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Arctic sea ice discussions

Filed under: — group @ 20 July 2011

This is a thread to discuss issues related to the 2011 Arctic sea ice minimum. The following graphs will update every day:

JAXA Sea ice extent:

Cryosphere Today sea ice concentration:

298 Responses to “Arctic sea ice discussions”

  1. 101
    Hank Roberts says:

    John, seeing a picture doesn’t mean much — what matters is understanding the facts behind the picture so you can interpret it. You’re probably having the common reaction to seeing a chart you don’t understand — “it’s spaghetti” — right?

    But what matters is where the longterm average is and how the world pictured is changing over time.

    You can’t see those in the picture, only in your own underststanding when you attain that.

  2. 102
    Rob Honeycutt says:

    John @ 97… You have to look at the numbers on the chart. Sept min for 2003 is ~6 million square km. The Sept min for 2007 is ~4 million square km. That’s a 30% loss of min sea ice extent in only a few years.

    Still skeptical?

  3. 103
    M says:

    Until Burgeson tells us why he’s more skeptical, we can’t target our arguments very well.

    Maybe he is skeptical because he doesn’t see a trend in the data, or because he doesn’t think the trend is alarming. That one is easy to address (for example, showing the NSIDC September monthly averages at, and seems to be the approach people above have hit on. (whether the trend is alarming is a value judgment, of course).

    But maybe he is more skeptical because he thinks that Arctic ice retreat isn’t a good measure of global warming because he believes it is all due to, say, PDO changes or BC deposition or something else not-GHG-related. That would require a different discussion. I would be very very surprised if GHGs weren’t the main driving force, but there is definitely room for other influences, and I don’t know of a good one-stop-shop that attempts to do the attribution.

    Or maybe he is skeptical because the record starts in 1979, and he’s one of those people who believe that 1979 is cherry-picked as a peak. So we’d point him to a longer reconstruction which shows that ice going back to 1953 was higher than 1979:

    etc. So, Burgy, which one is it?


  4. 104
    SecularAnimist says:

    The research by Micha Ruhl et al from the University of Copenhagen, published in Science and discussed above by Geoff Beacon in comment currently numbered 99, is reported in more detail at


    Prior to this research, most scientists have believed that the sudden extinction of nearly half of all life forms on the planet was due solely to the emissions from volcanic eruptions that were occurring in what was to become the Atlantic Ocean. Ruhl et al contend that instead, what happened, was that the small amount of atmospheric heating that occurred due to the exhaust from the volcanoes, caused the oceans to warm as well, leading to the melting of ice crystals at the bottom of the sea that were holding on to methane created by the millions of years of decomposing sea life. When the ice crystals melted, methane was released, which in turn caused the planet to warm even more, which led to more methane release in a chain reaction, that Ruhl says, was the real reason for the mass extinction that led to the next phase in world history, the rise of dinosaurs …

    This new research, though dire sounding, may or may not have implications for modern Earth. While it is true that humans have pumped significant amounts of carbon into the atmosphere, amounts that are approaching what Ruhl and his team say led to the earlier methane release, it doesn’t necessarily mean we are on the same path, because as Ruhl points out, things are much different today, the very structure of the planet has changed so much that it would be impossible to transfer what might have been learned about events in Earth’s history 200 million years ago, to what is going on today.

  5. 105
    MARodger says:

    Further to #102
    It’s not just the Extent that’s shrinking. The thickness is down as well. While PIOMAS is but a model, the inputs into it are real enough. Last year the PIOMAS anomaly bottomed out sometime in early June (I can’t be sure on the date – the POIMAS data page on their site is devoid of data here in UK). This year there is still no sign of bottoming out as of 30 June. All round, things look bad for summer ice.

  6. 106
    Joe Cushley says:

    John Burgeson – “Still “on your side” but confidence level has dropped over the past year.”

    Really? Really?!?!? Here’s the Climate Change section from Burgeson’s website…

    “Several class members are concerned about the global warming controversy. The following appears below in partial response to this. I claim no particular expertise in this matter.

    Is global warming real? Most scientists think so, although the evidence to date is scanty. Some think not. A Google search on global warming will turn up both kinds. Below are links (external) to some of the more controversial debates:

    A view from a well known scientist [Richard Lindzen] who believes there is no problem
    A very controversial debate on environmentalism
    Bjorn Lomborg’s web site on the controversy

    An essay on emergent teleology, by Dr. Robert Koons
    Bjorn Lomberg’s home page”

    So, he links to Christian philosopher Dr Robert Koons, 3 different pages related to and supportive of Bjorn Lomborg (including Lomborg’s site) and to a Richard Lindzen article at Cato Institute’s website. “On your side…” Puh-leaze….

  7. 107
    PAM says:

    Would be nice to see previous accuracy of models, Statistical and Heuristics in prediction.
    Can we have such data?

    Seems that someone who has been right in the past has more chances to be right in the future.

  8. 108
    Ron R. says:

    The following is from a few notes I have about the Barstovian/Luisian, a particular slice of the Miocene that I ma interested in.

    Below find a reconstruction of the North and South America c15Ma, the peak of the Middle Miocene Climate Optimum (MMCO), courtesy of Ronald Clyde Blakey of Northern Arizona University (although Clarence A Hall is said to have the most accurate – “palinspastic” representations). Note the lack of Arctic ice and the continental margins underwater. The global average temps are said to have been about 18.4 degrees C (about 65 F), 3 degrees hotter than today (caused by increased CO2 in the atmosphere) and within IPCC predictions for GW.
    The late great Daniel Axelrod said that an average temp of 14 degrees C is “ideal equable climate”.

    Hot and humid, Lots of mosquitos and ticks I suspect. Outer coaster waters down to about 30 degrees latitude are described by Clarence Hall as being “warm temperate” (temps: 23-25 celsius, 73-77 Farenheit) for for 7.2 months of the year. The waters below 30 degrees latitude and the inland seas are called “outer tropical” (temps: 25-27 C, 77-80+ F) for 9.4 months of the year. The coastal water temps are analogous to those between Pt. Conception and “Bahia Magdalena, Baja Calif Sur Mexico”. Peak warming from the Middle Miocene Climate Optimum occurred about 17 mya to 14.5 Ma, “considered generally to be the warmest period in Earth’s history within the past 25 million years”.

  9. 109
    Pekka Kostamo says:

    Todd @55: Some additional info on using the Northern Sea Route (a.k.a. NE passage)for commercial traffic.

    This is serious business. Shipping appears to be expanding despite of evident shortcomings of services in the area. Large tonnage bulk carriers/tankers are experimented with. The current market appears to be for carrying gas condensate from some Russian plant or Swedish iron ore (via a Norwegian port) to industries in Northern China.

    Icebreaker escorts are apparently required, for various reasons. The big ships are not built for use in icefields – surprises are still possible. Navigation and other services (i.e. search and rescue) in the area are not yet fully developed so a support vessel nearby is justified. Service charges appear to be modeled after the Suez canal costs, but leaving the benefit of a shorter transit time mostly to the ship operator (a good incentive). There is also the issue of piracy on the southern alternative.

    A long term prospect might be opening up major coal deposits on the Alaskan North Slope. This resource just might compete with Australian coal that is currently powering Europe. Some feasibility studies were carried out about 15 years ago.

  10. 110
  11. 111
    Lawrence Coleman says:

    A new University of Arizona study has concluded that during the last interglacial warming period 100+ky ago thermal expansion of sea water contributed very little to sea level rise which was in the ballpark area of 8metres. Only abut 40cms is contributed to thermal rise. Disturbingly ony 0.7C mean surface temp rise above today’s level locked in this cycle. Cause then was the earth’s orbit relative to the sun causing more pronounced seasonal variablty..thus winters were colder and summers hotter. Thus it was a long time coming but when the warming induced +ve loops became too severe the greenland and antarctic ice sheets melted rapidly causing the 8m rise n a short space of time. They also found that glacial retreat lags significantly behind warming ocean surface temps and that ocean surface temps lags significantly behind atmospheric warming. Thus the extent of inertia in the system is truly awesome. The situation today is worse because in the last interglacial period the temp incease was by largely hotter summers offset against slightly cooler we have significant atmospheric warming irrespective of what season it is. So the fact is – even if we were to miraculously stop carbon emmissions tomorrow we are still locked in to centuries of global warming and sea level rise which in all liklihood will eclipse the 8m of the last I.G.P. Question: does anyone have a rough idea how long it will take to raise the mean ocean surface temp by a further 0.7C based on a business as usual scenario? Taking into account elevated rates of thermohaline mixing due to more hurricanes/water spouts. Feedback on this will be much welcomed.

  12. 112
    Ray Ladbury says:

    OK, ‘splain me this. How does precipitous decline of Arctic sea ice toward what could be unprecedented levels make you more skeptical?

    Burgie, this is science. It’s just about where the evidence points. There are no “sides”. If you are taking sides, you aren’t doing science. If you have evidence that places serious doubt that the most successful theory of Earth’s climate is correct, produce it. If not, maybe you should pay more attention to the evidence and less to persuasive idiots who cherrypick evidence as a framework to support their lies.

  13. 113
    Lawrence Coleman says:

    Q.19 Lou Grinzo. Good point! I remember a few years back when it was possible to sail a boat and have a swim at 0degN in August. It hit the headlines for while and then was promptly forgotten by most. People have incredibly short memories!. I dont think it’s possible to shock people any more. We tend to blur fiction with reality with such effortlessness..maybe thanks to all the shock/horror movies desensitising us to the point of catatonic stupor. Even if it were still possible to reverse global warming within he next 10 years and preserve the planet for future generations of life, no-one would bother doing it..heaven forbid our economic bottom line could wobble a bit. I’ve given up with trying to educate people..the tide of denial and lethargy is way to strong to swim against.

  14. 114
    Geoff Beacon says:

    @ SecularAnimist 104

    Are you implying without saying that there is no cause to worry. You quote Ruhl

    … caused the oceans to warm as well, leading to the melting of ice crystals at the bottom of the sea that were holding on to methane created by the millions of years of decomposing sea life. When the ice crystals melted, methane was released, which in turn caused the planet to warm even more ”

    OK, now we have warming oceans. Now we have lots of sub-sea methane hydrate – just like then.

    It disassociated then. It’s beginning to dissociate now. Eliott have described a mechanism by which methane can reach the surface and escape to to the atmosphere.

    So Ruhl say “it doesn’t necessarily mean we are on the same path” because “things are much different today”. That only means we might not be on the same path, or to make a rational reconstruction, that we might not be on a similar path – we cannot be exactly on the same path. So does anyone have a meaningful measure of similarity? What parameters would you put in a similarity function?

    I suspect that Ruhl’s comments about “different today” are timid waffle of the I-am-a-scientist-I-need-to-be-99%-certain-before-commenting type.

    We don’t live in a world of certainty.

    SecularAnimist, put implication aside, just tell me your call.

  15. 115
    Didactylos says:

    Spaghetti plots like JAXA’s can be confusing. There isn’t enough data to show a clear time progression, but there is too much data to be able to see all the individual years well.

    I tried a similar plot using the longer PIOMAS dataset, using heat mapping to illustrate the change over time.

    Total Arctic Ice Volume by Day of Year

    What do you think?

  16. 116

    I obviously touched off a spark when Ray Ladbury posted:

    OK, ‘splain me this. How does precipitous decline of Arctic sea ice toward what could be unprecedented levels make you more skeptical? ”

    Obviously, it does not. It is simply not persuasive to most people I talk with (non-scientists).

    “Burgie, this is science. It’s just about where the evidence points.”

    It’s “Burgy”. And I agree w/ the science, as far as I understand it. Once again, it is not persuasive to most people.

    “There are no “sides”.”

    Of course there are. And there are shrill voices on both sides. Many of them are on the comments on this site. Shrill voices turn people off.

    “If you are taking sides, you aren’t doing science.”

    I make no claim to “doing science” on this issue; I am not qualified.

    “If you have evidence that places serious doubt that the most successful theory of Earth’s climate is correct, produce it. If not, maybe you should pay more attention to the evidence and less to persuasive idiots who cherrypick evidence as a framework to support their lies.”

    I read some of the denialist stuff from time to time. It is not at ALL persuasive. I have read several of the more scolarly books on CC, Weart, for instance. But these books do not impress the ordinary non-scientist.

    Someone pointed out that I have some denialist apers on my website. Yes, I have, mostly put there years ago when I first began paying attention to this stuff. My most recent two articles, published in a Colorado newspaper, defended the science.

    My sole and only point is that, after years of trying to sell this, it is failing. Just what would work is beyond my ken. The graph on this article does not help.

  17. 117
    Hank Roberts says:

    John, the chart isn’t the argument, and incomprehension isn’t a refutation.

    The chart’s just a picture of numbers you need to understand to explain.

    Robert Grumbine’s site teaches this stuff at the high school level, and he has what you need. Try there.

    “you really can get quite far in understanding the world, even climate, by understanding this sort of fundamental….”

  18. 118
    Neven says:

    I have written a new SIE update. Update conclusion:

    I’m not expecting extent decrease to radically stall like it did last year, but I’m not seeing any century breaks coming about either the coming 5-7 days. I was hoping we’d see more of that fast ice transport toward Fram Strait to see what it would do to the SIE and SIA numbers, but the highs aren’t in the right place. The low off the Siberian coast is pretty strong right now, but is forecasted to weaken in the coming days. It’ll be interesting to see what happens.

    At the moment 2011 is neither fish nor flesh. It could very well be losing its 100K lead to 2007 in the coming week.

  19. 119

    116, john burgeson,

    I’d like to point out that after years of trying to “sell” the idea that smoking causes cancer, it really only took hold after decades of smokers died, and the government had intervened to regulate tobacco packaging and advertising, and society had decades to undo prior decade after decade of glamorizing smoking.

    If anyone had been able to really understand the science (and scientists don’t “sell” anything, they just do science) all but the most foolish diehards would have quickly quit smoking. The fact that the tobacco industry was so able to hoodwink an entire population should be a wake-up call to just this sort of thing. That no lesson was learned is frightening.

    The fact that you can’t understand it, see it as a political debate, and understand so little that you can’t even properly decide whom to trust, let alone which aspect of the science is correct, is frightening.

    That you can’t even understand the graphs here well enough to realize how bad the situation has become? Bah…

    I would suggest that you read this: On Experts and Global Warming

    And by the way… your ignorance and inability to separate the wheat from the chaff, along with many others like you, does not absolve you of responsibility for where this planet heads in the coming decades, or for all of the suffering that results from your inability to decide whom to trust, or else to educate yourself well enough that you know that you can trust yourself.

  20. 120
    ccpo says:

    I have to agree with Hank that the problem with the chart does not lie with the chart, but with the person looking at it. I find it very persuasive, but, then, I am confident I understand it.

    I am tired or people saying we are talking about the science and the issues the wrong way. This is bull. There are people intentionally casting doubt on the science where doubt is not legitimate; it’s not based in the science, but in their greed and ideology. They are lying. For profit and ideology. THEY are speaking about it “wrong” and are not being held accountable.

    THAT is the problem with the science. Prosecute/sue these people for false testimony before Congress, slander, defamation, via class action suit due to harm to the health and well-being of… everyone… and you may see some change. Or, just call them out. Call them liars because they are. Let them bring it to court; they will lose.

    Let’s stop pretending Willie Soon, e.g., has a different opinion and speak forthrightly: his science is crap and he knows it. He’s not being honest. Monckton’s argument’s are so tortuously poor anyone believing he doesn’t know what he’s saying is utter bullocks is just naive. Same with the lot of them.

    And stop pussyfooting around with what the science means: The increased temperatures ARE affecting weather, ARE creating extremes, are costing lives, Are affecting food production, ARE affecting water supplies… and don’t bother being apologetic about it.

    [Response: No matter how great the temptation, we cannot say things that we have not obtained compelling evidence for. The examples you cite are all in the domain of climate change effects. These require an additional level of understanding beyond just climate change itself--and the level of such evidence varies fairly widely. Everyone needs to keep in mind, that given the current political/social climate, we absolutely cannot afford to say things that are not well supported.--Jim]

    When speaking to an American audience ALWAYS use Fahrenheit. 3(C) doesn’t sound nearly as bad as 5.4(F), e.g. And, scientists, when presenting the science to the public don’t speak as if you are speaking to scientists. Don’t speak of scientific uncertainty, translate it to colloquial uncertainty. E.g., don’t say the signal is “unambiguous,” say the signal is clear, because it is. Don’t say something is significant at a .01 level, say it’s as certain as you waking up tomorrow or the sun rising in the morning. Uncertainty in science is not the same thing as uncertainty to laypeople. The average American does not understand scientific/statistical uncertainty, so don’t talk to them as if they do.

    But, yes, do be polite. We live in a PC world and time after time I see outright lies, deeply insulting comments, etc., met with a smile and “everyone has an opinion” because they are said sweetly while the truth, stated directly and without polish, is treated like it’s a steaming pile of crap or a hissing viper because sounding rude is a mortal sin while being rude/lying is quite acceptable.

    /End rant.

  21. 121

    In reference to John Burgeson’s comments on the graph, I personally like the one at Arctic ROOS because it includes a 2-standard deviation gray area. This lets the observer compare this year to least year, as well as seeing how far below the norm all of the recent years fall.

    I like the image Didactylos supplied, as well, although I’d suggest running the colors from blue (older) to red (new) to provide a little more contrast (or, alternately, going from light gray to dark gray, which will draw the eye to the low, while making the distant past seem… distant — if the idea is to “sell” the truth to those out there who only understand marketing, jingles, subliminal advertising and commercials with funny punchlines).

    Separately, the new animated gifs from the Naval Research Laboratory are an outstanding supplement to Crysosphere Today.

    The daily photos from the North Pole Web Cams were also cool, until camera one toppled some weeks back due to melting beneath it, and now camera two has done the same in the past day.

  22. 122
    Ray Ladbury says:

    It’s pretty simple. Evolution tells us that an organism is equipped with sense organs and processing capability that allow it to survive in its environment, right? Should that environment change or should the organism become impaired so that the organism no longer accurately appraise its environment, it will become extinct, right? It would appear that climate change could well be an existential threat for human civilization, if not for human survival. It would also appear that the fact that humans SUCK at risk assessment and find reality too scary to accept is keeping us–or at least the bottom half of the class–from accepting it.

    Too bad. Maybe what comes after us will be smarter.

  23. 123
    Hank Roberts says:

    > Didactylos … using heat mapping to illustrate the change over time.


  24. 124
    Titus says:

    Peter Ellis @89. Thank you for that explanation. That does make sense.
    Another question that comes to mind when I see these graphs is that in a perfect world: ‘what would the ice extents be’?
    I know from recent history that it has been down as low as the Bay of Biscay and up far enough that folks made hay in Grennland.

  25. 125
    Titus says:

    Peter Ellis @89. Thanks for reply. That makes sense.

    Another question that comes to mind when viewing such graphs is that in a perfect world: ‘what would the extent be’?
    I know that from recent history it has been as low as the Bay of Biscay and far enough back that folks made hay in Greenland.

  26. 126
    Didactylos says:

    Titus: reference please? I don’t believe you are talking about the past few millennia, because that period has seen relatively stable Arctic ice cover.

    So what does this have to do with “recent history”?

    The Greenland myth is a common misconception, and easily answered. The thing about ice that is thousands of years old is that it can’t disappear one year and reappear the next.

  27. 127
    Septic Matthew says:

    81, SecularAnimist: If the USA experiences 5-figure death statistics from a heat wave, perhaps it will wake some people up.

    Deaths in heat waves in the US generally cause a flurry of stories about: the need for more tax-subsidized A/C for the poor or elderly; reminders that more people die in cold waves; reminders that the US had higher death rates and or higher temperatures or both in previous years.

    97, John Burgeson: Seeing this graph makes me more skeptical than ever.

    How does that make any sense? There is a clear continuation of a potentially threatening trend — how can it make you more skeptical? If for some reason you have discredited the trend, all that the graph should do is have no effect. If you give the trend some credit, its continuation ought to increase your concern.

  28. 128
    ccpo says:

    Everyone needs to keep in mind, that given the current political/social climate, we absolutely cannot afford to say things that are not well supported.–Jim

    This is precisely where you are wrong, Jim. The list of things acted on by regulation without them being “proven” is long, indeed. If there was ever a case where we must embrace this, it is this issue. We really have no choice.

    And, really, scientifically well-supported is too high a bar, which is my thesis here. If you and others, as scientists, are reluctant, the pull a little Deep Throat impersonation and find somebody to speak for you.

    [Response: Oh yeah, that will go over well. And I see you are back to your accusatory ways--Jim]

    In, I believe, Cancun, Greg (WonderingMind on YouTube) spoke with scientists privately that were prepping for “life boats”, though they would not say so publicly. The BBC did poll of scientists a couple years ago, anonymous, in which the results were depressing at best in terms of meeting 2C.

    [Response:Well, your previous comment was a rant that shows a lack of understanding of how science does, and does not, work. You are confusing issues. I am not, of course, objecting to taking action, nor am I reluctant to speak about it. I am objecting to using any reasoning, to do so, that does not have strong, documented evidence behind it. That evidence can vary in type. You can't just go running around saying "Heat wave--people are dying--global warming". It's a bit more complex and difficult than that I'm afraid. That people cannot see that any statement deemed less than solid will be quickly jumped on, after all that has happened, is beyond me.--Jim]

    Apologies for OT. Back to the topic at hand.

  29. 129
    Hank Roberts says:

    > spoke with scientists privately that were prepping for
    > “life boats”, though they would not say so publicly

    Those thinking in terms of prepping ‘one big lifeboat’ do speak out, notice.

  30. 130
    Geoff Beacon says:

    Everyone needs to keep in mind, that given the current political/social climate, we absolutely cannot afford to say things that are not well supported.–Jim

    The trouble is, Jim,

    [Scientists] cannot say X because it is not well supported”


    Scientists say X is loony”.

    You’ve got to do better than that.

    Here’s a question from the exam in Public Relations for Scientists:

    Carbon that is being released from melting Arctic tundra as carbon dioxide and methane.

    The next IPCC report, AR5, will be based on computer models that omit this.

    Please write a press release that could be used by the IPCC to excuse this omission.

    Want to answer it?

  31. 131
    ozajh says:

    Didactylos #115;

    As an interested layperson, I would second Spaerica’s comment about running the colours from blue (or perhaps green??) to red rather than yellow to red.

    In fact, I would suggest only colour-coding the last 10 years (or any other convenient number) and leaving the rest black. This would allow even a casual glance to notice the dramatic recent trend.

    The other suggestion I have is to really really emphasise the fact that this is a graph with a zero lower bound. I have noticed that an awful lot of graphs you see on TV have similar shapes, because the person producing the graph has used the software to maximise contrast by setting the Y axis bounds to or close to the observational extremes. This is especially true of financial channels; a graph showing a 0.1% move can LOOK exactly the same as a graph showing a 10% move until you check the Y axis value points.

    It’s a great graph, though. For anyone with even high-school statistics it makes the overall decline awfully (in every sense) obvious . . .

  32. 132
    Titus says:

    Didactylos @126. You ask for evidence.

    Not sure what you’re asking for. The last ice age was about 18k years ago when pack ice was down to Bay of Biscay. You can get that info form a huge pile of historical data. I don’t see much problem with that.

    On the Greenland bit it was certainly more accommodating when they arrived and got steadily worse. We can see their infrastructure revealed as the current ice pack has receeded. So it must have been less than it is now.

    So not following your line of reasoning here.

    And back to my question: “in a perfect (natural) world what would the ice extent be’?

  33. 133
    ozajh says:

    Further to my previous comment, the colour coding in the AMSR-E SIE graph at the top of this thread is part way to what I’m talking about (I would have a much darker violet for 2002, a light yellow-green for 2007, and then yellow trending to red for 2008-2011).

  34. 134
    Hank Roberts says:

    > computer models that omit this.

    The omitted “this” needs an associated number to put into models though.

    AR4 lacked any good number for sea level rise, and said so. The missing information got filled in over the following five years; we’ll see a better sea level section from the AR5, presumably.

  35. 135
    marcus says:

    One could also grant to climate scientists that it is not their exclusive duty, that every graph they produce cries out “global warming!” to every layperson on every level of understanding. It is perfectly legitimate to demonstrate other aspects, even if this sometimes obfuscates trends.

    Very instructive diagram from didactylos, though

  36. 136
    Didactylos says:

    The two graphs featured in the article are for observing the progress of the 2011 melt. John Burgeson is right: neither show anything about trend.

    That’s no excuse, of course. Plenty of other comments provide links to the graphs showing trend.

  37. 137
    J Bowers says:

    @ Jim Bouldin, I think lessons could be learned from Hugh Hammond Bennett’s approach to the Great Dust Bowl. If only Obama would actually step up to the plate.

  38. 138
    Lou Grinzo says:

    Once again, we’re up against the question of what scientists “can” and “should” say about climate change. It’s about as thorny an issue for scientists as one could imagine, probably equal to the decision of whether to help develop the atomic bomb in the 1940s.

    Over the years I’ve had private e-mail exchanges with a couple of dozen people in which I asked them, on the promise of strict confidentiality, to tell me what they really think our situation is regarding climate and public policy aimed at mitigation and adaptation. There were a few scientists in the group, but most were non-scientists who were deeply involved in the topic of climate or general sustainability. None of them were remotely close to the stereotypical left-wing tree hugger type at least some of you might be imagining right now.

    In almost every case the person admitted to being far more pessimistic than s/he acknowledged in public, sometimes startlingly so. Some of the most conservative, sober people I asked said we’re headed for a Lovelock-esque crash down to a population of 1 or 2 billion by 2100. In not one case was the person more optimistic privately, with the balance of them being too close to call.

    I honestly don’t know what I would advise a scientist friend to do in this regard if asked. The climate mess we’ve created is so immense, with so many timing aspects working against us, that I can’t see how we avoid some horrible outcomes regarding mass numbers of refugees and even mass starvation in some parts of the world, far worse than what’s unfolding right now in the Horn of Africa. But how do you explain that to a politicized, disaffected public that thinks changing light bulbs and recycling paper is “being green”, without sounding like a lunatic? Asking scientists to be brutally honest is asking them to commit career suicide. Perhaps we need many more scientists Hansen’s age and proximity to retirement, who love all the children of the world as much as he loves his grandkids.

    Personally, my view aligns very closely with Bill McKibben’s, as he expressed it in a recent interview: “We’ve already raised the temperature of the planet one degree. We’ve got another degree in the pipeline from carbon we’ve already emitted. What we’re talking about now is whether we’re going to have a difficult, difficult century, or an impossible one. And we may still have enough room to maneuver to affect the outcome of that question.” (I quote this and add my own thoughts here: Note the “may” in his last sentence.

    I think we have no choice but to keep fighting as hard as each of us can. And that begins with science — getting our facts right, understanding the insanely complex dynamics of the world and the ramifications of X ppm of CO2 or Y degrees C of warming or Z% increase in acidity of the oceans. But the non-scientists among us (like me) have our own burden. We have to listen to the scientists and their findings, and do everything we can to educate and activate those around us. This requires a balancing act between including the latest “it’s worse than we thought” revelation (and they keep on coming) ad avoiding overselling the facts.

    This is why I ask questions about quadratic fit Arctic ice projections that show zero ice for months just a few years from now. I know just enough about climate science to understand how important such an event would be, if it were to happen.

    To the climate scientists of the world: I cannot thank you enough for your work. Please keep hammering on every part of this huge problem and be as honest in public about what you really think as your comfort zone allows.

  39. 139
    Didactylos says:

    Titus: You are mistaken. Read the link I provided.

    I’m afraid you are the victim of propaganda – ancient Viking propaganda, as well as modern fossil fuel propaganda.

    You seem to be genuinely confused. Greenland has always been accessible by sea in the southern regions. Only the north part is permanently bounded by sea ice. That some parts of Greenland are not covered by the ice cap is undisputed, as is the history of settlements on Greenland. You are falling into the trap of assuming that this means Greenland was warmer then than it is now: that clearly does not follow from the evidence.

  40. 140
    Geoff Beacon says:

    Hank @134

    But policy makers don’t seem to know.

    Perhaps you could point me to some policy makers that understand the omissions of feedback effects in climate models. I spoke to the UK Secretary of State for Energy and Climate Change and he thought that the missing feedback from melting Arctic tundra was solved. Subsequent enquiry seems to have revealed he was wrong.

    You may see my report in Open letter to Chris Huhne

    He also told me he read Real Climate. Perhaps I can encourage him to respond to my last two letters here. The Department is blocking them.

  41. 141
    Pete Dunkelberg says:

    All right everybody, lighten up.

    But just for ten minutes, then break time’s over. Back on your heads.

  42. 142
    Didactylos says:

    Sphaerica (Bob) and ozajh:

    I’m pleased you like the graph. I tried blue->red, but blue and red have much closer brightness levels than yellow and red. When converted to grayscale, blue, red and the intervening hues are almost indistinguishable. It does look nice if you have full colour vision, though!

    I tried putting a line at y=0, but it looks odd. I could extend the y axis into the negative, but that has no physical meaning and also wastes space. So, I’m open to ideas for how to emphasise the zero.

    The suggestion for only colouring the last 10 years is interesting, and I may try that if I have a spare moment. However, one of my goals when creating the graph was to visualise the variance in the early part of the record, in order to make more sense of the 2 SD graph that PIOMAS provided.

  43. 143
    Titus says:

    Didactylos @139. Thank you for response.

    Accepting what you say about Greenland I’m still left with my question:
    “in a perfect (natural) world what would the ice extent be’?

  44. 144
    vukcevic says:

    To understand what is driving the Arctic Ocean it would be desirable to know what drives the Atlantic and Pacific.
    However the current state of knowledge is:
    The nature and origin of the AMO is uncertain, and it remains unknown whether it represents a persistent periodic driver in the climate system, or merely a transient feature.
    The PDO goes through warm and cool phases of the cycle with phases typically lasting about 30 years. It is closely related to the (inverted) SOI / ENSO. The causes of the oscillation are currently unknown.

    Sooner or later the above ‘known unknowns’ will become ‘known knowns’:

  45. 145
    John McCormick says:

    I’ve tried to post this numerous times.

    RE # 120

    Jim Bouldin, maybe your comment to ccpo is a more topical matter than the chart.

    You said to ccpo, “No matter how great the temptation, we cannot say things that we have not obtained compelling evidence for.”

    Well, I look at that chart and see the reason the Northern Alaskan Inuit village of Shishmaref is being destroyed by climate change. It is a community continually inhabited for nearly four thousand years. We have compelling evidence of that fact. Shishmaref, according to the US Corps of Engineers will be completely abandoned within a decade and its 660 inhabitants will be forced to relocate to the streets of Anchorage, Juneau, Fairbanks, and Nome. They will have lost their culture, families, language, and way of live. We have compelling evidence of how American Indians forced off their lands fared in their new resettlements.

    The reason Shishmaref is being destroyed in evident in that chart. Late refreeze allows early winter storm waves to tear at the shoreline. We have compelling evidence of that dynamic.

    Arctic ice meltback has reached a tipping point and Mark Serezze and others who have devoted their professional lives to understanding the mechanics of Arctic melt and freeze have convinced themselves and anyone with half a brain that the changing Arctic is due to warmed ocean and air temperatures.. the Arctic amplification as Mark calls it. We have compelling evidence of that.

    You have devoted your professional life to studying tree rings and try to decipher their story. I can see how you might be reticent to jump out front and say this ponderosa pine or that bristlecone pine (Pinus aristata) or that Coast Redwood (Sequoia sempervirens) each have a story to tell us about changing climates but those rings may be 5 or 6 hundred or 2 thousand years old. Not much of a convincing story of pending chaos for us 7 billion people that the beginning of the 6th extinction is at hand.

    However, plat maps of Shishmaref provided by the State of Alaska since 1980 give graphic proof that about a hundred yards of coast line have been ripped off the Island of Shishmaref and its public school building may soon have to be abandoned. WE have compelling evidence of that.

    So, Jim, you need to look beyond your own work and see the forest, so to speak, and realize we have compelling evidence all around us that climate change is impacting land, people, ecosystems and our future. Take a look at some of the images of Shisharef’s final days and blame that on climate change and dare to tell people, as a scientist, you connected the dots and say, unequivocally, that climate change is destroying the culture and homeland of 660 Inuit inhabitants of Shishmaref Island. Of that, we have compelling evidence.

    [Response: OK, good example from what appears to be a fairly short and simple cause/effect chain, but that's not something I study, so why do you expect me to be on a soapbox about it? And I have a very short fuse with those who say things starting "You need to [do this that or the other]“. I don’t need to do anything, nor do any of us here. When other people have no income and are living out of their truck for many months on end, while still contributing to blogs and trying to write papers in two different fields, then they can advise me of what I “should be” doing OK? I’m aware of much of the evidence of climate change on ecosystems (and no, I have not devoted my professional life to analyzing tree rings–it’s a very small part of what I’ve done), and in fact my first article here was specifically devoted to relating one aspect of tree mortality, to regional hydrological changes, and thence to global climate change. There is also evidence for climatic change effects on phenological events, carbon cycling rates, fire frequency and extent, insect outbreaks, and other things. And then there is also a bunch of evidence for non-climatic factors that affect those very same things, some of which are themselves affected by climate, others not. Your mentioning of the current extinction event is a prime example. It’s a complex world out there. But my point is to not get sucked into any traps of saying things off the cuff. And certainly not under pressure from anyone. And I ain’t yielding on it, for anyone. That’s not how we got to where we are. –Jim]

  46. 146
    John E. Pearson says:

    119: Bob Sphaerica discussed John Burgeson’s ignorance.

    I don’t know John Burgeson. I never really noticed him until the other day. After perusing his website for a half hour or so I certainly wouldn’t call him ignorant. He is certainly correct when he says (in 116) that “shrillness” does not work. That being said, it does take the patience of Job to remain calm when you see the same night of the living dead arguments appear over and over and over. As far as I can tell there is no graph what-so-ever that will convince large quantities of people that climate change is going to make life miserable. Maybe to understand why this is we ought to re-read CP Snow’s “Two Cultures”. I think it will take wide spread misery before mankind’s to global warming is concordant with the thread.

  47. 147
    John E. Pearson says:

    typos: I wrote “I think it will take wide spread misery before mankind’s to global warming is concordant with the thread.”

    I meant to write: “I think it will take wide-spread misery before mankind’s response to global warming becomes concordant with the threat.”

  48. 148
    John E. Pearson says:

    Didactylos: How about just plotting the PIOMAS data as a function of time then fitting a straightline to it?

  49. 149

    142, Didactylos,

    This is what I meant:

  50. 150

    (I forgot to fix the key on the image at It should show gray to black from 1979 to 2010, then 2011 as red).

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