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tcflood at 07:45 AM on 29 May 2013Uncertainty no excuse for procrastinating on climate change
In order to better understand this paper, I need to ask a couple of low-level questions.
How does a “simple” climate model give uncertainties that are more meaningful than a more complex model?
They say that a certain amount of uncertainty comes from climate sensitivity. I thought CS came from the calculation rather than being an input parameter?
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Brandon Shollenberger at 07:22 AM on 29 May 2013The 5 characteristics of global warming consensus denial
This post says:
This technique of unrealistic expectations was illustrated in another blog post claiming that only papers which quantify the human contribution to global warming count as part of the consensus.
Referring to a post which quotes arguments I have made. As I am a target of this criticism, I feel I am obliged to respond. My response is twofold. 1) Where in that post, or anywhere else, is it claimed "only papers which quantify the human contribution to global warming count as part of the consensus"? As far as I can tell, that post never defines the consensus. It merely (and accurately) says:
When stripped down to the bare truth, the actual number of studies in the Cook sampling that can be said to endorse the position that human activity is responsible for most of the experienced global warming is — get ready for this (drum roll …) — sixty-five.
That doesn't say only 65 endorse the "consensus." It says only 65 endorse a particular position. That particular position may or may not be the "consensus."
2) There is no clear, much less explicit, definition of "consensus" in the Cook et al paper. None was provided on Skeptical Science either. Obama's tweet about this paper, which Skeptical Science has used for publicity, describes the consensus found by this paper as something it could not possibly be. It's cheeky to criticize people for using a different criterion for the "consensus" when you never bothered to provide one of your own.
Unless or until a clear definition for the "consensus" is provided, it is silly to criticize people for using a different one.
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Dikran Marsupial at 05:48 AM on 29 May 2013Uncertainty no excuse for procrastinating on climate change
William Haas The IPCC already did pretty much that, for example the
20c3m experiments are forced with historical green house gas forcing as well as the time varying ozone, sulfate, volcanic aerosols, and solar output for the 1900-2000 period. This analysis uses 20th century experiments from 10 models. The B1, A1B and A2 experiments are forced with a predicted green house gas forcing scenario for the 2000-2100 period. (www)
so we have the 1900-2000 period to judge the model's performance. IMHO it is hubris to think that the worlds leading climate modellers didn't think to do this, and hubris2 not to bother checking first before posting.
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DSL at 05:36 AM on 29 May 2013Uncertainty no excuse for procrastinating on climate change
William, is Jones et al. 2013 not good enough?
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william5331 at 05:34 AM on 29 May 2013Uncertainty no excuse for procrastinating on climate change
Maybe we should forget climate change. (I'm kidding)
http://mtkass.blogspot.co.nz/2010/10/forget-climate-change.html
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William Haas at 05:33 AM on 29 May 2013Uncertainty no excuse for procrastinating on climate change
If the models are wrong the subsequent analysis will be of no value. I would like to have seen them use a starting date for their simulation of 1850 so we can compare what actually happened with what their simulation says should have happened. The real world should be a combination of greenhouse gas causes and other causes. If the simulation cannot accurately predict what has actually happened between 1850 and now then its predictions for beyond now are of no value.
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shoyemore at 05:29 AM on 29 May 2013The 5 characteristics of global warming consensus denial
Congratulations to John and his team, again.
I think future historians (let's hope the are some around long term :)) will highly value this contribution to "the science of doing science", or "the science of science interfaced with politics" in the early 21st century. Meta-science?
It's immediate practical contribution is to de-bunk the fake-sceptic argument (made now mostly by politicians like Mitt Romney) "We can't do anything until the scientists make up their mind".
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JasonB at 02:34 AM on 29 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
MA Rodger,
I don't think Lindzen and Spencer disagree that "a doubling of atmospheric CO2 levels would (by itself without feedbacks) cause a little over 1 C of warming". Spencer has even posted articles trying to "educate" the less-informed "skeptics" on the reality of the greenhouse effect. As CBDunkerson said, they rely on "undefined negative feedbacks" to support their beliefs in a low CS.
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DSL at 00:02 AM on 29 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
What gets me about this whole rigmarole is that in publication, almost no one actually questions the attribution studies that have been done. There aren't actually a large number of people working on this question. As CBD points out on another thread, "Actually, I am not aware of any 'legitimate scientists' who disagree that a doubling of atmospheric CO2 levels would (by itself without feedbacks) cause a little over 1 C of warming." Solar studies are virtually uniform in their pointing out that solar variation is either an insignificant and/or negative forcing for the trend of the last fifty years. Those two pieces of evidence alone should be enough to convince any scientist working in or near climate that anthro is the primary forcing behind the trend of the last fifty years.
The range of responses to the Cook study is telling. The un-engaged mainstream either accept it or don't, without investigation. Few of those aware of the attribution research quibble with the presentation of the study, because they know the above: the dominance of the human factor is pretty obvious. Now, who are these people who quibble? Why do they quibble? For some, it's obviously the same reason they quibble over Mann's "hockey stick" and the Marcott reconstruction. The message is simple and rhetorically powerful in the public domain, and undermining that message is job no. 1 (literally for some--Watts, Singer, Monckton, et al.). For others, I don't know . . . follow the leader, I guess. It's rather obvious, though, that if this level of scrutiny were applied to Soon & Baliunas (2003), Scafetta's work, or Chilingar et al., then there'd be fewer in the ranks of doubters and many more angry at the publication standards of petro journals (e.g. Energy & Environment). -
MA Rodger at 23:52 PM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
CBDunkerson @107.
You appear to be setting far higher standards for a "legitimate scientists" label than I would accept. Consider a scientist like say Lindzen who genuinely believes in his unorthodox scientific position despite the overwhelming evidence supporting the orthodox position. He will not balk at challenging that evidence, would not think twice at throwing light into dark corners that other scientists who accepts the veracity of the available evidence would never dream to disturb. While those dark corners continue to exist, the likes of Lindzen continue to do science a service, of sorts.
For instance, take Spencer & Bradwell 2008. Is this not legitimate science produced by a contrarian?The problem with the likes of Lindzen & Spencer is not the science. It is their behavour ouside the science that is unacceptable, things like Lindzen's presentations to non-scientific audiences in which he makes assertions he would never get away with within the science. The same goes with Spencer's book.
This extra-scientific comment from contrarians is part of the fuel for opinions like that presented by matzdj @102. 100% of the evidence supports AGW? "That can't be," writes matzdj.
Well surely, if AGW is the correct theory, bar the science misinterpreting evidence (available evidence won't always and unfailingly point in exactly the correct direction), I say, "It can be. Indeed, it must be!" -
CBDunkerson at 21:08 PM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
matzdj wrote: "Both sides do have legitimate scientists on them (more on the CO2-is-the-ogre side), but there is no legitimate way that every statement that either side makes can be wrong."
Actually, I am not aware of any "legitimate scientists" who disagree that a doubling of atmospheric CO2 levels would (by itself without feedbacks) cause a little over 1 C of warming. The evidence on that became overwhelming decades ago. Rather, the handful of 'skeptics' claim that undefined negative feedback effects will reduce this warming (and the known positive feedbacks) and that the observations of warming in line with rising CO2 over the past century must therefor have been caused by some other undefined factor. That's getting sufficiently implausible to start straining the "legitimate" scientist label on its own, but that is the extent of current disagreement. No one disputes the CO2 greenhouse effect except non-scientists whose views have no foundation in reality... and which therefor can indeed 'always be wrong'.
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JasonB at 20:23 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
barry,
Jason, can you define, precisely, the consensus position you rated under? If there are caveats regarding the 7 ratings, can you also indicate? I want to understand what you did.
I'll do you one better, I'll show you the abstracts I rated as 3 in addition to the one shown above.
1. http://www.sciencedirect.com/science/article/pii/S1359431106001980
I rated this as "3. Implicit endorsement" because the first sentence is "Climate change induced by global warming is a result of an excess of energy at the earth’s surface due to the greenhouse effect." My reasoning was that the author was unequivocal about the fact that global warming is due to the greenhouse effect, and since man is responsible for the enhancement of the greenhouse effect, I decided that it implicitly endorses man's responsibility.
Cook et al rated this as "4. Neutral".
2. http://onlinelibrary.wiley.com/doi/10.1002/asmb.530/abstract
I found this one to be tricky but ended up rating it as "3. Implicit endorsement" because the way the paper discusses "‘clean up’ (e.g. reforestation)" and "irreversible emissions" suggested to me that they were taking for granted man's effect with no indication that they thought anything else might be involved.
Cook et al rated this as "2. Explicit endorsement".
3. http://www.inderscience.com/info/inarticle.php?artid=4830
I rated this as "3. Implicit endorsement" because the paper talks about the economics of different greenhouse gas emissions abatement rates in the context of interactions between global climate change and the world economy, implying (to me) that they take for granted the relationship between emissions and climate change (discussing abatement rates would be pointless otherwise) with no indication that they thought anything else might be involved.
Cook et al rated this as "4. Neutral".
In each case, I felt that the authors were making a link between AGHGs and global warming and none of them indicated there was any other factor involved at all, so your four categories of ">50%", "dominant", "significant", or "some" don't apply at all — there is no clue in any of those abstracts that anything other than man is causing global warming.
Can you help me understand this? If a paper was rated as neutral, it was not included in the tally. Is that how this supposition is figured?
1,342 papers were rated by their authors as endorsing the consensus, while 39 were rated by their authors as rejecting the consensus. Hence the rate of endorsement was 1,342/(1,342 + 39) = 97.2%. If half of the "endorsement" papers were mistakenly rated as endorsing the consensus when they should have been neutral, the rate of endorsement would have been 671/(671 + 39) = 94.5%. (We are assuming here that no author is going to mistakenly rate their paper as endorsing the consensus when it actually rejects it, which seems to be reasonable given the motivation to draw attention to a "contrarian" paper that's passed peer review and the availability of levels 5, 6, and 7.)
Any case, that is not the argument I'm making. I need to know, definitively, the consensus position Cook et al were rating under. Is it this?
The consensus position Cook et al were rating under was very clearly spelled out in the paper: "that human activity is very likely causing most of the current GW (anthropogenic global warming, or AGW)"
Given they rated two papers as neutral that I thought were pretty clearly implicitly endorsing that very statement, it seems they used a very strict interpretation of it.
Because if the original Authors rated under the lower bar (any anthro influence) for 2 and 3, then the comparative results are not as robust as indicated.
That's a big "if", and one for which you are yet to provide any evidence whatsoever.
Why would authors rate under a lower bar? Why would they rate their own paper as "endorsing" if, in fact, it assumed or stated a minor human influence, when levels 5 and 6 were available for them to categorise their own paper? After all, the authors were working with their entire paper plus their own knowledge of what they actually meant by what they wrote, so if in their view their paper said nothing to imply something other than humans was the main cause in their entire paper, how can you argue that their paper is "actually" not endorsing the consensus?
Regarding Cook et al's ratings, if you feel that mistakes were made, feel free to check them yourself. They're completely open. There's no point discussing "potentialities" when you can actually check the reality. If you're just going to check a random subset, remember to count how many you check so we can assess the significance of your findings.
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barry1487 at 16:56 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Jason, can you define, precisely, the consensus position you rated under? If there are caveats regarding the 7 ratings, can you also indicate? I want to understand what you did.
I upthread asked for peopel to precisely define what they think is meant by 'consensus position' in Cook13, relative to rating options 2 and 3. I was interested to see if their was conformity or not.
a) >50% human influence
b) dominant human influence
c) significant human influence
d) some human influence
These are four ways that I can think of to legitimately interpret the consensus position for ratings options 2 and 3. When I did the public survey, I applied criterion d) (I missspoke earlier upthread). I am unsure as to what degree Cook et al would have applied to ratings 2 and 3.
As Tom mentioned before, in order for the original authors' level of endorsement to drop to 94.5% — a figure I would still consider overwhelming — you would need to believe that half of the original authors mistakenly assessed their papers as endorsing the consensus when they should have been rated as neutral.
Can you help me understand this? If a paper was rated as neutral, it was not included in the tally. Is that how this supposition is figured? Any case, that is not the argument I'm making. I need to know, definitively, the consensus position Cook et al were rating under. Is it this?We examined a large sample of the scientific literature on global CC, published over a 21 year period, in order to determine the level of scientific consensus that human activity is very likely causing most of the current GW (anthropogenic global warming, or AGW).
Because if the original Authors rated under the lower bar (any anthro influence) for 2 and 3, then the comparative results are not as robust as indicated.To put it simply, and assuming;
1) Cook et al rate with the consensus of >50% anthro as the standard for all ratings bar neutral. They get 97% endorsement.
2) Original Authors rate 1) same as Cook et al, but rate 2) and 3) as endorsing any amount of human influence of global warming. 97% endorsement, also.
You don't see a problem with this potentiality?
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JasonB at 15:56 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
barry,
Out of interest I compared the ratings I gave to the ten papers in the original exercise with the ratings that Cook et al gave.
The paper that I rated as a 1, Cook et al also rated as a 1.
The five papers that I rated as a 4, Cook et al also rated as a 4.
That leaves four papers, all four of which I rated as 3's. Of those four, Cook et al rated one a 2, one a 3, and two as 4. So of the five that I rated as endorsing the consensus, Cook et al only counted three as endorsing the consensus, applying a much stricter test than I did for the most part.
The original authors, on the other hand, had a higher endorsement rate than I did — my average was 3.3, the original authors' average was 2.8. However, knowing that the original authors were assessing the entire paper explains why so many of the 4's were recategorised, such as this one that I (and Cook et al) rated as a 4 based on the abstract, but who's very first sentence in the introduction of the actual paper was:
The anticipated increases in greenhouse gases, especially carbon dioxide, in the atmosphere are predicted to raise temperatures by about 2.1 to 5.0 C globally within the next 100 years (Wigley and Raper, 1992; IPCC, 2001).
Note that the 16% disagreement was over all seven levels of endorsement category. In my case, the paper I rated as 3 that Cook et al rated as 2 would be counted as a "disagreement", even though it would have no impact on the final endorsement vs rejection percentage. I suspect that when lumping the 1+2+3 and 5+6+7 categories together the level of disagreement would have been much lower. And the two that I rated as 3 that Cook et al rated as 4 would actually lower the final endorsement percentage.
I'm not especially concerned that they had to revisit and discuss the interpretations of the criteria as real-world examples were encountered so they could reach a consensus on how the criteria should be applied; I've encountered exactly the same issue when marking exams with written answers. I'm also not concerned that the original authors may have individually been applying a slightly different interpretation, for the same reason that nobody seeks to rigorously define exactly what "beyond reasonable doubt" means to jury members. When you get large numbers of people responding, unusual interpretations tend to cancel out.
All these factors mean is that there is an error margin when it comes to the precise level of endorsement in the literature but nobody should be getting hung up on the precise percentage. The fact is that the results are overwhelming. As Tom mentioned before, in order for the original authors' level of endorsement to drop to 94.5% — a figure I would still consider overwhelming — you would need to believe that half of the original authors mistakenly assessed their papers as endorsing the consensus when they should have been rated as neutral. Now, some may have made a mistake, but to assume that half did beggars belief, and even if they did it still wouldn't change the take-home message.
I have seen statements here and there to the effect that such-and-such is the final nail in the coffin of "CAGW" and that there is a growing opposition within the scientific community to the IPCC's statements or that a "silent majority" of scientists are sick of IPCC alarmism and are gradually coming out of the woodwork to speak out against the "corruption" of science, but there is absolutely no evidence of this, and Cook et al actually shows the endorsement growing with time. If that belief was reflected in reality then we wouldn't need to be arguing over whether "humans are causing global warming" means something different to "global warming is caused by humans", there would be a lot more papers unambiguously rejecting the consensus. No matter which way you cut it, that category is tiny, and that's before we even get into the nitty-gritty detail about the actual quality of those papers.
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gpwayne at 15:38 PM on 28 May 20132013 SkS Weekly Digest #21
Message to John Hartz: great work, but you really need to run your posts through a spell checker - examine the first paragraph please...
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barry1487 at 15:05 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
To elaborate on the argument of 'overlap' in the ratings - there may be no overlap in the mind of each rater, as each interprets the set differently, but the total results may include plenty of overlap because of each rater interpeting differently. I note that there was a considrable amount of disagreement on rated abstracts for Cook et al, who then got to discuss and amend their ratings according to clarified criteria.
Initially, 27% of category ratings and 33% of endorsement ratings disagreed. Raters were then allowed to compare and justify or update their rating through the web system, while maintaining anonymity. Following this, 11% of category ratings and 16% of endorsement ratings disagreed; these were then resolved by a third party.
Isn't this strongly suggestive of problems with definitions? One third of endorsement ratings disagreed, and Cook et al had been discussing the criteria during the first phase of rating. Even after the second phase there was still 16% disagreement. There was no such process of clarification for the self-rating Authors. Are these not fair grounds to wonder if the comparative results are not as robust as indicated?
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JasonB at 14:50 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
s_gordon_b,
Your entire argument that the abstract of the paper is an example of the spin you're referring to is based on the claim that "the consensus" referred to in the abstract is not the IPCC statement (stated explicity in the introduction) but rather a vague claim that humans are merely a signficant cause of global warming, and your entire evidence for that is the simple fact that categories 2 and 3 are rated as supporting the consensus.
In other words, you believe that categories 2 and 3 cannot be interpreted as endorsing the IPCC's statement of consensus and the only way to claim that they do is by watering down "the consensus" that is being referred to.
This belief of yours, however, has not been demonstrated at all. Where are the examples of papers that cannot be claimed to endorse the IPCC's consensus that were nevertheless rated by Cook et al as category 2 or 3 papers? The descriptions of each category cannot be read in isolation, independently of the other categories that were available, and they cannot be read without examining how they were actually applied.
You seem to believe that categories 2 and 3 were "catch-all" default categories that anything that remotely appeared to endorse the consensus was lumped in to. This is not the case. As a concrete example, here is one of the papers that I rated as a 3 (implicit endorsement) during the first exercise, well before any tiresome semantic argumentation here about how papers should have been categorised, or whether "humans are causing global warming" means something different to "global warming is caused by humans" (!):
Methodology for adapting metal cutting to a green economy
The advent of global warming, as attested by the Intergovernmental Panel on Climate Change (IPCC), has serious ramifications for various facets of the human endeavour. Manufacturing is one such activity that is poised to undergo significant changes for curbing green-house gas emissions. This paper presents schemes for reducing the energy consumed in machining and grinding operations — the workhorses of any typical manufacturing set-up. These schemes are based on the mechanics of the metal cutting process which have been well studied over the years. Besides lowering the energy drawn from national grids, such schemes will pave the way for improved energy-efficient manufacturing processes. In the foreseeable future, alternative fuel systems to power manufacturing processes together with both newer operations and schemes, such as those outlined in this effort, would have a positive impact on the energy consumption of the manufacturing sector.
Searching for the paper in the database showed that Cook et al also categorised this paper as a level 3. The paper is like many others in this category — it is not about the causes of global warming, it is one of many about the impacts or (in this case) steps we can take to mitigate the impacts. Yet it quite clearly accepts the IPCC's findings. Indeed, it's the motivation for the paper. This is the kind of paper that you would not want counted as endorsing the consensus because it doesn't say "humans are responsible for >= 50% of global warming" while at the same time you do want counted papers (such as this) which don't say "humans are responsible for < 50% of global warming" and yet get categorised as level 5 by Cook et al:
I think you've made a fundamental error here. For a paper to unambiguously support the IPCC et al. consensus, it does indeed have to fall into category 1. But for a paper to unambiguously reject or deny it, it only has to fall into category 5, 6 or 7. That's 0.7 of 11,944 papers = 84 (maybe a few more, judging by the responses to some to the queries Popular Technology sent to known anti-AGW scientists whose papers had been rated). So the proper comparison, it seems to me, is 64 vs 84 or 64 out of 148 explicitly, unambiguously endorsing vs rejecting the IPCC consensus.
No. The categories are symmetric. If a paper numerically quantifies human responsibility, it's either a level 1 or a level 7. If a paper makes an explicit statement about human responsibility without numbers, it's either a level 2 or a level 6. If a paper implies or assumes causation, it's level 3 or level 5. You can't count only level 1 and compare it with level 5 + 6 + 7. If you don't trust the implicit categories, fine — ignore them. Measure 1 vs 7, or 1 + 2 vs 6 + 7. And then wonder why the figures come out so similar anyway.
Your mistake is to assume that papers in categories 2 and 3 must be ambiguous, and that unambiguous papers must be category 1. That is not the case. To exclude papers like the one I showed above would not result in an accurate reflection on the level of support for the IPCC consensus within the scientific literature.
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barry1487 at 14:08 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
I am not 'hostile,' for the record.
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barry1487 at 14:08 PM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Tom,
...several cues require us to give "endorse AGW" and "reject AGW" the same meanings where ever they occur in the list of categories. Of these the most important is that if you do not, if you allow "endorse AGW" to mean "endorse the claim that humans have caused most of recent warming" in (1), but "humans have caused at least some part of recent warming" in (2) and (3), then abstracts can logically belong to both categories (2) {or (3)} and category (7) at the same time. Given that the categories are clearly intended to be exclusive, it follows that if "endorse AGW" and "reject AGW" can be interpreted in a way that makes them exclusive it they should be; and that any interpretation that makes them non-exclusive is a misinterpretation. If follows that "endorse AGW" and "reject AGW" must be given the same meaning whereever they occur in the rating system, and that the difference in ratings for endorsements and rejections is a difference not in the level of endorsement (or rejection) but in the clarity of the endorsement or rejection in the abstract.
Several critics of the consensus have bizarrely criticized the paper both on the grounds that both the ratings at different level vary the meaning of "endorse AGW" and that the ratings are inconsistent due to overlap. They do not appear to recognize that by doing so they make their criticism inconsistent. Specifically, they make it clear that they show their criticism to be based on a hostile, out of context interpretation of the ratings and therefore irrelevant.
Are you saying that because 1 and 7 are quantified, that it follows that 2, 3 5 and 6 must reflect that quantification (>/<50% human influence)?
If ratings 2, 3, 5 and 6 are perceived as purely qualitative, then they can be read as exclusive. But, as a supposed reflection of the following paper, they might not be so. 2 and 3 get a tick if there is any suggestion that the globe has warmed/will warm due to human activity. 5 and 6 get a tick even if warming has been acknowledged, but the abstract 'minimises' (qualitatively) the human contribution.
2 and 3 might get a tick if the abstracts contain a statement like "it is expected that increases in atmospheric concentration of CO2 from industrial emissions will cause the lower atmosphere to warm," but the paper's conclusion may be that human activity has contributed 30% to the total warming. This is why I want to know if Cook et al rated 2 and 3 with the >50% AGW in mind (with the original Author in this example self-rating by the lower standard of AGW to any degree). Same rating but different criterion. That's an issue, how much of an issue is difficult to say.
An example of the same potential disjoint for ratings 5 and 6; an abstract may say, "our results indicate a smaller contribution to global warming from human activity than our previous study," but only in the body of the paper do you discover that this contributon amounts to, say, 53% instead of 59%. Qualitatively, in the abstract, AGW has been 'minimised'.
Imagining that there is no more information in the abstract than what I have invented in bold, how would you rate the last one, Tom?
(When I have time again I'll check out relevant category results, and maybe compare to full version papers if possible)
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Bob Loblaw at 12:27 PM on 28 May 2013Medieval Warm Period was warmer
WIlliam Haas: "There is proxy data that shows that for a specific location, temperatures were warmer during the Medieval Warm Period then they are today and man's contribution of CO2 to the atmosphere could not have played a part."
I have direct, anecdotal evidence that it was warmer in my back yard the week before last than all the global warming scenarios ever created predict for the next 100 years. And I'm sure CO2 was not the cause of my back yard being warm.
On the other hand, I don't think that the specific location of my back yard being warm for one short period of time has much to do with global warming due to increased atmospheric greenhouse gases resulting from human burning of fossil fuels over a period of decades.
Perhaps you would actually be willing to provide us with an argument as to why your anecdote is more relevant than mine?
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nealjking at 09:37 AM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
s_gordon_b:
You wrote:
"Two and 3, by definition, lacked the scope to indicate one way or another whether they support the consensus. Basically, just as most of all of the abstracts that were rated lacked the scope to comment at all on causation; 2 and 3 lacked the scope to comment on the consensus quantification of causation."
That is an interpretation you can assert, but from my involvement and discussion with the study evaluators, I know that they would not have checked off on levels of support 2 or 3 without having come to the conclusion that the abstract was assenting to a support for a significant (not minimal) degree of global warming, due to human influence. They bent over backwards to avoid reading too much support into a statement: Why do you think there are so many neutrals? If the evaluators had been willing to interpret perceived lukewarm support or a tiny perceived impact as 2 or 3, there wouldn't be many neutrals at all.
What you're proposing is a conceivable interpretation of the words in the paper, but bears no relationship to how the evaluators actually worked.
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Tom Curtis at 09:18 AM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
s_gordon_b @220, you claim that categories 2 and 3 do not support the consensus because:
"Two and 3, by definition, lacked the scope to indicate one way or another whether they support the consensus. Basically, just as most of all of the abstracts that were rated lacked the scope to comment at all on causation; 2 and 3 lacked the scope to comment on the consensus quantification of causation."
First, whether or not the abstracts lack sufficient information to categorize them is irrelevant to the meaning of "endorse AGW". Your argument, if valid, at most shows that categories (2) and (3) should be empty sets.
Seting that argument aside, several cues require us to give "endorse AGW" and "reject AGW" the same meanings where ever they occur in the list of categories. Of these the most important is that if you do not, if you allow "endorse AGW" to mean "endorse the claim that humans have caused most of recent warming" in (1), but "humans have caused at least some part of recent warming" in (2) and (3), then abstracts can logically belong to both categories (2) {or (3)} and category (7) at the same time. Given that the categories are clearly intended to be exclusive, it follows that if "endorse AGW" and "reject AGW" can be interpreted in a way that makes them exclusive it they should be; and that any interpretation that makes them non-exclusive is a misinterpretation. If follows that "endorse AGW" and "reject AGW" must be given the same meaning whereever they occur in the rating system, and that the difference in ratings for endorsements and rejections is a difference not in the level of endorsement (or rejection) but in the clarity of the endorsement or rejection in the abstract.
Several critics of the consensus have bizarrely criticized the paper both on the grounds that both the ratings at different level vary the meaning of "endorse AGW" and that the ratings are inconsistent due to overlap. They do not appear to recognize that by doing so they make their criticism inconsistent. Specifically, they make it clear that they show their criticism to be based on a hostile, out of context interpretation of the ratings and therefore irrelevant.
Leaving that aside, consider how you would rate the following title and abstract:
"On Regional Labor Productivity
Global climate change will increase outdoor and indoor heat loads, and may impair health and productivity for millions of working people. This study applies physiological evidence about effects of heat, climate guidelines for safe work environments, climate modelling and global distributions of working populations, to estimate the impact of two climate scenarios on future labour productivity. In most regions, climate change will decrease labour productivity, under the simple assumption of no specific adaptation. By the 2080s, the greatest absolute losses of population based labour work ability as compared with a situation of no heat impact (11-27%) are seen under the A2 scenario in South-East Asia, Andean and Central America, and the Caribbean. Climate change will significantly impact on labour productivity unless farmers, self-employed and employers invest in adaptive measures. Workers may need to work longer hours to achieve the same output and there will be economic costs of occupational health interventions against heat exposures."
How would you rate it?
It certainly does not ascribe a specific portion of recent warming to anthropogenic factors, so according to your argument it should be rated as neutral (4) at best. It was actually rated as implicitly endorsing AGW (3)*, a rating I agree with because:
1) It explicitly indicates, "Global climate change will increase outdoor and indoor heat loads" (my emphasis), something we have no reason to believe if anthropogenic factors are not the main driver of recent and near future temperature changes.
2) It implicitly endorses the IPCC A2 scenario as a plausible scenario of future temperature evolution; thereby implicitly endorsing the causal connection between greenhouse gases and temperature rise shown in that scenario including the forcing history and relationship to temperature in recent times. That forcing history, of course, shows anthropogenic factors as the cause of greater than 50% of recent warming.
I think the suposition that categories (2) and (3) cannot endorse anthropogenic factors as causing >50% of recent warming is simply wrongheaded, as shown by the example above. Of course any proposition that can be stated explicitly with quantification can also be stated explicitly without quantification by the use of such terms as "most of" (as in "most of recent warming is due to anthropogenic factors") or "dominant" (as in "the dominant cause of recent warming has been anthropegenic factors"). Further, anything that can be stated explicitly can be stated implicitly by leaving part of the affirmation to background information.
In the end, your objection comes down to the claim that it is easier to make mistakes about categories (2) and (3) than category (1). As the endorsement becomes less explicit and precise, it becomes easier to mistake endorsement for a neutral paper, and vise versa. That, at least, is true. Given the comparison between abstract rated and self rated papers, however, the mistakes have overwelmingly been conservative so the papers conclusions stand.
*One of the author's of the paper has rated it as neutral (4), but in ongoing comments he has shown that he does not understand the rating system by indicating that he thinks there is a "luke warm" category (which is clearly a mistake), and implicitly endorsed a claim by a well known "skeptic" that the consensus position is that "... almost 90-100% of the observed global warming was induced by human emission", which is absurd given the actual statements from the IPCC. It follows that the author (Richard Tol) is so confused about what is being endorsed and the rating system that his self ratings are irrelevant. I discuss his claims further on my blog.
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Tom Dayton at 09:10 AM on 28 May 2013Medieval Warm Period was warmer
William Haas, read the Intermediate tab of this posting, and take special note of the description of the "seminal paper on this subject." Click that phrase on that page to get to the details. It is irrelevant that as you wrote "for a specific location" temperatures were warmer than today. "Global" warming means more than one specific location, and there was no synchronized global Medieval Warm Period. So your vague contrarian speculation is irrelevant; you are speculating about a non-event.
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Rob Honeycutt at 08:51 AM on 28 May 2013Medieval Warm Period was warmer
William Haas... No one claims that man-made CO2 had any effect during Medieval times. There are, though, other known factors at play during that period, including increased solar activity and low volcanic activity. But, overall, it is estmated that current global temperature is likely as high or higher than the MWP. This in spite of the fact that the planet has been on a 5000 year orbitally forced trend toward generally cooler conditions.
Currently there is no other rational explanation for the temperature trend since modern industrialization other than increased levels of man-made greenhouse gases.
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William Haas at 08:37 AM on 28 May 2013Medieval Warm Period was warmer
Estimates of global temperatures during the Me devil Warm Period are somewhat speculative because we do not have direct measurements of global temperatures dating back that far. There is proxy data that shows that for a specific location, temperatures were warmer during the Medieval Warm Period then they are today and man's contribution of CO2 to the atmosphere could not have played a part.
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Tom Curtis at 07:44 AM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
s_gordon_b @221, try searching for the terms " " (ie, a single space) or "i" for a generalized search.
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s_gordon_b at 07:09 AM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
JasonB,
I wrote: "I still don't see how I can use that page to get those figures."
D'oh. I mistook the search page for the "rate abstracts" page. It does insist you enter a search term, though, which limits the results.
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s_gordon_b at 06:42 AM on 28 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Hi JasonB,
You wrote in reply to my post:
Perhaps it would be easier to understand your point if you could point us to some examples of where the study is being spun?
Ironically, in light of the methodology of the paper, the spin (more neutrally, I should call it confusion or conflation) starts with my "rating" of where Cook et al.'s abstract stands on AGW (emphasis below is mine):
"We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW..."AGW is immediately defined as "the scientific consensus on anthropogenic global warming," not in the broadbrushed, imprecise, popular way that ranges from "we're a significant contributor, along with natural causes" to "we're the cause." In the next breath, we're told that "32.6% endorsed" that consensus. Ask anyone who reads climate science papers what the term "scientific consensus on anthropogenic global warming" means in the context of such a paper, and how many will say "simple: humans are a significant cause of global warming" vs "it refers to the consensus of the IPCC and pretty much all of the other major scientific review bodies that humans are the dominant (if not the only) cause of global warming, at least since the 1950s"? In climate science circles "consensus" has a precise meaning. And this is a climate science paper. This is why when I initially read about the paper - and based on my very high level of trust in SkS - I took the claim about support for "the consensus" literally, in the IPCC sense, and represented the paper that way on social media. It's also why I was stunned when I actually read the paper and got to the part where categories 1, 2 and 3 were rolled up together and rated as "the consensus." Not so. Two and 3, by definition, lacked the scope to indicate one way or another whether they support the consensus. Basically, just as most of all of the abstracts that were rated lacked the scope to comment at all on causation; 2 and 3 lacked the scope to comment on the consensus quantification of causation.
You continued:
Regarding the authors, again, they were asked to state whether each specific paper endorsed the proposition that anthropogenic GHGs are causing global warming, rejected the proposition that anthropogenic GHGs are causing global warming, or was neutral. If the author of the paper felt that their paper implied humans were having a minimal impact on global warming (e.g. by proposing an alternative as the main cause of global warming), or stated that human impact was minimal or non-existent, or stated that humans were causing less then half of global warming, then they would have categorised their own papers as rejecting the proposition.
I'm fairly confident that anyone who rejected the consensus view would have made damn sure their paper was counted as a rejection if it was at all possible to do so! And let's not forget that the authors of any papers who feel their paper should have been counted as a rejection are free to search for their paper in the results and alert us to the miscategorisation.
You're misunderstanding my argument. I'm not in any way suggesting that minimizing or denying papers were lumped into the "endorsing"/consensus-supporting abstract count. For example, if I wrote a paper that (to quote from the choices the authors were given) "... explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a given fact," I would concur if it was rated as category 2. Likewise, I would concur with a category 3 rating if my "paper implies humans are causing global warming. E.g., research assumes greenhouse gases cause warming without explicitly stating humans are the cause." But I would concur in both these cases even if my paper had zero to say for or against the IPCC consensus on degree of causation. Indeed, if my paper had supported the consensus, I would have rated it 1.
Anyway, the bottom line is that the authors of 97.2% of the papers that took a position stated that their papers endorsed the proposition that anthropogenic greenhouse gasses are causing global warming. That's it.
Exactly. They "endorsed the proposition that anthropogenic greenhouse gasses are causing global warming." "Are causing" can be read the same way as "obesity is causing Type 2 diabetes": it's a contribuitng cause. But, again, only a fraction of the papers were designed to endorse or reject the dominant cause IPCC consensus implied in the abstract and in all manner of coverage that has followed. E.g.:
From the lead in Suzanne Goldberg's story in The Guardian (http://www.guardian.co.uk/environment/2013/may/16/climate-research-nearly-unanimous-humans-causes):"A survey of thousands of peer-reviewed papers in scientific journals has found 97.1% agreed that climate change is caused by human activity."
When I write (as a journalist) or read "is caused by" in the context of the climate change social debate (it is a debate, in civil society; otherwise there would be no need for this paper and the Consensus Project), my meaning/understanding is primary causation, if not "the cause."
There's no shortage of argument on this board about the semantics used in the study and surrounding it. Cook et al. could simply address this by releasing a clarification, unless they really believe it's scentifically sound to infer that category 2 and 3 papers do endorse the consensus. Alternately, they could go through all their past writings and redefine their use of the word consensus to mean that human activities are at least a significant contributor to global warming.
Quoting and answering me:
*I've looked everywhere, but I can't find where the numbers of abstracts assigned to each of the original Table 2 categories is or the category assignments by the study authors. Could you point me to that data?
http://www.skepticalscience.com/tcp.php?t=search
I had already gone there. I still don't see how I can use that page to get those figures. Why isn't the data simply published somewhere? It's such basic information for people who want to understand the study's findings.
Perhaps you should spend some time reading the earlier comments to avoid rehashing the same points over and over again.
I read plenty and found little beyond arguments about semantics. But now you've provided me numbers for category 1 in your earlier post, where you write:
... of interest to this discussion is the breakdown between papers that quantify the human contribution to global warming as >= 50% and papers that quantify the human contribution to global warming as < 50% (i.e. levels 1 and 7), since there is no interpretation required for those. The former represent 88% of all papers that quantify the human contribution to global warming (64 of 73).
I think you've made a fundamental error here. For a paper to unambiguously support the IPCC et al. consensus, it does indeed have to fall into category 1. But for a paper to unambiguously reject or deny it, it only has to fall into category 5, 6 or 7. That's 0.7 of 11,944 papers = 84 (maybe a few more, judging by the responses to some to the queries Popular Technology sent to known anti-AGW scientists whose papers had been rated). So the proper comparison, it seems to me, is 64 vs 84 or 64 out of 148 explicitly, unambiguously endorsing vs rejecting the IPCC consensus.
For me, the lesson of this study is that it's very hard to find robust support for the IPCC consensus just by doing a head count of papers on climate change, because very few papers, so far at least, have explicitly (or implictly, I suppose) sought to test that quantified consensus. Maybe this is analogous to the relationship between any large body of literature and the relatively uncommon major reviews and meta-analyses that attempt to put it all together and draw those larger conclusions of which consensuses are made.
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John Hartz at 06:21 AM on 28 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Also see:
Cassano, E. N., Cassano, J. J., Higgins, M. E. and Serreze, M. C. (2013), Atmospheric impacts of an Arctic sea ice minimum as seen in the Community Atmosphere Model. Int. J. Climatol.. doi: 10.1002/joc.3723
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Rob Painting at 06:08 AM on 28 May 2013Uncertainty no excuse for procrastinating on climate change
Kev, my bad. And I did read the paper! Mind you the first sentence in the paper is misleading.
It's not easy tracking down all the sources for their inputs into the calculations, but their choice of climate forcing seems to be the clincher. The use of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) forcing moves the equilibrium climate sensitivity back up to 2.4°C - closer to the central estimate using other methods.
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John Hartz at 05:32 AM on 28 May 2013Land Surface Warming Confirmed Independently Without Land Station Data
Dana,
Your "Note" at the end of the OP needs an edit.
Also, shouldn't the rebuttal article, It's Urban Heat Island effect also be updated in a similar manner?
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william5331 at 04:55 AM on 28 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
R. Gates (18)
There is another phenomenon that is likely. When low pressure systems sidle up to the Atlantic side of Greenland, they induces katabatic winds down the flanks of Greenland. Presumably the same will happen if a low can get close to the northern coast. All that is necesary is for the ice to disappear. The ice shelf tends to hold low pressure areas off the coast and weaken them. Katabatic warming for descending air (no dew point involved as is the case with rising air) is 9.8 degrees per vertical km. From the very peak of Greenland to the coast is over 3km or about 300C. With a hurricane such as the one that we had Aug6, 2012, we should see some serious surface melting.
http://mtkass.blogspot.co.nz/2012/11/greenland-melting.html
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MA Rodger at 02:54 AM on 28 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
I continue my game of cosmological Where's Wally by crossing the Atlantic. The US Eastern seaboard stretches 1,500 miles so can provide a regional temperature by averaging a set of State data from NCDC, Maine, Massachusetts, Maryland, N Carolina & Florida being chosen. They have a very similar temperature record as shown in the tiny inset graphic. (The anomaly base 1895-1945 is probably the reason for the particularly close match during those years.)
The contiguious ocean SST from nomad3 were taken as 25-45N, 70-80W. (This isn't the most representitive part of the Atlantic SST-wise, lacking signs of warming 1981-date.) AMO is after Enfield.
The first graph shows the land & adjacent ocean temperatures 1981-date do have certain similarities but with warming only evident on land. Also, if the larger wobbles match up, they appear a month or so earlier on land, which is not good for any theory of AMO as a driver of land temperature.
The second graph attempts to compare those US temperature records with AMO over a 120 year period. I see there no evidence of AMO warming the Eastern coast of the USA over that period.
So where is Amo hiding?
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MA Rodger at 02:49 AM on 28 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
So where to look for evidence of AMO warming affecting climate beyond the shores of the N Atlantic?
My first thought was that if AMO was going to effect temperatures anywhere, it would be the UK. Indeed, the CET was invoked within T&Zh13. So I compared CET with the SST for the surrounding seas (45-65N, 20W-10E) with nomad3 providing monthly SST data - 1981 to date. The two temperature profiles are re-based for comparison and graphed below. with AMO also plotted (although AMO is of course subject to a de-trending).
The divergent record is evidently CET not the SST which suggests that during these divergent periods, AMO is not in any way a dominant influence in CET. So are divergent periods infrequent such that the period 1988-2004 is the norm where SST & CET can be married together?
A de-trended CET for the period of Enfield's AMO index (1856 to date) is next up for comparison being graphed below. Divergence appears the normal state here, with the two indices have little in common. I would conclude that the CET record does not support the suggestion that AMO drives UK temperatures.
Still. It's early days. There may yet be that local variation is swamping the signs of the AMO driving UK temperatures. And the UK is not the whole globe.
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MA Rodger at 02:39 AM on 28 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
Apologies for the non-functioning links @64 & @65 & thank you DB for providing links.
I feel the extra palaver of linking to view the graphics is a step too far so will attempt to find a host for the graphics that will allow on-page viewing.
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Daniel Bailey at 01:30 AM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
@ matzdj
About that 1970s ice age prediction:
This meme stems originally from a 1971 Rasool and Schneider study, which was predicated on a quadrupling of aerosol emissions; this possible pathway never happened.
Emissions actually went the opposite trajectory due to the establishment of the EPA and the Clean Water Act in 1970, the Vienna Convention on the Protection of the Ozone Layer of 1985, the The Montreal Protocol on Substances that Deplete the Ozone Layer of 1987 and the Clean Air Act of 1990.
http://www.sciencemag.org/content/173/3992/138
http://www.epa.gov/ozone/intpol/The meme originates with a 1974 Time article and a 1975 Newsweek report.
http://www.nationalcenter.org/Time-Ice-Age-06-24-1974-Sm.jpg
http://denisdutton.com/newsweek_coolingworld.pdfHowever, those are media articles, not scientific studies. A survey of peer reviewed scientific papers from 1965 to 1979 show that few papers predicted global cooling (7 in total). Significantly more papers (42 in total) predicted global warming (Peterson 2008). The large majority of climate research in the 1970s predicted the Earth would warm as a consequence of CO2. Rather than 1970s scientists predicting cooling, the opposite is the case.
http://ams.confex.com/ams/pdfpapers/131047.pdfSo only the alarmists still perpetuate the "70s Ice Age" meme, FYI.
Please do a better job of staying on-topic in this thread; thanks.
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Daniel Bailey at 01:22 AM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
Occasionally, scientific ideas (such as biological evolution) are written off with the putdown "it's just a theory." This slur is misleading and conflates two separate meanings of the word theory: in common usage, the word theory means just a hunch, but in science, a theory is a powerful explanation for a broad set of observations. To be accepted by the scientific community, a theory (in the scientific sense of the word) must be strongly supported by many different lines of evidence. So biological evolution is a theory (it is a well-supported, widely accepted, and powerful explanation for the diversity of life on Earth), but it is not "just" a theory.
Words with both technical and everyday meanings often cause confusion. Even scientists sometimes use the word theory when they really mean hypothesis or even just a hunch. Many technical fields have similar vocabulary problems — for example, both the terms work in physics and ego in psychology have specific meanings in their technical fields that differ from their common uses. However, context and a little background knowledge are usually sufficient to figure out which meaning is intended.
http://undsci.berkeley.edu/article/howscienceworks_19Below is a generalized sequence of steps taken to establish a scientific theory:
1. Choose and define the natural phenomenon that you want to figure out and explain.
2. Collect information (data) about this phenomena by going where the phenomena occur and making observations. Or, try to replicate this phenomena by means of a test (experiment) under controlled conditions (usually in a laboratory) that eliminates interference's from environmental conditions.
3. After collecting a lot of data, look for patterns in the data. Attempt to explain these patterns by making a provisional explanation, called a hypothesis.
4. Test the hypothesis by collecting more data to see if the hypothesis continues to show the assumed pattern. If the data does not support the hypothesis, it must be changed, or rejected in favor of a better one. In collecting data, one must NOT ignore data that contradicts the hypothesis in favor of only supportive data. (That is called "cherry-picking" and is commonly used by pseudo-scientists attempting to scam people unfamiliar with the scientific method. A good example of this fraud is shown by the so-called "creationists," who start out with a pre-conceived conclusion - a geologically young, 6,000 year old earth, and then cherry-pick only evidence that supports their views, while ignoring or rejecting overwhelming evidence of a much older earth.)
5. If a refined hypothesis survives all attacks on it and is the best existing explanation for a particular phenomenon, it is then elevated to the status of a theory.
6. A theory is subject to modification and even rejection if there is overwhelming evidence that disproves it and/or supports another, better theory. Therefore, a theory is not an eternal or perpetual truth.
http://www.oakton.edu/user/4/billtong/eas100/scientificmethod.htmFor a good discussion of science terminology (especially for the "Evidence, not Proof" bit), see here:
http://evolution.berkeley.edu/evosite/footshooting/Iterminology.shtmlAnd speaking of NASA again:
http://climate.nasa.gov/key_indicators
http://climate.nasa.gov/evidence/
http://climate.nasa.gov/causes
http://climate.nasa.gov/effectsWhich brings us full-circle to matzdj's comment sparking this line of discussion: anthropogenic climate change (ACC)/anthropogenic global warming (AGW) is indeed a theory. In reality, the National Academies of Science refer to it as "settled fact" instead of a scientific theory.
Per the National Academies of Science, in their 2010 publication Advancing The Science Of Climate Change (pp 44-45):
"Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small.
Such conclusions and theories are then regarded as settled facts.
This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities."
http://www.nap.edu/catalog.php?record_id=12782
And note that the above National Academies paper is available for free download after a free registration. No purchase necessary. And the quote is from pages 44 & 45.
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Kevin C at 01:05 AM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
matzdj: The point of this site is that there is a huge amount of misinformation concerning climate.
While to a casual observer it may look as though there are two balanced sides both arguing that the other is wrong, if you spend a little time comparing secondary sources against primary sources, I think you will very quickly spot a pattern and be able to draw some conclusions about what is going on. As a starting point, let me pick a couple of examples from your post:
No question we are hotter now than in the 1970's (when climatologists were predicting a coming ice age)
What is the basis for your belief that climatologists were predicting an ice age in theh 70's? Is there documentary evidence? Was it a widespread view?
but the monotonic correlation with CO2 does not correlate, except over a long term.
Does climate science predict a correlation with CO2 over the short term, or are the other factors which can affect short term trends? Do we know what these are?
Have any of the models predicted this stair-step climb of temperature? If none do, then maybe they are missing a driver or incorrectly including it.
Good question. Have you attempted to answer it? ('Hiatus decade' may be a useful search term if you are stuck.)
Is there any Experimernt, or any observation, that could occur that might lead the "settled science" folks to say, "We should look at that. We might be wrong".
Plenty. Here's just one to start with: If the Earth's IR spectrum as observed from space did not show CO2 absorbtion lines which broaden as we increase the CO2 concentration in the atmosphere, we would throw out climate science straight away.
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Tom Dayton at 00:47 AM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
matzdj, are you saddened by the overwhelming evidence that gravity exists? I don't know what field your PhD is in, but in science part of the definition of "progress" is that intentionally varied evidence converges on a picture of reality, because reality constrains the evidence. Scientists are motivated to show that all other scientists are wrong--that the consensus is incorrect--because that path leads to fame and personal pride and a feeling of accomplishment and contribution. So scientists leap on evidence that appears to contradict the consensus. But reality always eventually wins, as apparently contradictory evidence is refined until it reveals the truth.
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matzdj at 23:46 PM on 27 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
Every time I try to review information on this site, I always come away with the sad feeling that 100% of the data interpretations that might lead to some conclusion other than anthropogenic CO2 caused Global warming are wrong. That can't be.
Both sides do have legitimate scientists on them (more on the CO2-is-the-ogre side), but there is no legitimate way that every statement that either side makes can be wrong. (-snip-).
When it comes to the escalator effect, different data sets show somewhat different effect. The GISS data that I have seen seems to show a steady average Global T from 1970 to the early 1990's, a substantial step from the early 90's to the early 2000's and a relatively steady average from then until now.
No question we are hotter now than in the 1970's (when climatologists were predicting a coming ice age), but the monotonic correlation with CO2 does not correlate, except over a long term.
If we assume that the CO2 driver is the main driver in the background, where is the analysis of all other factors that cause no net temperature climb over these relatively flat periods with step changes when the sub-drivers stop neutralizing the CO2 effect. (-snip-).
Have any of the models predicted this stair-step climb of temperature? If none do, then maybe they are missing a driver or incorrectly including it.
Is there any Experimernt, or any observation, that could occur that might lead the "settled science" folks to say, "We should look at that. We might be wrong". If there is nothing that can ever prove that your theory is wrong, than it is not a scientific theory. it is just a belief.
Some day I would like to see a fair and balanced discussion on data linking CO2 to warming and on alternative potential drivers to global warming, rather than this constant barrage of why the other guys are 100% wrong?
David J Matz, PH.D
Moderator Response:[DB] In order to make best usage of what this site has to offer, you need to use the Taxonomic listing of arguments and the Search Function (located in the UL section of every page). Discussions of the intricacies you express interest in are best conducted on those specific threads.
For example, your claims about data interpretations might be answered by reviewing the Big Picture article and following the links as needed from there.
Discussions of the Escalator and its permutations are best done here.
For CO2:temperature correlations, see here.
CO2 is not the only driver of climate
Models are not necessarily as unreliable as you think
As for your theory vs belief, I will place a separate comment about that, as a proper response lies outside the aegis of this function.
Off-topic/sloganeering snipped.
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Kevin C at 23:37 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Rob: Otto et al looks at the following temperature differences:
- mean(2000...2009) - mean(1860...1879)
- mean(1990...1999) - mean(1860...1879)
- mean(1980...1989) - mean(1860...1879)
- mean(1970...1979) - mean(1860...1879)
These are compared to the change between the two periods in either forcing or (forcing-uptake) for TCR or EffCS. The trends within those periods do not appear anywhere in the calculation. Uptake is assumed to be 0 for the early period - i.e. the ocean is assumed to be equilibriated.
There is a copy of Otto et al online here. It's worth reading what the paper actually says, because it bears little resemblence to what most secondary sources say the paper says.
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chriskoz at 19:55 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Rob@8,
I concur with your doubts. David Keith looks to me as the guy who cares about the mythical limitless growth only rather than sustainability. Not even mentioning his perpetually-moving optimism about the law of thermodynamics. I wonder why the interviewer on this YT video didn't ask for that, I would have pressed the guy here and won't let him evade it.
I think the climate change due to athmosphere being treated as CO2 dumping ground is part of even larger problem facing overpopulated earth: complete disregard on sustainabily principles by the ravaging homo "sapiens". This larger context is not to be ignored, because even if we solve/stabilise CO2 problem soon, we may end up exposing another, equally alarming environmental degradation problem.
Meanwhile it's worth remembering This article + comments, which apears to be the latest SkS stance on this topic.
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Rob Painting at 18:26 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Shoyemore - I understand one of the Skeptical Science authors has volunteered to write about the Myles Allen piece. I'm not sure how he plans to overcome the laws of thermodynamics with this carbon capture scheme. Has the hallmarks of perpetual motion machine crankery about it.
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shoyemore at 17:48 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Professor Myles Allen (one of the authors of the Otto study) has written a strange article in that rag, the Daily Mail, advocating a new departure to seriously research carbon capture and sequestration (CCS). Naturally, the Mail distorts his views in its headline (and you could almsot say it serves him right!:))
Others have been writing about this lately, like the physicist Laurence Krauss in Slate, and Dr David Keith of the University of Calgary.
www.youtube.com/watch?feature=player_embedded&v=PilKYZ_VVnc
CCS proposals like Allen's will probably used to justify more procrastination, of course.
Perhaps Skeptical Science could so a full post on this, or even re-post Allen's article for discussion. I am sure he would agree.
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Rob Painting at 17:02 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Kevin - that makes no sense. How can they calculate the transient climate response (TCR) and equilibrium climate sensitivity (ECS) without feeding in the change in (near-surface air) temperature for each period? Change in (surface) temperature is an essential input into the equation.
In figure 1 of Otto (2013) they even give a break-down of TCR and ECS for each decadal period - from the 1970's to 2000's.
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Kevin C at 15:12 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
A recent study by Alexander Otto of Oxford University and colleagues, published in the journal Nature Geoscience, also considered future global warming in the context of observations of global mean temperature change over the last decade.
I'm puzzled by this sentence, since it seems to be based on the BBC's misrepresentation of the Otto paper, rather than what the Otto paper actually says.
The Otto paper is not based on temperature changes over the last decade - in fact Otto et al totally ignore changes over the last decade (except in OHC). Instead they take the average temperature over the last decade (and also the previous 3), and compare it to the average of a baseline period from 1860-1880. And the last decade does not stand out in any way - they find similar results for the 00's, the 90's, and the 80's. This part of the calculation is trivially reproducable.
Otto et al is not without it's limitations:
- HadCRUT4 only covers 5/6 of the planet even in recent decades. My best estimate is that this causes them underestimate the temperature change by 5%, although the global temperature distribution for the 1860s is based in totally inadaquate information and so I'm guessing this number should be closer to 10%.
- They note in the text that they are calculating effective climate sensitivity, which provides a lower bound for equilibrium sensitivity. They reference Armour et al, which finds that the effective sensitivity is about 15% lower than the equilibrium sensitivity.
If correct, these two factors alone would bring the Otto ECS to 2.4C, which is much more plausible, however the EffCS-ECS correction is currently based on only one paper (and my coverage work is not published at all). Until this is better constrained I wish they would be a bit clearer about the distinction between EffCS and ECS.
The method from the Otto paper is also totally dependent on the size of the forcings. They use forcings from this paper by Forster et al which looks very interesting indeed. I would like to try this data in my response function model.
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jyyh at 13:58 PM on 27 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
ulisescervantes: "negative AO, if associated with Arctic warming, tends to mitigate the (very strong) positive feedback of extra cloudiness."
This at least goes well with the ages old weather proverb (on lake ice) from Finland that states (translation):"clear skies, strong ice, icing with snow, on ice don't go". I don't know how well this applies to salty sea ice, though.
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Tom Curtis at 13:56 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
tonyabalone @3, agreed about The Australian's publications of letters. I have never had one of my letters pointing out (even subtely) their constant misrepresentation of the science actually published. I'm now trying a new tactic. I just sent of my email complaining about the article, but copied it to David Karoly and mediawatch (mediawatch@your.abc.net.au. Perhaps the knowledge that they cannot simply disappear the email will encourage them to publish. And if not, perhaps mediawatch will take an interest.
Who knows?
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tonyabalone at 13:49 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Tom Curtis @ 2 yes I suspect that you are correct that the paper has been bombarded with complaints. I fired off an email to the editor compaining about the misinformation in the article. It won't be published of course. Limited News is very careful about their image and they don't take kindly to criticism, even when they know it is justified.
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Tom Curtis at 13:37 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
tonyabalone @1, the Australian is schizophrenic on this study. In print the headline the article "Scientists now expect 2C rise", which is doubly misleading. First because it lacks the words "at least", and second because it suggests this is news, ie, that scientists have not been expecting at least a 2 C rise since about 1990.
The then state (as you point out):
"The earth's temperature is unlikely to increase by more than 2C by 2100 - significantly less than earlier predictions - assuming carbon dioxide emissions are substantially reduced."
This contrasts sharply with the abstract of the study which states:
"This results in an increased probability of exceeding a 2 °C global–mean temperature increase by 2100 while reducing the probability of surpassing a 6 °C threshold for non-mitigation scenarios such as the Special Report on Emissions Scenarios A1B and A1FI scenarios6, as compared with projections from the Fourth Assessment Report7 of the Intergovernmental Panel on Climate Change."
(My emphasis)
The abstract does not discuss scenarios with substantially reduced emissions at all.
The in print article goes on to say:
"The results are based on a scenario in which action is taken to mitigate emissions, though no reduction target is specified. It says under a 'business as usual' approach, temperatures are likely to rise by more than 2 C."
Well, I guess 4 C (the expected rise under BAU) is more than 2 C, so it is not exactly a lie - but hardly informative.
In contrast, the online version of the Australian leads with:
"Doubt will remain on climate
BY:MITCHELL NADIN From: The Australian May 27, 2013 3:00AMSCIENTISTS have narrowed the range of possible global temperature rises due to greenhouse gas emissions, but say uncertainty will always remain because of the complexity of factors in climate change.
Research conducted at the Melbourne University, and published today in Nature, found previous estimates of a 6C rise in temperatures by 2100 were "unlikely", but that exceeding a 2C change was "very likely" given business-as-usual emissions."
Same author, same study, different title and a balanced if much truncated text. Oddly, that article is listed as being posted "1 hour ago", ie, 12:30 PM AEST, not the 3:00 AM listed under the byline. My guess is that complaints were made about the transparent and misleading bias of the inprint article, resulting it being pulled online and a better version substituted. Without, of course, any admission of error.
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