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Unforced variations 2

Filed under: — gavin @ 1 January 2010

Continuation of the open thread. Please use these threads to bring up things that are creating ‘buzz’ rather than having news items get buried in comment threads on more specific topics. We’ll promote the best responses to the head post.

Knorr (2009): Case in point, Knorr (GRL, 2009) is a study about how much of the human emissions are staying the atmosphere (around 40%) and whether that is detectably changing over time. It does not undermine the fact that CO2 is rising. The confusion in the denialosphere is based on a misunderstanding between ‘airborne fraction of CO2 emissions’ (not changing very much) and ‘CO2 fraction in the air’ (changing very rapidly), led in no small part by a misleading headline (subsequently fixed) on the ScienceDaily news item Update: MT/AH point out the headline came from an AGU press release (Sigh…). SkepticalScience has a good discussion of the details including some other recent work by Le Quéré and colleagues.

Update: Some comments on the John Coleman/KUSI/Joe D’Aleo/E. M. Smith accusations about the temperature records. Their claim is apparently that coastal station absolute temperatures are being used to estimate the current absolute temperatures in mountain regions and that the anomalies there are warm because the coast is warmer than the mountain. This is simply wrong. What is actually done is that temperature anomalies are calculated locally from local baselines, and these anomalies can be interpolated over quite large distances. This is perfectly fine and checkable by looking at the pairwise correlations at the monthly stations between different stations (London-Paris or New York-Cleveland or LA-San Francisco). The second thread in their ‘accusation’ is that the agencies are deleting records, but this just underscores their lack of understanding of where the GHCN data set actually comes from. This is thoroughly discussed in Peterson and Vose (1997) which indicates where the data came from and which data streams give real time updates. The principle one is the CLIMAT updates of monthly mean temperature via the WMO network of reports. These are distributed by the Nat. Met. Services who have decided which stations they choose to produce monthly mean data for (and how it is calculated) and is absolutely nothing to do with NCDC or NASA.

Further Update: NCDC has a good description of their procedures now available, and Zeke Hausfather has a very good explanation of the real issues on the Yale Forum.


1,394 Responses to “Unforced variations 2”

  1. 351
    Rattus Norvegicus says:

    Tim @348:

    In both links you supplied the unadjusted data is being plotted. Click on the “Adjusted” checkbox at the right of the page to show the adjusted data. the old MKI eyeball shows pretty strong warming since the 1970′s, although the warmest decade is from about the mid to late 20′s through the 30′s. This is no surprise, this was when the dustbowl happened and the GISS analysis has 1934 in a tie with 1998 for the warmest year in the lower 48.

    I looked at the station nearest my house BOZEMAN/MSU and it shows a strong warming throughout the record, even after the adjustments which remove some of the recent warming. Same thing for the shorter record at BOZEMAN/GALLATIN FIELD.

    However, if you are looking mostly at stations in the USA, you are going to find fewer stations which show strong warming since the US has not shown as strong a warming signal as some other regions of the planet.

    So, I think these are the real McCoy. The Bozeman/MSU charts are very similar to those from GISS. GISS is currently plotting 2009 for this station which comes in almost 2C(!) cooler than last year, which seems about right, we had a very cool first 8 months of the year and a pretty cool December. Here is the Bozeman chart from Appinsys. Bear in mind that GISTEMP does not use the GHCN adjustments, but rather uses their own method. Code is available at the GISS website.

  2. 352
    Don Shor says:

    If you can read this:
    http://www.polarbearsinternational.org/polar-bear-status-report/

    and conclude that climate change is the primary problem facing polar bears, or even conclude that there is solid evidence that their populations are declining, then you are reading the data through an ideological prism. It is just as reasonable to say they are “stable or increasing” as it is to say they are decreasing. “Data deficient” seems to be the predominant condition.

    “The total number of polar bears is still thought to be between 20,000 and 25,000.”

  3. 353
    Leo G says:

    Brian @ 326

    thanx. didn’t understand the first paragraph to well, but your summary made it “icy” clear! :)

  4. 354
    Doug Bostrom says:

    Looking particularly at the generally rigorous and useful contributions of Hank Roberts, Ray Ladbury, Timothy Chase et al on this site in comparison to slackers repeating nonsense, is there any reason why reader-contributed thread input containing assertions of a scientifically remarkable, controversial or novel nature should not be accompanied either by a reference of reasonable quality, or a justification containing enough detail and method to be assessed on its merits?

    Some minimum standard of performance would be helpful in maintaining the quality of discourse here. Presently it seems too easy for threads to be degraded by regurgitated baseless talking points by persons too lazy to make an effort to discover if they’re spewing nonsense. Worse, RC is exploited as an echo chamber to “keep the debate alive” on dead thoughts that ought to be pushing up daisies.

    Posts not up to snuff could then be dumped into a publicly accessible bucket, indicating “revise and resubmit” as an available recourse.

    This of course would not apply to questions or remarks of a general nature, just claims such as “polar bear populations are increasing”, “I believe sea ice extent/volume is increasing” and the like.

    Yet another suggestion…

  5. 355
    Doug Bostrom says:

    Don Shor says: 5 January 2010 at 2:13 AM

    Your ideological prism has a higher refractive index than does mine.

    Funny thing is, I rejected the link you cited because I thought it too ideologically biased in favor of hysteria about declining polar bear populations; the actual release from the actual group of experts is sufficiently foreboding, thanks.

    http://pbsg.npolar.no/en/meetings/press-releases/15-Copenhagen.html

  6. 356
    Ray Ladbury says:

    FWIW, I don’t share the contempt some of my fellows have for Lomborg. Yes, he plays a bit fast and loose with the facts at times. And his risk analysis is crap. However, he does at least acknowledge that we are warming the planet and doesn’t try to defend the absurdly indefensible.

    The biggest problem I see with Lomborg is his risk analysis. He doesn’t consider ALL the potential risks, and is particularly scrupulous about ignoring those risks that we cannot bound at present. The first rule of risk analysis is that you cannot ignore an unbounded risk. You must either find a way to bound it or avoid the realization of the threat. An unbounded risk can be absolutely ruinous–as AIG found out the hard way. In the case of climate change, there are some risks that could result in the end of human civilization and a massive population crash–and we cannot yet preclude them.

    Ironically, the absolute best tools for bounding risk are the climate models–you know, the ones the denialists keep bashing as unreliable. They had better hope they are wrong (and they are), because if we don’t have bounding models, avoiding the threat becomes the only viable strategy, and that would mean limiting CO2 to pre-industrial levels.

  7. 357
    Ray Ladbury says:

    Matthew L.,
    You are missing the point. The constraints on CO2 sensitivity tell us that the answer–including ALL feedbacks–has to work out to between 2.1 and 4.5 degrees per doubling. We have the answer in the back of the book. Now it is a matter of figuring out all the contributing factors. The fact that we have more than 10 independent lines of evidence that all pretty much agree on this range is pretty damned strong evidence that we know this quantity (CO2 sensitivity).

    Now as to the second part of your question, have you ever studied infinite series? They can be convergent as long as each successive term decreases enough–and this is the case for climate feedbacks. Even on Venus, the series converges–it just does so at a temperature above that of a pizza oven.

    Matthew, there are two ways to approach this issue: science and wishful thinking. Thinking that all the uncertainties will line up to save our sorry asses, despite all the evidence to the contrary is wishful thinking. Thinking that the consequences will not be so bad is wishful thinking. Thinking that we’ll come up with a magical solution like carbon gobbling trees is wishful thinking.

    You talk of previous environmental scares like the population crisis. Do you think those crises solved themselves by wishful thinking or do you think a bunch of smart people worked their asses off to come up with ingenious (and as it turns out temporary) fixes? Do you realize that even with all those efforts, about 20% of the global population remains hungry?

    Well, Matthew, you can pick science or anti-science (wishful thinking). I think science has a much better track record.

  8. 358
    Completely Fed Up says:

    Don Shor, I call “strawman”.

    Nobody said that.

    And your quote doesn’t necessarily say what you want to say. If polar bear populations were at 25-30,000 50 years ago, then a cut of 5,000 would leave the population still at 20-25,000.

    Still going down.

  9. 359
    Completely Fed Up says:

    Dave Bassage: “A google search on any related topic will yield at least as many hits on credible sounding but scientifically indefensible points of view as it will examples of diligent application of the scientific method.”

    Actually, it will almost entirely consist on the first page of denialist pages. trollbots up the link count by posting “A friend of mine pointed this out to me $URL TO TROLLBOT CENTRAL$ and I was wondering if anyone had counterpoints”.

    The trollbot central link gets another plus point for being linked to on RC, a widely referred site and overtakes the legitimate science.

    It also shows how many times you get fake concern from “noobs”.

  10. 360
    Completely Fed Up says:

    “So, is climate science inevitably going to be misrepresented in the press? No. But only if scientists work hard at simplifying the picture”

    Nope, been tried. AIT tried it.

    And despite being accepted, the judge recommended that for EDUCATIONAL USE FOR CHILDREN there should be a few additions to clarify (and that complicates the picture, so your simplification is undone) the uncertainties in climate science, this has been pounded to death ever since as “proof!!!!” that AIT is just false propoganda.

    Simplifying the science lets the denialists, who do not have a theory to prove, say “but you missed this out, therefore your conclusions are wrong”.

    Doesn’t work, kid. Doesn’t work.

  11. 361
    Jiminmpls says:

    #352 Don Shor

    Only one who is thoroughly brainwashed could read the article and state that “It is just as reasonable to say they are ‘stable or increasing’ as it is to say they are decreasing.”

    The article itself may be biased. There may be other evidence contradicting the conclusions of the article, but there is NO WAY that a rational person could read the article and conclude that polar bear populations are stable or increasing.

    You have been brainwashed and rendered incapable of rational thought.

  12. 362
    Alan Millar says:

    It seems to be accepted that in the 1950s there were far fewer Polar Bears than now. Estimates seem to range around the 5000 figure. Given than current estimates are around 20 – 25000 I would call that an increase and a large one. Is anyone declaring that as a decrease?

    That increase has taken place in the period that the AGW signal has been detected at its strongest. Of course you could say that the population would be even higher if not for GW. Is there any evidence for this?

    What studies exist to show what the ideal population should be. What would be the maximum population that the environment could support?

    Without this information why would anyone be worried about polar bears? How do we know that that the population is not oscillating between its natural low and high points at the moment?

    Alan

  13. 363
    Nick Barnes says:

    Don Shor @ 352:

    If you can read this:
    http://www.polarbearsinternational.org/polar-bear-status-report/

    and conclude that climate change is the primary problem facing polar bears, or even conclude that there is solid evidence that their populations are declining, then you are reading the data through an ideological prism.

    The title of that article is “Unprecedented Loss of Sea Ice Renews Concerns for Survival of the World’s Polar Bears”. The first sentence says “the PBSG renewed the conclusion from previous meetings that the greatest challenge to the conservation of polar bears is ecological change in the Arctic, resulting from climatic warming”.

    If you can read that article and conclude that climate change is not the primary problem facing polar bears, then you are doing it wrong.

  14. 364
    Completely Fed Up says:

    It doesn’t even have to be a primary problem, Nick.

    It just has to be a major problem.

    But Don wants to see it as no problem. This is creating a few difficulties for him…

  15. 365
    Completely Fed Up says:

    “It seems to be accepted that in the 1950s there were far fewer Polar Bears than now”

    Reporting bias?

    1) It’s easier to fly over Polar Bear habitat nowadays
    2) With polar bears moving south and humans expanding north, you’ll get lots more reports of polar bear sightings.

    “How do we know that that the population is not oscillating between its natural low and high points at the moment?”

    We don’t. But the assumption that there is an oscillation is more wrong than assuming that they are in decline.

    There is a clear causation for the decline and no causation why those reasons have no effect.

  16. 366
    Ray Ladbury says:

    Tim Jones and Dave Bassage,
    While I sympathize with the layman trying to make sense of all of this complicated science, I have to wonder why people don’t avail themselves of the tried and trusted remedy in such situations: ask the experts. After all, appeal to authority is not in fact a logical fallacy. Now it is true that your opponent can also cite an authority. However, there are objective ways of deciding which authority is more trustworthy (e.g. peer-reviewed publication record, # of citations, etc.). No one can be an expert on every subject, and no one should be allowed to diminish the importance of expertise gained by a lifetime of devoted study, innovation and hard work. And as to the question of an individual scientist having a personal agenda–that is one of the reasons why scientific consensus is important. It dilutes any personal motives/grudges, etc.

    One of the reasons why denialists resort to ad hominem attacks is because they have no evidence they can cite–ad hom is all they have. However, another more sinister reason why denialists attack experts and expertise in general: If you can’t trust the experts, then everyone’s opinion on every issue becomes equal, and even an asshat, ignorant food tube like Steve Milloy counts! The attack on scientific consensus is part of the same strategy.

    It’s time to take the initiative back from the idjits. Get them sputtering mad and reveal them for the tin-foil-hat-wearing nutjobs they really are.

  17. 367
    Ryan says:

    @Jim Eager:

    “Only if the feedback amplification produces an increasing series, as in: 1 + 1.25 + 1.5 + 1.75 etc. ”

    That is an example of positive feedback.

    “But not if the amplification produces a decreasing series, as in: 1 + .75 + .5 + .25 etc. ”

    That is an example of NAGATIVE feedback.

    Positive feedback always results in instability – i.e. a “tipping point”.

    The social politics of climate science relies on climate chnage not being a slow progression over time to a warmer climate, which could likely easily be adapted to by man and beast, but to a point being reached where positive feedback results in positive feedback resulting in catastrophic climate change – i.e. a tipping point.

    Belief in the “tipping point” is based on the idea that certain feedbacks for the climate are positive, and result in increased levels of CO2 and hence increased warming. It also relies on the belief that no such tipping point has ever been reached in the recent past, e.g. the earth’s climate has not been pushed to the tipping point by a large volcanic eruption releasing large amounts of CO2 which would then also result in the same catstrophic and unrecoverable climate change scenario.

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

    [Response: This is not the definition used in climatology (and although that Wiki article mentions climate, it's intro paragraph and discussion do not apply). Where's Connolley when you need him? In climatology, there is an easy to calculate no-feedback response to a forcing, 'positive' feedbacks are those processes that amplify the signal from that no-feedback case, while negative feedbacks damp that signal. It does not imply runaway instability. Please note that this is how things are defined in this field - arguing that climatologists have defined things differently from other fields and therefore are confused is pointless. Actually, the wiki article would be a good place to give the varying usages across fields and resolve the confusions that sometimes occur. Any volunteers? - gavin]

  18. 368
    Ray Ladbury says:

    Alan Millar says: “It seems to be accepted that in the 1950s there were far fewer Polar Bears than now. Estimates seem to range around the 5000 figure. Given than current estimates are around 20 – 25000 I would call that an increase and a large one. Is anyone declaring that as a decrease?”

    Yes, it’s amazing how much better the population does when you restrict the overhunting that was prevalent in the 1940s-60s. Populations recovered until about 1987, and then…

    The latest situation:

    At the most recent meeting of the IUCN Polar Bear Special-ist Group (Copenhagen, 2009), scientists reported that of the 19 subpopulations of polar bears, eight are declining, three are stable, one is increasing, and seven have insufficient data on which to base a decision. (The number of declining populations has increased from five at the group’s 2005 meeting.)

  19. 369
    flxible says:

    Alan might need to consider a more expert opinion about just what “seems to be accepted” concerning historic bear populations and climate change

  20. 370
    Rod B says:

    Doug Bostrom (354 et al): why do your rules of posting apply to many but not, for instance, yourself? Almost every source that deals with it agree that polar bear population has at least doubled since 1970. Even taking into account that polar bear population estimates are wildly uncertain (including the ones taken today) and exceeded in their uncertainty only by projections of population. Why would, under your rules, be allowed to boldly assert otherwise?

  21. 371
    Phil. Felton says:

    Re #224
    Ray Ladbury says:
    3 January 2010 at 7:22 PM
    Leo G., WRT absorption of CO2 by water. The thing that determines how much CO2 the water CAN absorb is the chemical potential (it has to equalize between atmosphere and the water for equilibrium), and that will not depend on other solutes unless they react with CO2. In practice, CO2 uptake will depend on how much overturn of the surface there is–more turbulence means more mixing and more absorption. Hopefully that helps.

    In the case of seawater and CO2 the other solutes do react and therefore influence the absorption of CO2. That’s why strictly Henry’s Law does not apply to CO2-water, CO2 reacts to form carbonic acid which partially dissociates to bicarbonate ion (the predominant species in seawater) which can further dissociate to carbonate ion.

  22. 372
    Ray Ladbury says:

    Ryan says “Positive feedback always results in instability – i.e. a “tipping point”.”

    This is just flat wrong! An infinite series can converge provided the terms tend toward zero with sufficient rapidity. Each term still contributes positively to the total, is positive definite and depends on the previous term–and so it is a positive feedback.

  23. 373
  24. 374
    Doug Bostrom says:

    Comment by Rod B — 5 January 2010 @ 11:29 AM

    Hi, Rod.

    According to the “polar bear experts”, the horse’s mouth when it comes to polar bears, of the population groups with reasonable measurements available most are in a state of declining population. That’s the available data. One can speculate about the state of the groups with unknown populations, but the actual data we have indicates a declining population.

    From the most recent meeting of the experts group:

    “Reviewing the latest information available the PBSG concluded that 1 of 19 subpopulations is currently increasing, 3 are stable and 8 are declining. For the remaining 7 subpopulations available data were insufficient to provide an assessment of current trend. ”

    Here’s a useful link:

    http://pbsg.npolar.no/en/index.html

    Now, as to your objection, I’ve referred to summary data from the ultimate authority on polar bear populations. I can’t do better.

    If you google polar bear populations, you’ll be overwhelmed with links referring to a single study with optimistic projections about polar bear populations. This study has been disavowed by the experts group. As to population rebound since the 1950s, that does not seem relevant today, since the experts group concludes that of the groups with known populations, most are in decline.

  25. 375
    Jim Eager says:

    Re Ryan @367: “That is an example of NAGATIVE feedback.”

    No, Ryan, it is an example of a positive feedback with a diminishing effect.

    Let’s say the initial forcing = X and the initial feedback to X = 1
    Now let’s say the second iteration feedback to X+1 = .75
    The feedback is still positive, but of diminishing value.

    Now let’s say the second iteration feedback to X+1+.75 = .5
    The feedback is still positive, but of diminishing value.

    A negative feedback actually requires a negative sign, not just a reduced value, I.E., X-.25, X-.5, X-.75.

  26. 376

    General FYI on Polar Bears

    For those denialists using the polar bear increasing argument, can we please bear in mind that polar bear population increased due to conservation efforts. That does not change the fact that global warming is still a threat to them.

  27. 377
    Completely Fed Up says:

    Ryan, a negative feedback REDUCES THE SIGNAL.

    As in

    INPUT: 5. FEEDBACK. OUTPUT: 3

    the feedback is negative.

    A positive feedback INCREASES THE SIGNAL

    INPUT: 5. FEEDBACK. OUTPUT: 8

    the feedback is positive.

    So if your feedback adds a reducing amount, you have a POSITIVE feedback.

    The hint is in the maths:

    1 + 1/2 + 1/4 +…

    Note the “+” signs. Positive.

  28. 378
    Walter Manny says:

    Ray,

    If Lomborg “plays a bit fast and loose with the facts at times. And his risk analysis is crap. However, he does at least acknowledge that we are warming the planet and doesn’t try to defend the absurdly indefensible,” you should have a big problem with him. Just because he lands on the favored warming side of things doesn’t justify the looseness that got him there, given it could possibly have landed him on the flat or cooling side of things — how loose is he? Surely rigor is a requirement for any academic you might take seriously? I know you are not a Gore fan, for instance, though he is famously “right-thinking”.

    As to the “asshats” and “foodtubes”, for the life of me I can’t understand why you keep falling victim to the temptation to denigrate people as opposed to their arguments. Failing that (resisting the temptation) if what they are saying is silly, why respond at all?

  29. 379
    Matthew says:

    350, Doug Bostrom: Answered with other questions: Why do people get to claim the population of polar bears is increasing, when it isn’t? Why do they get to say that mangrove swamps are unaffected by sea level rise, when we know that these swamps are at equilibrium for any given sea level and must in fact retreat with any rise of sea level?

    I suppose that it wouldn’t work to be too strict in maintaining standards. But I had a technical comment deleted even though it contained a reference to a recent peer-reviewed article in a prestigious journal.

  30. 380
    Ray Ladbury says:

    Walter, In science, the evidence is the foundation upon which all arguments are based. Refusal to accept or even acknowledge the evidence is indefensible as it precludes all possibility of scientific debate. It places one in the “not even wrong” category. Unfortunately, denialists refuse to acknowledge the evidence, all they are left with are repeatedly resurrected zombie arguments, ad hominem attack and conspiracy theories. I am afraid that when science itself is under attack, the insult cannot go unanswered.

    Lomborg at least acknowledges the evidence, so civil debate is possible. His mistakes stem from his lack of understanding of risk management–which is not his specialty. This makes him wrong, but wrong can be corrected. “Not even wrong” cannot.

  31. 381
    RB says:

    Gavin,
    Would it be correct to say that the standard definition of positive feedback still holds but there is no instability so long as the negative feedback effects come into play over longer time scales to damp the buildup: such as decrease in temperatures due to solar orbit resulting in greater absorption in the oceans, the weathering of rocks etc.? In other words, if the positive feedback occurs with greater magnitudes at shorter timescales before the long term damping effects kicked in, one could have a runaway unstable effect such as occurred on Venus?

  32. 382
    Matthew says:

    376, John P. Reisman: For those denialists using the polar bear increasing argument, can we please bear in mind that polar bear population increased due to conservation efforts. That does not change the fact that global warming is still a threat to them.

    If it is true that the polar bear population grew while the CO2 was rising and global temps were rising, and if previous population loss was due to hunting, and if contact between polar bears and humans is increasing, then the next question is How much of current polar bear decline is caused by the human-polar bear interaction, and how much is due to recent (up till 2007) summer Arctic ice loss?

  33. 383

    #378 Walter Manny

    “why respond at all?”

    For the benefit of those that wish to learn.

  34. 384
    David B. Benson says:

    Todd Friesen (349) — Ok, but I’m unclear just what you are fitting to and whether you are using annual or decadal averaged data. Can you explain just what you have done?

    As the average solar sunspot cycle is 10.448 years according to a NOAA(?) website, a 5-6 year lag is exactly out-of-phase. Seems quite odd.

    By the way, as I understand it, Leif Svalgaard claims no change in TSI (other than solar sunspot cycles) over the last 175 years. So even changes in TSI does not seem to be a settled matter.

  35. 385
    Don Shor says:

    Re: polar bears

    Completely Fed Up: “If polar bear populations were at 25-30,000 50 years ago, then a cut of 5,000 would leave the population still at 20-25,000.”

    Where did you get your 25-30,000 number? I’m not asking rhetorically. I just couldn’t find that figure anywhere.

    “But Don wants to see it as no problem. This is creating a few difficulties for him…”

    Where did you get that idea? I just don’t think that polar bears are presently very good poster animals for AGW. You might just as well use panda bears, and they’re cuter.
    Climate change is a long-term potential problem for the polar bear population. Hence the “threatened” status they’ve been awarded.

    Jiminmpls: “You have been brainwashed and rendered incapable of rational thought.”
    Great riposte! Say, isn’t this a moderated forum?

    Alan Millar: “It seems to be accepted that in the 1950s there were far fewer Polar Bears than now. Estimates seem to range around the 5000 figure. Given than current estimates are around 20 – 25000 I would call that an increase and a large one. Is anyone declaring that as a decrease?”

    Which supports the idea that the major factor affecting polar bear populations has been the management of hunting. The site I linked also mentions bear/human interactions and pesticides as risk factors. Climate change is a potential long-term threat.

    Doug Bostrom: “According to the “polar bear experts”, the horse’s mouth when it comes to polar bears, of the population groups with reasonable measurements available most are in a state of declining population.”

    8 out of 19 subpopulations are declining. The same experts indicate their estimate of the total population hasn’t changed (20 – 25,000) since 2005.

    “…of the groups with known populations, most are in decline.”

    Take a look at the detailed table (unfortunately, only available from 2005 that I could find):
    http://pbsg.npolar.no/en/status/status-table.html
    5 – 10% annual removals in certain subpopulations seem to be the major factor. If we know anything, it is that we need more information.

  36. 386
    David B. Benson says:

    RB (381) — Not at all. A positive feedback is an amplification of the orignal signal; it need not lead to unstable runaway. The standard example is

    1 + 1/2 + 1/4 + 1/8 + … = 2.

  37. 387
    Completely Fed Up says:

    “Would it be correct to say that the standard definition of positive feedback still holds but there is no instability so long as the negative feedback effects come into play over longer time scales to damp the buildup”

    No need to.

    If positive feedback is a convering series, there’s no need for negative feedbacks.

  38. 388

    #382 Matthew

    Good question? I don’t know. Someone in the area that is doing the studies might be able to establish attributions to varying degrees but I doubt with extreme precision. There are always error bars in such estimations. Someone may have already done a study but I don’t know. Not the most pertinent issue in my mind when examining evidence on AGW effects (not saying I don’t care about the polar bears so please don’t jump on me). Personally I hope never to meet one. I hear they are quite ferocious.

    I have seen many use the polar bear argument and no doubt some bears are being affected and even drowning due to increased distances. But for my money, if we are looking for a smoking gun in the Arctic on AGW it’s the predictions and confirmations in the ice volume and ice extent loss rates.

    It’s to easy to just say the polar bear population is increasing so AGW is wrong (a classic strawman and non sequitur).

    http://nsidc.org/images/arcticseaicenews/20091207_Figure3.png

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20070822_oldice.gif/view

  39. 389
    Doug Bostrom says:

    Matthew says: 5 January 2010 at 1:22 PM

    A “/dev/nul/” non-thread would be great. Just a linear sequence of rejected posts, for all to see, no need for support of discussions. Like I suggest, an invitation to puzzle out what was wrong, revise, resubmit. No further effort on RC’s part required.

    The posts I’ve made that have vanished have consistently not deserved to see the light of day. Perhaps I’ve just been the beneficiary of fortuitous technical glitches; considering the “quality” of many posts on RC it’s hard to believe any get moderated out. Whatever the reason, I’m grateful.

    Matthew says: 5 January 2010 at 1:45 PM

    Here’s what the polar bear experts conclude from their most recent convocation:

    “The PBSG renewed the conclusion from previous meetings that the greatest challenge to conservation of polar bears is ecological change in the Arctic resulting from climatic warming. Declines in the extent of the sea ice have accelerated since the last meeting of the group in 2005, with unprecedented sea ice retreats in 2007 and 2008. The PBSG confirmed its earlier conclusion that unabated global warming will ultimately threaten polar bears everywhere.

    The PBSG also recognized that threats to polar bears will occur at different rates and times across their range although warming induced habitat degradation and loss are already negatively affecting polar bears in some parts of their range. Subpopulations of polar bears face different combinations of human threats. The PBSG recommends that jurisdictions take into account the variation in threats facing polar bears. ”

    http://pbsg.npolar.no/en/meetings/press-releases/15-Copenhagen.html

    Also, if you look here and dig around

    http://nsidc.org/arcticseaicenews/

    you’ll find ample evidence to indicate that 2007 by no means marked a terminating punctuation mark in the continuing decline of Arctic sea ice.

  40. 390
    SecularAnimist says:

    Ray Ladbury, your comments about Bjorn Lomborg reflect a generosity of spirit that I unfortunately cannot share, and which I don’t think Lomborg deserves. I don’t think Lomborg makes “mistakes”. I believe he engages in deliberate, knowing deceit about the urgency, necessity, costs, and benefits of emissions reductions. Lomborg is every bit as deceitful as those who seek to deliberately, knowingly deceive about the basic science. Lomborg is just creating public confusion and undermining public support for action in a different area, that’s all.

    And as I said above, all of his sophistry boils down to one simple bottom line, which is the same bottom line that ALL the denialist sophistry ALWAYS boils down to: there is no need for urgent action, particularly for any government policies, to rapidly phase out fossil fuels on a large scale.

    It is always the same, whether the particular denier is denying the basic science, or acknowledging the basic science but denying the urgency and severity of the danger, as Lomborg does: whatever we do, we must not do anything that would reduce the fossil fuel corporations’ profits.

  41. 391
    Matthew L. says:

    #340 – FurryCatHerder
    You are right, it is not correct. I have gone back to basics and done some numbers.

    Waxman-Markey sets a target of reducing total U.S. GHG emissions by 83 percent below 2005 levels by the year 2050 (with intermediate benchmarks at 2020 and 2030). I have seen estimates that this is a reduction from a projected 5.7 billion tons in 2009 to just a little over 1 billion tons in 2050.

    The United States last emitted 1 billion tons in the year 1910, when the nation’s population was only 92 million people, so per capita consumption was roughly 10.9 tons per annum. By the year 2050, however, the United States is expected to have a population of circa 420 million meaning 1 billion tons is 2.38 tons per capita per annum – less than a quarter of the amount consumed per capita in 1910. Even at the current population it is only just over 3 tons.

    Assuming that similar levels are needed throughout the world, that will involve hugely disruptive changes to our production and consumption of energy. We will need to be very sure of the science if we are going to convince the world that such a change is necessary. I don’t envy the climate scientists task.

    I think it is self evidently a “good thing” to reduce our dependence on fossil fuels for all sorts of reasons. However there are many out there who do not think that way (several billion Chinese for a start) and you need to convince them – not me!

    I have tried resonding to other posts but am getting blocked.

  42. 392
    Matthew L. says:

    Aha! That one worked, so will try a shortened version of the original post I tried to get through.

    #337 – Doug,
    sorry you feel that way Doug. I thought this was a discussion, I am quite happy to be proved wrong where better information is available, not all of us have the time and resources to seek out and cite relevent research. A paper written that way would appear in the main blog not in the discussion. I am sure you can tell from my posts that our Environment is very much my major concern.

    I am very much a product of the current state of the internet on this subject. It is impossible for me to tell whether research is s__t or truth, old or new, current or superseded. This is a great place for guidance. Much of what I say is playing ‘devil’s advocate’. I am aware that I may be completely wrong, but I, and people like me, need to be convinced.

    In the light of better information I am more than happy to concede the point on the Polar Bears.

    #338 – Jim Eager
    Thanks! That clarifies the position a lot and I now understand. Do you have a reference to an article that shows what the series looks like as applied to feedbacks used in climate models? How does the series look going backwards? Tried looking on this site but can only find generalities.

    Similarly Ray’s point on the 10 supporting analyses supporting positive feedback.

    Further replies to follow if I don’t get blocked again.

  43. 393
    Matthew L. says:

    #341 – Doug,
    a bit uneccessary Doug. Much of my assertions are from memory, I don’t keep a book of citations. I have a day job and little spare time so just read lots of stuff and try and remember it.

    I have done more research on Coral Bleaching and concede that warming of the seas has caused bleaching in the past. Much of this was attributed to the exceptional Nino event in 1998. More minor and localised events have occurred since, most notably in 2002. Much of the coral (where isolated or protected) has since started recovering so this could just be an exceptional natural event and part of the natural process of adpatation to change. That has not stopped a lot of coral being damaged by human sewerage and exploitation in the meantime.

    Apart from the Polar Bears and (possibly) coral bleaching, can you think of any other environmental catastrophe (in particular plant or animal extinction) that has happened, or is happening, as a result of global warming and that cannot be attributed to direct human intervention?

    I am genuinely interested to know as I have failed to find any yet.

    I could give you several thousand instances where plant and animal species populations are declining due to habitat destruction, hunting or over exploitation.

    #350 – Doug (you’re busy!)
    sea level is rising at a rate of around 2mm a year and has done at least as fast, if not faster, since approximately the end of the last ice age. Despite that Mangrove swamps have grown and thrived throughout the tropics, helping to build river deltas and providing a wonderful habitat for unique species of birds, mammals, amphibians and insects. There is no evidence that Mangrove forests are unable to adapt to rising sea levels. Sure they retreat as all species will do as sea levels rise, but just because they retreat does not mean they get smaller, unless constrainted by man or geology they will encroach at the rear as well as retreating at the front. However, there is plenty of evidence that they are unable to adapt to being cut down and replaced by marginal agriculture and human habitation.

    If this gets through then, irony of irony, the bit that got me blocked was a citation!

  44. 394
    Matthew L. says:

    The United Nations Environment Program estimated that shrimp farming causes a quarter of the destruction of mangrove forests.
    (Botkin, D. and E. Keller (2003) Enrivonmental Science: Earth as a living planet (p.2) John Wiley & Sons. ISBN 0-471-38914-5 )

  45. 395
    Arthur Smith says:

    There is a heap of confusion on the feedback issue, with various people’s intuitions mostly right but at odds with one another, even among climate scientists. For that matter, even recent papers (such as this one just out by Mike Lockwood on solar forcing: http://rspa.royalsocietypublishing.org/content/466/2114/303.full ) can get significant things wrong – Lockwood seems to have a differing definition of forcing (measuring at the surface, rather than Top of Atmosphere) which leads to discussion of how the feedbacks are somehow part of the forcings…

    From my limited understanding of the issues, I think the best explanation is to be had by looking at the precise mathematical definition in terms of partial derivatives of various terms, in particular Appendix A of Bony et al’s review article in Journal of Climate, Vol. 19, p. 3445 (2006); the appendix is titled appropriately enough “How are Feedbacks Defined?” from which we see the main issue immediately is the central negative stabilizing feedback that everybody knows about but forgets to include among the feedbacks as usually understood:

    “The most fundamental feedback in the climate system is the temperature dependence of LW emission through the Stefan–Boltzmann law of blackbody emission (Planck response).”

    This is large and negative; all other feedbacks, positive or negative, add to this one. Positive ones move the climate to a less stable state, negative ones make things a little more stable. But overall, as long as the sum of the positive feedbacks doesn’t become larger in magnitude than the negative Planck response, the climate system is stable.

  46. 396
    Completely Fed Up says:

    “The United Nations Environment Program estimated that shrimp farming causes a quarter of the destruction of mangrove forests.”

    Therefore 75% by NOT shrimp farming!

    QUICK! START FARMING SHRIMP!!!

    Come on.

    And this:

    “1 billion tons is 2.38 tons per capita per annum – less than a quarter of the amount consumed per capita in 1910. Even at the current population it is only just over 3 tons.”

    You know what we’ve got that we didn’t have in 1910?

    Modern electric vehicles.

    Modern Solar PV

    Modern Wind Turbines

    Modern insulation

    Double Glazing

    TECHNOLOGY.

  47. 397
    Completely Fed Up says:

    “Where did you get your 25-30,000 number? I’m not asking rhetorically. I just couldn’t find that figure anywhere. ”

    It was an example.

    if it WAS 30,000, then “still 25,000″ is both correct AND proof of reduction in numbers. It’s still a lot of polar bears. It’s not like it’s about to go extinct like white bengal tigers or anything.

    And that is despite, I may add, controlling the predation by humans.

  48. 398
    SecularAnimist says:

    Matthew L. wrote: “… that will involve hugely disruptive changes to our production and consumption of energy.”

    It sure will — it will involve a massive transfer of wealth from the fossil fuel corporations to other sectors of the economy. Very disruptive to ExxonMobil’s tens of billions of dollars in annual profits. Can’t have that, now can we? Much better to accept “disruptive changes” like the total failure of agriculture and mass famine.

    Matthew L. wrote: “… I think it is self evidently a ‘good thing’ to reduce our dependence on fossil fuels for all sorts of reasons. However there are many out there who do not think that way (several billion Chinese for a start …”

    China is moving more aggressively to reduce fossil fuel use and build up a wind and solar energy infrastructure than is the USA, and even has higher fuel economy standards for vehicles than does the USA. Not to mention that China is already on track to become the world’s largest exporter of wind and solar technology — all technologies that were invented in the USA.

    Phasing out fossil fuels will be “disruptive” and the Chinese won’t do it anyway. Sounds like the same old, same old denialist, obstuctionist sophistry to me.

    First deny the science.
    If that barricade falls, then deny the urgency or severity of the problem.
    If that barricade falls, then deny that we have the ability to change.
    If that barricade falls, then blame the Chinese.

  49. 399
    SecularAnimist says:

    Matthew L. wrote: “… that will involve hugely disruptive changes to our production and consumption of energy.”

    You know, the invention of the networked personal computer involved “hugely disruptive changes” to what was then known as “data processing”.

    The invention of the cell phone involved “hugely disruptive changes” to telecommunications.

    And yes, the proliferation of technologies that will enable businesses, communities, factories, family farms and individual homeowners to harvest limitless, ubiquitous, clean, free wind and solar energy will surely cause “hugely disruptive changes to our production and consumption of energy.”

    I’m looking forward to it.

  50. 400
    Matthew L. says:

    Hmmm… this spam blocking is a mystery. I have managed to post all of the text of my original blocked post in bits, but the whole post won’t go through.

    To those who have commented that my views are just wishful thinking that future discoveries will save my sorry a_s (or ar__e in English) you have a point :)

    However – struggling hard to analyse my own scepticism – I don’t think that really is my motivation. It is more that experience has taught me to be sceptical of extreme views and extreme predictions that diverge from previous experience so radically – particularly when the true outcome is not likely to be apparent until long after I am dead and gone.

    I am also sceptical of precitive models that make best guess assumptions about major factors (such as clouds and ocean current feedacks and forcings) – particularly where (in the case of clouds) those assumptions are all biased either to the neutral or positve.

    Is it wise to discount the possibility that cloud feedback might be negative? Has anybody run climate models scenarios that assume just that?
    http://www.realclimate.org/images/soden_fig1.jpg

    My fear is that this is not done because it might show that the range of outcomes for a doubling of CO2 might be more like 0 – 6 kelvin rather than 2 – 6 kelvin. In which case we still have the probability of global warming but just with a huge range of uncertainty.


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