Talk:Scientific opinion on climate change

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Lovejoy paper[edit]

In this pair of edits, a very recent single paper was added. It is an interesting work and worthy of mention somewhere, but I don't think any single recent paper should appear in the lead (see WP:RECENTISM). If these findings "stick" they will work their way into future large literature reviews from PNAS, RoyalSociety, etc.

Can anyone suggest a good alternative place for including this very recent paper? NewsAndEventsGuy (talk) 14:09, 17 April 2014 (UTC)

@NewsAndEventsGuy - FWIW - Thank You *very much* for your comments - and suggestions - regarding several recent and relevant (afaik atm) references =>

< ref name="MCG-20140411">Lovejoy, Shaun; Chipello, Chris (11 April 2014). "Is global warming just a giant natural fluctuation?". McGill University. Retrieved 17 April 2014. </ref>

< ref name="CD-201404">Lovejoy, S. (April 2014). "Scaling fluctuation analysis and statistical hypothesis testing of anthropogenic warming". Climate Dynamics. Retrieved 17 April 2014. </ref>

Not sure atm about a good place to insert the references in the Scientific opinion on climate change (or some related?) article(s) - perhaps a new section to accomodate such studies may be in order (or, at least, considered)? - in any case - Enjoy! :) Drbogdan (talk) 15:54, 17 April 2014 (UTC)
Besides WP:RECENTISM also beware of WP:LINKFARM NewsAndEventsGuy (talk) 17:21, 17 April 2014 (UTC)
The conclusion from the paper appears noteworthy, Even in the most unfavourable cases, we may reject the natural variability hypothesis at confidence levels >99 % prokaryotes (talk) 18:03, 17 April 2014 (UTC)
Part of the idea is that other professionals get a chance to digest and criticize. Ink has barely dried yet. If it proves to have "stick" then their conclusion will bubble up to color major lit reviews down the road. I note that Drbogdan did add it to Global warming controversy, in what I at least think is a more appropriate place, at least so far. NewsAndEventsGuy (talk) 23:28, 17 April 2014 (UTC)
Agree with NewsAndEventsGuy here, this article needs to be based on well established stuff rather than the latest idea that hasn't been pored over properly yet. Dmcq (talk) 23:35, 17 April 2014 (UTC)

the 97% consensus claim by SkS authors[edit]

This thread relates to this ref {{cite journal |author=Cook, J.; Nuccitelli, D.; Green, S.A.; Richardson, M.; Winkler, B.; Painting, R.; Way, R.; Jacobs, P.; Skuc, A. |title=Quantifying the consensus on anthropogenic global warming in the scientific literature |year=2013 |journal= Environ. Res. Lett. |volume=8 |issue=2 |pages=024024 |doi=10.1088/1748-9326/8/2/024024 |bibcode = 2013ERL.....8b4024C }} NewsAndEventsGuy (talk) 22:39, 1 May 2014 (UTC)

The reference 119 has been heavily criticized for its unorthodox methods of assessing "consensus". For instance here: Legates, D. R., Soon, W., & Briggs, W. M. (2013). Learning and teaching climate science: The perils of consensus knowledge using agnotology. Science & Education, 22, 2007–2017, [for which this is the journal's link] http://link.springer.com/article/10.1007%2Fs11191-013-9647-9 [and it contains this quote] "However, inspection of a claim by Cook et al. (Environ Res Lett 8:024024, 2013) of 97.1 % consensus, heavily relied upon by Bedford and Cook, shows just 0.3 % endorsement of the standard definition of consensus: that most warming since 1950 is anthropogenic."

Cook et al should therefore either be removed or at least be accompanied by the peer-reviewed criticism. (It is obvious when the underlying data are at hand, that the 97,1% claim is pure fiction. Which has been shown also elsewhere). http://www.bordermail.com.au/story/2234817/accepted-climate-quote-is-wrong/

/JPC Lindstrom (Note: this "talk" contribution is also a part of a science project where Wikipedia is tested for its neutrality in controversal discussion subjects. All activities connected to this contribution will be recorded. It does not mean, however, that the contribution is not sincere.)— Preceding unsigned comment added by 83.183.9.239 (talkcontribs) This user's comment has been slightly tweaked by me for clarity. My text changes are in square brackets.NewsAndEventsGuy (talk) 22:56, 1 May 2014 (UTC)

We had this same debate someplace else and i was trying to find that again. Anyone recall where that was? NewsAndEventsGuy (talk) 23:05, 1 May 2014 (UTC)
As far as I can see the paper does not give statistics on how many papers gave an opinion about the source of carbon dioxide so it does not address the question at all. The other link you gave was referring to the same study. So this is all irrelevant here. It is like saying you looked at 10000 papers about the English language and only 0.1% said that most words in the dictionary started with S. Dmcq (talk) 23:31, 1 May 2014 (UTC)
IP, I have read the entire Cook paper, which is online and open access. Have you?
  • Cook etal "97% of these things sound like ducks, walk like ducks, and swim and fly like ducks. Er go, 97% are ducks.
  • Legates etal It's all a LIE! Only .3% had a name tag reading "duck" around their necks!
NewsAndEventsGuy (talk) 23:49, 1 May 2014 (UTC)
While I would oppose removing the Cook survey, I would certainly support an accurate characterization of the results of that survey, and criticisms of the survey. Sadly, I doubt you'll reach consensus among the active editors here.
I encourage anyone interested in the subject to read the Cook survey for himself (http://iopscience.iop.org/1748-9326/8/2/024024/article), and draw his own conclusions. It's clear from the survey itself that only 62.7% of the subject authors endorse anthropogenic global warming (Table 4).
Even the 62.7% figure is dependent upon Cook, et al.'s skewed definition of "endorse." If I were to admit that spitting in the ocean adds to its volume, Cook's methodology would conclude that I endorse the view that human spit is causing the oceans to rise.
Naturally, intellectual honesty calls for noting the methodologies used by Cook, et al., that lead to their flawed conclusions, and to set forth the opposing view. Allow readers to draw their own conclusions.
Scientists have been trying to get away from the "quacks like a duck" approach since, well... the beginning of science. When you're trying to find ducks, everything quacks. John2510 (talk) 16:13, 12 May 2014 (UTC)
Your use of column 1, table 4 (instead of column 2 table 4) minimizes the strength of the consensus by including papers in which the subject was not an issue in any way shape or form. It's like asking chefs to self-rate 10,000 dessert recipes and drawing conclusions about the views of 33% of these chefs because only 67% of the recipes in the pile included ice cream. Making a dessert with jello tells us nothing about the chef's opinion whether (1) vanilla is better than chocolate ice cream, (2) chocolate is better than vanilla ice cream, or (3) both chocolate and vanilla ice cream are equally tasty. To say anything "intellectually honest" about chef's opinions on preferred ice cream based on their self-rating of individual recipes in a collective pile of recipes, one has to focus on those recipes that in one way or another actually refer to ice cream. THat's the number in column 2 table 4. NewsAndEventsGuy (talk) 17:03, 12 May 2014 (UTC)
As you know, we've been through this before, and I doubt we'll change each other's minds, but for the OP's sake... It's more like ten chefs write about the relative qualities of vanilla and chocolate ice cream. Only one expresses a preference, and it's for vanilla. Cook, et al. would conclude that 100% of chefs prefer vanilla. Actually, Cook, et al. would reach the same conclusion if one chef said he'd EATEN more vanilla than chocolate (because that must evidence a preference).
My old suggestion stands: describe the methodology (and/or include published criticisms) and trust the reader to reach his own conclusion. I haven't tested the waters lately, but I suspect that would not reach consensus among the active editors on this subject. John2510 (talk) 17:37, 12 May 2014 (UTC)
More like a hundred people wrote about how they like vanilla ice cream and a ten wrote how to make vanilla ice cream and nine out of those ten describe the same method. Except it is far more than nine out of ten. This wasn't a proper criticism, it was just sophistry. Dmcq (talk) 20:10, 12 May 2014 (UTC)

Peer reviewed paper: Cook et al mistaken, biased, invalid, etc.[edit]

"Quantifying the consensus on anthropogenic global warming in the literature: A re-analysis" by Richard S.J. Tol

Abstract: A claim has been that 97% of the scientific literature endorses anthropogenic climate change (Cook et al., 2013. Environ. Res. Lett. 8, 024024). This claim, frequently repeated in debates about climate policy, does not stand. A trend in composition is mistaken for a trend in endorsement. Reported results are inconsistent and biased. The sample is not representative and contains many irrelevant papers. Overall, data quality is low. Cook׳s validation test shows that the data are invalid. Data disclosure is incomplete so that key results cannot be reproduced or tested.

See: http://www.sciencedirect.com/science/article/pii/S0301421514002821

That study may be relevant to this discussion. —Blanchette (talk) 23:34, 4 June 2014 (UTC)

Topic also discussed here, though I don't recall and have not checked if the Tol paper was referenced.NewsAndEventsGuy (talk) 23:39, 4 June 2014 (UTC)
See also http://www.desmogblog.com/2014/05/30/richard-tol-s-attack-97-cent-climate-change-consensus-study-has-critical-errors We need to wait for the Tol thing actually to be published, as it will be debunked by Cook straight off, in the same issue apparently. --Nigelj (talk) 23:50, 4 June 2014 (UTC)

Geological Society of Australia has declared itself unable to publish a position statement on climate change[edit]

Per Earth scientists split on climate change statement at the Australian [paywalled]:

AUSTRALIA’S peak body of earth scientists has declared itself unable to publish a position statement on climate change due to the deep divisions within its membership on the issue.

There's a fuller quote and some backstory at JoNova

-- which would move them into the "Non-committal" category. No hurry on this, but an interesting trend. --Pete Tillman (talk) 04:46, 4 June 2014 (UTC)

Ha ha! That's funny. Calling one data point a 'trend' in this context. They weren't even in the article until recently added. --Nigelj (talk) 17:48, 4 June 2014 (UTC)
You will note that all 5 "Non-committal" scientific societies are geological. --Pete Tillman (talk) 05:37, 5 June 2014 (UTC)
A good illustration of Roosevelt's maxim “If you've got them by the balls, their hearts and minds will follow.” Dmcq (talk) 06:01, 5 June 2014 (UTC)

antropogenic contribution and data uncertainty[edit]

I agree for 'opinion' instead of 'consensus' on the title. However, in my opinion, the contents are too strongly single-minded.

I may admit that a number of organisations supports the opinion on 'global warming'. However, —the significant data are based on a limited period of time —the experimental temperature values are affected by a limited accuracy and a very limited traceability until very recently, generally not published —the computation of an average earth temperature is critically affected by the model used, and an evaluation of the resulting inaccuracy should be published and always indicated

Any extrapolation for any future time period should be accompanied by the indication of a band of uncertainty with its confidence level (or degree of bielief): it would probably show that an extrapolation cannot sensibly be provided at present.

The distinction between the estimated 'global warming' and the 'anthropogenic contribution' should be much more carefully stressed. The fact that the observed increase of +0.6 °C of global earth temperature is partially due to human activities is even less supported and arises to a larger extent from an inference. Other factors, like some components in the atmosphere, can better and directly correlated to human activities, temperature increase only indirectly. For example, from a computation I made using literature data, of the human contribution due to respiration to the atmospheric content of CO2, I found that it amounts to about 50% of the 2010 contribution due to fossil+cement+use of land. I was unable to find in the literature (possibly my fault) this datum, which would show that the increase of population (together with other human-induced non-energetic sources, like the increase of animals-for-food) is not a minor contribution to the increase of CO2 production.

In all instances, for the anthropogenic influence I consider a confidence level of 95% by far to low for pretending the urgency in action that the article implies. In some important fields of physics things start becoming considered when they reach a confidence level of 6-sigma.

I would like to see the article modified in a more neutral sense, according to Wikipedia policy -and its reputation.

Franco Pavese (Dr., Principal Scientist in Thermal Metrology, Torino, Italy) 2.36.58.176 (talk) 17:15, 4 June 2014 (UTC)

As it now reads, this is a rambling discussion and overly generalized critique. In other words, it sounds like a WP:FORUM type post. You said, "I would like to see the article modified in a more neutral sense, according to Wikipedia policy..." Please specify in detail one change you would like to see and since one of our core policies is WP:VERIFIABILITY, on what reliable sources are you relying for the suggestion? NewsAndEventsGuy (talk) 17:37, 4 June 2014 (UTC)
Right. As an aside, if the human population is growing, it is necessarily binding carbon dioxide (by converting it to body mass). Biological systems in equilibrium are carbon neutral - the CO2 humans exhale is made from carbon that was previously extracted from the atmosphere via photosynthesis and made it into food. --Stephan Schulz (talk) 20:13, 4 June 2014 (UTC)

As a scientist for many years, I perfectly understand the issue of verifiability. However, if it means that one has necessarily to cite the article of somebody else as the Bible (reliable sources) on the subject to become credible, I do not necessarily agree. Also references can be carefully screened. As a scientist in thermal metrology at international level, though not specifically in climate, I think I can say something credible of myself from my expertise and experience in energy-balance computations. I think I already did in my previous post, at least on some points. 1) For a community asking a giant change in the world economy based on data taken with reasonable accuracy over a very short period of time, a 95% confidence level for boldly assessing an anthropogenic effect is to be considered definitely insufficient, and certainly not credible on extrapolation. I am asking for a higher future confidence level and in the meantime that, as, e.g., IPCC does, a complete picture of the extrapolation scenarios be provided; 2) Temperature (my most specific field of expertise) is probably the worst possible indicator, as to definitional and instrumental difficulties. I am asking specifically that the uncertainty and traceability of the data (something different from the dispersion of the data collected over the years) is made explicit, as a normal best practice in measurement; 3) Possibly by chance, possibly not, the trend toward an increase of several 'adverse' parameters looks matching quite well a similar trend (trivially easy to find in the literature) in the human population increase. I am not sure how much one can still rely on the mantra of benign nature "Biological systems in equilibrium are carbon neutral". The key word here is "in equilibrium", so the statement is actually a tautology. When does the population increase (with its consequences on food and other primary and less primanry needs) go out of equilibrium? I think it is a relevant question. Franco Pavese 2.36.58.176 (talk) 19:12, 12 June 2014 (UTC)

General discussions of the topic, like this thread, are what we call a WP:FORUM. Such threads are deletable or collapsible as being off-topic. Please search thru the talk page guidelines for each instance of the word "forum". If you want to specify some specific change to the text, you could then explain the logic and tells us on what sources (that wikipedia rules consider "reliable") you are relying? Second request. Please see WP:DISRUPT which says one shouldn't ignore imple reasonable questions. NewsAndEventsGuy (talk) 21:19, 12 June 2014 (UTC)
To quote your previous post: "For example, from a computation I made using literature data, of the human contribution due to respiration to the atmospheric content of CO2..." (emphasis mien). That a growing population has indirect effects on the environment is a trivial truism. You also seem to be engaged in a bit of inverse appeal to consequences. The science is what it is. If you want 6 sigma for political decisions, that's plainly weird (would you step onto a street without looking? Chance of being hurt is less than 50% in most situations), but in no way influences the results we get out of the scientific process. --Stephan Schulz (talk) 21:25, 12 June 2014 (UTC)

About verifiability, the importance of data uncertainty in scientific inference on global warming can be found in the activities of a specific European Project going on since 2011, METEOMET (http://www.meteomet.org), where, for example, one can appreciate a comparison between IPCC IV FAQ 3.1, Figure 1 and the actual error bars (still +- 0.3 K in the 1970’s, while IPCC cited figure indicates +- 0.1 K), and the influence of uncertainty on the reliability of extrapolations. The article does not report in its first figure any uncertainty band: I suggest that is added. A small increase of global temperature over the past 50 years can be real, but I maintain my point that a confidence level of 95% is insufficient also from a scientific point of view to presently allow any reasonable extrapolation to future decades. Therefore, according to the rule “Wikipedia is not a crystal ball” (“Articles that present original research in the form of extrapolation, speculation, and ‘future history’ are inappropriate”) this article should drop all extrapolations, or provide a full range of predictions in the relevant section or move it to the article “Global warming controversy”, and be less dogmatic in its first 6 lines. I suggest a statement simple to read be added about the size of the total sample which forms the scientific bases assumed for the 95% evaluation of the scientists sharply convinced of the human-induced reason for the global warming: I consider the figure in section “Surveys of scientists and scientific literature” insufficient. Concerning the factors influencing the increase, I notice a change of argument in Stephan Schulz replies: now he admits a contribution of the human population and calls it trivial. Certainly this was not only my opinion and if Wiki asks for references, I will find them with no difficulties. The point that I think relevant to this article is the total amount of carbon dioxide emissions from human-bodies compared with other types of human-induced emissions more commonly considered, like from burning fossils, for which I did not find consistent figures. In the article, the origin of the ‘greenhouse gases’ is not indicated, and I suggest be separated in components. The strong correlation between the growth of the human population and of the greenhouse gases can be not by chance. This point was not appreciated in the site http://www.skepticalscience.com: it is not clear why the carbon dioxide emitted by humans should be differently treated from that emitted by other ‘natural’ sources. Considering that for sure the earth resources are finite, this is important because it would be much simpler to reduce the world population increase than promoting a “happy decrease” in economy and life style. Both solutions equally allow alleviating the carbon-cycle unbalance. This point is not discussed in the article, and I suggest that it should be. Finally, why the separation of the article “Scientific opinion on climate change” and the article “Global warming controversy”? It strongly induces in the readers the idea that scientifically it is proved, but politically or in general-public opinion is less accepted. This issue is also prompted to me by last Stephan's reply "but in no way influences the results we get out of the scientific process": 'certain results' ? Also scientifically is only a hypothesis, presently supported by more scientists than the opposite opinion. Franco Pavese2.36.124.167 (talk) 16:43, 14 June 2014 (UTC)

This comment reads like nonsense with no actionable components. Example quote "Both solutions equally allow alleviating the carbon-cycle unbalance." NewsAndEventsGuy (talk) 17:05, 14 June 2014 (UTC)
That all comes under WP:original research unless you can find references saying what your trying to say. Dmcq (talk) 23:05, 14 June 2014 (UTC)

Do some "Non-committal" organisations actually disagree?[edit]

The last paragraph of the introduction was blatantly false and inconsistent with later sections:

No scientific body of national or international standing maintains a formal opinion dissenting from any of these main points; the last was the American Association of Petroleum Geologists, which in 2007 updated its 1999 statement rejecting the likelihood of human influence on recent climate with its current non-committal position. Some other organizations, primarily those focusing on geology, also hold non-committal positions.

The cited 2007 statement from AAPG says "current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data." It also says "the AAPG membership is divided on the degree of influence that anthropogenic CO2 has on recent and potential global temperature increases" (which is quoted futher down in the article). This is in clear disagreement with every point of the IPCC Fourth Assessment summary.

This article is worthless if it doesn't fairly represent what opposing organisations actually say, even when they're totally wrong. I've changed the paragraph to:

No scientific body of national or international standing opposes reducing fossil fuel emissions or researching climate change, however some generally disagree with the findings, holding that the data is still unclear on whether human contributions to climate change are significant, and pointing to many periods in the past 10,000 years where the planet has been far warmer.

The "Dissenting" section was similar and in disagreement with the article it linked to - I removed this sentence:

As of 2007, when the American Association of Petroleum Geologists released a revised statement, no scientific body of national or international standing rejected the findings of human-induced effects on climate change.

Please don't revert this without discussion. ··gracefool 11:45, 15 June 2014 (UTC)

Note the subjunctive mood. This is what makes the statement non-committal as opposed to opposed (pun noticed, but not intended). --Stephan Schulz (talk) 11:54, 15 June 2014 (UTC)
How does subjunctive mood override what they actually say? Their statement clearly disagrees with every point. ··gracefool 11:57, 15 June 2014 (UTC)
I haven't actually counted, but I suspect the glossary alone for IPCC WG1 AR4 (2007) contains more vocabulary words than the entire statement from the AAPG. Thus, your claim that AAPG statement "clearly disagrees with every point" isn't exactly persuasive. NewsAndEventsGuy (talk) 12:09, 15 June 2014 (UTC)

e/c

Holding in abeyance my other comments - and I do have them - your edit is objectionable because you provided no RSs to support your assertion that "no scientific body of national or international standing opposes reducing fossil fuel emissions or researching climate change". So we don't really need to process this any further until an RS for that claim is provided. As a minor sidebard, your edit also changed a "see also" template to a "main" template. The section was discussing opposing organizations. The see also points to a list of individuals, which you changed to "main" as though a list of individuals is a "main article" discussing organizations. NewsAndEventsGuy (talk) 12:00, 15 June 2014 (UTC)
This all started with me adding a {{fact}} to the existing statement "No scientific body of national or international standing maintains a formal opinion dissenting from any of these main points" - however the AAPG is clearly such a dissenting formal opinion. My statement is *weaker* than the existing one - and the existing one is contradicted even within the article. I don't need a new RS because existing ones support my change. ··gracefool 12:06, 15 June 2014 (UTC)
Fair point re the plurality of the "see also" link; but the fact remains that the only sentence in that section is completely misrepresentative. ··gracefool 12:10, 15 June 2014 (UTC)
Please prove this statement "I don't need a new RS because existing ones support my change." with respect to your revised text "No scientific body of national or international standing opposes reducing fossil fuel emissions... by specifying which precise RS(s) you think support that statement? Claims are easy to make, but show me the evidence, please. NewsAndEventsGuy (talk) 12:15, 15 June 2014 (UTC)
Because my statement is weaker than the existing one, which supposedly doesn't need an RS either. I agree that I need a source; I'm just pointing out that my change is better than what we currently have. ··gracefool 12:26, 15 June 2014 (UTC)
As usual with cherry-picked quotes, Gracefool left out half of the quoted sentence. It begins, "AAPG respects these scientific opinions but wants to add that..." In other words, the AAPG 'respects' the mainstream opinion (i.e. does not actively disagree with it, or dispute it), but says there could be more to it. That is the very essence of a non-committal statement, to me. Their position is made even clearer in their first paragraph: "the AAPG membership is divided on the degree of influence that anthropogenic CO
2
has". Non-committal. Divided. Wanting to add something in the subjuctive (a wish, emotion, possibility, judgement, opinion, necessity, or action that has not yet occurred).[2] --Nigelj (talk) 12:32, 15 June 2014 (UTC)
Respecting an opinion doesn't mean you don't disagree with it. Why else do they bother to say anything at all beyond respect? I agree AAPG is non-committal regarding human influence (I was wrong to go so far as to say "their statement clearly disagrees with every point"). Looking at their full statement, they certainly disagree with the other three parts of the report: "warming of the climate system is unequivocal", "net effects are more likely to be strongly negative with larger or more rapid warming" and "the resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change..." ··gracefool 12:38, 15 June 2014 (UTC)
I'm sorry, but I find nothing to that effect in the statement. They simply don't talk about ecosystems or net effects. --Stephan Schulz (talk) 12:45, 15 June 2014 (UTC)
  1. Warming of the climate system is unequivocal. AAPG: "In recent decades global temperatures have risen. Certain climate simulation models predict that the warming trend will continue, as reported through National Academy of Sciences, American Geophysical Union, American Academy for the Advancement of Science, and American Meteorological Society."
  2. Most of the global warming since the mid-20th century is very likely due to human activities. AAPG: "the AAPG membership is divided on the degree of influence that anthropogenic CO
    2
    has on recent and potential global temperature increase"
  3. Net effects are more likely to be strongly negative with larger or more rapid warming. AAPG: no comment
  4. The net damage costs of climate change are likely to be significant and to increase over time. AAPG: "However, emission reduction has an economic cost, which must be compared to the potential environmental gain"
  5. The resilience of many ecosystems is likely to be exceeded this century. AAPG: no comment
So, to my eye we have (1) Agree, (2) Divided, (3) No comment, (4) A platitude, (5) No comment. They seem to be closer to agreeing than disagreeing. However, 'non-committal' is probably the best overall summary. --Nigelj (talk) 13:56, 15 June 2014 (UTC)
Agree non-committal is an accurate description. There is no clear disagreement unless the organisation says it disagrees with the IPCC or some of its major points. As the OP says their members disagree with each other and they haven't an agreed position. Overall they haven't a position. Dmcq (talk) 14:08, 15 June 2014 (UTC)

Are you kidding me with that first point? And I'm accused of cherry-picking?

  1. Warming of the climate system is unequivocal. AAPG: "In recent decades global temperatures have risen. However, our planet has been far warmer and cooler today than many times in the geologic past, even within the past 10,000 years... Certain climate simulation models predict that the warming trend will continue... AAPG respects these scientific opinions but wants to add that the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data." Disagree - it's not unequivocal (unless any temporary temperature increase is global warming)
  2. Most of the global warming since the mid-20th century is very likely due to human activities. AAPG: "the AAPG membership is divided on the degree of influence that anthropogenic CO
    2
    has on recent and potential global temperature increase... AAPG supports research to narrow probability ranges on the effect of anthropogenic CO2 on global climate" Equivocal & Divided - we need more data
  3. Net effects are more likely to be strongly negative with larger or more rapid warming. AAPG: again, "the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data." Disagree - we do not believe existing data is sufficient to know that
  4. The net damage costs of climate change are likely to be significant and to increase over time. AAPG again, "the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data." Disagree - we do not believe existing data is sufficient to know that
  5. The resilience of many ecosystems is likely to be exceeded this century. AAPG: again, "the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data." Disagree - we do not believe existing data is sufficient to know that (unless natural variations are considered a danger to ecosystems)

That's 4/5 disagree for AAPG. Similarly AIPG in their 2009 and 2010 statements emphasize uncertainty, and clearly disagree with #2, saying the data does not clearly show that human activities have had a large impact. Thus the statement "No scientific body of national or international standing maintains a formal opinion dissenting from any of these main points" is false. ··gracefool 08:46, 16 June 2014 (UTC)

I'm sorry, but you lost me with your claim that "In recent decades global temperatures have risen" somehow disagrees with "Warming of the climate system is unequivocal". --Stephan Schulz (talk) 10:28, 16 June 2014 (UTC)
The AAPG is quite correct in saying the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data. They are geologists and they have data about quite extreme variations. They are equivocal on the main point that the IPCC says - that humans are probably causing another such extreme event. Just because such an event is within geological variation does not mean it will not cause grave disruption. They have simply written a document to try and keep their members quiet by them being all able to read into it what they wish and not being technically wrong. It is simply equivocal and does not assert a position. Dmcq (talk) 11:00, 16 June 2014 (UTC)
Another problem is that you appear to be guessing how AAPG is using the technical term "natural variation". NewsAndEventsGuy (talk) 11:34, 16 June 2014 (UTC)