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Did Murdoch's The Australian Misrepresent IPCC Chair Pachauri on Global Warming?

Posted on 25 February 2013 by dana1981

As we have discussed many times at Skeptical Science, although the warming of global surface air temperatures has slowed over the past decade due to a preponderance of La Niña events, the rate of heat accumulation on Earth has not slowed at all.  In fact over the past 15 years, the planet has accumulated more heat than during the previous 15 years (Figure 1).  That's global warming.

Fig 1

Figure 1: Land, atmosphere, and ice heating (red), 0-700 meter OHC increase (light blue), 700-2,000 meter OHC increase (dark blue).  From Nuccitelli et al. (2012).

Unfortunately many people (often even including climate scientists) mistakenly equate the warming of global surface air  temperatures with global warming.  That is simply inaccurate.  Approximately 90% of global warming goes into heating the oceans (Figure 2).

heat going

Figure 2: A visual depiction of how much global warming heat is going into the various components of the climate system for the period 1993 to 2003, calculated from IPCC AR4 5.2.2.3.

So the reality is that global warming continues unabated.  Despite this reality, an article by Graham Lloyd in The Australian (paywalled) claims that the chairman of the Intergovernmental Panel on Climate Change (IPCC), Rajendra Pachauri agreed that there has been a 17-year pause in global temperature rises.  Unfortunately we don't know exactly what Pachauri said on the subject, because Lloyd did not quote him directly (which is a red flag). 

The IPCC communications office tells Skeptical Science that The Australian has not provided a transcript or audio file of the interview for verification, but it does not accurately represent Pachauri's thoughts on the subject - namely that as discussed in this post, global surface temperatures have plateaued (though over the past decade, not 17 years), and that this in no way disproves global warming.

Despite the lack of useful verifiable content, the story headline has nevertheless gone viralThis is not the first time Lloyd has been caught misrepresenting climate science in The Australian - in January of this 2013 he wrongly claimed that a study had found no link between global warming and sea level rise.  Oceanographer John Church, who was co-author on the misrepresented research in question and also Nuccitelli et al. (2012) from which Figure 1 above originated, set the record straight, and The Australian was forced to retract the article.

Here are the relevant passages from Lloyd's latest piece:

THE UN's climate change chief, Rajendra Pachauri, has acknowledged a 17-year pause in global temperature rises

{...}

Unlike in Britain, there has been little publicity in Australia given to recent acknowledgment by peak climate-science bodies in Britain and the US of what has been a 17-year pause in global warming. Britain's Met Office has revised down its forecast for a global temperature rise, predicting no further increase to 2017, which would extend the pause to 21 years.

Dr Pachauri said global average temperatures had plateaued at record levels and that the halt did not disprove global warming.

"The climate is changing because of natural factors and the impact of human actions," Dr Pachauri said.

The claim about the "peak climate-science bodies" undoubtedly refers to another misleading newspaper article wrongly claiming that global warming stopped by the Mail's David Rose, and Lloyd's comment about the Met Office prediction is also inaccurate.  Ultimately the only statement the Australian article attributes to Pachauri on this subject is that "global average temperatures had plateaued at record levels and that the halt did not disprove global warming."

Again note that the story is paraphrasing Pachauri rather than quoting him directly.  Had he said that global surface air  temperatures have plateaued and that this doesn't disprove global warming, he would be 100% correct.  Though it's also worth noting that over the past 17 years, the global surface temperature trend is approximately 0.10 ± 0.13°C per decade, which is most likely positive (warming).

More importantly, over the past 17 years the planet has accumulated the equivalent energy to detonating 3.7 Hiroshima atomic bombs per second, every second.  It takes a fundamental misundertanding of the global climate to deny that immense amount of global warming.

As long as humans continue to increase the greenhouse effect by adding more and more CO2 to the atmosphere, global warming will continue.  That is a physical reality that cannot be changed by misstatements or misquotes or misrepresentations or denial.  Global warming will not stop until we do something to stop it.

To hear what Pachauri actually thinks about global warming without first passing through The Australian's filter, you can listen to interviews with him on Radio Australia and ABC News.  Also see a similar debunking of this myth by The Australian Climate Commission.

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Comments 1 to 50 out of 102:

  1. One does not expect the Australian to accurately climate change. However, I don't think climate scientists "mistakenly equate the warming of global surface air  temperatures with global warming. Instead, I think that is the meaning of the term in the literature. Planetary heat increase is another thing.

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  2. Physically, the term 'global warming' can only refer to one thing, the globe.  I understand that atmospheric scientists have loosely referenced the atmosphere when using the term but it doesn't change what's implied by the words in the phrase.  The proper term is 'global heating', but they got the 'global' part right.

    Its necessary to point out because as this article states, the REASON the atmosphere isn't warming as rapidly as expected is because of an unexpected preponderance of La Nina events in the last decade.  Which basically means the atmosphere isn't heating as rapidly because the ocean is pulling more of that heat into her deep layers.  What does this mean for the 'globe'?  Nothing.  Its still heating.

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  3. Pete @1 - climate scientists often make this mistake when communicating with the public.  If you want people to understand the subject, you can't refer to surface air warming as 'global warming', because then when we have a temporary 'plateau' in surface air temperatures as is currently occurring, people think global warming has stopped.

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  4. It's a failure to communicate the obvious by people who should know better. As Dana points out, extra heat has built up in the subsurface ocean. That has led to limited warming of surface air temperatures over the last decade but, based on past observations, it will not last. When the climate moves into a period dominated by El Nino (a lot of heat escaping the ocean) it is going to get warm very quickly, and the weather that accompanies this is likely to be very nasty.

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  5. We are using the wrong null when we (or anyone else) says something like "no significant" warming in the past x years. 

    The fact is that we have solid physics-based reasons to know that the planet is warming. Therefore the correct null is that current warming is running at the same rate as past warming, and not that current warming is greater than zero.

    For example: HADCRUT4 dataset (annual time series) has a slope of .0047° C per year during 1997-2012, with a 95% confidence range from -.0041 to +.0135°C. The relevant question is not whether this range includes zero; the relevant question is whether this range includes the warming rate of the previous 30 years. Since the warming rate from 1967-1996 was .0128°C per year, there is no statistically significant difference between the current warming rate and the previous warming rate.

    And that's the message we need to send.

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    Moderator Response: [DB] All-caps usage converted to italic bold, per Comments Policy.
  6. The full article can be found here: Nothing off-limits in climate debate

    Relevant excerpt:

    Dr Pachauri said global average temperatures had plateaued at record levels and that the halt did not disprove global warming.

    “The climate is changing because of natural factors and the impact of human actions,” Dr Pachauri said.

    “If you look at temperatures going back 150 years, there are clearly fluctuations which have occurred largely as a result of natural factors: solar activity, volcanic activity and so on.

    “What is quite perceptible is, in the last 50 years, the trend is upwards.

    “This is not to say you won’t have ups and downs – you will – but what we should be concerned about is the trend, and that is being influenced now to a large extent by human actions.”

    He said that it would be 30 to 40 years “at least” before it was possible to say that the long-term upward trend in global temperatures had been broken.

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    Moderator Response: [DB] Your linked article, itself based on a GWPF document, does not contain a link to the actual quote but to paraphrased versions of the quote, as noted in the OP of this thread. It is thus hearsay and not very germane to the discussion.
  7. It would be perfectly reasonable to have a desire for different terms, or to think that also mentioning ocean heat content would give people greater understanding. But such desires and views do not make others, using a standard term in the standard way, mistaken. Recall if you will the discussion of "ocean acidification."

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  8. Rather than speculate on whether Dr Pauchauri was misrepresented, can't you ask him directly?

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  9. It's just an unfortuante reality that technically incorrect definitions are sometimes used by scientiests when they are earnestly responding to a question.The crux is that it is difficult for experts to always avoid "shorthand-speak" in interviews or general explanations of the science, yet so easy for "skeptics" to use that inexact terminology to misrepresent.  

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  10. Kiethpickering is entirely correct. A horizontal line is arbitrary and implies a system in stasis. IOW - starting with a flat line is automatically cherry picking the result you are looking for.

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  11. Pauchauri should speak up on this - It would be great for the Australian to get a follow up smackdown.

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  12. If there is a question mark about what The Australian actually said, then Googling for this

    "nothing-off-limits-in-climate-debate/"

    (complete with quotes) leads me to a scanned version of the print edition. I am not sure I can provide a direct URL as it seems to link ot a generic URL for the viewer that shows the latest copy. The URL is here if you are interested http://theaustralian.newspaperdirect.com/epaper/viewer.aspx

     

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  13. Dr. Pachauri doesn't recall his exact words, hence the IPCC request to The Australian (not yet answered) for the interview transcript and/or recording.  However, Dr. Pachauri does not think the '17 years' comments are an accurate representation of what he said (though it's possible he misspoke), and certainly not of what he believes, as noted in the post.

    Regardless of what he said, the most important point is that global surface air warming is not the same as global warming/heating.  Certain parties intentionally conflate the two because the former has 'plateaued' while the latter has not, so it allows them to pretend global warming has 'stalled'.  This is simply wrong, and a misinformative error which must be corrected.

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  14. @ DB, re. post 6: two issues here. First, when hunting for ways to link to paywalled articles one takes what one can. In this case GWPF has rerun the first half of the article, complete with byline and accompanying photograph..

    The article contains multiple direct quotes attributed to Pachauri that could easily be replies to a prompting question from Lloyd (e.g., "But hasn't the rise in global temperatures recently slowed or stopped?" etc.).

    Yes, a number of Lloyd's framing remarks are clearly leading ("record northern summer[sic] Arctic ice growth", "recent acknowledgment by peak climate-science bodies", etc.). But it hardly seems an egregious example of bad journalism, including paraphrasing statements or responses by Pachauri. That a host of commenters have seized on a single ambiguous lead-in to the generally thoughtful and carefully-worded comments by Pachauri is a reflection on their desperate scramble to grasp at straws.

    The concluding half of the article is as follows:

    (-snip-)
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    Moderator Response: [DB] En masse block-quoting snipped per the Comments Policy.
  15. The IPCC communications office tells Skeptical Science that The Australian has not provided a transcript or audio file of the interview for verification, but it does not accurately represent Pachauri's thoughts on the subject

    Are you able to provide a link to this statement from the IPCC? 

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  16. AndyS @15 - no, "tells Skeptical Science" = personal communication.

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  17. "Did Murdoch's The Australian Misrepresent IPCC Chair Pachauri on Global Warming?"

    Has the Australian ever published anything accurate on climate?

     

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  18. Dana #13 you say:-

    >"...the former [atmosphere] has 'plateaued'..."

    >"...the most important point is that global surface air warming is not the same as global warming/heating"

    Both correct but I assume you mean the latter to be anthropogenic ocean warming/heating. That's a very different story if you do because then you are arguing against natural planetary enthalpy (including 8 - 20 year thermal inertia) which - going by the solar bicentennial componant having only just dipped slightly below Grand Maximum over the last 20 years or so but is now dipping rapidly in SC 24 - is about to go into reverse out to maybe 2050 along with the attendant feedbacks.

    Apart from that, the IPCC has not yet firmed up an anthropogenic ocean heating mechanism after 25 years of existence. They are merely "extremely certain" of their assumption based on assunptive studies. So if - now that atmospheric temperature is at standstill - you wish to transfer the focus from an atmosphere unmoved by rising CO2 levels to the ocean where energy accumulation is still evident, the science you and the IPCC have to support anthropogenic attribution to ocean heating is tenuous at best and still only at fledgling stage.

    Therefore your "most important point" appears to be a strong argument against aGHGs being the major climate driver of the atmosphere and a weak argument for aGHGs being the major ocean heating agent. What will you do then when OHC plateaus too as it inevitably will without elevated solar input?

     

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    Moderator Response: [DB] Interested parties should take discussions of ocean warming mechanisms to this thread. It is off-topic on this thread. Discussions of OHC itself should go to this thread.
  19. Richard, we've talked about ocean heating here a million times.  Heat doesn't just magically accumulate in the oceans.

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  20. Oh yes it does! Tell them about the magical undersea volcanoes, Dixie! ;-)

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  21. Richard C:

    Repeating a debunked argument doesn't magically make it correct.

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  22. This article seems very speculative. I understand that you think 'The Australian" has form, but until either Dr Pauchauri or his press office responds I would have thought it is moot.

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  23. Dana #19

    >"Heat doesn't just magically accumulate in the oceans."

    I agree, it (-snip-)

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    Moderator Response: [DB] Off topic snipped. See the previous moderation guidance given you.
  24. Richard C (23) claims :

    0 - 2000m OHC is now at a lower level than end of 2011

    That is not what NOAA are claiming. See here:



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    Moderator Response: [DB] Please take any discussions of OHC to the appropriate threads, as indicated above. [RH] Fixed image width.
  25. (-snip-)

    I wonder at Ian's ability to read a graph too given the last datapoint at Oct-Dec 2012 is lower than Oct-Dec 2011..

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    Moderator Response: [Sph] Moderation complaints snipped.

    Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
  26. Richard C: "the last [OHC] datapoint at Oct-Dec 2012 is lower than Oct-Dec 2011"

    NOAA OHC data:  4Q2011: 14.983609,  4Q2012: 16.831072

    Pop Quiz Richard:  Which is larger, 14.98, or 16.83?

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  27. Dana, (-snip-)

    Back on topic.

    "'Did Murdoch's The Australian Misrepresent IPCC Chair Pachauri on Global Warming?'"

    Pachauri can always make a complaint and ask for accurate representation from The Australian or make a correction by press release. If he's not bothered to do so then what's the problem? (-snip-)

    If Pachauri's criteria is 30 - 40 years of statistically insignificant warming before atmospheric warming can be considered to have ceased in terms of any human forcing (or whatever his exact words were) and we're 56% - 42% on the way there (closer by UAH 19 yrs and RSS 23 yrs), doesn't this detract somewhat from the immediacy of a crisis attributed to annual rises in CO2?

    (-snip-)

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    Moderator Response: [DB] Off-topic snipped.
  28. Richard C,

    Pachauri can always make a complaint and ask for accurate representation...

    No, he can't.  The Australian can print what it likes and say what it likes.  We've been down this road before with David Rose (multiple times).  It seems that deniers get to lie, twist, steal, hack, and do whatever they please, and they are hailed as heroes by those who desperately wish that the science were not true — as do we all, but for them it is to such a degree that they'll delude themselves into believing it's not, and fail to take the necessary action.

    No, Pachauri has no choice.  Lloyd very explicitly quoted him every chance he got.  The article has dozens of direct quotes.  And yet there's no direct quote about"17 years."  Why is that?

    Because it doesn't matter, and Lloyd knows it.  Sprinkle in the other quotes, claim that Pachauri said it, then play a game of he-said/he-said.  If he has a transcript of the conversation, then just destroy it.  The fact is that Pachuri, like other scientists, will come across as trying to weasle out of something he said, no matter what the truth is behind the matter.  And those uncritical fools who only hear what they want to hear (my, aren't there a lot of them?) will fall in line behind Lloyd.

    And of course there are also those zillions of (uncritical, unskeptical) denier blogs that picked up the quote and echoed it around the Internet, because it was exactly what they wanted to hear and say.

    No, this deal was done the moment the thought creeped into Lloyd's brain that he could get away with it.

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  29. The climate change spin continues.

    David Rose was at it again over the weekend, here is the brain exploding article.

    Good thing I have a strong stomach, otherwise I would be sick.

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  30. (A re-write of the comment 3 up-thread hopefully in a form that is readable by wysiwygs & humans all.)

    This "17 year" strapline in Murdoch's Australian that denilaists love so much they cannot help telling each other about - it may be no more than 'cheeky chappy' journalism but accounts of the type 'AGW cannot happen without GW' do have a long history. They doubtless began decades ago before GW even started let alone 'paused' and certainly took on added potency with the famous Roger Harrabin/Phil Jones interview of 2010.
    So 15 years became 16 years and is now 17 years without the slightest care as to what "statistical significance" actually means or what the data actually shows.

    What has been missing in all this is a robust reply to these silly right-wing press stories.

    Up until mid-2007 there was no 'pause' in the global surface temperature rise. Up until mid-2007 the global surface temperature rise was actually accelerating.
    This is evident from the monthly global surface temperature data. Calculating a straightline regression (from Jan 1980) shows that the slope, the rate of warming, increases as newer data is included in the regression and does so up to mid-2007 as illustrated here.

    Thus anyone suggesting a 'pause' in warming longer than 5½ years is seriously overstepping the mark into a fictitious La-La-Land.

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  31. It is no more likely that Dr. Pachauriwould say human-caused climate change ("global warming") has "paused" for 17 years than he would say Earth is a flat disk that the universe spins around.

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  32. "...there is no statistically significant difference between the current warming rate and the previous warming rate."

    There is an excellent reason why statisticians tend to not use the phrase "statistically significant," even though scientists love the phrase: it can, and does, mean significantlydifferent things and therefore without defining the phrase every time it is used (a tedious chore), statisticians don't often use it.

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  33. The following is interesting, and telling too.  When one Google's a key sentence from Lloyd's article ("Britain’s Met Office has revised down its forecast for a global temperature rise, predicting no further increase to 2017, which would extend the pause to 21 years"), most of the hits are to sites that deny the theory of AGW and/or fake skeptic sites. Please not that the quoted text made by Lloyd is not strictly true.  Note too how "skeptics",  suddenly become completely confident in models and predictions when the answer can be twisted to fit their beliefs, despite claiming for years now that models are useless ;)

    This is what global cooling looks like to those in denial:

    [Source]

    Caption: 

    Observed (black, from Hadley Centre, GISS and NCDC) and predicted global average annual surface temperature difference relative to 1971-2000. Retrospective predictions starting from June 1960, 1965, ..., 2005 are shown as white curves, with red shading representing their probable range, such that the observations are expected to lie within the shading 90% of the time. The most recent forecast (thick blue curve with thin blue curves showing range) starts from November 2012. All data are rolling annual mean values. The gap between the black and blue curves arises because the last observed value represents the period November 2011 to October 2012 whereas the first forecast period is November 2012 to October 2013.
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  34. #30: Good points about the graph until 2007. Also interesting to note that 2007 was the very year that Arctic sea ice truly started to collapse.

    Pretty handy for the disinformers that the part of the globe that is warming the fastest is not well accounted for in the global average, but the cold air that should have stayed up there gets dumped down here, where it is accounted for in the average temp, introducing a substantial cool bias.

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  35. #29 MightyDrunken - I agree that the Rose article in the Daily Mail is pretty stomach churning (particularly the picture of Tim Yeo), but other than that it seems a fairly accurate description of the state of British energy policy.

     

    Is there a bit that you object to? I guess this is relevant to the post.

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  36. I have notice several references to the GWPF (Global Warming Policy Foundation).  It should be noted that recently The Australian has run several articles under the byline of the GWPF, so not only have they become an echo chamber for denier propaganda, they have started mainlining denier sources.  It is sad for long time readers to see what once a great newspaper so abase itself.

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  37. So is discussing and being critical of Global Warming "Policy" now make you a "denier"?

    There appears to be a lot of use of the word "denier" on this thread which indicates to me a lack of interest in science and a politically biased world view

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  38. AndyS, the GWPF is fronted by a prominent denier, has a board of trustees consisting of well known (in Britain) deniers; and has an academic advisory board whose only qualifications appear to be a degree in science, and the fact that you are a denier.

    The fact that they include "policy" in their name does not mean they only discuss policy issues, and they publish a large selection of pseudoscience.  Nor do their policy prescriptions come down to anything other than "do nothing about climate change".

    Finally, it is the fact that I care about science that causes me to object to, and despise the large group of people who cherry pick, lie, falsify data and graphs, and slander genuine scientists in almost every post they make.  I call those people deniers.  I am astonished that somebody could mistake objecting to such unscientific practises as being politically biased.

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  39. Andy S - not to be confused with SkS's own - is a serial who has recently been finally blocked entirely from Hot Topic, which he had haunted for some time with his abusive ramblings, having been granted far more tolerance than he deserves.

    (-snip-).

    This gives a good idea of what to expect. He regularly refers to us all as 'Eco-Nazis'. I'd suggest that his blocking from this site is inevitable.

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    Moderator Response:

    [JH] I deleted Andy S's offensive comment.

    [DB] References to deleted comments and inflammatory snipped.

  40. In a randomly varying system, we expect that after an outlier, the graph will revert toward the mean.  We would expect, for instance, that in 2013, there will be more ice cover on Sept15 than in 2012.  If each year the system goes further and further in one direction, it becomes clearer and clearer that something is pushing it.  The ice extent this year and next should (but probably won't) shut down the sceptics.  I get the sense that the 2012 ice extent, sandy and the present drought in America is causing a paradigm shift amonst a lot of deniers.

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  41. Which offensive comment? By the way, I did get banned from Hot Topic (-snip-).

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    Moderator Response:

    [JH]Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

    [DB] Off-topic snipped.

  42. Ok, I understand the policy. Nuff said

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  43. Tom Curtis @38
    The GWPF's self-porclaimed position is more contradictory than simply its choice of name.
    The GWPF tells us its "main focus is to analyse global warming policies and their economic and other implications" but most of their output is about the science, or their version of it. This is an even stranger situation for the GWPF because they make great play of not having "an official or shared view about the science of global warming. On climate science, our members and supporters cover a broad range of different views, from the IPCC position through agnosticism to outright scepticism."
    This does not stop them bashing out ad nauseam the denialist non-scientific line with, for instance, their present 'headline' story "Lord Lawson Calls On Sir Paul Nurse To Acknowledge Global Temperature Standstill. In a letter to the President of the Royal Society, Lord Lawson has criticised Sir Paul Nurse for denying the reality of a global temperature standstill."
    In his "call" as Chairman of the GWPF Lawson directly accuses Nurse of lying because "there has been no further recorded global warming at all for at least the past 15 years, as even the IPCC Chairman, Dr Pachauri, has now conceded.  Whatever the precise reason for this, it cannot simply be dismissed or denied." So here we have a denier denying he is in denial, indeed accusing another of being in denial - this on a subject of science which his organisation has supposedly no official or shared view.

    there has been no further recorded global warming at all for at least the past 15 years, as even the IPCC Chairman, Dr Pachauri, has now conceded.  Whatever the precise reason for this, it cannot simply be dismissed or denied. - See more at: http://www.thegwpf.org/lord-lawsons-letter-sir-paul-nurse/#sthash.m6tA4kBV.dpuf
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  44. Why was one of my comments removed? I stated a fact: there is no such thing as "AGW theory." There is the theory of physics, which explains human-caused climate change.

     

    Meanwhile: "There appears to be a lot of use of the word 'denier' on this thread which indicates to me a lack of interest in science and a politically biased world view"

     

    1) If a Denialist objects to the word "denier," the Denialist can suggest a better, or different, word to use for her or his behavior: is there a better one? The mental health care profession, when discussing the rejection of the evidence for human-caused climate change, uses the words "denier" and "denialism" and "denialist."

     

    2) Science is supposed to be biased: science that is not biased is not science.

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  45. Hello Desertphile @44,

    If I recall correctly, according to the US National Acadamy of Sciences it is correct to refer to the "theory of AGW".  But this discussion is now straying off topic.

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  46. Leaving aside the ocean warming issue, does SkS accept that there has been no warming of land temps for the last 15 years or so?


    i.e there is a difference between the statement "global warming has stopped" and "there has been no significant change in surface temperature anomaly".

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  47. AndyS @46 - "does SkS accept that there has been no warming of land temps for the last 15 years or so?"

    Nope, that's not accurate.  The surface temp trend over the past 15 years is small, but still positive, even if starting in 1997/8 (which is a cherrypick due to the massive El Niño that year).

    "there is a difference between the statement "global warming has stopped" and "there has been no significant change in surface temperature anomaly".

    That's certainly true.

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  48. Signs are accumulating that point to an increasing likelihood of any exchange with Andy S to be a waste of time.

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  49. Still haven't bothered to learn any statistics, eh Andy? Leaving aside the issue of cherrypicked time periods, it is not true to say that if the slope of a linear trend is not significantly different from zero then the slope is equal to zero. It is simply that zero is included in the range of the possible values of the true slope of the trend.

    Also, confidence limits on a regression are two-tailed, so it would be equally justified to claim that the rate of warming has increased over the last 15 years, as the high end of the confidence limits includes values greater than the warming trend over the last 40 years. This highlights the importance of choosing the correct null, as keithpickering pointed out earlier. The question is not whether or not there has been warming in the last 15 years, but is the trend of the last 15 years consistent with the earlier warming trend. Until such time as you can demonstrate that the current trend has deviated from the previous trend in a statistically significant way, you cannot claim that there has been "no warming".

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  50. AndyS @46, the IPCC AR4 prediction for increase in global mean surface temperature over the period from 2001 - 2030 is 0.2 C per decade.  Checking Gisstemp, the only global surface temperature record (HadCRUT3 and 4 and NCDC are not global, and UAH is not a surface temperature record), I find the that 15 year trend is 0.058 +/- 0.248 C per decade.  That indicates that the short duration of measurement means there is insufficient data from the temperature record from Jan 1998 forward to determine whether trend is 0.306 C per decade, or - 0.19 C per decade, or some point in between.  The error bars do not just tell you that the trend cannot be distinguished from zero.  They also tell you that it cannot be distinguished from a value 50% greater than the IPCC projections.

    So, I am certainly happy to accept the temperature record since 1998 is two short to distinguish between accelerated warming, and a reversal of warming.  That, of course, being all that the error bars tell you.  I am also happy to accept that the measured trend is positive, not zero.

    I am not happy, as the deniers are trying to do, to say that the temperature record alone since 1998 is insufficient to distinguish between zero trend and 50% greater than IPCC projected trendand that therefore the IPCC projection has been falsified - which is what the deniers have been repeatedly trying to do.  

    I will certainly not do so when the use of additional information beyond the temperature record (ie, the ENSO record, etc) shows the underlying trend to be about 0.212 +/- 0.097 C per decade.

     

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