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In science, the only certainty is uncertainty

In the lead up to the release next month of the Intergovernmental Panel on Climate Change’s (IPCC’s) Fifth Assessment Report we are exploring concepts of confidence and certainty in climate science. You…

We are used to thinking in probabilities: will it be stormy enough to need an umbrella? Luis Martins

In the lead up to the release next month of the Intergovernmental Panel on Climate Change’s (IPCC’s) Fifth Assessment Report we are exploring concepts of confidence and certainty in climate science. You can find the first article here, and the second here

Scientists have built a theory of climate change from multiple lines of consistent, high-quality evidence. Just as we are confident that penguins can’t fly and that our skydiving scientist plummets under gravity, we are also confident in our understanding of human-induced climate change.

But simple statements implicating the human causes of climate change contain many complexities. The specifics are important too - what’s in store for the future? And how sure are we of these future climate impacts?

Even with our increasingly sophisticated knowledge of the climate system, there are aspects where questions remain and uncertainties we need to consider. Scientists need to be able to express these nuances in scientific findings, which means quantifying how much we understand.

We can again think of the evidence of climate change as a jigsaw puzzle. All information has at least a small degree of uncertainty, so we can imagine each puzzle piece is imperfect: they might be a little bit out of focus, or perhaps slightly discoloured. But despite their imperfections, they are still recognisable.

These are tangible uncertainties, our “known unknowns”. The same measurements of the same phenomena will always be slightly different. There are limits on our computing capacity and representing the earth’s complex physical systems with numbers is complicated.

These uncertainties can be quantified and accounted for as part of the scientific process. We have a good idea of just how blurry or discoloured these pieces are and what they are showing us.

Then there are the bits of the puzzle we don’t even realise are missing yet. These are “unknown unknowns”. They are bits of our puzzle at the limits of our reasoning or modelling, so their uncertainties can’t be quantified.

In science, there are complexities in all questions. For example, we can ask what kind of changes we will see in temperature extremes in coming decades. Scientists are confident that temperature extremes will become more frequent, but in order to express some of the complexity encompassed in that outcome, scales of likelihood are used describe the level of certainty.

We are “virtually certain” (99-100% probability) we will see an increase in the frequency and severity of extreme high temperatures. Here, the uncertainty of a particular finding has been quantified in probabilistic terms.

Using probabilistic thinking comes naturally to us in everyday life and we use it to weigh up risks. For example, we decide whether to take an umbrella to work based on the likelihood of rain.

But despite our familiarity with probabilities, the language of uncertainty can be confusing. When taken out of a scientific context, “uncertainties” seem to indicate that scientists are just plain wrong.

In scientific discourse, “uncertainty” does not imply that the science is unreliable. Instead, uncertainty is about probabilities and likelihoods that describe our understanding of a particular outcome.

Like those unexpected rainy days that keep us guessing, scientific information is never completely, unequivocally certain. All our attempts to understand complex systems and future changes come with uncertainty. So, we do not, and should not, draw conclusions from a single piece of evidence. We discern the picture of climate change by looking at all our puzzle pieces together.

Ultimately, the only scientific certainty is uncertainty. At times, these inevitable scientific uncertainties have been framed as synonymous with doubt and used to try to discredit findings.

But uncertainty is not a weakness of science. Rather than eroding our scientific confidence in human-caused climate change, using probabilities to talk about scientific uncertainties allows scientists to communicate findings more precisely and transparently.

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  1. Mark McGuire

    climate consensus rebel

    Quote from article: "We are “virtually certain” (99-100% probability) we will see an increase in the frequency and severity of extreme high temperatures.

    This important statement comes with a link that DOES NOT support it.
    It does have a link to the front page of a UN-IPCC report.

    If you are insinuating the quote is from UN-IPCC report, a link to the page, paragraph, highlighting the line would be appreciated, and also be more convincing.

    Cheers.

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    1. Mike Swinbourne

      logged in via Facebook

      In reply to Mike Hansen

      More to the point Mike, now that you have shown Mark the evidence, will he admit his error and accept the science, or will he continue to base his views on ideology and ignore all the evidence that he keeps being shown?

      I know where I would be putting my money.

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    2. David Arthur

      resistance gnome

      In reply to Mark McGuire

      Here's a link that might help:
      "Historic and future increase in the global land area affected by monthly heat extremes", Environmental Research Letters, 2013; 8 (3): 034018 DOI: 10.1088/1748-9326/8/3/034018 http://iopscience.iop.org/1748-9326/8/3/034018/

      To guide and inform your learning journey, here are a couple more:
      Extreme Weather Events Fuel Climate Change (Aug. 14, 2013) http://www.sciencedaily.com/releases/2013/08/130814132316.htm
      Climate Change's Costly Wild Weather Consequences (Feb. 17, 2013) http://www.sciencedaily.com/releases/2013/02/130217084553.htm

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  2. Marc Hendrickx

    Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

    The notion of scientific uncertainty with respect to climate science well dealt with by Judy Curry and PJ Webster in their AMS article "Climate Science and the Uncertainty Monster". "This paper explores ways to understand, assess, and reason about uncertainty in climate science, with specific application to the IPCC assessment process."

    It is sad to see The Con continue to publish articles from a very narrow range of perspectives rather than seeking broader academic input in this area. A sign perhaps The Con's "curators" have become quite lazy in their search for contributions. It is also surprising the authors of the piece above were not aware Curry's paper, referencing instead the discredited SS site.

    Curry's in-depth article that expands greatly on the points above can be found at the link below. Perhaps The Con's curators can request a contribution from Curry?

    http://journals.ametsoc.org/doi/pdf/10.1175/2011BAMS3139.1

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    1. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Felix MacNeill

      Felix,
      That is off topic but recent images made by SS members of themselves that show an odd fixation with Nazi imagery are enough for me to think something is quite unusual with the demeanor and behaviour of the site's authors. But if you support this sort of behaviour good for you. I find it highly odd and somewhat offensive.

      See as a starting point http://rankexploits.com/musings/2013/the-sks-nazi-images-thoughts-on-fair-use/

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    2. Mike Swinbourne

      logged in via Facebook

      In reply to Marc Hendrickx

      Well a couple of things Marc.

      Firstly, who said the authors were unaware of the Curry paper? Just because they did not reference it does not mean they were unaware of it. I am willing to bet there are many papers they were aware of but did not reference.

      Secondly, since you have put so much faith in the Curry paper, I have to assume that you accept the statements in the paper which state unequivocably that climate change is real, the Earth is warming, and that humans are at least partially responsible.

      ".....There is general agreement that the percentages of warming each attributed to natural and anthropogenic causes is less than 100% and greater than 0%. The challenge is to assign likelihood values to the distribution of the different combinations of percentage contributions of natural and anthropogenic contributions...."

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    3. Mike Brisco

      Scientist at Flinders University of South Australia

      In reply to Marc Hendrickx

      Geology, Marc... that wouldn't be coal geology, or gas geology, would it? .

      1. You ask for more discussion on uncertainty. The denialists routinely talked up uncertainty, as a PR tactic, to further their political ends..

      2. you asked for ' broader academic input' . The denialists also routinely used this tactic, pretending their esoteric, minority, imaginative view had been ignored by the media. In fact the media cover, is disproportionately large.

      3. Denialists dressed both…

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    4. In reply to Mike Brisco

      Comment removed by moderator.

    5. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Mike Swinbourne

      1. Don't you think Curry's paper is relevant to the topic at hand? If the article above had gone for peer review an informed reviewer would have been aware of Curry's extensive publications on the issue and would have requested some reference to the work. However as The Con's curator's have long favoured one view on this issue, over another; one particular group over another, it appears they were ignorant of the available literature on this topic. I grant you the authors may indeed have been aware of the work but for some reason they decided to ignore it, preferring instead references to odd web sites whose author's see themselves in unusual ways. It is up to informed editors to direct authors to cover the most important papers on a given subject, including those which the authors may have issue with. That this did not happen in this case suggests The Con's curators are not up to the task at hand.

      2. I agree 100% with that statement, do you? I somehow doubt it.

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    6. Mike Swinbourne

      logged in via Facebook

      In reply to Marc Hendrickx

      If you are asking me if I think the Curry paper is relevant, then my answer would be no. Because it isn't a paper, it is an opinion piece. It offers no evidence one way or the other. There is no data, no methods - just a discussion. All it does is provide the authors views on the subject, without any underlying data to support it. It is nothing more than someone's views that it is impossible to distinguish the underlying anthropogenic signal from natural climate variability. Whether or not…

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    7. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Mike Swinbourne

      So if you see Curry's piece as irrelevant, there is really nothing left to discuss. Indeed given the title I find it odd that you commented here at all. Or are you just on the troll?

      In regard to your notion of there being greater than 100% anthropogenic contributions to climate change I'll leave others to ponder your logical fallacies and odd mathematical constructs. As I am afraid I don't have the time nor the patience.

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    8. Mike Hansen

      Mr.

      In reply to Marc Hendrickx

      Troll? That would be the sad individual who refers to the Skeptical Science website as "SS" and links to an extremely bizarre conspiracy theory.

      As it happens, Mike's point about the anthropogenic contributions being > 100% is not difficult to understand. We know that volcanic eruptions, a natural event which release sunlight reflecting sulphate aerosols can produce a negative forcing. Reduced solar activity will also cool the planet. So adding negative forcings to the positive anthropogenic forcings can see an anthropogenic forcing > 100%.

      This article explains with reference to a number of peer reviewed papers.
      http://www.skepticalscience.com/a-comprehensive-review-of-the-causes-of-global-warming.html

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    9. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Mike Hansen

      Mike,
      I have not commented here in quite some time. It is quite sad to see the state and quality of the discussion has not moved at all in that time. Not one iota. The standard of pieces also a lot lower. The above a case in point.

      In regard to the now very aptly named SS. They use the term themselves. Indeed one of the images made up by SS shows John Cook in Nazi uniform with the title "Riechsfurher SS J Cook". Another shows SS co-author Dana Nuccitelli in various Nazi poses. It seems the shoe fits.

      SS removed the embarrassing images discovered on their website by others but they are preserved forever at Anthony Watts site: http://wattsupwiththat.com/2013/08/06/skeptcial-science-takes-creepy-to-a-whole-new-level/

      Perhaps Mr Cook can provide an explanation for these bizarre and embarrassing images. Odd that you appear to hold this group in such high regard.
      .

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    10. Felix MacNeill

      Environmental Manager

      In reply to Marc Hendrickx

      Marc, what on earth are you talking about?

      Your link is broken and you are spouting stuff that is impossible to understand, let alone verify.

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    11. Felix MacNeill

      Environmental Manager

      In reply to Marc Hendrickx

      Marc, I see you've reverted to tangential abuse at the first sign of disagreement.

      Why don't you try talking like a rational adult for a change rather than resorting to veiled insults?

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    12. Felix MacNeill

      Environmental Manager

      In reply to Marc Hendrickx

      Marc, the endless repetition of the phrase 'the Con's curators' is really getting distinctly paranoid.

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    13. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Felix MacNeill

      Felix,
      I appreciate that you don't get out much. Here's the link (below) I checked twice it works for me.

      Again I look forward to "Riechsfurher SS J Cook"'s explanation for this bizarre business. Perhaps the Curators here can facilitate it, afterall "Riechsfurher SS J Cook" does appear to be one of their favourites.

      http://wattsupwiththat.com/2013/08/06/skeptcial-science-takes-creepy-to-a-whole-new-level/

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    14. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Felix MacNeill

      The Con is short for "The Conversation" nothing sinister.

      "curators" is the term the editors here refer to themselves as. It's strange but not my term.

      as in "Curated by professional editors"

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    15. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Felix MacNeill

      You asked for evidence that SS lacked credibility. If the authors of that site masquerading in NAZI regalia doesn't raise questions then there is no hope for you Felix.

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    16. David Rennie

      IT Contractor

      In reply to Marc Hendrickx

      Marc,
      As these images you refer to come from a directory of images uploaded by readers of Skeptical Science how can you seriously claim that they have some relevance to the science discussed on the site. Any reader, whether a accepter or denier of AGW could have put them there.

      http://www.sksforum.org/images/user_uploaded/ according to WUWT

      Lets be honest, there's a very high degree of uncertainty as to whether the images were placed on the folder by deniers or accepters. But given it is the deniers that want to denigrate the information provided I'd say its 'very likely' they were placed there by your compatriots,

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    17. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to David Rennie

      Seems you are in denial David. Again Riechsfurher SS J Cook could provide an explanation. As to the so called "compatriots" these the figment of a conspiratorial mind.

      Amazing that the only comment relevant to the article remains my first. The con side tracked by the bizarre

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    18. Mike Swinbourne

      logged in via Facebook

      In reply to Marc Hendrickx

      ....In regard to your notion of there being greater than 100% anthropogenic contributions to climate change I'll leave others to ponder your logical fallacies and odd mathematical constructs. As I am afraid I don't have the time nor the patience.,,,"

      Nor the ability to do maths it seems

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    19. David Rennie

      IT Contractor

      In reply to Marc Hendrickx

      Marc,
      You get weirder and weirder.

      Deniers post a lot of rubbish on the web. Have you any evidence that the images you refer to are anything but the infantile productions of juveniles given that the WUWT directly refers to a folder of reader uploads.

      The IPCC constantly acknowledges the uncertainty in their assessments, deniers have no such qualms about their rejection of the evidence.

      The article refers to SS once and not Curry's dense opinion article on 'uncertainty'. So what!! Curry's point is obscure and badly argued but seems to but nothing more than "they are wrong because [she] disagrees with them" while acknowledging that AGW is indisputable. I suspect she has the same inability to assess a body of evidence that you display.

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    20. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to David Rennie

      David,
      It strikes me as rather odd that so called Riechsfurher SS J Cook has not provided an explanation for the bizarre images posted on his website. This all took place in early August. We can only speculate on their origin.
      Your comments on Curry's piece don't do you any credit.
      The level of bile directed at anyone who dissents from the alarmist's end of the world meme that is represented by commentary on this site is truly astonishing. It seems there will be no end to your two minutes of hate.

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    21. David Rennie

      IT Contractor

      In reply to Marc Hendrickx

      Marc,
      Oh Come on Marc, Bloggers don't have the time to respond to everything on their website.
      Did it actually appear on the Website or was it just a comment from a denier!!!
      The only reference you provide is via WUWT which isn't exactly a reliable source.

      Curry's article is dense and and her point is obscure, when everyone in the debate acknowledges a level of uncertainty. Statistically we can reduce obscurity by using meta data analysis which supports the views of the Climate scientists.

      Your continued reference to 'Riechsfurher SS J Cook' demonstrates your infantile presentation of the deniers case. You can only speculate about their origin but I'm pretty sure they didn't represent the opinions of the publishers of the site.

      Not content with attempting to portray the science as 'Communist' you now seek to present it as 'Nazi". What a wuss you are!

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    22. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to David Rennie

      Are you one of Riechsfurher SS J Cook's minions?

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    23. David Rennie

      IT Contractor

      In reply to Marc Hendrickx

      Marc,
      Can't give up your childish posturing can you. Why don't you make an intelligent comment worth responding to!!!

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    24. David Arthur

      resistance gnome

      In reply to Marc Hendrickx

      "It is sad to see The Con continue to publish articles from a very narrow range of perspectives rather than seeking broader academic input ..."

      1. "Narrow" perspective? Do you have a problem with the Con only publishing articles from within the "reality-based community"

      2. By "Broader academic input", are you asking more space be allocated to fantasy?

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    25. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to David Arthur

      David rather than post pointless bluster what specifically about Curry's article do you have issue with.
      Unlike the article above Curry's actually passed a meaningful review.

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    26. Mike Swinbourne

      logged in via Facebook

      In reply to David Rennie

      I fear that your call for Marc to make an intelligent comment is rather wasted.

      Once someone invokes Godwin's Rule as the basis for their argument, it is impossible to reason with them and they are best ignored.

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    27. David Arthur

      resistance gnome

      In reply to Marc Hendrickx

      Here's what's certain.

      Earth is warmed by absorption of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same amount of energy to space. That is, solar shortwave energy is balanced by the earth re-radiating to space as a 'black body' radiator with a characteristic temperature of ~255K; that is, from space the earth's spectrum is roughly that of a radiating body with an optical surface temperature of around 255K.

      Earth's surface cools by evaporation…

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    28. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Mike Brisco

      I see The Con's curators still practice an odd form of comment moderation. Mike's comment above that accuses me of having contacts with coal. I don't but so what if I did. My reply pointing out the hypocrisy of this reasoning is removed.

      Seems to be an on going problem with double standards being practiced at this site. I had hoped that there had been some improvement over the last 12 months but alas it just gets worse.

      Shame curators shame.

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    29. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Mike Swinbourne

      I can't help it that you chose to align yourself with a group of NAZI fetishists.

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    30. Mike Swinbourne

      logged in via Facebook

      In reply to Marc Hendrickx

      Hmmm Marc, so you are concerned that the Conversation is not properly adhering to the moderation policy are you?

      That loud noise you just heard was my irony meter exploding.

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  3. Henry Verberne

    Once in the fossil fuel industry but now free to speak up

    The deniers are certain that either there is no climate change "the climate is always changing", or "humans are not causing it", or "it won't be bad" or " it will wreck the economy/our way of life to anything about it" etc etc.

    Certainty is not science, it is ideology and/or vested interests trying to promote doubt as per the tobacco industry strategies.

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    1. Geoffrey Henley

      Research Associate

      In reply to Henry Verberne

      The oft dredged up link between those who question the theory of CAGW and those who promote doubt regarding the link between cancer and smoking is pure mythology and not supported by a shred of evidence.

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    2. Mike Hansen

      Mr.

      In reply to Geoffrey Henley

      That would be the theory of AGW.

      Probably the world's best known climate science denial organisation is the Heartland Institute. Almost every climate crank of note has spoken at their conferences or like Australian climate science denier Robert Carter, has taken money from them to promote climate science denial.

      This is from their current website.

      "The public health community's campaign to demonize smokers and all forms of tobacco is based on junk science"

      "The actual odds of a smoker…

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    3. David Rennie

      IT Contractor

      In reply to Geoffrey Henley

      In Merchants of Doubt. Naomi Oreskes identified that many of them were the same scientists. Hardly mythology.

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    4. Geoffrey Henley

      Research Associate

      In reply to Mike Hansen

      It is well known among the well-informed that wikipedia is completely biased in regarding the subject of climate so any links to wikipedia are without credibility.

      It is a complete falsehood that Fred Singer received money to downplay the health effects of SHS. Singer was critical of the methodology used in an EPA report regarding SHS and cancer. His assessment was independently verified.

      Warmies love to evoke the tired old tobacco smoking issue to discredit sceptics rather than science, such is their desperation.

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    5. Geoffrey Henley

      Research Associate

      In reply to David Rennie

      Is that the book that claims that any opposition to environmental regulation of greenhouse gases is based on anti-communism!

      Truly bizzare!

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    6. Mike Hansen

      Mr.

      In reply to Geoffrey Henley

      The problem Geoffrey is that you are so deep in denial that no amount of evidence is going to have any effect on you. I notice that you avoided Heartland's involvement in tobacco denial completely.

      As a result of the extensive billion dollar litigation against the tobacco industry in the USA which forced them to cough up (no pun intended) internal memos etc, the efforts by the tobacco companies, particularly Philip Morris, to set up various pseudo-science front groups to sow doubt and attempt to discredit the science has been revealed.

      Here is a document that demonstrates Singer's involvement.
      http://tobaccodocuments.org/landman/158433.html

      This is a scanned document.

      Please go ahead and claim it is a fake. :-))

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    7. Chris O'Neill

      Retired Way Before 70

      In reply to Geoffrey Henley

      "those who promote doubt regarding the link between cancer and smoking is pure mythology"

      Here's some more "pure mythology" for you:

      "In 1979, Fred Seitz was hired by the R. J. Reynolds Tobacco Company, makers of Camel cigarettes, to head their Medical Research Committee. In this position, Seitz was in charge of the campaign to smudge the facts regarding the harmful effects of tobacco. Seitz directed $6.3 million to researchers who consistently found no evidence conclusively linking tobacco to serious medical problems." http://en.wikipedia.org/wiki/Frederick_Seitz

      Sad, really sad.

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    8. David Rennie

      IT Contractor

      In reply to Geoffrey Henley

      Geoffrey
      No Geoffrey the book never makes a claim like that. It refers to anti-communism on pages 27, 36-38, 57, 164, 236, 238, and 251-253; but NEVER makes a claim like the one you are suggesting.
      Please provide references if you disagree.

      It does point out that certain scientists Frederick Seitz, Fred Singer, William Neirenburg and others involved in the pro smoking / pro fossil fuels lobby were virulently anti communist.

      And yes it does identify that the same small group of scientists supported the pro smoking, pro Chlorofluorocarbon , pro CO2 emissions policies.

      So even if they were right, which all the EVIDENCE says they weren't, they were still the same people.

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    9. David Rennie

      IT Contractor

      In reply to Geoffrey Henley

      Geoffrey,
      Well informed deniers claim that every thing on Wikipedia that undermines their case is a conspiracy against their beliefs.

      For everybody else Wikipedia is as reliable as any other encyclopedia.

      Wikipedia is as biased as the ABC, that's right it makes some attempt to present evidence based reporting not BS.

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    10. David Arthur

      resistance gnome

      In reply to Geoffrey Henley

      "... those who question the theory of CAGW and those who promote doubt regarding the link between cancer and smoking is pure mythology and not supported by a shred of evidence ..." Err, no.

      The activities of the George C Marshall Institute (http://www.marshall.org/, http://en.wikipedia.org/wiki/George_C._Marshall_Institute) are well-documented by Oreskes & Conway ("Merchants of Doubt" http://en.wikipedia.org/wiki/Merchants_of_Doubt).

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    11. David Arthur

      resistance gnome

      In reply to Geoffrey Henley

      Hey Henley, all you need to be a warmie is a basic understanding of some atmospheric physics.

      Matter of fact, if you have that basic understanding, you cannot avoid being a "warmie", as you would have it; if you yourself are not one of these "warmies", there is no doubt that you are non-cognisant of that basic understanding. To help you, start with this:

      Earth is warmed by absorption of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same…

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  4. Geoffrey Henley

    Research Associate

    One of the obvious facts that CAGW advocates continue to ignore is that the IPCC is principally a political organisation, rather than a scientific one. This was born out in Donna Laframboise's brilliant expose 'The Delinquent Teenager Who Was Mistaken for the World's Top Climate Expert'.

    This book showed evidence of inexperienced scientists being promoted to positions of lead authors years before getting their PhDs, strong links between several influential IPCC scientists and environmental activist organisations, the IPCC breaking its own rules to ensure certain papers got included and a whole host of other shenanigans.

    The IPCC is not what it purports to be. It was set up on the assumption that AGW was already a given rather than to objectively assess the state of climate science.

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    1. David Rennie

      IT Contractor

      In reply to Geoffrey Henley

      Geoffrey,
      This is definitely a denier meme.

      The IPCC was set up to assess the evidence, and many of the bureaucrats there are appointed to prevent anything detrimental to their governments' pro fossil fuel polices getting through unless its virtually irrefutable.

      The fact that the IPCC has repeatedly and more confidently stated that GW is caused by human activity is just a consequence of the increasing evidence that the statement is true.

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  5. David Arthur

    resistance gnome

    Thanks for this article.

    Perhaps uncertainty arises from probabilistic inferences, where a probability of 1 (ie certainty) doesn't ever arise.

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