C02 800 years later, at which point the mysterious process slows down and C02 takes over. Which looks like hand waving. IS hand-waving, frankly. It implies by omission much more uncertainty than there is about Milankovich cycles.

    What he should have said:

    The argument that a graph showing a correlation between temperature and C02 with a lag for the latter shows changing T causes changing C02 is flawed for a number of reasons. I’ll give as a counterexample a model of T/C02 feedback over the 5,000 years it takes for the Earth to warm up from a glaciation. That fits the ice-core derived data well, including even the 800-year lag at the end of the glaciation. In other words, I can easily give a counter-example in an artificially minimalist case where we don’t even have to quibble over what warmed the ice up to begin with that matches the data, therefore, logically, your claim that the data shows change in T causes change in C02, period, is invalid.

    I can’t even speculate* on why Severinghaus chose to use “currently unkown.” The reason that correlation graphs are not generally not sufficient evidence of causation is fundamentally the possibility that a third factor is causative both of the correlated variables. I’d be intrigued as to what possible observations we could have that would change the causes of the ice warming up from “currently unkown” to “currently known.”

    *Okay, I’ll GUESS from this:

    “Changes in the amount of summer sunshine, due to changes in the Earth’s orbit around the sun that happen every 21,000 years, have long been known to affect the comings and goings of ice ages. Atlantic ocean circulation slowdowns are thought to warm Antarctica, also.”

    that the point was supposed to be something like, “…whatever the relative contributions of the known factors turns out to be.”

    Comment by Marion Delgado — 31 Mar 2007 @ 9:34 AM

  165. 64. Barton Paul Levenson:

    They, and we, do know. However, unfortunately, on RC there’s an explanation of that 800-year lag talking about warming from a glaciation that starts with the Antarctic warming for “cause unkown” which same “process” causes C02 to rise 800 years later. Moreover, people in comments on RC are repeating that “cause unknown.” So it’s “our” fault, not just INCLUDING RC, but in fact, ESPECIALLY RC’s fault, frankly. And it should be fixed ASAP.

    Comment by Marion Delgado — 31 Mar 2007 @ 11:00 AM

  166. This is off-topic, but I really wish somebody from RealClimate (or someone as knowledgeable) would take apart Margaret Wente’s columns on climate change in the Globe & Mail (www.globeandmail.ca) — the woman is a mine of disinformation.

    Comment by bob — 31 Mar 2007 @ 11:55 AM

  167. To a non scientist it certainly seems that there is an accelerated rise is sea level height and whilst this may seem small over a decadal period, beyond that it will have a significant impact on waterside communities, particularly in the third world who are least able to adapt to sea level rise. Interestingly no one seems to take responsibility. Even wealthy pro AGW seem quite happy to go on with their lifestyle and travel choices and offset thier “carbon foot print”. However this approach to me is similar to suggesting being a paedophile is OK as long as I pay for a thirld world school or other childrens project. Wrong is Wrong.

    Comment by FatBoy — 31 Mar 2007 @ 1:59 PM

  168. CO2 only changes from 180 ppm to 280 ppm from the height of the ice age to the height of the interglacial.

    Is that enough to contribute to the temperature change of 5C? How much does it contribute?

    Comment by George K — 31 Mar 2007 @ 3:09 PM

  169. Re: #167 (George K)

    The increase in CO2 contributes about 2 deg.C to the net warming from glacial to interglacial. The other 3 deg.C is mostly from reduced albedo, caused by wasting away of the ice sheets.

    Comment by tamino — 31 Mar 2007 @ 3:51 PM

  170. very very nice blog.thank you for your informations…

    Comment by evden eve nakliyat — 31 Mar 2007 @ 3:51 PM

  171. Re #167: George K — About half.

    Comment by David B. Benson — 31 Mar 2007 @ 4:20 PM

  172. Re 163. Sea level rise is a big problem. It is the problem that is making governments and corporations sit up and consider what action needs to be taken. If the IPCC sea level rise numbers are wrong or deficient, there are urgent implications for protection of infrastructures on coasts. These infrastructures have multiple mappings into global supply chains and national and regional infrastructures. If we use James Hansens terminology in his Scientific Reticence and Sea Level Rise paper (linked above), there are three terms to consider. Terms 1 relates to thermal expansion of ocean water and term 2 relates to melting of alpine glaciers. For the sake of simplicity (superposition and coupling arguments etc), these are the linear terms. Term 3 is the nonlinear term and relates to ice sheet disintegration. If I understand the situation correctly, the IPCC has broadly focussed on terms 1 and 2 and so the sea level rise number is at most 1 meter, ingoring all the fiddle factors.

    By their nature committees and groups seeking consensus and groupthink don’t do nonlinear because nonlinear doesn’t easily sit with consensus or groupthink. But James Hansen suggests the nonlinear bit could give about 10 meters. If the IPCC did consider the nonlinear effects but just lost the report because it was put in the wrong filing cabinet then they should come clean. If they didn’t do the nonlinear bit, they should also come clean. What the world needs is for climate experts to step up to the line and suggest what they think the missing third term might be. Upper and lower bounds would be OK. Statements that they don’t know would be OK. To ignore it as an unspeakable is surely not acceptable because that misleads many into thinking sea level rise = term 1 + term 2 + zero and so BAU is probably OK. At least if there were a distribution of experts estimates and bounds for the third term then others who are risk mapping the effects (eg on global supply chains, on infrastructure) can apply relevant bounds.

    James Hansen has written that he thinks the sea level rise by 2100 may be about 10 meters. What do other climate change experts think? What do climate change experts expect the component of sea level rise due to nonlinearity to be?

    How should the world’s public interpret the experts silence about the missing third term?

    Comment by Michael — 31 Mar 2007 @ 4:22 PM

  173. Actually he said five meters. This is a ballpark figure that assumes thermal expansion, meltwater runoff and the collapse of West Antactica, derived by simple decadal doubling of the 1 cm/decade increase in the ice sheet contribution of global sea level rise observed today. Thermal expansion may increase that figure.

    Since we thought we were looking at a 1.8 mm/year increase, and it turns out the actual increase may be 3.2 mm/year, there may be some cause for concern. But what the hell, it’s only water.

    Comment by Thomas Lee Elifritz — 31 Mar 2007 @ 4:57 PM

  174. Re #172 (Michael): Did Hansen actually say 10 meters by 2100? Where? I had the impression that he was actually being somewhat “reticent” about stating a worst-case for 2100, probably because it would just be a guess.

    Comment by Steve Bloom — 31 Mar 2007 @ 5:06 PM

  175. The sea level rise numbers reported in the IPCC seem to be estimates of the transient climate response. It seems that they should have also included an equilibrium sea level response, after the estimations of the equilibrium temperature sensitivity of the climate models. The issue of the ice sheets is discussed at http://www.gfdl.noaa.gov/~tk/climate_dynamics/climate_impact_webpage.html (section 4.0):

    “With the effect of ice sheets included, the total rise could be larger by a substantial factor. However, projections of the contribution of the ice sheets to future sea level rise are not presented here due to the difficulties of performing a credible calculation. For reference, the volume of ice in the Greenland and Antarctica ice sheets is equivalent to a sea level rise of 7 and 73 meters, respectively”

    What this seems to mean is that there is little scientific basis for claims that there is a low-percentage chance of abrupt climate change based on model runs that ignore the ice sheet response. 95% confidence that there is little chance of abrupt climate change is unsubstantiated if you are basing that on models that ignore ice sheet dynamics and carbon cycle feedback effects. Nobody knows. If you don’t know if a gun had a bullet in it or not, would you point it at your head and pull the trigger?

    On the other hand, rapid melting of the ice sheets might have a temporary cooling affect on the upper ocean temperatures, if the results of Lyman et al are correct (RC: Ocean heat content: latest numbers). They estimated a cooling upper ocean with no reduction in sea level due to thermal contraction, pointing toward increased meltwater flowing into the oceans. This negative feedback would reduce the possibility of drastically abrupt climate change…perhaps. A better system for monitoring ocean heat content and transport is needed, and NASA and NOAA should cooperate on this… though under the current situation (political comissars overseeing these institutions) it seems unlikely. Maybe Congress could provide some kind of earmarked funds?

    The only legitimate scientific discussions over anthropogenic climate change are how fast will it happen, and how far will it go. The fact that it is happening has already been settled.

    Comment by Ike Solem — 31 Mar 2007 @ 5:24 PM

  176. Some of you may find this link to “Disappearing Islands” a page concerning sea-level rise and various island nations of interest.

    http://www.globalislands.net/news/newsdeskitem.php?newstype=Special&newsid=4660&mfxsr=8

    And you all may have additional links that will help to improve the link above. I suggested RC to them and they added it.

    (Note: When using the Safari browser the site above automatically reloads as soon as it is loaded. At least with Safari one has to actively stop it using the stop loading button once it has fully load. With my old Netscape browser there was no problem.)

    Comment by Tavita — 31 Mar 2007 @ 5:54 PM

  177. I was under the impression that the Antartic Ice sheet is gaining more mass than it loses. At least every paper I can find is saying that. Why do you say it is losing mass Stefan? I know the Antartic pensisula is warming, but the continent as a whole is getting colder not warmer and the ice sheet as a whole is growing not retreating. Is there a study that states otherwise? (I posted something similar a while back and Ray Pierre agreed with me at the time, however he postulated it would change in 10 years.)

    Comment by Jim — 31 Mar 2007 @ 7:08 PM

  178. I was under the impression that the Antartic Ice sheet is gaining more mass than it loses

    That’s odd that you say that, because this result has been out there for a while now. Do you read science papers? They are easy to find :

    http://www.sciencemag.org/cgi/content/abstract/311/5768/1754?ck=nck

    Comment by Thomas Lee Elifritz — 31 Mar 2007 @ 7:49 PM

  179. “A 3 degree Celsius global average warming would lead to a sea level rise of 80 feet,” said Hansen.

    http://www.northernlife.ca/News/LocalNews/2007/02-22-07-weber.asp?NLStory=02-22-07-weber

    … “Equilibrium Sea Level Rise for ~3 C Warming (25+- 10 m = 80 feet) Implies the Potential fo Us to Lose Control” …

    http://www.2010imperative.com/downloads/GreenBuildings.pdf

    As I see it, although we may see a … “3 degree Celsius global average warming” … an … “Equilibrium Sea Level Rise for ~3 C Warming … may be delayed quite a bit by thawing, break-up and heat-expansion factors and other uncertainty factors.

    Comment by pat neuman — 31 Mar 2007 @ 8:00 PM

  180. Jim, would you be willing to explain your approach to finding things out? How did you search for information about Antarctica and come to the conclusion that you gave? I’m sincerely curious — did you ask your librarian, or use Google, or rely on websites you trust?

    I’m very interested in how people try to find out about climate change — and particularly, how people look for information as you say you did, and not only don’t find the current science, but find information somehow that leads them to wrong answers.

    It’s not an easy process, and learning how it goes wrong is sometimes very helpful. How’d you look?

    Comment by Hank Roberts — 31 Mar 2007 @ 11:12 PM

  181. Apologies. In the Scientific Reticence paper Hansen wrote “That time constant yields sea level rise of the order of 5 m this century.”

    Re 179. What might be an estimate for the time constant in the equilibriation delay, eg if WAIS disintegrated? Non-equilibriated levels would presumably be somewhat uneven and so ports / coastal plant would be exposed to different levels of risk in different regions. Has modelling been done of the equilibriation process assuming distinct (eg high risk) ice sheet disintegration events?

    Comment by Michael — 1 Apr 2007 @ 12:26 AM

  182. I’ve been contemplating how to get our lethargic minds away from American Idol and to pay attention for a few nanoseconds to the discussion on potential and threatening global climate changes??

    Guys, if you were to discover that with possible draught conditions from warming climates, that hops, barley, and grapes will no longer grow, you can assume there won’t be any more beer and wine!! We will never get laid again!

    Perhaps if you discovered that tobacco plants are not draught tolerant, you might deduct that there won’t be any more cigarettes and cigars!! There will be lots of weeds but not the right kind of ‘weed’!

    And ladies, as well as metrosexuals, what if the cacao tree can no longer flourish? Do you know what this means? It means no more chocolate!!

    Disasters in the Middle East, and anything else that idiot-Bush causes, will pale in comparison to a life without beer, cigarettes, and chocolate! Get the point??

    Now…regarding CO2 emissions that we hear about 24/7, I realized most people cannot grasp this concept because CO2 is invisible! There’s a solution for everything! I believe our federal government should ‘require’, for a one-month period each year, that all oil and oil-based fuels are to be laced with a harmless black dye! This will allow each and every one of us to visibly see CO2 emissions!! Just imagine every car, motorcycle, truck, construction equipment, farm implement, train, bus, factory, airplane, military vehicle, power plant, lawnmower, and weedeater spewing black soot??!!

    If this does not heighten the discussion about CO2 emissions, then gawd help us…

    I know some reading this post are in a ground hog-day funk reading and re-reading paragraph number two above, but for the rest of us, I ask that we at least gain a better understanding of global climate changes, and that we get personally involved in the discussion.

    How about it…a CO2 Awareness Month????

    Comment by OldManOnFire — 1 Apr 2007 @ 8:51 AM

  183. Last autumn, it was reported that the Arctic winter sea ice had declined far more rapidly than before during the 2004/05 and 2005/06 winters. Is there a figure for the overall sea ice anomaly for the winter just past, or does anybody know when this is likely to be published? Many thanks!

    Comment by Almuth Ernsting — 1 Apr 2007 @ 9:32 AM

  184. O.T. It’s looking to be the driest rainfall year on record for California central coast.

    http://www.wrh.noaa.gov/lox/Assets/pns_03_07_07.pdf

    http://www.wrh.noaa.gov/lox/Assets/pns_03_08_07.pdf

    Comment by Ron R. — 1 Apr 2007 @ 9:38 AM

  185. Re#172 & 163, I totally agree sea rise is a very serious issue (I should have made that clearer). My main point was that it is only one of many problems GW is bringing us, and that we need a holistic perspective, at least to keep in mind, while looking at single aspects of GW. Otherwise the contrarians will pick GW problems off one-by-one.

    Like, “Species X is going extinct; well, we can live with that. Species Y is going extinct? Too bad, but no problem.” Without considering that a lot of species are going extinct or threatened with extinction due to GW (& other human-caused problems) — and we have no idea how much we can rip apart the web of live without it seriously harming us, maybe a lot, but maybe just a little & it will come back to kick us in the face.

    And species loss is just one of many problem due to GW (& to our other environmental harms). Polar bears might make good poster species for some people, but others couldn’t care less. A poster with all the species that are going extinct, and with all the problems from GW might be more appropriate. Of course, then people might be overwhelmed and stymied — but at least it would be more honest.

    Comment by Lynn Vincentnathan — 1 Apr 2007 @ 9:47 AM

  186. Oh I don’t know,

    maybe this one

    http://www.physorg.com/news4180.html.
    and the FAQs on this site (Written in 04 though)

    I did some more quick digging.
    One year 2005 they say it is growing the nex they say it is losing 2006. Just never can tell these days.

    James

    Comment by Jim — 1 Apr 2007 @ 9:53 AM

  187. Re 180.

    I read alot, but it is mostly online texts. Doesn’t everyone use google?

    James

    Comment by Jim — 1 Apr 2007 @ 9:54 AM

  188. Posts 182-184 (by Pumuker) are spam, and should be removed. How did this get through in the first place?

    Comment by tamino — 1 Apr 2007 @ 10:09 AM

  189. You can find all the daily data on polar ice back to 1979 at this site. The 2006 summer ice minimum was higher than 2005 and 8 of the last 16 years including 1990. 1999 was the lowest level.

    http://arctic.atmos.uiuc.edu/cryosphere/

    In terms of antarctic ice mass, those measurments from the GRACE satellite (which use gravity measurement) are not very accurate. There are significant variations in gravity levels by season, by day and significant modeling is required to produce the results. In addition, Grace doesn’t have very good resolution (400 kms.)

    http://www.tcsdaily.com/article.aspx?id=030306H

    Comment by George K — 1 Apr 2007 @ 10:41 AM

  190. I read alot, but it is mostly online texts

    Then why do you continue to spread your FUD here?

    #188 – More FUD.

    Comment by Thomas Lee Elifritz — 1 Apr 2007 @ 11:04 AM

  191. Jim, consider going to a school or library and asking a reference librarian for help. They know how to tell wheat from chaff, needles from haystacks, science from public relations.

    Online, look using Google Scholar instead of Google.
    Compare the results you get — you’ll see how different even Google’s weak filter for garbage makes the results.

    Make sure the search you use will look for articles in peer-reviewed science; look at the footnotes and read them to see if they’re being properly used.

    There’s a whole lot of public relations/political/bogus fake info available.

    The TCS site is the latter; they’ll rush stuff out like the above when science is being published that threatens their publisher’s interests (you do know who owns that place don’t you, George K? Know how to look it up?).

    “Opinions Differ on Shape of Earth” headlines happen because of places like TCS.

    http://www.sourcewatch.org/index.php?title=Tech_Central_Station

    Comment by Hank Roberts — 1 Apr 2007 @ 11:05 AM

  192. Re #186 That summary states, “…the interior of the East Antarctic ice sheet is actually gaining mass”- Note the word “interior.”

    If you had checked out the research article to which it referred, you would have seen this:

    Science 24 June 2005:
    Vol. 308. no. 5730, pp. 1898 – 1901

    (Originally published in Science Express on 19 May 2005)

    Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise
    Curt H. Davis, Yonghong Li, Joseph R. McConnell, Markus M. Frey, Edward Hanna

    Satellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6°S increased in mass by 45 ± 7 billion metric tons per year from 1992 to 2003. Comparisons with contemporaneous meteorological model snowfall estimates suggest that the gain in mass was associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by 0.12 ± 0.02 millimeters per year.

    Free abstract available at: http://www.sciencemag.org/cgi/content/abstract/308/5730/1898)

    It doesn’t say the entire ice sheet is gaining mass, only a portion of the interior, meaning the overall loss of ice is occurring more slowly than previously thought.

    Comment by Chuck Booth — 1 Apr 2007 @ 11:10 AM

  193. Re 188:
    Thanks – the Northern Hemisphere sea ice anomaly is on this page: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.jpg .

    Looks like we’ve got the greatest Arctic sea ice anomaly on record right now.

    Comment by Almuth Ernsting — 1 Apr 2007 @ 11:24 AM

  194. Sorry, George and Jim, but the net result, known for over a year, is a net loss of Antarctic ice. See for example:

    http://www.csr.utexas.edu/grace/publications/press/12212006_spacedaily.pdf

    This includes results from ICESAT as well as GRACE, and other techniques.

    Comment by Ray Ladbury — 1 Apr 2007 @ 11:26 AM

  195. “A 3 degree Celsius global average warming would lead to a sea level rise of 80 feet.”

    This figure is based on estimated sea levels three million years ago (the Pliocene), when global average temperature was about 3 degrees warmer than today. But the Pliocene was a time of cooling and ice cap formation, while the near future is a time of warming and ice cap melting. An ice cap creates its own regional climate by reducing local temperature. For example, if you removed all of the ice from Greenland, a new ice cap would not form at today’s temperatures. This implies that three degrees of warming will leave a much larger ice cap than the Pliocene started with, so sea level increases may not be nearly so high.

    It is also noted that sea levels in the previous interglacial period (the Eemian) were 4 to 6 meters higher than today, with global average temperature only about one degree higher. But the ice reacts to local temperature, not the global average. Conditions during the Eemian were very different than the predicted greenhouse warming. Solar forcing in the polar regions during the critical spring period was more than 60 watts per meter above normal due to the Milankovitch orbital changes. Compare this with 3.7 W/m2 of direct forcing from the doubling of carbon dioxide levels expected in the 21st century. It is quite possible that this was the cause of the extensive melting in the polar regions, and the one or two degrees of global temperature rise was mainly a side effect.

    The critical factor for sea level rise from melting ice caps is the time required for the ice cap to reach equilibrium at a certain temperature. This could be from a few hundred to a few thousand years. Hansen comes in at the low end. If the equilibrium time is longer than the pulse from greenhouse warming, the full melting potential may never be reached.

    So while I believe that sea level rise from global warming will be a serious problem over the time frame of the next few centuries, the total amounts have been overstated.

    Comment by Blair Dowden — 1 Apr 2007 @ 11:45 AM

  196. On page 34 of the report entitled “The Future Oceans – Warming Up, Rising High, Turning Sour” from the German Advisory Council on Global Change at http://www.wbgu.de/wbgu_sn2006_en.html it is written:

    “rates for sea-level rise of up to 5m per century are documented, and these probably do not represent an upper limit”

    it is also written on that page

    “the assumption that ice masses would have melted significantly more rapidly with faster warming is quite plausible.”

    Page 34 of the above-quoted report also states “Thus climate history shows that a much more rapid rise than that expected by the IPCC for the 21st century is possible”.

    In his article in the New York Review July 13 2006, James Hansen, who is not an author of the German report, quoted above, states “The Earth’s history reveals cases in which sea level, once ice sheets began to collapse, rose one meter (1.1 yards) every twenty years for centuries.”

    Climate change experts, can you please provide answers to the following:

    Q1. What is special about the warming conditions in the 21st century to say that a 5 meter rise may or may not occur?

    Q2. Has the IPCC discounted the prior historical rises and if so on what basis?

    Q3. With regard to the first quote, what might an “upper limit” be?

    Q4. With regard to the quote from Hansen’s article, what phenomena might be taken to construe the point at which “ice sheets began to collapse”, and have such phenomena yet been observed?

    Q5. When the Larsen B ice shelf collapsed, were you taken by surprise and had you prior to the event thought that such a thing would not happen so quickly?

    Comment by Michael — 1 Apr 2007 @ 1:21 PM

  197. Note, read for content, don’t rely on sequence numbers. Here, numbers after 182 changed (subtract three from what they were briefly) when three spams that got by were deleted by the moderators.

    Sequence numbers sometimes increase; posts appear in timestamp order; if one’s held by moderators longer than later ones, it will then pop into the sequence later, causing all the posts “below” it to be renumbered).

    Happens on all web forums.

    Re “fud” — Jim, George, no shame being fooled the first time, but you have to develop real skepticism when reading claims, to tell the science from the “fear, uncertainty, and doubt” garbage being used to confuse people about the science.

    Say where you get your ideas; check whether you’re being fooled by someone with a political or commercial public relations website. There are more of them than there are science websites. They have more money to fool people. Read carefully.

    Comment by Hank Roberts — 1 Apr 2007 @ 1:32 PM

  198. Re 188. Lynn, I share your concerns and did not mean to detract from the broader and very important issues you were raising. The web of life is creaking under the pressure of GW and causing great harm, and yet so many choose not to see it, let alone care.

    Comment by Michael — 1 Apr 2007 @ 4:21 PM

  199. Re #199: Michael, I am not an expert, but I will try to respond to your questions. As for what is special about warming conditions in the 21st century, I would like to suggest that what is special is the conditions under which a sea level rise of 5 meters per century actually occurred.

    Twenty thousand years ago the northern part of North America was covered by an ice cap larger than that on Antarctica today. Unlike the Antarctica and Greenland of today, this ice cap was centered well below the Arctic Circle. That made it much more sensitive to a warming event. In addition, it was a temporary ice cap, in contrast to the permanent ice cover of today’s ice caps. The weight of the ice caused the ground to sink, leading to warming of the bottom of the ice because it was closer to the center of the Earth, and lowering the altitude of the top of the ice, also adding to its warming.

    So you had this huge, unstable ice mass almost collapsing under its own weight, which melted very rapidly when changes in orbital parameters caused some warming. I do not think it is valid to extrapolate its melting rate to the situation in the 21st century.

    I think this answers your Q2, which is why the IPCC has discounted it. As for Q3, no one really knows what the maximum melting rate will be, but we have every reason to expect it will be considerably less than that during the recovery from the last ice age.

    While sea level rise due to global warming is a real concern, I argue that the 5 meters per century is another overstatement of the issue based on faulty extrapolation from the past, similar to that which I talked about in my post #198.

    Comment by Blair Dowden — 1 Apr 2007 @ 6:53 PM

  200. **I hope I’m not violating any rules by recommending a book; if I am, I hope the moderators will delete this. No, I don’t know the author (darn it) nor am I benefitting in any way from this post**

    “Something New Under the Sun: An Environmental History of the Twentieth-Century World” by J.R. McNeill (Norton & Co., 2000).

    Lynn, I think you and your students would like this book. It’s pretty much as the title describes: a history of humanity’s interaction with the environment. It has extensive notes and a massive bibliography (40 pages! I’d say McNeill’s done his homework). It’s a fairly easy read, and the organization is excellent. Also, McNeill manages a fairly objective tone throughout.

    As an historian I think it’s important for people to understand how we got ourselves into this global warming mess. I think it helps us get a grip on what’s happening now and pushes us to imagine the future.

    Comment by Arvella Oliver — 1 Apr 2007 @ 6:54 PM

  201. So you had this huge, unstable ice mass almost collapsing under its own weight, which melted very rapidly when changes in orbital parameters caused some warming. I do not think it is valid to extrapolate its melting rate to the situation in the 21st century.

    The carbon dioxide forcing today is occurring orders of magnitude faster than natural Milankovitch forcing. If anything, ice sheet melting will be faster, and we have historical proxy records to back that reasoning up.

    More FUD, anyone?

    Comment by Thomas Lee Elifritz — 1 Apr 2007 @ 9:10 PM

  202. re 199.

    My answer to Q5: From what I’ve read, heard and saw (Explorer Will Steger’s presentation on the collpse of the Larsen B ice shelf), scientists were taken by surprise and had not thought that such a thing would happen so quickly?

    Comment by pat neuman — 1 Apr 2007 @ 9:23 PM

  203. A bit off topic, but this might be of interest:

    Climatologists Secure Funding To Breed Glaciers In Captivity
    March 30, 2007 | Issue 43â?¢13

    FAIRBANKS, AKâ??Researchers from the National Oceanic and Atmospheric Administration received a $42 million federal grant for a captive-glacier breeding project that will attempt to spawn three to five of the massive, slow-moving bodies of land-carving ice by 2020…

    http://www.theonion.com/content/news_briefs/climatologists_secure

    Comment by Chuck Booth — 1 Apr 2007 @ 9:55 PM

  204. Re 205 Oops! Wrong thread…sorry!

    Comment by Chuck Booth — 1 Apr 2007 @ 10:02 PM

  205. Glaciers breed like tribbles too, but my understanding of the situation is that President Al Gore stopped them cold, at the Canadian border, thus preserving the American way of life yet again. Sorry, couldn’t resist.

    Comment by Thomas Lee Elifritz — 2 Apr 2007 @ 12:29 AM

  206. #104 & #118 The question was what role, if any, economists should play in climate change analysis. Here are two papers which clarify, I hope, why economists are vital to the climate change debate

    http://nordhaus.econ.yale.edu/SternReviewD2.pdf

    http://www.econ.cam.ac.uk/faculty/dasgupta/STERN.pdf

    Comment by Alan K — 2 Apr 2007 @ 2:03 AM

  207. Re #204: Thomas, the net Milankovitch forcing is close to zero. However, as I pointed out, the local, seasonal forcing (where the ice is actually located) can be more than 10 times that expected from greenhouse gas emissions. See this paper in Science.

    I would also like to add, in response to the original Q1, that a special condition of the near future is the West Antarctic ice sheet which largely rests on land below sea level. A combination of warming and rising sea level could cause a rapid partial collapse. This may have happened during the previous Eemian interglacial, but we have no idea how rapid it happened, if at all.

    Comment by Blair Dowden — 2 Apr 2007 @ 5:45 AM

  208. RE #164, “something kick started the temperature jump [after past ice ages], which led to the co2 rise…”

    As I’ve pointed out before, the fact that CO2 increases have followed warming trends in the past just lends more support to the positive feedback idea, and that we could be triggering a really whopping heating trend, maybe the greatest in all of Earth’s history, since the GW we humans are causing is (I believe) more rapid than any time in history. And we are at a sort of thermal maximum as it is, not in the valley of some deep ice age; so from the high launch pad we increase the heat even further, then nature releases GHGs, which cause more warming, which causes more releases, which cause more warming, and so on.

    It really behooves us to reduce our GHGs ASAP. Time for action. Or we may not be able to avoid hysteresis & the die off of a large chunk of earth’s biota, including humans.

    It’s like we’re pulling the trigger on our own children and grandchildren…but we’re claiming that it’s the gun that’s killing them, not we, the ones pulling the trigger.

    Comment by Lynn Vincentnathan — 2 Apr 2007 @ 8:07 AM

  209. “… we increase the heat even further, then nature releases GHGs … ”
    Methane anybody? Currently paused because the Asian mires have dried (hope these never catch fire, but … Pesumably residence time in the atmosphere is longer over the pole? Yet warmer winter? What happens to the vertical temperature atmospheric profile and the stratospheric feedback over N Atlantic?

    Comment by Phil Harris — 2 Apr 2007 @ 11:52 AM

  210. Re #206: [Here are two papers which clarify, I hope, why economists are vital to the climate change debate...]

    While I’m not by any means an economist, both those reviews are quibbling about one factor in the Stern Report – the appropriate value of the social discount weight, which measures the relative importance of the well-being of future generations – while basing their analyses on the assumption that well-being is a linear function of consumption.

    That assumption seems to have remarkably obvious flaws. The change in one’s well-being between for instance an annual income of $0 and one of $20K is far greater than that between $20K and $40K, with each successive increment having less and less effect. Then too, there are a considerable number of goods where the supply is fixed, and increasing consumption either drives prices exponentially higher, or degrades the resource to where it is simply no longer available at any price.

    Unless economists are willing to change their models to include such factors, their input is going to remain marginal, rather than vital.

    Comment by James — 2 Apr 2007 @ 11:59 AM

  211. What puzzles me in the second graph of Stefan’s presentation is the discrepancy between the observed 1990-2000 sea level and what the IPCC 2001 models say.
    How comes the models can’t even correctly account for PAST temperatures ?

    Comment by Demesure — 3 Apr 2007 @ 4:06 AM

  212. Re #211: Because what they are trying to model is very complex. I would be suspicious if they got it exactly right. An honest model uses the best information available, and honest researchers publish the actual results. There are deficiencies in the models, which need more research to figure out. That is how science works.

    Comment by Blair Dowden — 3 Apr 2007 @ 6:40 AM

  213. Re 211, Demesure–you need to read the text as well as look at the pictures–the observed trend does in fact follow the upper limit of the IPCC predictions taking into account “land ice uncertainties”. This merely reinforces the impression that IPCC is being quite conservative in its analysis.

    Comment by Ray Ladbury — 3 Apr 2007 @ 7:02 AM

  214. [edit]

    West Antarctica sits on land that resides BELOW SEA LEVEL. We are forcing climate an order of magnitude or more beyond any previous known natural climate forcing, and we have ample recent evidence (Meltwater Pulse 1a) of many meters of sea level rise per century, and clearly the atmosphere and the oceans are warming, ice shelves are disintegrating, and sea level is rising at almost twice the rate previously thought. Yet Blair continues to claim that ‘nature is too complex’, using a supercomputer to post on a global high speed network. Anybody can use the googles to google Blair, just as anyone can use the googles to google me, or google nature, or google science.

    [edit]

    Comment by Thomas Lee Elifritz — 3 Apr 2007 @ 10:09 AM

  215. Has sea level ever fallen since the end of the ice age? Or has it continuously risen at a very low level (1 mm to 3 mm per year)?

    Comment by George K — 3 Apr 2007 @ 8:00 PM

  216. Re: 210 – James: “The change in one’s well-being between for instance an annual income of $0 and one of $20K is far greater than that between $20K and $40K, with each successive increment having less and less effect.”

    That is certainly true, and is generally taken into account in economic analysis of GW policy. It is one reason that the presently poor in India and China are likely to prefer cheap energy now, and with growing incomes will later be willing to forego that cheap energy.

    Comment by Steve Reynolds — 3 Apr 2007 @ 9:33 PM

  217. Re #214: I was trying to defend the climate modelers. I did not claim nature is “too complex” to model, rather that we should not dismiss modeling results because they are not perfect. Climate modeling is an important and useful activity, but we must understand the limitations of the models.

    West Antarctica is indeed very interesting. Not only is a large part of it grounded below sea level, but the ground slopes down from edge of the glacier towards inland. This means the more it melts the less stable it gets. See this recent article in Science, or look at this image.

    But note that the ice is about 2 km thick, with half of it below sea level. Compare that with about 5 meters we might get from substantial melting in Greenland, and it is less than half a percent. I don’t think sea level will have much effect.

    There is another rather interesting Science paper that claims the ice sheet has been retreating for centuries, and will continue to do so no matter what. I would like some informed comment on this:


    We suggest that modern grounding-line retreat is part of ongoing recession that has been under way since early to mid-Holocene time. It is not a consequence of anthropogenic warming or recent sea level rise. In other words, the future of the WAIS may have been predetermined when grounding-line retreat was triggered in early Holocene time. Continued recession and perhaps even complete disintegration of the WAIS within the present interglacial period could well be inevitable.

    Comment by Blair Dowden — 3 Apr 2007 @ 9:40 PM

  218. http://globalwarmingart.com/wiki/Image:Holocene_Sea_Level_png

    The error bars are fairly wide here, but there may have been a slight depression right around the rise of widespread agriculture and civilization. But overall it looks like a slow rise and then flattening off. I mean, it looks flat to me. Clearly the tide gauge data shows flat, with a gentle rise at the onset of the industrial era.

    Overall, the holocene was great run, was it not? Agriculture, civilization, astronomy, industry, technology, information, and now, tourism! Ah … the good old days. Too bad the holocene is over now.

    Comment by Thomas Lee Elifritz — 3 Apr 2007 @ 9:48 PM

  219. RE #210, I agree, there are lots of problems with (neo)classical economics that reduces all to money. There are problems with “overconsumption” such as diseases of the rich. And even holding prices steady, we need a variety of materials things to survive. There are qualitative aspects that make the abtract quantitative calculations ridiculous. For one small instance, we need a variety of nutrients and vitamins. If global warming harms our ability to meet our biological needs, then what’s the use of all the diamonds and gold in the world (which, BTW, are not harmed by GW). We need a more use-value economics, or a quality of life or “green” economics. Classical econ is only a good tool in a world that is environmentally healthy.

    I just saw on TV how bees are dying off in the U.S. They do a lot of free eco-services, pollinating food crops & trees. But they aren’t even accounted for in economics. Only when we lose something, do we realize its value….but sometimes there is no feasible replacement.

    Comment by Lynn Vincentnathan — 3 Apr 2007 @ 10:05 PM

  220. I wonder what A. Einstein had to say about bees?

    Certainly nothing that would approach alarmism, I hope.

    Comment by J.C.H — 3 Apr 2007 @ 11:25 PM

  221. Re: #20 (sea-level rise in Texas) & economics

    SEA LEVEL & STATES
    States differ in their planning for the future.
    In California, we don’t have hurricanes, but we have earthquakes, floods, droughts, forest fires, and mudslides … which makes even governments try to plan ahead for disasters (because there’s lots of practice), and sue Federal government on occasion :-)

    In any case, CA state folks take sea level rise seriously, see for example:

    http://www.energy.ca.gov/2005publications/CEC-500-2005-202/CEC-500-2005-202-SF.PDF

    Section 6.0, page 45 talks about impacts on SanFrancisco Bay and the Delta (of which a lot is at or below sea level): http://en.wikipedia.org/wiki/Sacramento_River_Delta.
    Also, there are issues with sewage plants, airports (San Francisco’s is at 8 feet, Oakland’s at 9 feet, and both stick out in the bay).

    Of course, along with the Pacific Northwest (RC March 20), we depend heavily on snowpack for water, only worse, because most precipitation in most of CA is limited to half the year. When it’s warmer, more rain and less snow fall, and then the snow melts faster, which creates water spikes (floods, levee breaks), and then later, droughts. Floods aren’t helped by rising sea levels,and there the easiest places for dams … already have dams.

    CA grows about 50% of the fruit & vegetables in the US, and is a major wine and dairy producer, none of which are helped by water and temperature problems.
    Minor by comparison, CA ski resorts take this seriously:
    http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/10/27/SKI.TMP

    CA had $50B net deficit of payments with the US Government, about 20% of the total such deficit (a few years ago, probably worse now), so CA matters to the US economy:
    http://www.ppinys.org/nybalpayments.htm

    ECONOMICS
    I think economists have a very important role to play (i.e., helping figure out tradeoffs and priorities), but I worry if:
    a) They are accounting for potential really bad non-linear effects, wit hreally high costs.

    b) They are accounting for the extra wars over water and migration pressures.

    c) They are expecting to get “richer,” i.e., under NPV calculations, do nothing.
    But:
    - We’ve been getting a “cheap ride” on fossil fuels, and I wouldn’t expect that to continue forever.

    - Anyone on the coasts is going to have to spend serious $$ on mitigation, and that’s an extra cost just to stay even.

    - In CA, there is going to have to be serious $$ spent on the water system.

    - There will be dislocations in agriculture, so I’d expect food to get more expensive.

    [Can anybody summarize how much of the above they are accounting for?]

    I’m not an economist, but none of this makes me feel good about assuming rising average *real* incomes for people, because mitigation = $$$ in taxes. CA (and the Bay Area) are rich, but we’re going to spending a lot of money just to stay even…
    so I’m not sure who’s going to be paying to make sure New Orleans is still there in 2100 (between floods, hurricanes, and Mississippi jumping track, i.e., as in John McPhee’s fine book “Control of Nature”.)

    Anyway, a lot of people and local/state governments here take all this quite seriously.

    Comment by John Mashey — 3 Apr 2007 @ 11:30 PM

  222. Lynn: actually, bees are accounted for in North American economics, since you have trucks with beehives going back and forth for fertilization. Honeybees are non-native european imports. So if they die off, the natural ecosystems should still be fine with butterflies and other pollinators… though we might not have sufficient pollinator density for our “artificial” food crops.

    (I do agree with your general point that the value of many goods are not well captured by market forces)

    Comment by Marcus — 4 Apr 2007 @ 9:19 AM

  223. Albert Einstein supposedly predicted mankind would last just 4 years past the end of bees on earth.

    Comment by J.C.H — 4 Apr 2007 @ 9:37 AM

  224. #221,John I’m glad CA is taking AGW seriously (that’s my original state, and it makes me proud). I also think CA was party to the MA suit against the EPA, which they recently won. TX, OTOH, submitted a brief on the side of the EPA (& Bush), denouncing the right of states to make laws re GHG emissions.

    Re the mitigation costs, I believe how it would work from the gov’s POV is that the gov, say, taxes GHGs in some way. Then the price of emitting goes up. (Of course, simply taking away the subsidies & tax-breaks to coal & oil would also do the trick – & I wouldn’t have to feel like a schmuck April 15th paying for other people to emit GHGs.) Then people start thinking that “this costs too much, how can I use less gas or electricity.” Then they supposedly reduce, maybe buying energy efficient products — so there’s an upfront cost, that in most cases pays for itself within a certain timeframe.

    However, the gov has collected those taxes, and it can, say, plow them into war, or give them back to the people in the form of subsidies for their energy efficiency — to help offset the upfront costs or solar water heaters, etc. So, actually the mitigation money doesn’t disappear, it’s just shifted around.

    You wrote, “So I’m not sure who’s going to be paying to make sure New Orleans is still there in 2100.” I was just thinking something similar to this. I’ve figured out the official U.S. gov strategy GW (there’s probably some classified papers on this) is to make our country so poor (with war costs, & a do-nothing approach to mitigating GW now — which could actually help our pocketbooks & strengthen our economy) that we won’t even be able to help the poor nations of the world (who are least responsible for GW) mitigate.

    I guess that’s one way to get us off the hook of responsibility.

    Comment by Lynn Vincentnathan — 4 Apr 2007 @ 9:51 AM

  225. RE #222, if we’re counting on butterflies, we’re headed for problems. I understand they are dying off too (maybe in part due to GW, but also due to other environmental problems, such as pesticides, habitat loss, & GMO corn that has the pesticide built in). Biologists, feel free to jump in here, since I don’t know what I’m talking about.

    Yes, the TV program did show bee keepers supplying bees, but these were also dying off, and they didn’t know why exactly. There was some mention of mites….but it seems to me that lower immunity due to stress would allow mites to infest.

    If this isn’t due to GW, then it’s probably due to other human-caused harms.

    Any, we do need a holistic, big picture of all this, going beyond sea rise and even the myriad of GW harms.

    Comment by Lynn Vincentnathan — 4 Apr 2007 @ 11:46 AM

  226. William F. Buckley weighs in:

    ” … There is, now and then, offsetting good news. The next report from the Intergovernmental Panel on Climate Change (IPCC), we have learned, will be less pessimistic than earlier reports. It will predict, e.g., a sea-level increase of up to 23 inches by the end of the century, substantially better than earlier IPCC predictions of 29 inches — and light-years away from the 20 feet predicted by former Vice President Al Gore. …”

    http://www.realclearpolitics.com/articles/2007/04/business_of_global_warming_fee.html

    Comment by J.C.H — 4 Apr 2007 @ 11:52 AM

  227. Re: #224, Lynn’s comment.

    I’d certainly agree with GHG taxes or equivalents, to help change behavior, but every credible source I’ve seen says that there’s so much momentum in the climate system it’s going to get somewhat hotter no matter what we do, for a while.

    That leaves us with the real issues:

    a) How fast does it get hotter? [the faster, the more expensive to deal with, and the harder it is for ecosystems to adapt]

    b) How hot does it get before it flattens off? [discomfort level]

    c) How long does it stay there before it starts coming down? This will certainly affect how much of Greenland and WAIS melt.

    and of course, in the really long term (thousands of years]:
    d) Assuming human civilization is around as long as it has been, can humans gain enough control of the climate’s thermostats to keep the temperature range comfortable [as it has been in the Holocene], i.e., neither the “too hot” likely to be seen in the next few centuries, nor the “too cold” that has Toronto and Stockholm under kilometers of ice.
    Ruddiman’s book has nice discussions of all this [Chapters 16 & 17].

    Regarding mitigation money disappearing vs being shifted around:

    I *know* CA will have to spend more $$ than before on mitigation, because some warming is already locked in, and mitigation is like maintenance on a house: you must do it, but it doesn’t improve the house or make it worth more, it just helps avoid disastrous losses.

    CA has already done a lot to get more efficient, and many individual towns are beavering away on energy efficiency and GHG-control [even our 4,500-person town has a serious committee on this]. I’d certainly be happier if more tax money stayed more local, rather than going to Washington DC.

    My problem is that I’d much rather spend tax money investing in education, research and improved infrastructure [not just in mitigation efforts to stay even]. Local Silicon Valley venture capital firms are investing like crazy in various green *development* efforts, but we still need to fund the basic science that precedes such (VCs don’t), and mitigation efforts will compete with those uses.

    Finally: Texas: I thought Texas claimed last year to have exceeded CA’s windpower capacity (2,370 megawatts versus CA’s 2,323), so there’s hope yet. Hopefully, as an ex-CAer, you’re at least located in Austin, which as UT friends of my have said: “Austin is not really part of Texas, although it’s surrounded by it.”

    Comment by John Mashey — 4 Apr 2007 @ 12:08 PM

  228. Hank, and Thomas(who is real nasty for some reason.)
    Not trying to be a pain, but if something lists itself as from NASA I am going to believe it. Hank I am quite intelligent enough to evaluate the source on my own so don’t be so condescending. (Even though you were trying to help.)

    The source I gave above referenced this study:

    http://www.nasa.gov/centers/goddard/news/topstory/2005/sea_ice.html (I guess these people should not be trusted or something.)

    My only mistage was more recent report from NASA using grace that has the opposite conslusion 1 year later. I don’t think that is FUD like Thomas says it is, just out of date. Excuse me! Thomas back off and lower the faith setting some!

    Re 192.
    Huh?
    If the Antartic as a whole is gaining mass, then it is gaining mass. If it is losing mass as a whole then it is losing mass(As stated here many times).

    Comment by Jim — 4 Apr 2007 @ 5:45 PM

  229. #227, from my own experience, mitigation can be done at least to a one-half or two-thirds reduction of GHGs cost-effectively (see http://www.natcap.org for inspiration — they claim that in some cases it can even be done cost-effectively down to nine-tenths reduction cost-effectively by “plowing through”) — which means there may be a little or a lot of upfront money required, but within a certain time frame (1, 2, 5, or 20 years) the measure will pay for itself and perhaps go on to save money.

    Of course, we should go for the cheaper measures with the most payback first. Like low-flow showerheads (with off-on soap-up switch), which can save 1/2 the hot water without any noticeable difference in the shower; that’s a $6 upfront cost that pays for itself in less than a month and goes on to save about $100 a year in water and heating the water — or $2000 over its 20 year lifetime. Other measures also save. (Note that these showerheads reduce GHGs in 2 ways, by reducing water, which needs energy to pump it, and by reducing the energy to heat it.)

    Now that money that’s saved can be used to plow into adaptation to GW costs — which really do not save us anything, but only prevent great losses in the future. (It is cheaper to build a high, strong levee before the sea surge that prevents harm, than to rebuild a town, then have to build that same strong levee after the surge anyway.)

    I guess even the mitigation savings are also costs, but reduced costs — since we still have a water & energy bill, only that it’s lower. I suppose that’s what you mean.

    And, of course, once all these low-hanging fruits are plucked (& we have a very loooong way to go here in the U.S. to pluck all of them), we may have to actually pay more for mitigation in non-cost-effective ways (that will only be cost-effective in avoiding some future harms from GW) — such as higher rates for wind powered electricity. I’m not in Austin, but I do get Green Mountain Energy’s 100% wind-powered electricity for a few dollars more per month. Since I had already reduced our KWHs way down, the extra cost is hardly noticeable. I’m awaiting the plug-in hybrids (which will be far from cost-effective, esp since we are only 2 miles from work & shops), so I can drive on the wind.

    Comment by Lynn Vincentnathan — 4 Apr 2007 @ 7:09 PM

  230. #229: we agree violently on good measures to take to save energy. [And sorry for the sloppiness, I sometimes use "mitigation" in the sense of reducing the effects of something, whereas IPCC uses it as reducing CO2, and uses "adaption" for minimizing the bad effects of CO2.]

    In our town GHG committee, we’re working hard on mitigation [IPCC-style], to measure what we’re doing, prioritize things to do, figure out how to help education, and when necessary, think about changing town laws. Many of us have already been over the houses with Watts-Up, started using compact fluorescents years ago, use solar heating for pools, PV solar (when possible;, this town adores trees, but they can get in the way :-)), use geothermal, etc, etc. Some people are building new houses that are not only energy neutral in operation, but try to minimize the carbon load from materials and construction.

    I would never argue against any of this; many of these have fine ROIs.

    My point was that even if everybody on the planet magically did all this tomorrow, the temperature and sealevel will still go up for a while [just slower], and we’ll still have to spend money on adaptation/extra maintenance. For instance, in CA, there will almost certainly have to be some serious engineering works ($, energy), and these will be necessary, but just to avoid worse disasters, and they will cost $$, and they do compete with other uses for the money. It is definitely better to fix levees ahead of time, but it still costs $, and it is still sometimes hard to get people to pay for the bond measures… even in a rich place that usually plans for disasters. I have no idea how well the economists are modeling all this, although I’m certainly sure that some efforts better start earlier rather than later. For instance, we ought to get really serious about where people can build new houses at low altitudes.

    Comment by John Mashey — 4 Apr 2007 @ 8:05 PM

  231. Jim, you’re not understanding the paper you’re quoting. I am not intending to be condescending, I am reading this along with you, I have no expertise here, I’m “reading out loud” the same way you are. People who understand this can step in and help.

    Let me say how I read it, will you? I’m not _telling_ you how it is, I’m telling you what I read.

    What I see there doesn’t match what you’re saying about the abstract. I was guessing you were quoting from something based on some other website’s description; if you found it on your own and just didn’t find the more recent page, no shame there. There are a lot of sites out there misrepresenting the science, and I’ve seen others come here saying the same thing you did, based on misinformation.

    So, ok, you found it on your own, nobody misinformed you. Let’s look at what you read.

    You say you read it as meaning the ice sheet is gaining mass. ‘

    Please look again.
    It says: “… the East Antarctic ice-sheet interior north of 81.6°S increased in mass …”

    Look at a polar projection map. That latitude isn’t stated as defining the whole ice sheet, just a part of it.

    Look further in the abstract: “A gain of this magnitude is enough to slow sea-level rise by 0.12 ± 0.02 millimeters per year.”

    That means a reduction in the rate of rising sea level — somewhat less melting because part of the ice cap is accumulating snow. Not enough to _cancel_ or _reverse_ sea level rise, just to slow it.

    Then look at the bottom of the page, at the link to papers that came out more recently that make reference to it, for example this one:
    http://www.sciencemag.org/cgi/content/abstract/315/5818/1529

    “Although the balance between these opposing processes has varied considerably on a regional scale, data show that Antarctica and Greenland are each losing mass overall. ….”

    That’s not an absolute proof. That’s the current information, from the new instruments, to date.

    Comment by Hank Roberts — 4 Apr 2007 @ 11:55 PM

  232. Re 224: Lynn V.
    Throughout history, settlement sites have been abandoned, whether one is discussing Ur or English medieval villages following the Black Death. Whilst it is tempting to heap further approbium on the Bush Administration for the tortoise-like rebuilding of New Orleans, your point has wider ramifications. It is not impossible to imagine a future time when ‘the West’ will not be able to help other countries hit by natural disasters – not because we are to busy pursuing diplomacy by other means around the world, but because we will no longer have the resources, distracted as we are likely to be by our own climate problems. Katrina was a foretaste of political responsiveness; it is interesting to note that the US also received offers of aid from overseas post-Katrina. With apologies to all from Louisiana, it might be politically expedient to rebuild New Orleans, but the science would suggest it is a futile gesture and that future Americans could very well be telling their grandchildren stories about the lost city in the Gulf.
    For botched aid, see http://www.jhu.edu/~gazette/2006/05sep06/05katrin.html amongst many others.

    Comment by Serinde — 5 Apr 2007 @ 4:47 AM

  233. Jim, the antarctic is not gaining mass, get over it. Your continued insistence that Antarctica is gaining mass, in conflict the evidence, including even the paper you quoted, makes you look … irrational.

    Comment by Thomas Lee Elifritz — 5 Apr 2007 @ 9:14 AM

  234. You guys don’t read well do you? I said I was running off of year old studies. You pointed me to new data. (Thanks BTW) Hell I even said that I was out of date. (Hence I had to correct my thinking.) Come on people, quit looking for an adverary to attack when there is not one.

    Comment by Jim — 5 Apr 2007 @ 12:38 PM

  235. Jim, when you wrote:

    “One year 2005 they say it is growing the nex they say it is losing 2006. Just never can tell these days.”

    It read to me as saying that you couldn’t tell [which was better information]. Thus the pointers to the text.

    Science writing gets read literally, even more than other text on screen.
    It is easy to miss — or misread — irony or humor or sarcasm, and most of us readers here are as Tamino points out trying to get the facts clear not just with each other but for later readers who may be confused by unclear writing. We give each other and the journalists heck. And if I counted the number of times I’ve begged the Contributors to hit the Return key twice to put paragraphs between major ideas instead of running on text ….

    Your later posting is clear:
    “I was out of date. (Hence I had to correct my thinking.)”

    Thanks for clearer writing — and specifying your source. That’s most helpful, especially later (next year there will be new science — and we can find the newer by going to the older pages and tracking cites forward in time).

    Comment by Hank Roberts — 5 Apr 2007 @ 2:00 PM

  236. #232, “It is not impossible to imagine a future time when ‘the West’ will not be able to help other countries hit by natural disasters – not because we are to busy pursuing diplomacy by other means around the world, but because we will no longer have the resources, distracted as we are likely to be by our own climate problems.”

    I think that was one of my points in #224, except I implied (jokingly) that perhaps that is our secret official policy — to let GW run rampant, so we will be too impoverished with Katrina-level disasters to help the poor, let alone ourselves (due to our own GW-induced poverty).

    I suppose Bush doesn’t really understand what he is doing by fiddling while the world heats. We must give people the benefit of the doubt.

    Also, #230, I’m on your same page. I realize even if we totally stop our GHG emissions today, there is plenty of warming & disaster already in the pipes. I’ve even written on RC that I think the scientists can’t really say whether or not we may have already (or shortly will) pass a tipping point, at which the warming we have caused & that yet to happen from our past emissions, may trigger nature to emit GHGs & reduce albedo to the extent the warming spirals much higher than it would have simply from our human emissions (without such positive feedbacks kicking in). We may already be in for many millennia of increasing GW & harm to much of the world’s biota (even if we reduce our GHG emissions to nada). But hopefully not.

    OTOH, we must never give up trying our very best to reduce. Even in the most dire of scenarios, a little bit a salve can be very helpful. And even if it makes no material difference in reducing the harm (bec it’s all too late), the fact that we earnestly try to do our best to reverse it means something.

    I did my thesis on environmental victimology. Victims can much more easily accept natural harm or unintentional harm than they can intentional harm of the same magnitude.

    Since the 1st scientific studies reached 95% confidence on AGW in 1995, I think we can say that the harm caused by our GHG emissions from that time on is intentional, or at least done with some knowledge about what we are doing. I can understand why denialists don’t want to accept that responsibility; it hurts.

    Comment by Lynn Vincentnathan — 5 Apr 2007 @ 2:00 PM

  237. http://www.sciencenews.org/articles/20070331/bob9.asp
    Week of March 31, 2007; Vol. 171, No. 13 , p. 202
    Fits and Starts
    What regulates the flow of huge ice streams?
    Sid Perkins

    Comment by Hank Roberts — 5 Apr 2007 @ 2:53 PM

  238. RE#215 (George),

    See the graphic here http://upload.wikimedia.org/wikipedia/en/1/1d/Post-Glacial_Sea_Level.png – rates used to be much faster.

    Comment by Michael Jankowski — 5 Apr 2007 @ 3:45 PM

  239. RE: #221 – With notable exceptions due to peat compaction (Delta) and ground water mining induced local subsidence (Alviso) the main problem, historically, has tended to actually be maintainence of navigability. The combination of siltation and tectonic emergence has tended to continuously push the low tide line versus fixed geodetic reference points in an offshore / estuary mouth direction. I would be curious to see if, assuming it is consistent, global rise of MSL would counter these trends, or even significantly slow them.

    Comment by Steve Sadlov — 5 Apr 2007 @ 4:47 PM

  240. Antarctica froze over about 35 to 45 million years ago. It is not going to melt. CO2 levels at the time are estimated to be as much as 1,000 ppm, nearly 3 times today’s level.

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

    http://earth.geology.yale.edu/~mp364/index.cgi?page-selection=2

    In fact, if you follow the CO2 estimates over geologic time, the best estimate you can get for the temperature sensitivity of CO2 per doubling is 1.0C.

    http://en.wikipedia.org/wiki/Image:Phanerozoic_Carbon_Dioxide.png

    Comment by George K — 5 Apr 2007 @ 6:52 PM

  241. George, where in Rhode’s picture do you find a climate sensitivity of one degree? Are you deriving it somehow, or just asserting it?

    A different conclusion here:
    http://fermiparadox.wordpress.com/2007/03/30/greenhouse-gas-effect-consistent-over-420-million-years/

    Comment by Hank Roberts — 5 Apr 2007 @ 8:46 PM

  242. Antarctica froze over about 35 to 45 million years ago. It is not going to melt.

    Incredibly naive and simplistic. You’ll have to research it yourself, because apparently you haven’t yet.

    CO2 levels at the time are estimated to be as much as 1,000 ppm, nearly 3 times today’s level.

    At 2 to 3 ppm/year, and a carbon reservoir that is an order of magnitude greater than what we have yet tapped, we’ll run by that easliy. Antarctica is most definitely going to melt unless we reverse the trend. Physics demands it.

    In fact, if you follow the CO2 estimates over geologic time, the best estimate you can get for the temperature sensitivity of CO2 per doubling is 1.0C.

    Well, since we’re driving CO2 an order of magnitude faster than the Paleocene Eocene Thermal Maximum, physics says otherwise. The models say otherwise. Antarctica is most definitely going to melt. To claim that it isn’t is like claiming an asteroid will never strike the Earth. Antarctica is surrounded by a southern ocean that is not disconnected from the rest of the world. Once those waters warm, and the oceans overturn, it’s all over. Good thing it’s dry land, because it will make a nice refuge for the weary at that point.

    Comment by Thomas Lee Elifritz — 5 Apr 2007 @ 9:36 PM

  243. Re #240:

    Antarctica froze over about 35 to 45 million years ago. It is not going to melt.

    It is already melting.

    Your statement needs two qualifiers: It is not all going to melt quickly.

    (But some apparently is.)

    Comment by Gareth — 5 Apr 2007 @ 9:54 PM

  244. Both present and previous IPCC reports are based on model predictions. If warming is there ice will melt and sea will rise. Is it going to happen or not? What are the thresholds? are the real questions. Try to understand those by real research.

    Comment by Sajith — 5 Apr 2007 @ 10:25 PM

  245. Re #240: [Antarctica froze over about 35 to 45 million years ago. It is not going to melt.]

    But it doesn’t have to actually melt to contribute to sea level rise. You’ve got much of the continent covered with a mile or two of ice, and ice flows under pressure, no? So if you break off and/or melt bits around the edges, there’s less pressure holding back the ice flow. Ice flows more quickly to the coast, breaks off as icebergs, and floats north to where the water’s warm enough to melt it. So what you could plausibly wind up with is an Antarctica that’s still frozen, but with an ice cap that’s much thinner than now.

    Comment by James — 5 Apr 2007 @ 10:31 PM

  246. Just read re AR4 of IPCC, “scientists angrily confronted government negotiators who they feared were watering down their findings”

    I’m really hoping that RC addresses all the things that were taken out or watered down by heel-dragging governments (like mine). We need to know. Enquiring minds want to know. I’d like to see what was cut out and what was changed. I’m an adult. I can take it, and think for myself. I’ll understand it’s not “official.”

    And I’m really glad Stefan shared his understandings about the IPCC’s statements on sea rise with us.

    The news story also said some scientists quit bec of gov changing stuff too much.

    I think there will be lots of RC contributions on this report & the processes & the stuff surrounding and reverberating out of it.

    Comment by Lynn Vincentnathan — 6 Apr 2007 @ 9:42 AM

  247. RE #244, I think you may be satisfied, Sajith, with the new IPCC report. The newsstory also said:

    “There was little doubt about the science, which was based on 29,000 sets of data, much of it collected in the last five years. ‘For the first time we are not just arm-waving with models,’ Martin Perry, who conducted the grueling negotiations, told reporters.”

    Comment by Lynn Vincentnathan — 6 Apr 2007 @ 9:45 AM

  248. Thanks for illuminating some of the reasons for the difference between the previous estimates of sea level increases and current estimates.
    It seemed odd that the spread in temp. estimates would be on the order of 6x, while the seas level estimates would be 3x. It would in fact sugest that temp could be more accurately projected from sea level rather than the other way round. Anyways, I am hoping you can help me understand the various SRES, as they seem to drive the largest component in the error estimates of temp. That is, the temp estimates vary between 1.1 and 6.4 C ( correct me if I’m wrong) but these estimates are driven by economic models that don’t seem to be tied to climate models at ALL!

    In the AIB scenario, we see a warming of like 2-3C and a global GDP of 550 Trillion. The B1 scenario is approx. 1 C cooler, but has a global economy of 350 Trillion. That would seem to imply that hotter is richer and better. From a modelling perspective what it implies is that the climiate models are decoupled from the economic models. Yet, we know this isnt true. We know rising sea levels and changing climate will impact economics, yet the modelling suggests some of the richest futures are hotter ones.

    Explain

    Comment by steven Mosher — 6 Apr 2007 @ 11:26 AM

  249. RE #248, I think these projection scenarios include both climate sensitivity and emission scenarios. And maybe (I’m hoping) some positive feedback scenarios, like nature releasing carbon in response to the warming (if that’s not include we may be in for really nasty surprises). And then, if there’s mention of econ figures, there must be some mention of effects from GW.

    Now all of these have error margins or confidence intervals. And some of these intervals probably overlap, so I can see how a high econ harm estimate in a low warming scenario might project greater econ harm than a low econ estimate in a high warming scenario.

    At least I think that might be why there are discrepancies and seeming contradictions.

    At any rate the prudent policy is to reduce GHGs as much as possible ASAP in the face of all these unknowns and error bars. We need to keep our sights trained on the high end & on, oops they forgot to account for xxxxxx, which could jump up the warming or econ harms even higher.

    And of course econ figures don’t assure us there will be food left on earth. It might only be $trillions in gold or diamonds.

    Comment by Lynn Vincentnathan — 6 Apr 2007 @ 1:33 PM

  250. RE 249

    “RE #248, I think these projection scenarios include both climate sensitivity and emission scenarios. And maybe (I’m hoping) some positive feedback scenarios, like nature releasing carbon in response to the warming (if that’s not include we may be in for really nasty surprises). And then, if there’s mention of econ figures, there must be some mention of effects from GW.”

    Actually, no. I think if you look through the various SRES you will see that they are decoupled from the Global Warming Models. They are stories. (http://www.grida.no/climate/ipcc/emission/025.htm).

    In order to Drive the Climate science predictions ( the real science) “scenarios” or stories about the future were “selected.”

    I don’t think any of these stories allowed mitigation strategies. At one end of the spectrum you have a story about economic developent and population. This is a “low emission story” . In this story the world warms about 1.5 degree C ( +-.5) At the high end you have another “story” ( their word not mine) In this story, you have different economic assumptions, different populations, and different emmissions. In this high end story, you’ll see temp increasing 6 C ( +-.5)

    The issue is this. GIVEN a projection about emissions, the models predict a temp increase with an error band that is fairly consistent. The low end scenario about 1.5 C +- .5… the middle emmsion scenarios.. 2 C +-.5.. the high end, scenarios… 6C +-.5. What you should note is this. The variability in projections ( 1-6 C) is NOT due to variability in the climate science models! It is due to variability in the SRES. The input models! that is, the variability is due to Stories about the future, not climate science. The climate science models give errors in +-.5C range. The range explodes when you drive these models with wildly divergent economic and population models.

    The climate science is straight forward. Only nuts deny the science. The stories about the future, on the other hand, The SRES, are frankly and admittedly, stories. It COULD BE MUCH WORSE. Or not so bad. In looking through the data sets for the SRES, I found no feedback between Climate and economics. The datasets appear to be decoupled from the models. I can understand why they would do this. But it harms the validity of the projections. Fairy tales in. fairy tales Out.
    Even though the math and science in the middle is by all measures correct and valid.

    You can actually see that they might be decoupled by looking at the predictions for temp increase. If the emission scenarios were coupled to economics, and if being warmer were worse, then you might NOT expect to see the kind of linear increases you see in all the SRES temp projections from current day until 2100. When you look at the projections for all of the SRES, it’s a good guess that the input and output were decoupled. Now, I could be wrong.. but that’s my hunch. That is why I asked for an explaination.

    I will have to recheck the data sets ( they are public domain), but Since these datasets ( assumptions for 100 years) are INPUTS to the models, then it’s hard to see how the models modify the data set, especialy since there were about 20 models run. But That’s why I asked. You have 20 models or so being run from a given dataset; and you know the output of the model SHOULD change the characteristics of the input dataset.. well how was this handled? Just curious.

    So, that is what I am asking. I’m asking if the OUTPUT of the climate models modify the data input into them?? ( my guess is not).They should because we all know flooding will impact economic activity which will impact C02. All of this means the following. The climate science is wonderful and nice and neat. But if the output of your climate model ( temp, and sea level) SHOULD modify your INPUT ( economics and emissions) BUT it does not, then your model needs a tweak or two.

    Basically, the SRES scenarios ( the high emmission ones) make assumptions that are silly. Namely, imagine that everyone acts like the USA for the next 100 years; and that we see the world getting hotter decade after decade, and do NOTHING. basically the High emmission SRES are just scare tactics and they don’t serve science. They may serve Policy, but I think people can be rational. The only reason to scare people into the correct economic decision is if you believe they are too stupid to see reason. And if you believe they are too stupid to see reason, then you are a fascist of sorts.

    Let me put this another way. The higher emission scenarios make assumptions about economic growth ( 3% ) that the climate models would argue cannot be sustained because of damage to the enviroment.
    Put another way. We cant afford to get that hot, so we won’t. Behavior will change, or people are not rational. And I refuse to be a fascist and bleive that people are not rational.

    You further wrote:

    “At any rate the prudent policy is to reduce GHGs as much as possible ASAP in the face of all these unknowns and error bars. We need to keep our sights trained on the high end & on, oops they forgot to account for xxxxxx, which could jump up the warming or econ harms even higher.”

    I’m not sure what the “prudent” thing to do is because of the error bars. The issue is not personal risk. You are not figuring the probability of dying from a disease by having unprotected sex. You are looking at imposing a cost on yourself for the benefit of future generations. Kinda religious and creepy if you ask me.

    But back to the question of PRUDENCE.

    Let’s take something simple like the SCC. ( social cost of carbon)
    Today the IPCC documented that the SCC of C02 could vary between
    13 dollars a TON and 130 dollars a ton. at the lower end I can buy carbon credits for my car at 100 bucks a year. At the high end it’s 1000 bucks a year. Nobody with any sense argues with climate science.
    Long wave raditation, shortwave,water vapor, evaporation, sea temp. ice cores, tree rings, coral, cow farts, huricanes, etc etc.. the science.

    Climate economics, however, is a different matter. Now, If I am going to pay 1000 a year extra to drive my car, I want to know this: Is sea level in Malibu Colony, going to go up 20 CM or 60 CM? and I want to know that people living there are taking precautions and pulling their weight. Over the past 100 years the sea level has gone up about 20CM. Pretty much a straight line. Vegas would bet, that over the next 100 years it will go up another 20 CM. If, you think otherwise, THEN SHORT SELL COASTAL REAL ESTATE . That is really my test of whether or not somebody believes in a sea level projection or projectin from an SRES.

    Finally you wrote:

    “And of course econ figures don’t assure us there will be food left on earth. It might only be $trillions in gold or diamonds.”

    OK, I see you are not serious. One of the biggest factors in Emissions is Population and economic activity. Simply put, when people are more well off, they buy things that burn gas, and consume electricity. That is why we americans spew out so many greenhouse gases. As other nations modernize ( build stuff, make stuff) they tend to emit more greenhouse gases per captia. Making cemet emits gases. making electricty. burnng trees. driving cars. In fact, one could say that increasng your emissions is POSITIVELY CORRELATED with wealth. The rich spew more gas.
    ( no I am not slamming gore and his heated pool, somebody has to continue the good life).

    Now, making people spew less gas will not impact most people. I can buy a carbon indulgence for 100 bucks a year, but if the cost is 1000 a year, then you can bet economic activity will be impacted. Less activity, less C02. This should be clear to you, Any question that the richest nation ( the US) has the most emissions.

    My vote is that people on the coasts of the country should pay more to abate carbon emissions. That seems fair.

    So, Climate science is fine. Economics is the issue.

    Comment by steven Mosher — 6 Apr 2007 @ 5:16 PM

  251. i posted a post on “gardening by the globe”, it recieved only 4 comments but was viewed by over 50 people and i got a email from one of the big shots on there who said my post would be deleted,here is what she wrote to me

    Community Stats: 52964 forum posts, 1449 entries in 85 blogs have been added by 1464 members.

    from the forum on gardenstew….
    Home | Forums | Blogs | Calendar | Plants | | 14 new posts | 1 new blog entries

    Inbox :: Message
    From: toni
    To: katsback
    Posted: Sat Apr 07, 2007 2:05 am
    Subject: The Global warming topic
    Kat,
    This topic is becoming too volatile and political so for the sake of the entire forum it will have to be deleted.

    If you wish to argue about whether global warming is coming immediately please find a forum where that topic is allowed.
    In a discussion, each persons opinion has just as much importance as anyone elses whether they agree with you or not.

    Toni
    co-moderator

    i feel it shouldnt have been deleted, i just wish i could have sent you the post,it was deleted before i had a chance to save it!

    the world has no chance of ever being saved if people like that are in charge!!!

    Comment by kat mccarthy — 6 Apr 2007 @ 9:36 PM

  252. Kat, unfortunately, the forum is geared to a particular group and the moderators have to exercise their judgement as to whether a particular subject is so controversial that it threatens to sew animosity. I do think that it would be appropriate to ask for guidance–is the entire subject of climate change off limits (an unreasonable, but probably legal position) or are there tight limits on tone, etc. that should be taken.
    You are right, climate change is a crucial subject and should be of concern to any gardener that thinks about invasives, pests, etc.

    Comment by Ray Ladbury — 7 Apr 2007 @ 7:41 AM

  253. RE #250 (&249), I hope I wasn’t assuming a coupled model (except hoping for one between warming & positive feedbacks). I was imagining that they feed in different emissions amounts into the warming models & thus the different scenarios (the models working very well with small confidence intervals). And then the economists taking their scenarios and feeding them into their own models-of-sorts to see how these might impact our economic situations, and for each climate story coming up with various econ stories, because if climate is complicated, the econ aspects become even more complicated with wild card factors.

    And I was dead serious (tho exaggerating) re $trillions in diamond or food. Bec macroeconomics does not really distinguish between these. It does not address what is biologically needed to sustain life. And even microoeconomics only gets at our desires, not our biological needs.

    Which is why I would never leave the world’s fate in the hands of neoclassical economists alone. Biologists and others need to weigh in on how GW will impact the world.

    And when I say “prudent” I in no way refer to my own risk (tho from experience I’ve found I only save money without reducing living standards by reducing GHGs — that’s just a plus). Prudent means for the entire world into its distant future. My sole motivation is to reduce my killing of people & other biota now and for many millennia. So the prudent path for me is to reduce GHGs as much as possible.

    If others don’t mind killing people willy nilly now & into the distant future (bec they are having too much fun living wasteful, inefficient lives — they sort of remind me of those nasty boys who delighted in kicking down my sand castles), then that’s their bag. I’d only hope more people and governments would choose good rather than bad for the sake of the world and for their souls.

    Comment by Lynn Vincentnathan — 7 Apr 2007 @ 9:34 AM

  254. RE #249, I feel funny about “carbon offsets.” I think it’s fine to give carbon offset gifts — like giving people CF bulbs or low-flow showerheads, rather than traditional gifts or charities.

    However, we must actually reduce our GHGs, not simply buy the right to spew them bec supposedly someone else is reducing for us (they may have thrown that CF bulb away, for all I know).

    So carbon offsets can be used, but mainly as carbon offset gifts – the gift that keeps on giving. But instead of buying offsets to drive the same as usual, why not move closer to work, or take a shorter vacation, or run multiple errands, or turn off the motor in drive-thrus. Or buy an EV and plug it into your all wind power electricity (that’s what I hope to do as soon as such vehicles are available at an affordable price — which they should be, since they are so much more simple than ICE cars).

    Then buy those offsets anyway to help others reduce.

    Comment by Lynn Vincentnathan — 7 Apr 2007 @ 9:50 AM

  255. re Steven Mosher:

    Put another way. We cant afford to get that hot, so we won’t. Behavior will change, or people are not rational. And I refuse to be a fascist and bleive that people are not rational.

    Unfortunately, people are not always rational, and large aggregations of people are often not rational. Your assertion that this observation makes me a fascist speaks more to you limited observation of the world than to my political leanings.

    First, if people were rational, the US wouldn’t have 30,000 deaths from drug abuse every year, nor would we arrest 2 million folks on drug charges. If markets were rational, we would not have crashes like 1929 or 1987.

    You are right that behavior will change, but the obvious effects of AGW lag the causitive bahavior. In the case of sea level rise, it may well go on for 800 years after the behavior stops. If there are hidden triggers in the system that amplify warming (and it takes a lot of faith in a lenient, protective God to believe there are none) then we are in deep trouble before the mass of humanity sees the need to change.

    Finally, you say “In fact, one could say that increasng your emissions is POSITIVELY CORRELATED with wealth. “ This is simply not true. In the decade or so after the 1973 oil shock, Japan decreased energy consumption by 1/3 while doubling GDP. Even today, Japan, Britain, Germany, and France produce about half the CO2 per capita that the US does.

    The thing that frustrates me the most about the discussions of AGW is assumption that mitigation will depress standards of living. That is only true if we are too dense to imagine, and then develop alternate ways to generate and consume energy. The country that develops effective renewable energy sources first will be more prosperous than the rest of the world for generations. The other mostly ignored factor in the economic debate is what the status quo costs. The US ships about $30 billion per month to pay for imported oil. We spend (by my calculations) about another $20 billion a month to protect overseas oil supplies. Western dependence on Middle Eastern oil funds Islamic terrorism.

    Conservation and renewable energy sources are the only path to energy independence. Energy independence solves a lot of our current problems.

    Comment by Tim McDermott — 7 Apr 2007 @ 2:03 PM

  256. re. 255

    That is only true if we are too dense to imagine, and then develop alternate ways to generate and consume energy.

    It’s at least as much about pointless wastage. The main reason European countries use well under half as much energy per capita as the US is that they don’t waste as much, but even in Europe we waste a ridiculous amount. Over 80% of houses in the UK aren’t insulated properly. Over 90% use inefficient light bulbs. A huge percentage of people in the UK go on regular car trips of well under a mile (I’ve forgotten the percentage but it’s incredibly high). Cycling or walking for such short journeys wouldn’t only save energy but would increase health and reduce traffic jams. Most shops and offices leave large numbers of incandescent lights on all night (frequently halogen lights, the most inefficient ones of all), even in well lit street with CCTV. Most street lighting could be solar and is not. Our electricity grid is incredibly inefficient; a decentralised grid could increase efficiency by around 40%. Almost all existing cars could be converted to LPG for a fairly low outlay that would typically pay for itself in 2-3 years, and that would reduce emissions from cars by 20%. New cars, even without using alternative fuels, could use fuel around 30% more efficiently than they do on average, using existing technologies. Glorification of SUVs has nothing to do with standards of living, and there are many fuel-efficient cars that are a pleasure to drive. Most people throw away several plastic carrier bags every time they go shopping, when they could get a couple of sturdy shopping bags that last a lifetime and use them. I could give hundreds of other examples. We could cut our energy usage dramatically with no technology breakthroughs whatsoever, and with no reduction in living standards whatsoever – it’s just a matter of wanting to. At the moment most of us simply don’t care enough to want to, although many of us pretend that we care.

    Comment by Dave Rado — 7 Apr 2007 @ 7:39 PM

  257. RE. 254, you can’t reduce your emisssions to zero. Reduce them as much as you feel you can, and offset the rest.

    Comment by Dave Rado — 7 Apr 2007 @ 7:41 PM

  258. Re. 255

    The thing that frustrates me the most about the discussions of AGW is assumption that mitigation will depress standards of living. That is only true if we are too dense to imagine, and then develop alternate ways to generate and consume energy

    Even more that is only true to the extent that we continue to be addicted to waste and inefficiency. Living standards in Western Europe are broadly similar to those in the US but per capita CO2 emissions in Western Europe are less than half those in the US, and that is almost entirely due to waste and inefficiency. And even in Western Europe waste and inefficiency is extraordinarily high. We could probably cut emissions in Europe by 50% purely by reducing waste and inefficiency, with no need for any new technologies at all. But the political will isn’t there currently.

    Comment by Dave Rado — 8 Apr 2007 @ 6:09 AM

  259. As countries such as the UK (eg through its Climate Change Bill and associated measures) move to implement high-impact energy-conservation and efficiency, resource efficiency and waste minimisation, green business strategies etc, the US seems (from the outside) to remain entrenched in old-world dogmas that to go green is bad for business and bad for the economy.

    If going green (through integrated implementation of the above plus implementation of businesss ecointelligence etc) can strip huge costs out of a business and improve competitiveness and facilitate entry into and formation of the emerging green markets, as well as (when implemented across the economy) delivering carbon downsizing on the massive scale required to suppress climate change and its impacts as far as possible, then it must make business sense and planet sense.

    The longer the US decides not to implement full-scale high-velocity carbon downsizing on a national scale, the greater the opportunity for its businesses and industries to be competitively zapped when world markets transition. Making an ultra-fast transition to becoming ultra-low carbon is equivalent to becoming highly competitive and at the same time brings powerful positive benefits to climate change mitigation.

    Those who argue that the US should resist attempts to maintain / become competitive through carbon downsizing have not really thought it through. They might not put it in those terms – for example, they might argue that climate change mitigation is too costly – but the effect of their digging-in-of-heels and addiction to the past is the same.

    Finally, to keep this post on thread (IPCC sea level numbers), like the ice melt that is flooding down the moulins, there is a phrase that one could use about where US businesses and industries might flush if its leaders don’t rise to the global competitive challenge and carbon downsizing opportunity.

    Comment by Michael — 8 Apr 2007 @ 7:06 AM

  260. #255, fully agreed. When I first started outreaching to people in the early 90s to reduce their GHGs cost-effectively (& save money, without lowering living standards, as I had done & and knew thru experience was quite doable), and in that way reduce harm from GW & other environmental problems (& other – as you mentioned – harms & expenses), I thought all I’d have to do is tell people, start the ball rolling, then get back to “my life.”

    I thought the regular people (not drug addicts, of course) were rational enough to want to save money or do good (at no cost, even savings). But alas alack, they simply are not rational! I can’t even get goody-two-shoes religious people to reduce GHGs cost-effectively for the sake of saving the world for their progeny. The anti-abortion activists seem to be the most opposed to even believing GW is real, and couldn’t care less about all the other harms, such as “natural” abortions from local pollution. It is the hardest nut to crack I’ve ever experienced.

    OTOH, it was not rationality that motivated me, but a profound conversion experience or change of heart. I was reviewing the film IS IT HOT ENOUGH FOR YOU? (about GW) in 1990, a film I had shown my classes several times. Nothing new. All of a sudden during the part about drought starvation in Africa I cried out (internally), “Why don’t they do something about this?” Then it hit me like a tons of bricks. “I’m the one causing this. I have to do something.”

    That was around Ash Wednesday of 1990. I spent Lent in anguish not knowing what to do, caught up in structures of high GHG emissions (knowing my husband would not go along with a primitive lifestyle). I was the Good Thief on the cross, repentant but unable to correct my fault, until I realized I was the Roman soldier pounding in the nail – forgiven, but unable to stop my killing.

    Then the week after Easter I went to the Earth Day fair & watched Earth Day TV programs, and began to realize there were solutions. But it was mainly many many little things (turning off the water while brushing teeth, etc), and a few big things.

    Over the years I reduced by about 1/3, then went on Green Mountain 100% wind powered electricity. And I’m counting GHGs from all things, not just gasoline & electricity. All products and water have GHG components. REDUCE, REUSE, RECYCLE can go a long way to reducing GHGs. And now I’m awaiting plug-in hybrids, which will be a high cost for us, but our savings over the past 17 years from reducing GHGs should help off-set that cost.

    So rationality does NOT work. Our only hope is if many many people & businesses & our gov have conversion experiences that touch their hearts, open them to reducing GHGs. The actual changes and implementations of GHG reduction measures then become easy by comparison.

    Comment by Lynn Vincentnathan — 8 Apr 2007 @ 9:03 AM

  261. #259, that catchy about the moulins. “Don’t flush the world down the moulins.” Then let people ask, “What are moulins?” Then let them find out.

    And just in time for Earth Day.

    Comment by Lynn Vincentnathan — 8 Apr 2007 @ 9:09 AM

  262. Well, I can’t begin to answer all of the various comments so, I’ll just point out a few things.

    First, as a stated above my main concern is not with the climate science or the models used to make future projections. But every good modeler knows “garbage in; garbage out. I would recommend that everyone read the SRES. you can find it on the IPCC site. Here is a link to the emmission scenarios

    http://www.grida.no/climate/ipcc/emission/116.htm

    Note the huge spread in emission assumptions. What this indicates to me is a very large uncertainty in the future of emmissions. So, who decides what scenarios to use. Some of them are scary; sme benign

    Now, as I read it the models are fed with data from the scenarios. The output of the models do not feedback into the scenarios. I’m somewhat suspect of this.

    Second, the scenarios are broadly classified into 2 dimensions. The dimension that intersts me is the A/B dimension. In the A scenarios people are driven toward economic development. In the B scenarios the drivers are Enviromentalism, roughly speaking. So, for example in A1F1,
    the scennario that shows the highest sea level rise, there is a global focus on economic development and there is a focus on Fossile fuels.
    According to this scenario sea level goes up between .26 and .59 meters.
    In the B1 scenario there is a global drive ( the one indicates global as opposed to regional ) toward eniroment concerns. And here you see a rise of .18 to .38 ( i think the average over the past 100 years is something like .2)

    Anyways, these two scenarios are given equal weight. Now read through the AIF1 scenario. In shrt form, it assumes the entire world will start to follow a US strategy with regards to economic development and fossile fuel usage. Not very sensible, not very probable. Yet, it’s given equal weight and it drives the highend of the estimates in the models. Put anotherway, AIF1 is not realistic because its not sustainable. I suppose one includes it to motivate folks, but it kinda verges on a scare tactic.

    Now, with regards to the correlation between wealth and getting hotter.
    I’ll go look through the reports again. my initial impression from glancing at a couple numbers was that wealthier (global GDP) was warmer, and poorer was cooler. If true ( i’ll double check) then this also seems odd since a bunch of folks here seem to argue just the opposite. If being green were to lead to a poorer future, then of course one couldn’t rationally convince people to do it. One would have to scare them. The point is these data sets drive the models. Only goofballs question the science within the models, but it seems we ought to have a glance or two at the data driving them. At this point I just have a bunch of questions. I don’t see it discussed much. I could be wrong so I was hoping somebody else here had actually looked through the input data.

    Comment by Steven Mosher — 8 Apr 2007 @ 10:36 AM

  263. Steven, I believe that the wealthier vs. poorer look mainly at short term wealth production, while the hard times fall in the medium to long term. Also, if you think the rest of the world is unlikely to follow the US example of short-term thinking, then you have a much rosier impression of humanity than I do. Humans do a poor job of perceiving risk–especially when the risk may seem a long way off. And the recent IPCC report can be looked at two ways. An altruist sees an assertion that the hardest hits will knock the poor and thinks we must address the problem or help the poor deal with it. One who is less altruistic thinks, “Hmm, I’d better not be poor.” Which attitude do you think predominates within our species.
    As to future supplies of fossil fuels, we have plenty of cheap dirty coal to bring about the toasty, warm future envisioned by the IPCC–and worse. This is the path we are on now, with roughly 40% of humanity in India and China VERY energy hungry and the US showing no sign of diminishing thirst for oil and othe cheap energy. To date, we have shown no more intelligence than a colony of yeast in fermenting grape juice. And I doubt that we will produce a good vintage.

    Comment by Ray Ladbury — 8 Apr 2007 @ 12:36 PM

  264. > AIF1 is not realistic because its not sustainable.
    But it describes business as usual, and it describes what both India and China are doing now. That’s a big enough part of the world to be considered as a high end estimate.

    Nothing highly profitable is sustainable — natural stocks grow at the average three percent a year, broadly speaking. An economy growing faster than that is an extractive economy, able to generate a surplus to buy up other resources and extract those later.

    Remember the suggestion that the best economic approach to whaling was to liquidate the resource and put the money in the bank, because interest rates are higher on money than the rate of growth of whales.

    Comment by Hank Roberts — 8 Apr 2007 @ 12:48 PM

  265. Returns on investment on energy conservation etc are much greater than returns from the stock market.

    Comment by Michael — 8 Apr 2007 @ 1:24 PM

  266. Re #262. I think Steven has a good point, insofar as (AFAIK) none of the climate models include the results of adaptation, which could modify climatic outcomes considerable (and in either direction). For example, farmers and other land managers will certainly respond to climatic change (indeed, are already doing so), and to government or other mitigation initiatives, with complex consequences. Integrating land use change into climate models may be the next major step in improving them, but will be very hard.

    Re #260, #263. I think you are both too pessimistic. The greatest ground for optimism is that objectively, all individuals and institutions concerned about what happens more than two or three decades ahead now have a central common interest – cutting GHG emissions fast. What’s more, agreement between a relatively small number of governments could make a big difference – the G8 plus 5 major “developing” countries, representatives of which are to discuss climate change this summer, would certainly be enough. Indeed, even if a few of these were to refuse to cooperate, a sufficiently large and powerful coalition, able to exert economic pressure on all other states to fall in line, might still be possible. Of course, all are likely to want others to make the biggest sacrifices, no agreement reached this year is likely to go anything like far enough, and given Bush’s baleful influence, the chances of any agreement at all before 2009 are slim, but the political shift that is currently going on should not be underestimated – consider the views of likely candidates in the 2008 US presidential election, the way environmental issues have shot to the top of Australia’s political debate, the Stern report and its repercussions in the UK. Sufficient GHG emission reductions are going to require radical socio-political change, but the shift in direction has begun, and I believe it could be fast enough.

    Comment by Nick Gotts — 8 Apr 2007 @ 2:11 PM

  267. RE #263.
    Thanks Ray.. I’ll make a couple points. See what you think. I don’t think you’ve read the SRES. Have a look. Anyways You wrote:

    “Steven, I believe that the wealthier vs. poorer look mainly at short term wealth production, while the hard times fall in the medium to long term. Also, if you think the rest of the world is unlikely to follow the US example of short-term thinking, then you have a much rosier impression of humanity than I do.”

    Interesting. So you thnk that short term thinking is wrong. You think most people will think in a short term way, ie follow the US, So you would propsoe that a few people decide what is best for our long term interest? Put another way, you think that I have a rosy view of humanity because I believe they can figure out their rational interest. So are some people just smarter at figuring out my interest for me? and how do we decide who these deciders are? Can’t ask the stupid short termed thinkers now can we? I mean if they can’t spot their interest how could they pick leaders? Hmm..The main reason I think people can’t follow the US down a Fossil intense path is the MODELS say such a path will cause enormous economic impacts. Simply put, A1F1 assumes developing areas pursue our path. But the impact statements state the opposite. That those ares will be hit heaviest by warming. This relates to my initial complaint that the inputs to the models are not coupled to the outputs. But hey, thats looking at the long term.

    And you go on

    “Humans do a poor job of perceiving risk–especially when the risk may seem a long way off. And the recent IPCC report can be looked at two ways. An altruist sees an assertion that the hardest hits will knock the poor and thinks we must address the problem or help the poor deal with it. One who is less altruistic thinks, “Hmm, I’d better not be poor.” Which attitude do you think predominates within our species.”

    So essentially this is the same argument. Most people can’t assess risk.
    Most people don’t care about others. Therefore, some privaledged people will do it for them. Sorry. If most people can’t assess risk and won’t be altrusitic, then who will decide? And who will pick the deciders?
    According to you The majority of people of can’t assess risk or be trusted to do the right thing. A few posts back I think I called this philosophy fascist. That was overly harsh. let’s call it elitist.
    Don’t know why I did that. had a hunch I suppose that people would come out and say… most people are stupid, most people are evil, trust the master race. Good thing nobody took that bait!

    And then you wrote:

    “As to future supplies of fossil fuels, we have plenty of cheap dirty coal to bring about the toasty, warm future envisioned by the IPCC–and worse. This is the path we are on now, with roughly 40% of humanity in India and China VERY energy hungry and the US showing no sign of diminishing thirst for oil and othe cheap energy. To date, we have shown no more intelligence than a colony of yeast in fermenting grape juice. And I doubt that we will produce a good vintage. ”

    My mistake. I wasnt speaking to the SUPPLIES of Fossil fuels. I was speaking to a different issue. If china and India Follow the US, we will see economic impacts ( droughts, famine, dislocation, disease, see the impact report) before 2100. Simply, the economic activity in A1F1 is not sustainable because of the damage it inflicts. A1F1 assumes that fosile fuel can be consumed without enviroment damage and without economic impact. Like I said the climate outputs of the model are not fed back into the dataset.

    In short, A1F1 can’t happen. To put it another way, you can’t have it both ways. You can’t use a dataset (A1F1) that assumes you can emit with impunity and flourish economically ( A1F1 has some of the highest GDP) and then argue that emitting with impunity leads to economic disaster.

    Ah well, you can argue that, but that’s an emotional scare tactic. For some views of humanity these tactics are justfied.

    Lets see. basically you said people are stupid. Then you try to convince me ( i think I’m human) of something. But if I’m stupid, how can I be convinced? especially by an argument that people are stupid.Now, I can be threatened. You’ll go to hell. I can be bribed. You’ll go to heaven. But, if I’m stupid, then I can’t be convinced. Isn’t it kinda self defeating from a rhetorical point of view to convince your audience by telling them that people are stupid.
    Oh ya, except for us smart guys.

    Comment by Steven Mosher — 8 Apr 2007 @ 2:28 PM

  268. Gee, Nick, did you see what China, Russia and Saudi Arabia managed to do to the recent Summary for Policy Makers–only remove any reference to scientific consensus. The fact remains that to date no country has undertaken any policy that meaningfully reduces CO2 emissions. So, I really do not find any comfort in the fact that politicians are making the right noises. They’ve been making the right noises on healthcare in the US for decades.

    Comment by Ray Ladbury — 8 Apr 2007 @ 3:45 PM

  269. re: #266
    I don’t think the world is inherently doomed either, BUT:

    a) Reading Jared Diamond’s “Collapse” doesn’t make one believe that people consistently are able to make good long-term decisions. Perhaps we know more now, but it is still clear that many people are able to ignore even strong evidence.

    b) The AGW problem seems unusual, in that humans are just not used to dealing with causes whose lag-time to effects are decades/centuries. Many people think that AGW can’t be true because the temperature rise in the 20th century didn’t immediately track the CO2 buildup, i.e., they don’t understand the lag-times and inertia in the system.

    Comment by John Mashey — 8 Apr 2007 @ 3:51 PM

  270. Interestingly, moulins are a key plot point/device in my novel Warm Front. I think I used them in a way no one else has.

    Comment by Mark A. York — 8 Apr 2007 @ 3:54 PM

  271. Let me truthanize everyone. THE FACTS: 1) Global climate (and sea level) has NEVER remained constant. It is ALWAYS gradually changing in one direction or another. 2) Over the last 20,000 years, the earth has warmed enough to raise sea level 400 feet WITHOUT ANY ANTHROPOGENIC INFLUENCE! 3) Even if we abandon the planet or become extinct, SEA LEVEL WILL CONTINUE TO RISE! (just probably not as fast). 4) We can’t stop it, nor should we try (it’s NATURAL). While I am VERY MUCH in favor of limiting/reducing GHGs, preserving our oceans, and reducing habitat loss worldwide, it is a waste of time and energy to worry about a piddling 18 to 59 cm rise in sea level over the next 100 years. Instead of worrying about what causes sea level change and how to stop it, (because WE CAN”T!), we should figure out how to manage it and live with it. “let me assert my firm belief that the only thing we have to fear is fear itself – nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance” FDR

    [Response: Hemlock is natural but I wouldn't advise eating any. The issue is whether we can avoid really big sea level rises due to melting ice sheets - if that starts to happen, there will have been nothing 'natural' about it. -gavin]

    Comment by Louis Hooffstetter — 8 Apr 2007 @ 5:46 PM

  272. #264.

    Hi hank. Thanks for your thoughful comments. Have a look at the SRES. It makes for good reading. Just google SRES IPCC. Since you were kind enough to respond, I’ll make a few comments back. Ok?

    You wrote:

    “But it describes business as usual, and it describes what both India and China are doing now. That’s a big enough part of the world to be considered as a high end estimate.”

    Yes, that is roughly correct. My issue is this. The SRES dataset make assumptions for the next 100 years about emmissions. These emission assumptions are driven by scenario assumptions. Like so: assume china, India and the whole developing world follow the US….. they spew C02 like the US does… over time.

    From this Assumptipon about the futur, you get, roughly, a decade by decade projection of emmissions.So much C02. so much methane, land use like this, deforstation like that, cement production like this, population like so ( fun stories, you should read them. population control SHOULD be high on our agenda, according to the data). But in A1F1, by 2100 we are all hot and wet. ( ok sorry about that, but we all need to laugh ok)

    This is issue.

    INTERMEDIATE RESULTS. ( say 2050 results) of climate models are not fed back into the datasets to make adjustments to the economic activity assumptions, land use assumptions etc underlying them. In short, A1F1 assumes that people will continue to act in stupid, ignorant destructive ways when their countries suffer. When their countries are drought ridden, disease ridden, flooded, refugee ridden, hurrican ridden..In short, A1F1 assumes that people are too stupid to realize their behavior is destroying the world they live in. Even when they are knee deep in sea water. Even when malaria kills their kids. Even when…. If people are this stupid, they need to be controlled and governed by those us us who know better.
    They will appreciate it. In the end. We should control them… Opps.

    A1F1 assumes that people can continue to act in these ways, despite being, parched, infested,drowned, and living in tent cities. Huh? Global warming will have an impact on economic activity. In the AiF1 scenario, it does not. In that scenario everyone burns carbon and gets richer. What the F over?. Why input Junk assumptions into validated models? WHY?

    Now, we know that if the A1F1 predictions are right, if our coast areas flood, that economic activity WILL change. But….A1F1 scenarios predict GDPs at TWICE the level of B2 GDPS (futures where we think global act local) So, I find this funny. The hot future under water is projected to be better off economcally. Nobody beleives this is a realistic future.

    Then you wrote:

    “Nothing highly profitable is sustainable — natural stocks grow at the average three percent a year, broadly speaking. An economy growing faster than that is an extractive economy, able to generate a surplus to buy up other resources and extract those later.”

    I believe the A1F1 scenario.. maybe the A1B is the 3% per year model. BUT you make my point. Thanks. A1F1 assumes sustainable economic activity over the next 100 years, regardless of enviromental impact. You are right A1F1 is a crock. Opps, that was my point.A1F1 philosophy is this: growh rate has been 3% since 1850, it will be 3% until 2100. REGARDLESS OF WHAT WE SPEW. We will emit like hell, and this growth rate will not be impacted. Climate be damned. That is the asumption of A1F1, and you know it’s false. I call that a fairy tale.

    If you give people a choice between B2 ( 200-250 Trillion GDP) and A1 ( 500-550 Trillion GDP) only irrational fools will pick the green B2 . Hmm, I didnt say that. maybe I should argue FOR A1F1. Hot wet rich and dirty.

    But.. I wonder..let me simplify this because I have not been clear… From 100000000 feet:

    F(Economic activity) = emissions;
    F(Emissions )= warming;
    F(Warming) = sealevel;
    F(sealevel ) = economic activity;

    To explain the last. F(sealevel) = economic activity: New york under water. Flooded coast ain’t good for bidness. we could also substitute F(climatechange) = economic activity. Hot drought ridden land doesnt grow food!. See the impact statement.

    Now, clearly the entire model insinuates that economic activity ( choice of fuel types, population, etc etc) drives carbon, which drives the enviroment, which drives economic activity. So feedback. The whole POINT of policy recommendations is that there is a feedback loop. BUT, the modelling approach doesnt use a feedback loop. The climate science is great. The policy loop is disconnected. So, you can predict debates in that area. See, we are having one. Confirmed.

    Anyways,the SRES scenarios are static. That is, the last term, where we would feedback the climate outputs ( sea level, temp etc) to MODIFY the inputs ( economic activity) is missing. The models run Open loop. That is, they don’t modify the inputs ( economic activity and emissions output) that their outputs ( temp, sea level, disaster) insinuate. oh well, B+.

    Put another way. The climate science part of the System { F(emmissions) =warming; F(warming) = enviromental impact)} Is not an issue.

    the issue, the uncertainty lies in this.

    F(Enviromental impact)= economic activity.

    That’s missing. Now, you can prove to yourself that is is missing ( the feedback between climate output and econimic activity input) by witnessng the debate over the impact statement. You go ahead and object, I’ll explain.

    And you finish with this florish, you little ahab.

    “Remember the suggestion that the best economic approach to whaling was to liquidate the resource and put the money in the bank, because interest rates are higher on money than the rate of growth of whales.”

    No I don’t recall this, but economists and fishmongers say many stupid things. Oh hell, we all do. First, the probability of finding whales decreases with decreasing numbers of whales according to accepted search algorithm metrics and the cost function of finding them correspondingly increases with diminishing numbers of whales, dimisnishing thereby and consequently the cost basis of the investment and adversely impacting the overall ROI; so the strategy, while numerically sound in the abstract, is practically impractable in the concrete. Follow?. This Much like emitting all the C02 you can without facing consequences ( see A1F1). The A1F1 data sets say this: If you emit TWICE the C02 of the B2 scenario ( a green scenario) THEN, you will be twice as rich. Or if you’re twice as rich, you’ll spew twice the gas ( this is the Gore formulation of the rule) You will also be hotter ( around twice as hot.. near abouts) and nearly twice as wet..

    Let me put this all in another frame.
    the last 100 year average for sea level increase is 20CM; give r take. Eyeball that data out to 2100. Kentucky windage.
    “Errr. I don’t know earl. that’s like fancy Phd math. maybe Like another 20CM? ”

    Projections for for 2100.

    B2: 20 to 43 centimeter.
    A1F1: 26 to 59 cm.

    “round abouts there earl.” low end of the projection is round about 20 CM.. Goes up from there somewhats, iffin more ice melts”

    Now, what could happpen over the next hunert years or so. Could be an inflection point ahead earl. Could be that big old
    greenland melts. Why then, kentucky windage would be all wrong.

    “so, iffin greenland melts, them californi folks and new york city folks, will be under water?”

    Yes earl.

    “Hmm. Why them folks should move inland. Otherwise, they would be following the dodo bird to extinction. Ain’t they got no common sense. why a cockroach got more survial instinct than them.”

    Personally, I never extrapolated beyond the data without wearing a condom

    Comment by Steven Mosher — 8 Apr 2007 @ 5:46 PM

  273. Thanks Nick,

    I think the unrealistic scenarios continue to be evaluated because they make for sensational headlines. Apocalyptic scenarios and end of days tales that have the tendancy to push us into less democratic governance structures. You can’t trust yourself to do the right thing, therefore trust these people, this agency, this institution, to do the right thing.

    Witness the people who said humans don’t know what’s best for them.
    Kinda midevil. Kinda religious. Kinda pre enlightement. kinda elitist.

    But I have seen this of late in the half/hard sciences. in the hard sciences, we would just follow Popper. Make your prediction, see you in the lab tommorrow. Bring cash.

    Comment by Steven Mosher — 8 Apr 2007 @ 6:07 PM

  274. RE #269.

    ” Reading Jared Diamond’s “Collapse” doesn’t make one believe that people consistently are able to make good long-term decisions. Perhaps we know more now, but it is still clear that many people are able to ignore even strong evidence.”

    So, you read a book. You processed black marks on a page, and that made you believe something? WOW. Some people ignore strong evidence. Other people believe what they read. Go figure. There are times when ignoring strong evdence has adaptive value. There are times when jumping to conclusions has adpative value. Go figure.

    Now about this book and what you read. Did you test it? Nope. It’s historical analysis. Not science. You read it. You believed. Confirmation bias. Yes, you can find examples of people consistently making the wrong decisions.. short term or long term. Yes, someone will win the lottery. Sometimes, People go wrong by engaging in group think. By stifling voices that say something different. they listen to other people, who tell them they don’t know any better. They read bibles and history books that tell them the truth. So, yes, I suppose one can find examples through history of societies that have collapsed by channelling behavior and thought in very narrow ways. In some cases this channellng of behavior destroys the means of living.

    So, one could precipitate a societal collpase through the group think of “CUT EVERY TREE DOWN.. easter island” or one could freeze to death by the group think of “freeze rather than kill a tree”

    Then you wrote.

    “The AGW problem seems unusual, in that humans are just not used to dealing with causes whose lag-time to effects are decades/centuries. Many people think that AGW can’t be true because the temperature rise in the 20th century didn’t immediately track the CO2 buildup, i.e., they don’t understand the lag-times and inertia in the system ”

    Perhaps, attentiveness to problems with long time lags HAS NO ADAPTIVE VALUE. Put another way, preventing the eruption of the Yelowstone Caldera is a long term issue. The earth will be totally destroyed. But we are doing nothing about it.

    People see a generation or two ahead. That time scale for integrating and evalutating interest has had adaptive value.

    Comment by Steven Mosher — 8 Apr 2007 @ 7:53 PM

  275. re: #271
    Based on past inter- glacials (using Ruddiman: Plows, Plagues & Petroleum as an accessible reference):

    a) Without human civilization, glaciation seems likely to have restarted (Baffin island, Labrador) about 4,000-5,000 years ago [Ruddiman: Chapter 10], and almost got started during the later Little Ice Age [p.145].

    b) Hence, the natural course would be that (with the usual jiggles), sea level should already be lower, and going *down*, not up, right now. When we’ve used up most of the fossil fuels, the temperature will likely go down, and so will the sea level. In the meantime, given that we haven’t even seen the effects of the CO2 already out there, it will get hotter & higher sea levels for a wile, although I suppose we could lower the temperatures for a while, in some local areas, by encouraging sulfate-generating industry and accpeting really intense acid rain…

    Nevertheless, it seems that the likely next few hundred years is the equivalent of:

    a) In summer, turning the thermostat as high as possible, and searching hard to buy as much energy as possible to heat it even more, rather than saving it.
    b) And then, in winter, discovering energy is expensive, because it’s been used up.

    For most people, that’s a completely backward way to run a home’s thermostat, but some people seem to be urging that we run the plant’s thermostat that way :-)

    Comment by John Mashey — 8 Apr 2007 @ 8:18 PM

  276. RE 269.

    The reason I love historical analysis is you can always find a contrary opinion. Like I said. CONFIMRATION BIAS. I read this book. It confirms we are ecological monsters. Therefore, since I believe we are, I believe it more now. And you should too.

    Here is a cite of a different explaination of easter island. Damned rats and europeans

    http://www.livescience.com/history/060309_easter_island.html

    Now the debate over appeals to authority would be engaged.

    Comment by Steven Mosher — 8 Apr 2007 @ 8:29 PM

  277. I think the unrealistic scenarios continue to be evaluated because they make for sensational headlines. Apocalyptic scenarios and end of days tales that have the tendancy to push us into less democratic governance structures. You can’t trust yourself to do the right thing, therefore trust these people, this agency, this institution, to do the right thing.

    You are over-interpreting what the scenarios are for. They exist as a means of asking “what if?” questions. It doesn’t matter that some are intrinsically more likely (or feasible) than others. The object is to generate emissions trajectories to drive GCMs to allow us to evaluate the climate system’s transient response at different greenhouse gas levels. They have served that purpose well. They have never been a policy-relevant tool.

    The challenge over coming years is going to be move from “what if?” to “how?”. We need to work out how we can reduce emissions so as to avoid damaging climate change (so far as that is possible). The modelling exercises will then be more subtle – answering questions about global and regional climate at GHG levels corresponding to various policy options. This work is already being done, and is directly policy relevant.

    Meanwhile, climate modellers will continue to refine their models. As we get a better idea about the scale of, for example, ice sheet melting or carbon-cycle feedbacks, and a better idea of regional-scale changes, so we will be able to adjust our mitigation targets and improve adaptation strategies.

    Your view of what the best policy response will be coloured by your political outlook, but the evidence will not be.

    Comment by Gareth — 8 Apr 2007 @ 11:09 PM

  278. Meanwhile, back at the ranch:
    http://scienceblogs.com/integrityofscience/2007/04/white_house_offices_twofisted.php

    Comment by Hank Roberts — 9 Apr 2007 @ 4:07 AM

  279. RE #268 You have a valid point Ray, and I’m certainly not confident that the right decisions will be made in time, but the shift over the last year has been greater than I’d imagined possible – in the US as much as anywhere. You mention the Russian-Chinese-Saudi sabotage on the IPCC SPM, which is certainly disappointing, but raises a number of points:
    1) Everyone interested knows about it, and most know that this is nothing to do with the science. I hardly think even the denialists are going to be boasting about how they have the support of these three regimes.
    2) All three of the saboteur governments are profoundly undemocratic. A year or two ago you’d have found the US and Australian governments in there with them – now they don’t dare.
    3) I’ve suggested that a sufficient consensus for real action could be built by a relatively small number of governments (meaning, rather than through the IPCC). An initial agreement could certainly do without Saudi Arabia, and even Russia – as primary fossil fuel producers, they would just have to lump it if consumer countries reduced demand. China looks an essential partner, but I think its regime is likely to want to be included in such an initial agreement; and would be very vulnerable to “GHG tariffs” on its exports. The trick may be to make such inclusion a matter of being recognised as a first-rank state.

    Re #273. Steven, I said you had a point. Not that I agree with your overall viewpoint, which appears both incoherent (it would help us all if you stated, in a straightforward way, how you think both science and policy should proceed from where we are now, but I suspect you won’t and indeed can’t do anything of the kind), and condescending towards anyone who disagrees with you. It made perfectly good sense for modellers to concentrate first on the physical science, in order to tell us, as far as possible, the climatic effects of putting certain amounts of GHGs into the atmosphere on a certain schedule. It’s once we turn from the scale of the problem to the search for solutions that we need to incorporate feedbacks from human responses to both actual and anticipated change. In my view, we’re now at or near that point, although of course refinement of the physical science models should continue.

    Comment by Nick Gotts — 9 Apr 2007 @ 5:09 AM

  280. re: 271

    Liquid falling from the sky can be natural (rain, sleet, snow) or it can be someone emptying a slop jar (you don’t want to know).

    You’re employing a rhetorical/logical wowzer by trying to shoe horn all possibilities under a single umbrella.

    Comment by Jeffrey Davis — 9 Apr 2007 @ 8:37 AM

  281. RE #271

    Louis, you said:

    [Instead of worrying about what causes sea level change and how to stop it, (because WE CAN"T!), we should figure out how to manage it and live with it.]

    I suggest you put down your sea level rise stove pipe and look through the ocean acidification stove pipe. Long term, not something we can manage and live with.

    Then pick up your melting glaciers stove pipe (particularly the Himalayan glacier metlback stove pipe. Frightening thought — nearly a half billion people will have to find another source of irrigation and drinking water.

    Now, grab the permafrost and tundra melting stove pipe. See the increasing outflow of carbon dioxide and methane being released to the atmosphere and making the darned problem even worse.

    Louis, read a bit more than the newspaper accounts of the IPPC estimates of sea level rise and you will learn there are many facets to this AGW problem. Some will bite harder than others and may well be consequences we cannot [figure out how to manage and live with]

    Comment by John L. McCormick — 9 Apr 2007 @ 8:48 AM

  282. Stefan, thanks for your thoughtful insights.

    My personal objection to the discussion of the threat of sea level rise is the opposite of yours, namely that the threat of near term sea level rise is nearly always overinflated.

    For example, on Friday’s Science Friday, Ira Flatow made a comment (paraphrased) “if the East Coast is submerged in 100 years…” There were three guests there, I suppose all experts on climate change, and not one jumped in say that this is an extremely remote possibility not supported by any climate model. That adds nothing to the credibility and perception of objectivity of any of the guests present.

    Too much of the dialog on both sides is self-serving for either side of the debate to make any claim of moral high ground, in my humble opinion.

    And what’s with quotes on “skeptic”? Anybody who questions the veracity of your arguments has to have an ulterior motive? This distracts from your otherwise strong arguments by making you look as agendized as you claim the skeptics to be.

    Comment by Carrick — 9 Apr 2007 @ 11:40 AM

  283. Re #273: [Witness the people who said humans don't know what's best for them.]

    So here I am, one human forced by the realities of nature to share the planet with six billion or so others, a good many of whom seem bent on rendering the Earth, if not completely uninhabitable, at least a far less pleasant place for me to live. I don’t claim to know what’s best for the rest of those six billion humans: I just want to live my own life unmolested by their byproducts. When I advocate CO2 reductions, or any other environmental action, it’s not altruism that motivates me, it’s self defense.

    It seems to me that you’ve adopted the collectivist point of view, arguing as though “humans” or “the people” were a singular entity, then urging me to adopt a sort of indulgent altruism and subordinate my own needs and desires to the gratification of the masses. This is not an argument that appeals to me at all.

    Comment by James — 9 Apr 2007 @ 12:47 PM

  284. [[For example, on Friday's Science Friday, Ira Flatow made a comment (paraphrased) "if the East Coast is submerged in 100 years..." There were three guests there, I suppose all experts on climate change, and not one jumped in say that this is an extremely remote possibility not supported by any climate model. That adds nothing to the credibility and perception of objectivity of any of the guests present.]]

    Recent evidence is that the dynamics of ice sheet movement in times of warming may be strongly non-linear. That’s why the climatologists didn’t jump on the host. If things go badly enough, New York and Miami really could be underwater in 100 years. At this point, we don’t know how likely or unlikely that is. Things are happening in Greenland and Antarctica that nobody predicted, and until we understand what’s going on there, all bets are off.

    Comment by Barton Paul Levenson — 9 Apr 2007 @ 1:59 PM

  285. Thanks gareth.

    I’ll be quick and to the point. You wrote.

    “You are over-interpreting what the scenarios are for. They exist as a means of asking “what if?” questions. It doesn’t matter that some are intrinsically more likely (or feasible) than others. The object is to generate emissions trajectories to drive GCMs to allow us to evaluate the climate system’s transient response at different greenhouse gas levels. They have served that purpose well. They have never been a policy-relevant tool.”

    since the scenarios drive the boundaries of the estimates ( for example .59 M in the A1F1 case) then assumming a uniform probably of occurance for the scnearios does matter. Since a .59M increase in sea level will impose a cost, one should like to know the probablity of occurance to constrcut an appropriate cost/benefit fucntion. If the sea rises 20 CM over the next century as it did in the last. Then costs will be X. I would suppose 59CM would be more. Does it make sense to abate this potential outcome?

    You continued:

    “The challenge over coming years is going to be move from “what if?” to “how?”. We need to work out how we can reduce emissions so as to avoid damaging climate change (so far as that is possible). The modelling exercises will then be more subtle – answering questions about global and regional climate at GHG levels corresponding to various policy options. This work is already being done, and is directly policy relevant.”

    The issue I raise is the opposite. Scenarios that show low emisions are impoverished. Scenarios for high emissions are wealthy. Hot looks good. Also, note how you assume that climate change is bad. How can we reduced emmissions to avoid damaging the climate? damage? see the coloring of your observations. You think change is bad. Maybe its good? Maybe change is just change. Why valorize the state we are in? The climate will change. Man will impact his enviroment. These changes will impact man. We will change. I’ve never understood why generations of people who are brought up and taught the truth of darwin, suddenly forget this stuff.

    Let me put this another way. What is the cost of climate change?
    EPA documents suggest that a 1 meter rise in sea level would only cost the country 250B over the next hunderd years. Not a risk that requires global action in some peoples opinion. 250B is peanuts over 100 years. Hint: don’t rebuild new orleans under water. look ahead! no climate model required there. hey, you got gills? No? then don’t build your house below sea level sponge bob!. Sheesh. But no. we will tax your carbon, so that guys without gills can build their houses below sea level.

    And you finish..

    “Meanwhile, climate modellers will continue to refine their models. As we get a better idea about the scale of, for example, ice sheet melting or carbon-cycle feedbacks, and a better idea of regional-scale changes, so we will be able to adjust our mitigation targets and improve adaptation strategies.”

    Do you see the bias here? MITIGATION? why would you assume that hotter is worse off? why? Look at temp growth in the past 100 years. Look at the growth of wealth. Just look. Observe. Hotter and richer. Now, given that the historical data shows that the more C02 you put out the higher your GDP, ( why else are we scared of china and india output) what evidence driven, fact driven, hypothesis testing, rational being would assume the opposite. Do you want to be poor? I would say the data suggests we should burn more not less. I mean just look at the evidence.

    The evidence should not be colored by your outlook.

    And you conclude:

    “Your view of what the best policy response will be coloured by your political outlook, but the evidence will not be.”

    I’ll give you a reading list. Then we can have a fun discussion. Quine. Popper. Jerome Bruner. Thomas Kuhn. That’s a good start.

    Your view of the evidence can be colored by your outlook. Witness the nutjobs who talk about the Gore effect.

    Comment by steven mosher — 9 Apr 2007 @ 3:58 PM

  286. Re #285: steven mosher — You have left out anything regarding biology. Roughly speaking, hot is bad. Now a with a slow change, over many millennia, hot is ok. But many biological organisms cannot quickly adjust to the heat. Let’s see, just last summer, tens of thousands of cows died in the U.S. Do you know what happened a few summers ago in France?

    Comment by David B. Benson — 9 Apr 2007 @ 4:26 PM

  287. … and a trigger point has been reached at which photochemical structures in plants change. Over past months, the nature and level of sugars in grass has changed and animals, such as horses, susceptible to enhanced sugar levels (giving equine laminitis) are suffering. The level of equine laminitis, resulting in a most painful death as hooves twist off, is going through the roof around where I live. It is just one example.

    More generally, take a look at bedrock maps, soil maps, and species maps. Study them carefully. In many cases there are strong links between surface-living species, soil structures and the bedrock geology. As the climate at the top of the stack changes, species cannot just shift en masse, because of the deep connections. Multiple wipe-outs are a consequence because so much is tied in an intricate delicate web. It is a web that we have so taken for granted.

    Hot is bad. We must do everything we can as fast as we can to reverse the terrible situation we have created.

    Comment by Michael — 9 Apr 2007 @ 4:59 PM

  288. Hi Nick,

    Thanks for engaging. Let me see if I can respond to your comments.

    “Re #273. Steven, I said you had a point. Not that I agree with your overall viewpoint, which appears both incoherent (it would help us all if you stated, in a straightforward way, how you think both science and policy should proceed from where we are now, but I suspect you won’t and indeed can’t do anything of the kind), ”

    Ok, My overall viewpoint is this. Economic assumptions ( fuel choices, land use, mitigation strategies) and population assumptions drive the emissions scenarios. The emission scenarios drive the climate outputs. climate outputs will impact economic activity. But in the current modelling approach, they do not. I don’t question the climate science. My issue is two fold. 1: the use of input scenarios that may drive boundary estimates in unrealistic ways. namely, A1F1. and two. The lack of coupling ( climate output to economic actvity) in a system that we all know is coupled, otherwise if changing the enviroment didnt change our way of life why would we be worried about change?

    So, I would think that the science should proceed in the following way.
    Instead of working with a 100 year data set, with input parameters that vary by almost an order of magantude. look at 30 year datasets.take the outputs. Feed these to the scenario writing teams, refine the inputs. Run another 30 years. Repeat rinse etc. My sense is you would see a narrowing of the error bounds. Certain “green” scenarios are unrealistic. Other doomsday scenarios where we burn everything are unrealistic. And we will end up with an estimate that is something like
    1-3C warming.

    Policy wise;

    When the estimates are suitably constrained we can convince people to make changes that make sense from a cost benefit standpoint. I’ll reference something Noted earlier. In one EPA paper the cost of abating a 1M rise in sea level in the next 100 years.. is on the order of 250 B. Looking at the past increase of 20CM over 100 years, and estimates for the future,I can see planning for and funding this abatement. You live in a coastal region. Here’s your new tax assesment. You buy a property that could be inudated in the next 100 years, you pay into the risk fund. basically tie consequences to behavior. This lets mr darwin operate.

    On the other hand, when we have a prediction that is “how shall I say” very non linear. As in 7M over the next 100 years, because of a catostrophic event, then we have a harder time, 1:evaluating that risk and 2: selling the abatement of that risk. Its like buying insurance for losing an arm or leg.

    The other point here is how we allocate resources. Do we allocate more resources to study this potental catostrophe? or money to study tree rings? I’d opt for the former. I’d buy insurance against the most likely outcomes ( measuring of course the cost of prevention against the cost of remediation) and I’d focus research on the low probablity high cost outcomes ( like greenland melting) since the expected value of those outcomes may be high. I would not, willy nilly, simply impose a carbon tax or carbon trading scheme. Witness the EU mess with that.
    Ah yes, they will get it right second time around.

    You continue:

    “and condescending towards anyone who disagrees with you. It made perfectly good sense for modellers to concentrate first on the physical science, in order to tell us, as far as possible, the climatic effects of putting certain amounts of GHGs into the atmosphere on a certain schedule. It’s once we turn from the scale of the problem to the search for solutions that we need to incorporate feedbacks from human responses to both actual and anticipated change. ”

    Yes, I agreed condescending was bad form. And I understand fully the need to excercise models at the limits. However, there is a danger of blowback. One could, as I did, look at the scenarios and conclude. hey, this A1F1 world is prety good. 500 Trillion GDP! and its only a few degrees hotter. compare that with a B1 or B2 world. You’d pick a fossil fuel future. So, I don’t think people can step back and say ” hey I’m just running the data” Seriously, you know if you ran a model, that you excercised it with a 2Xc02, 3X, etc etc commitment scenario, etc etc, before the new SRES ever came out. The real focus was probably on matching history and coordination with other models. In all seriousness, you do not believe that the A scenarios are equally likely as the B scenarios. Maybe you do. I don’t.

    Any you conclude

    “In my view, we’re now at or near that point, although of course refinement of the physical science models should continue. ”

    Here is what I saw. With close to 20 models running in a coordinated manner the error band for any given scenario ( say b1) was probably about as tight as it needed to be for Policy. Just eyeballing the chart in the summary report it looks like +-.5 c or so. Now, the bigger variation is BETWEEN scenario. You tell me. When you have one projection for the future that assume 5Gt per year and another that assumes 35Gt.. where would you look to refine your understanding.

    That’s right. If you wanted to maximize a research dollar you will get more bang from the buck if it spent on SRES refinement rather than climate science. Simply, spend money on areas of high uncertainity that relate to high high costs. Study ice and economics.

    Comment by steven mosher — 9 Apr 2007 @ 5:11 PM

  289. I am glad that the oceans are finally getting the attention they deserve, as it was time to stop discussing car emissions and talk about the really important factors in the climate change process.
    You may have read my previos comments, and know by know that I don’t agree to many points of the IPCC report, because I consider it being superficial. To give you a reason, this is a letter that I read and that I think expresses well what I feel about the report.

    Comment by Adrianne — 9 Apr 2007 @ 6:57 PM

  290. re: #289:
    “And what’s with quotes on “skeptic”?”

    The problem is some fuzziness in the use of English:

    1) SKEPTIC: To me, the terms “skeptic” and “skeptical thinking” have usually meant someone takes nothing on blind faith, examines alternate viewpoints carefully, weighs evidence, and changes their mind when new data arrives. I think those are good things. Of course, if you look it up in various dictionaries, you find various meanings.

    I’ve known lots of good scientists, and they generally work this way, and are mostly perfectly happy with real skeptics. I’m always happy to have a few well-informed skeptics poking at mainline theories, since sometimes advances come from studying inconsistencies. Occasionally, really wacko-sounding ideas work out.

    2)CERTAINTY: However, some people have been 100% sure (often in temporal order) that:
    - there is no warming, temperatures jiggle naturally anyway, and scientists don’t understand any of this
    - well, satellites disagree with with ground stations
    - well, maybe there is warming, but it’s not caused by humans
    - well, if some of the warming is caused by humans, we don’t know how much
    - well, if there is warming, it’s caused by {changes in Sun, cosmic rays, etc},and besides the Mars polar cap is melting, so it’s nothing to do with humans.
    - well, we can propose mechanisms that might cancel the warming.
    - well, even if there is AGW, we can’t do anything about it, so we shouldn’t try, people should just migrate away from the coasts.
    - well, we aren’t 100% certain, so we should study it more.
    - well, under no circumstances should we damage our economy by conserving energy [i.e., we should never be so silly as to act like California, which is relatively energy efficient, and whose economy must therefore be just awful. (The Wall Street Journal editorial page regularly mocks CA for such activities, even as the news sections applaud CA business. :-)]

    The problem is, such a view is “skeptical” of AGW, but many people have trouble according it the positives of the classical skeptic in 1), and hence write “skeptic” or sometimes *denialist*. In my experience, good climate scientists are happy to answer questions from real skeptics [RC is a fine example], but rightfully get weary of denialists.

    3) SKEPTICAL THINKING For instance, a *real* skeptical thinker might want to do the following: do as I did in 2002-2003, averaging an hour a day across several years. It would take much less time now, because there’s a lot more data, and some of the annoying inconsistencies have evaporated, and some of the lingering questions now have plausible hypotheses to help explain them, and there are good websites like RC. Here’s what I did then (and for background, my undergrad work was math+physics, followed by MS/PhD in computer science, and I’m a AAAS member, so I’m fairly comfortable looking at primary research articles when needed. I’m certainly not part of any climate-science establishment, although I used to help design supercomputers used by such people.)

    a) Read books by mainstream scientists, such as the IPCC books, several of Stephen Schneider’s, John Houghton’s “Global Warming”, Mackay et al “Global Change in the Holocene”, Krauskopf & Bird, “Introduction to Geochemistry”, etc. If someone were starting now, Ruddiman’s Plows, Plagues, and Petroleum” is my favorite, especially if one doesn’t have a technical background.

    Read Science (or Nature) every week.
    Join the AGU for a while to see what else the professionals are doing.

    b) Get a few alarmist books, like Berger’s “Beating the Heat” (which irked me by lamenting the future disappearance of penguins from the Arctic.)

    c) On the other side, read Lomborg’s “Skeptical Environmentalist”; Fred Singer’s “Hot talk Cold Science”, Essex & McKitrick’s “Taken by Storm”, etc.

    d) Follow ongoing discussions, websites, Look at NOAA, USHCN, etc to understand measurements. I also watched John Daly’s website, and CO2science, and GreeningEarthSociety, etc, etc. I followed the McIntyre & McKitrick papers, and later (2006) studied the Wegman Report.

    e) Keep a list of outstanding objections to AGW. When appropriate, backtrack references to primary research papers. Watch how the list changes with time,and how it relates to ongoing research.

    f) When possible, interact with real climate scientists. I had the fun of being the “skeptical discussant” for a (very good) Stephen Schneider seminar at Stanford: I brought in my current stack of booksd, asked a few tough questions, and asked what else I should look at. He explicitly had no problem with someone questioning AGW, if they were doing it rationally, rather than reflexively. His talk carefully discussed degrees of uncertainty, and if he was upset at anyone, it was at those were 100% sure that AGW didn’t exist, not at those who approached AGW as classical skeptics.

    g) MOST IMPORTANT, and the reason one can’t do this overnight: to understand the science and (necessarily) politics of a theory like AGW, you need to track it for several years, especially to calibrate the players. If you study history of science:

    - a new hypothesis appears, which of course must at least be consistent with existing data, and preferably makes further predictions that can be tested, and preferably, is as simple as possible, but no more.

    - as new data arrives, the hypothesis might be rapidly disconfirmed, or it might need to be adjusted (Ruddiman gives a good example in PPP: Chapter 11).

    - there is *always* ambiguous or contradictory or missing data.

    For a hypothesis to become a well-accepted theory:
    + new data tends to confirm it
    + ambiguities tend to get narrowed
    + contradictions tend to get resolved

    BUT, you have to watch it for a while to see that happening.

    Over time, better theories tend to be better approximations of reality, but even great theories (like Relativity or Quantum Mechanics) don’t explain *everything* – legions of physicists have labored mightily for decades to create a theory that subsumes both of them, but in the meantime, GPS satellites work and so do transistors, even in the absence of an all-encompassing theory.

    Scientists, being human, sometimes defend their data and hypotheses like a lioness defends her cubs, but most are careful to calibrate the quality of data and areas of uncertainty, with numerous caveats, and most change their minds as data accumulates. This puts them at great debating disadvantage with people who have always been 100% sure that AGW doesn’t exist, especially in a sound-byte era.

    4) AGW After watching all this for a few years, my opinion got increasingly firm:

    - In the early 1990s, there had been plenty of room for uncertainty about AGW (not about the basic physics, of course), but there were more loose ends, temperature jiggles for which the explanations were more uncertain. It seemed to me that there were alarmist views that were premature, but:

    - Over time, data piled up overpoweringly, contradictions (like satellites vs ground stations) got resolved… etc. I’m used to science: there are always measurement errors, and one would always like more data, and yes, clouds and aerosols are not perfectly understood, but That’s Life.

    - This left very little room for doubt of the basic AGW theory, if one actually studied the science, and especially if one had even modest technical background. I was pretty clear that mainline scientists were not being alarmists, but had pretty good reasons for saying what they were saying.

    - Occasionally, I was uncomfortable with the ways summarization happened, and data presented graphically. Specifically MBH98+MBH99 (well-caveated) -> IPCC TAR main report -> IPCC TAR TS -> IPCC SPM
    (whose specific hockey-stick chart with gray error zone had to be unconsciously misleading for the intended audience, which I’d guess is unlikely to think much about error bars and uncertainty.) I was sensitive to this because of long-running similar issues in my own discipline (computer science, especially performance characterization, which often tries to be overly precise to make things simple.)

    I always thought that was an unfortunate evolution, which started with studies heroically trying to extract signal from difficult historical data, with appropriate caveats, but emerged looking like everyone was really sure of one line, even though that certainty was clearly not true when one back-tracked through the eventual layers of proper caveats. It’s too bad IPCC didn’t think of a better way to present that data, but I sympathize with people who do understand uncertainty arguing with people who are always 100% sure.

    I thought that it really didn’t matter whether the current temperature was slightly above or slightly below the peak of the MWP. What mattered to me was that the temperature was going up fast, that the lag time effects meant it would keep going up for many decades, no matter what, and that there were at least 10X more people on the planet now. Having grown up on a small farm, I heard about “carrying capacity” before I was 10.

    5) “SKEPTICS” It also became clear was that there existed a relatively small number of vocal people and organizations, who were not acting like classic skeptics, but had the clear point of view described in 2), apparently arising mostly from other-than-scientific concerns:
    - specific political or ideological beliefs
    - economics
    “It’s hard to convince someone if their livelihood depends on not believing.”

    Certain tactics became apparent, a lot like those used to obfuscate research on smoking-cancer link (unsurprising: some of the same people/organizations, but funded by ExxonMobil rather than RJ Reynolds Tobacco).

    -Arguments were made via whitepapers, web pages, OpEd pieces, not peer-reviewed research.

    -Old, long-debunked claims were cited over and over.

    -New data was ignored.

    -Completely irrelevant claims were thrown up (Mars!)

    -Sham polls were produced. [I might be interested in a real poll by AGU or AAAS of their members who are practicing climate scientists. "Polls" like OSMI's: no way.]

    -Claims of major scientific controversy, based almost always on the opinions (but not usually peer-reviewed) of a minuscule handful of scientists, of whom only a few were actually climate scientists. Scientists are always always arguing about details, but I sure couldn’t find major controversy, just normal observational science in progress.

    -Claims that some paper contradicted AGW, but when I’d go read the primary research journal, it wasn’t true.

    -There was constant cherry-picking of data [like saying the Wegman Report was a refutation of AGW (it wasn't), like picking a few weather stations showing downward trends, like saying there was no sea-level rise by citing Stockholm's sea-level records. A random layperson might be forgiven Stockholm, but not a professional oceanic meteorologist, who couldn't possibly be unaware of Post Glacial Rebound (PGR).]

    -In general, the arguments seemed directed to keep the public confused, as opposed to contributing to science. That is, it would be plausible for someone to propose a testable, alternate hypothesis that explained the existing data, but this wasn’t that, this was “anything but AGW”. The closest I could find that looked like a serious hypothesis was Lindzen’s IRIS hypothesis, which remains up in the air, at best, and in any case, is more of a claim of a mechanism that could automatically ameliorate AGW.

    It is quite easy for people who haven’t studied this in detail to pick up denialist ideas, because they are usually packaged as simple sound-bytes that are easy to remember. There may be masses of real science that refutes them, but the latter do not lend themselves to quick simplicity. I’m actually surprised that climate scientists are as patient as many are, giventhat they’ve had to deal with this for years.

    Anyway, over time (and it takes a while, because a snapshot at any onetime doesn’t capture the dynamic behavior), it became clear that the underlying position:

    (“under no circumstances conserve fossil fuels or regulate CO2″)

    was the constant, and that there were a continuing (but ever-changing) series of ideas thrown up against AGW, not with the idea of improving scientific models to better approximate reality, but in support of particular political/economic views, using tactics to keep the public as confused as long as possible. (And it’s OK with me to promote one’s views … but I’d rather it be done by being upfront, not by obfuscating science.) Such tactics can work fairly well, as they did for RJ Reynolds (it took a long time to restrict smoking, didn’t it?) It is totally unsurprising that trying to mitigate AGW (especially by conservations) is simply not in the short-term interests of some companies, just as restricting smoking is not in RJR’s.

    6) CONCLUSION So, I started from a classical skeptic viewpoint, studied the problem in fair depth (for a non-climate scientist), and got convinced that the AGW science was quite solid, notwithstanding some occasional problems in graphics/statistics presentation akin to ones I’ve seen in my own discipline).

    I also got convinced that there was a small, but vocal group who were *not* skeptics, but “skeptics” or denialists. I don’t think that real climate scientists have a problem with classical skeptics, just with 100%-sure denialists calling themselves skeptics.

    Comment by John Mashey — 9 Apr 2007 @ 8:43 PM

  291. Re #285 Mosher:

    As someone else has pointed out, you ignore or drastically underestimate the impacts of warming. If you are so keen to hand out reading lists, then I will respond with only one: start with the Summary For Policymakers of the IPCC’s WG2 report (available here), then move on to the full report when it’s out in May. With luck you might change your tune. But I won’t be holding my breath.

    Comment by Gareth — 10 Apr 2007 @ 3:10 AM

  292. [[I am glad that the oceans are finally getting the attention they deserve, as it was time to stop discussing car emissions and talk about the really important factors in the climate change process.]]

    Adrianne, the oceans emit about 90 gigatons of carbon per year, but they take in about 92. They’re a net sink for CO2, not a source of it.

    Comment by Barton Paul Levenson — 10 Apr 2007 @ 9:43 AM

  293. Re #288
    Thanks Steven, you confounded my expectations. I’ll reply in full when I’ve had time to give your post the consideration due.

    Comment by Nick Gotts — 10 Apr 2007 @ 11:44 AM

  294. RE #290, A marvellous piece of elaboration on â??skepticâ?? you kindly brought to my attention. Cordial thanks!

    I should have presumably more straight, and should have put it as follows: In 2004 Bengtsson et.al., said that the Arctic 1920-1940 warming is one of the most puzzling climate anomalies of the 20th Century, assuming that this was probably a result of the influx of warmer water into the Barents Sea, resulting from a short-lived change in wind patterns.

    That makes me sceptical for the following reason: Already 1936 Scherhag asserted as a reason for Spitsbergen warming after WWI had ended an increase of atmospheric circulation, to which C.E.P. Brooks (1938) made the correct diagnosis, that this pushes the problem one stage further back, for one should still have to account for the change in circulation. All reference on the link previously given, respectively here.

    Hopefully we do understand better now:).
    Best regards,
    Adrianne

    Comment by Adrianne — 10 Apr 2007 @ 12:52 PM

  295. Re #288: [One could, as I did, look at the scenarios and conclude. hey, this A1F1 world is prety good. 500 Trillion GDP!]

    Do you suppose GDP might be an overly simplistic measure of well-being? How is a $500 trillion GDP better than a $250T one, if the $500T has to spend half (or more) to cover additional costs arising from the higher GDP?

    Or for a personal example, I once worked in Switzerland. The pay was about half again what I might expect in the US, but the cost of living was nearly double. Did having a higher income mean that my standard of living, my basic well-being, was higher? Of course not, and neither does just a simple comparison of GDP numbers provide a useful measure of quality of life.

    Comment by James — 10 Apr 2007 @ 1:50 PM

  296. RE #290,
    excellent post, John, thanks.

    RE #285,
    Steven, i don’t think you should suggest further reading for others (#285), given your attitude to other posters reading, as displayed in #274.

    “So, you’ve read a book…WOW…You read it. You believed. Confirmation bias.”

    You clearly haven’t read “Collapse: How societies choose to fail or survive”. I’m glad to say i have, because its a good book, tho maybe not as good as the Pulitzer Prize winning “Guns,Germs and Steel”, Diamond’s first book.

    If you had read it, you would know that mankind is not portrayed as an “ecological monster” (from your post #276), very far from it. In fact Diamond is reasonably positive about mankinds future, and gives numerous examples of successes, as well as failures.

    So who is displaying confirmation bias here, I wonder? Hoist by your own petard, i fear.

    Comment by mark s — 11 Apr 2007 @ 10:25 PM

  297. Re #286: [...Now, given that the historical data shows that the more C02 you put out the higher your GDP...]

    I think you’ve allowed a fundamental misconception into your reasoning there. The causative relation is much more accurately between energy use and GDP. Of course if you look at the GDP of a country that historically gets a certain fraction of energy from fossil fuels, then of course CO2 rises as a consequence of increased energy use, but the correlation is just due to technology choice.

    If you look across countries, you’ll see some that for various reasons have a lower percentage of fossil fuel in their energy mix. Here’s a link to a table of per-capita CO2 for European countries for the year 2002:

    http://www.dataranking.com/table.cgi?LG=e&TP=ee02-1&RG=3

    Now I think we can agree that Switzerland is pretty close to the head of a per-capita GDP list, no? Yet it is quite far down the CO2 list. Why? Because it gets much of its electricty from hydropower, and runs a good bit of the transport sector on it as well. (Trains and most urban streetcars/buses are electric.) France is another such case: since it gets a large fraction of its electricity from nuclear power, it’s well up the GDP list (despite internal problems) while staying low on the CO2 list.

    Thus there’s no inherent contradiction between CO2 reduction and economic growth. Just start thinking outside the energy == fossil fuel box.

    Comment by James — 12 Apr 2007 @ 12:18 PM

  298. Hey, here’s a story about this guy who’s a big-time Global Warming denier; you should read it and post some comments for him to know what we think about his ideas.”

    The link: “Global Warming Is The Biggest Tale Ever Told to Humanity” http://www.orato.com/node/2160

    [Response: "This guy" is non other than Tim Ball. - mike]

    Comment by Simon — 13 Apr 2007 @ 8:48 PM

  299. And the content of this story is pathetic: a slight cooling between 1940-1970, climate models are not perfect, carbon dioxide is not a poison, dumping iron filings in the ocean to reduce carbon dioxide is a bad idea. Even by the usual (low) denialist standards, this is rather feeble stuff. I find it shocking that someone trained as a scientist could write such drivel.

    Comment by Blair Dowden — 14 Apr 2007 @ 8:05 AM

  300. Simon is pointing us to a story on his own website (orato is linked both to Simon’s signature and to the “this guy” story). So Simon certainly knows who “this guy” is. Just asking for attention by asking for people to tell “this guy” “what we think” about his ideas, I’d bet, for pagerank?
    Curious “news” site. “Seal Hunting is My Life” is reminiscent of “CO2 is Life.”

    Comment by Hank Roberts — 14 Apr 2007 @ 2:38 PM

  301. Hi gareth,

    RE 291:

    You wrote:

    “As someone else has pointed out, you ignore or drastically underestimate the impacts of warming. ”

    Acually you get this exactly wrong. My argument is THIS.

    A1F1 ( fossile fuel intensive future SRES ) shows a Global GDP that is DOUBLE that of green futures. The scenario (A1F1) is internally inconsistent. Here is what I mean, if we burn fossile fuel at the rate assumed in A1F1, the economic activity it assumes cannot be sustained BECAUSE OF the enviromental impact. Garbage in; garbage out. I don’t underesimate the impacts of warming, A1F1 does!

    Like I said in other posts. If you ask me to guess about future warming, I’d say +1-3C at 2100. Less than 1 degree C over the next century has Zero probablity (according to the SRES) , more than 4C has a POSITIVE probablity. Ok, wanna bet? Looks like I would get infinite odds by betting less than 1C against your bet of >4C. Right? Again, the issue is the SPREAD of the projections. This is a function of two things: The error in the models and the assumptions of the scenarios. The error or uncertainty within a scenario is half of the uncertainity between scenarios.

    just look at the sea level data in the data set above.See the spread within the scenarios… 18, 23 25 20 27. That variation is within model varition.

    Now look at the range between SCENARIOS. 18CM to 59CM.

    Its a rather simple observation.

    So, I would think, that better policy would be supported by better projections, and better projections could be had by doing better scenarios. read the SRES, you’ll see that they have serious self admitted uncertainity about the data sets. yet, it gets stuffed into a physically based, validated, scientific model. Garbage in.

    Now, you want to improve projections, improve the SRES. reduced the biggest source of error and uncertainity first.

    Now, be honest have you read the entire SRES?

    You went on:

    “If you are so keen to hand out reading lists, then I will respond with only one: start with the Summary For Policymakers of the IPCC’s WG2 report (available here), ”

    Thanks I’ve read every report in full the day they hit . THAT is what got me interested in the SRES. (So I read that too.. did you?). I looked at the graphs. what the heck is this B1 scenario? what is A1T, A1B….. Look at the error band around B1… hmm looks like the error band around A1T.. but why is one scenario so far away from the other? INPUT ASSUMPTONS. What are the input assumptions? Who made up this data? garbage in.

    To repeat I think the high emission scenarios are unrealistic. BUT as the SRES makes clear every scenario is given equal weight in making the projections.

    So, simply, I would suggest that people take more care in selecting input scenarios and look at issue like internal consistency. Namely, a scenario that assumes the that increased C02 will lead to a doubling of C02, ASSUMES that there will be no negative economic feedback. This is my other complaint.. no feedback between climate outputs and economic inputs. Simple feedback. See you first point. I dont under estimate the impact of warming, A1F1 does. A1F1 assumes that
    we can output c02 with impunity. THIS, as you point out, makes no sense. So A1f1 makes no sense. This is your position.
    but you don’t realize it.

    You conclude:

    “then move on to the full report when it’s out in May. With luck you might change your tune. But I won’t be holding my breath. ”

    To reapeat. I don’t question the science. Let me make this very simple.
    A GCM tells me this: “If c02 goes up 2X, sea level will go up xy cm”
    I would not question it. Seems rather silly to question the climate science.

    That is not my issue. Let me answer laconically. IF…..

    IF c02 goes up 2x. what about 1 X, what about 2.76547X what about 3X, what about 4X. The SRES. the IFs. So, that has been my focus. I read the report. made sense. My issue is the inputs. Were the scenarios self consistent.

    1. the green scenarios with less C02, had lower GDPs. Green is poor.
    2. The dirty future (A1f1) had twice the C02 and twice the GDP.

    Now, I ask you. Do you think that greener will be poorer? I dont. Do you think we can sustain economic growth AND
    destroy the enviroment as A1f1 suggests? I don’t.

    Personally I’d focus on an A1T future, high GDP, low emmissions. Green and rich. Put another way, A1F1 is just a scare tactic. I’m not confortable with this. Strikes me as a eco version of you’ll go to hell.

    And then beyond this, the issue is the policy. What’s the right sea level? if it’s rising, and rising is bad, then what exactly is the correct level? what’s the “natural” level? ( like there is an unnatural level) Funny question huh? But one really can’t attempt to control something without a goal. I mean one has to close the loop on something right? What is the exact right temp? We can’t realy close the loop on a target level because of the time lags, so do we implement a rate controller? First order lag? how much overshoot? steering an oil tanker is way different than steering a jetski.

    Honest question. Is having a radiative balance a good goal? Do you think that we can actually control the enviroment with enough fidelity to manage the radiative balance. What would be the best things to measure.. air temp? ocean heat storage etc etc. THAT would be a cool probem for a control systems guy. Lots of measrement errors and long time lags for control inputs.. anyways..

    Comment by steven mosher — 17 Apr 2007 @ 5:00 PM

  302. [[Honest question. Is having a radiative balance a good goal? Do you think that we can actually control the enviroment with enough fidelity to manage the radiative balance.]]

    In the long run, radiative balance, at least at the top of the atmosphere, will be enforced by conservation of energy. If the temperature stabilizes, solar energy input to the planet will equal reflected and emitted energy output.

    Comment by Barton Paul Levenson — 18 Apr 2007 @ 8:29 AM

  303. Anyway you cut it, that is a lot less then the 27 ft. Al Gore quoted [edit] in Senator Boxer’s Senate hearings on Global Warming.

    [Response: 20ft is the rise (from ice sheet melt) that eventually occurred during the last interglacial when global temperatures were maybe only a degree or so warmer than today. But the timescale over which that plays out is uncertain. -gavin]

    Comment by ER Barker — 18 Apr 2007 @ 11:59 AM

  304. #290

    On the subject of books hereâ??s one I recommend â??The Last Generationâ?? by Fred Pearce (Eden project books £8.99). Itâ??s got that famous (?) picture of a river acting like a thermal lance in Greenland (p85). Pearce also states â??In all probability, the Pine Island and Thwaites glaciers are already the biggest causes of sea level worldwideâ??.

    If thatâ??s true I think it shouldâ??ve got a mention in a thread about sea levels.

    Has anyone seen my pet glacier? It was there a few days ago and itâ??s gone! Iâ??ve reported its disappearance to the police and RSPCG. If you have kidnapped it please donâ??t mistreat it. It responds well to ice cubes and cold temperatures. It answers to â??Glassieâ??.

    Comment by Mike Donald — 22 Apr 2007 @ 9:05 AM

  305. I did not make this up.. It appeared in the Bangkok Post
    yesterday.

    Expert predicts no local rise in sea

    (dpa) Global warming is not likely to cause the sea level in the Gulf of Thailand to rise because the body of water is too far from melting glaciers, a leading Thai hydrologist claimed on Monday.

    Recent forecasts by the United Nations’ Inter-governmental Panel on Climate Change (IPCC) – which predict a 40 centimetre rise in sea levels by the end of the century will cause flooding for up to 94 million Asians living in coastal areas – may not apply to the Gulf of Thailand, according to Suphat Vongvisessomjai, a former professor in water resources engineering at Bangkok’s Asia Institute of Technology.

    “The climate change panel’s projection was wrongly accepted to apply to the Gulf of Thailand,” Suphat told The Nation newspaper. “We are too far from melting glaciers or ice sheets.”

    Suphat added that, in fact, recent research shows that the average sea levels along some coastal provinces on the gulf have declined 0.3 to 0.6 centimetres over the past eight years.

    The hydrologist, now an employee of Team Consulting Engineering, called on the public not to panic over the IPCC findings.

    “The climate change panel did not deceive us or exaggerate. Its scientific findings are just based on the environment of their scientists, most of who live in Europe,” he told the English-language daily.

    [Response: oh dear.... - gavin]

    Comment by John L. McCormick — 23 Apr 2007 @ 9:18 AM

  306. re: #305

    Clearly a complete wacko ….

    OOPS: turns out, it is very likely that he isn’t, and in fact, this is a good reminder to be really careful, especially when an expert tries to explain something complex to a reporter writing a tiny summary in the popular press, and how over-simplifications may come back to bite.

    When I saw this, I laughed, but then, from personal experience, I know how things sometimes get mangled by newspapers, especially with potential language issues. Since I’m in the middle of Naomi Oreskes’ fine book “The Rejection of Continental Drift” (about why American geoscientists resisted this theory so long in the face of mounting evidence for it), I thought “I know SouthEast Asia is complex geologically (colliding plates), could some of Thailand be rising? Maybe this guy isn’t crazy?”

    Searching for the author Suphat Vongvisessomjai in Google Scholar [easier than Joe Smith :-)], I find that he actually has a good multi-decadal record of scholarly publications, and at least looks a like a serious expert on anything to do with water around Thailand.

    Then I found:
    “Will Sea-Level Really Fall in the Gulf of Thailand?”
    [Abstract in both English & Thai, but the article is in English].
    http://www.aseanenvironment.info/Abstract/41013003.pdf

    This is a reasonably clear discussion of the various issues that affect local sea-level change, followed by a lot of discussion about the Gulf of Thailand’s specifics. It may or may not be right, and a few of the words describing it may be poorly chosen (stuff about glaciers) but it’s certainly neither denialist nor uninformed.

    This paper, at least, is *not* making a generic claim that there is no sea level rise in the world [i.e., he is not doing the denialist "No Sea level rise near Stockholm" trick.] He is really just pointing out that average sea level rises aren’t seen anywhere, and there are specific data and reasons to not expect much rise in he Gulf of Thailand.

    Comment by John Mashey — 23 Apr 2007 @ 3:55 PM

  307. #305 #306

    Still oh dear. Someone will have to tell The Onion about this.

    http://www.theonion.com/content/node/44676

    Comment by Mike Donald — 24 Apr 2007 @ 6:29 AM

  308. I am learning day by day from reading these posts and everything I can find about global warming. To me the time has come to begin the radical transitions needed to mitigate the damages. Here are my top ten ways to slow global warming. Let’s see how they compare to the IPCC’s recommendations.

    Preamble: Our one and only planet is heating up, fast. CO2 burned 200 years ago is still lingering up above us, warming the planet, compounded every day by still increasing tonnage that won’t go away for a thousand years, melting ice caps and glaciers, heating and acidifying oceans, decimating phytoplankton that grows best in cold water, removing the foundations of Earth’s entire biotic ecosystem, from crab larvae to terrestrial mammals like us. The bountiful oceans have been strip-mined and are now losing their ability to grow back.
    Sea levels are rising. According to an IPCC climatologist on realclimate.org

    “59 cm (23 inches by 2095) is unfortunately not the â��worst caseâ��. It does not include the full ice sheet uncertainty, which could add 20 cm or even more. It does not cover the full â��likelyâ�� temperature range given in the AR4 (up to 6.4 ºC) â�� correcting for that could again roughly add 15 cm. It does not account for the fact that past sea level rise is underestimated by the models for reasons that are unclear. Considering these issues, a sea level rise exceeding one metre can in my view by no means ruled out… Greenland ice is good for 7 metres and the WAIS for 6 metres of sea level rise. 20 feet is about 6 metres so either ice sheet alone, or half of each, could lead to a 20 feet rise.â��

    A blogger points out that: â��The rise will continue rising and there is no possibility for the sea rise to retreat….not in centuries or longer.â��
    These rising waters will soon, in coming years, not decades, wipe out massive human populations (The low countries, northern Europe and especially Bangladesh, come to mind, but coastal communities everywhere will be flooded) while disrupting the most productive tidal nurseries needed for life in both land and sea.
    Droughts are already drying up wide swaths of tropical and temperate latitudes, where most of Earth’s 6,708,290,000 humans live, (on 04/30/07). That’s at least three times, and probably ten times, the number of people this planet can support for more than one or two generations, and land surface suitable for human habitation is rapidly shrinking. See E.O Wilson on Acting now to save life on Earth. Rising seas, droughts and floods will push 100′s of millions, maybe billions, of surviving refugees to ever-shrinking higher, greener ground, overwhelming those habitats and inhabitants, the stores, schools, hospitals, and criminal justice systems, creating lawless gang warfare and warlords dominating the daily lives of survivors. It’s gonna be bleak. Public awareness of the realities of global warming is ramping up every day, but we’re still deep in the darkness of denial about what’s really starting to happen

    So here, for all leaders and citizens alike all around this imperiled planet, by the wonders of global internet broadcasting, are the top ten things that truly will need to be accomplished while we still have functioning societies, that should have been started generations ago, if we desire to keep our lives tolerable and intact:

    1) Stop having so many wars. Wars, and the buildup for wars, burn more oil and create more CO2 than any other single human endeavor. As resources become harder to find, the tendency will be to start more wars, but if we can stop having wars now, and accomplish the other nine items on this list, we won’t consume nearly as much of Earth’s natural resources, so we won’t be so tempted to start wars. Wars also justify the entire military/industrial complex, which directly and indirectly burns oil without reflection on the consequences, by the millions of barrels daily. Wars are interactions – “they” say or do something bad, like own a resource we think should be ours, or we think they did, so “we” answer with something bad toward them, and the spiral descends into uncontrollable war. We need a better way to respond and interact with each other, a new modus operandi in our society and government, new philosophies at colleges and think tanks, new conversations everywhere, etc. That’s impossible, you say? OK then, welcome to the world of Mad Max Mutual Murder worldwide. Or, we can change our ways and get along, if we try.

    2) Stop having so many babies. This is also contrary to our habits and customs known as “human nature,” but let’s face it, one way or another the human race is about to be drastically reduced. It’s far better to take some control over our sheer numbers by reducing births rather than by increasing deaths. We need an international resolve to distribute clear educational truth on the realities of global warming and overpopulation, and condoms and IUDs, etc. on every streetcorner, and in every school, tea room and post office, worldwide.

    3) Stop traveling so much. Overconsumption of resources leads to global warming and wars, so we’ll need to radically reduce our travels in every way possible. Games, concerts, vacations, family visits, conferences, weekend getaways, and other important occasions, need to be severely reduced, worldwide. Like almost everything else on this list, we’re talking about major personal and economic disruptions, with lots of people out of work while transitions are made to resettle into more integrated communities with our families and our daily needs close by. Hard to imagine? So is Mad Max.

    4) De-throne the corporate rulers. When you’ve got the political muscle, you don’t have to make sense, apparently. We need to see some investigation into exactly who is orchestrating the campaigns to lie about global warming to sell oil, who is pushing unnecessary drugs on people, who is poisoning the Earth with pesticides, who is weakening the will of the people to have livable, logical societies by corrupting our democracies. Of course we have their chosen political officers like Cheney and Bush, and the lobbyists and the “industry reps,” but behind them have to be actual individuals with names and faces, who own the industries, or own the investment groups that own the industries, who hand down their wishes through boards and CEOs, who hire think tanks, media conglomerates and PR firms who hire lobbyists who then say they represent “the industry.” They proclaim their faith in Reaganite simplicity: “Government is bad, taxes are bad, corporations are good.” “For every complex problem, there is a solution that is simple, neat, and wrong. –H. L. Mencken
    I’d like to pull back the curtain and see exactly who is shaping the campaigns to overpower elected officials and shape the consciousness of the public to accept their faulty, simplistic logic. I think we need a public conversation with these individuals. They have a big influence on our lives and our future, and yet they’re just people like the rest of us, once we can see them and talk to them.
    Who are they? They have a big influence on our lives and our future. I want names, faces, bios and contact information. Who set up the think tanks and endowed positions that spew out the pundits that are nothing but loyal team players who have no standards of truth to fall back on, but only allegiance to the captain and to making the scores and claiming moral superiority over the other team? Who does Rupert Murdoch, for instance, have dinner with, meet at the club, go hunting with? The campaign to declare that global warming is a hoax perpetrated by corrupt scientists and greedy environmentalists was not just spontaneously concocted by Sean, Rush and Glenn Beck, to name a few. These hired guns were carefully taught to tell such preposterous lies by….who? These lies are immensely damaging to the consensus we all desperately need if we are to change our lifestyles rapidly, and for the major industries to take seriously the increasingly obvious threats of global warming, or we will indeed cook in our own exhaust fumes. It’s as if we’re all on a train that is headed over a cliff, and some of us see the danger, but we can’t get the engineer to stop or turn, because the crowd in the club car are laughing at us and calling us kooks, in an orchestrated, coordinated fashion, like a trained choir. Who trained them?

    5) Return to simple pleasures, like playing music, making love (using birth control), reading and writing, drinking beer, smoking grass, bird-watching, woods-walking, wood-carving, knitting, yoga, jogging, card-playing, story-telling and listening, rowing, swimming, walking the dog, visiting friends and old folks for no good reason. These are the positives that have been mostly lost due to wars, over-population, over-consumption, social fragmentation and alienation, and obedience to corporate masters.

    6) Conserve power. Buy and use florescent light bulbs, low-power appliances. Use less water, replant lawns with gardens or native ground cover, etc. Enjoy the sounds of nature and the natural relaxation of darkness. Recycle, re-use, reduce. Obvious, I know.
    7) Find locally grown food, building material and everything else as much as possible. Corporate agriculture and those container ships and trucks bringing cheap goods (such as polluted pet food) from far away places, like Mexico and China, are destroying the air, the climate, and our health. Again, there will be personal and economic disruption, worldwide, while we make transitions, but we have no other choice.

    8) Use wind and solar power for homes, industries, businesses, offices and public buildings, every chance you get. This should be politically mandated and demanded by consumers.

    9) Demand inexpensive, plug-in biodiesel hybrid cars, and get as few of them as possible and use them as little as possible. Walk or ride bicycles whenever possible, which also provides strength and vitality and reduces health care costs.

    10) Support Earth-bound politicians, organizations, businesses, teachers, friends and relatives, and avoid religions and philosophies that degrade Earth in favor of any supernatural heaven or afterlife. We won’t know what’s after life until we get there, but our life, and all life, on Earth is too important to let it burn up in our own exhaust fumes, toxic chemicals, radioactivity, etc.

    Iâ��m sure others can think of additions to these ten items, but before we can do these things in a scale to meet the effects of global warming, we’ll need to talk about them.

    Comment by stormboy — 29 Apr 2007 @ 1:59 PM

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