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Dumb Scientist at 03:40 AM on 22 May 2013Has the rate of surface warming changed? 16 years revisited
A few months ago I calculated trends and uncertainties for the UAH data. The second page of that PDF has a black line for the trends of the UAH data up to 2012 for different starting years. The red lines are 95% confidence uncertainty bounds which account for autocorrelation with ARMA(1,1) noise. Notice that the larger uncertainty bounds of more recent trends overlap with the smaller uncertainty bounds of the longer trends. This means that there hasn't been a statistically significant change in the surface warming rate. Here's the R code if anyone's interested.
It's even easier to use the SkS trend calculator to confirm that there hasn't been a statistically significant change in the surface warming rate. Here's an example:
GISTEMP, 1990-2000: 0.201 ±0.322 °C/decade
GISTEMP, 2000-2010: 0.096 ±0.256 °C/decade
Note that the error bars overlap, showing that there hasn't been a statistically significant change in the surface warming rate. I've tried many datasets with many potential change points, and so far all their error bars overlap.
As you say, the total energy content of the climate is a more direct measure of global warming. It's also worth pointing out that global land ice and global sea ice continue to decline, absorbing heat without warming as they melt.
Troy's analysis is interesting; I'm still reading it. However, I don't think it's necessary to withdraw the video. In my view, Foster and Rahmstorf 2011 was merely trying to improve the signal-to-noise ratio of the surface temperature record by accounting for some extraneous influences. I even pointed out that other influences like multidecadal oscillations haven't been removed.
But that's not a fatal flaw, because it's impossible to remove all extraneous influences. Similarly, when a better estimate of the long-term effects of Pinatubo becomes available, that will build upon previous work rather than demolishing it.
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Bob Loblaw at 03:13 AM on 22 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Dr. Tung.
OK. Let's follow up on my comment in #71, and apply it to your study. I am not an expert on AMO, but from what I have read here, I would state the following:
- temperature can be classified as an observation
- pressure can be classified as an observation
- I'd even be content classifying the pressure difference between two locations as an "observation" - e.g., Southern Oscillation Index based on Tahiti-Darwin - so when it comes to linking an oscillation (ENSO) to temperatures, SOI is a methodologically-independent observation and it is appropriate to use it to try to explain temperatures.
AMO, which from descriptions here and in the NOAA link is described as a detrended areal average of temperatures, is not an observation. It is an interpretation of a rather large number of observations, and it includes processing that removes part of the signal contained in the original observations (the detrending).
Once you start using that interpretation of the data as if it is an "observation", and then attempt to use your analysis to deternine the portion of the observed temperatures that is attributable to AGW, then you are at risk of making errors. The AMO, as an interpretation, has built-in assumptions. The detrending has changed the character of the information contained in the result (as compared to the original temperature observations). The averaging and detrending are based on a statistical model, and the remaining values (the AMO) represent the parts that the model doesn't remove or smooth.
Now, if your goal is to get people to accept your conclusions, then you are going to have to go back over the steps from observation, through interpretation, to your conclusions. You are going to have to provide an analysis that clearly demonstrates that the result you want us to believe is not affected by the assumptions (especially detrending) that are inherent in the application of processing/modeling to derive the AMO.
From what I have read here and elsewhere on the web, this is a serious methodological flaw, and you have not addessed the criticisms that have been made here. Please go back over Dumb Scientist's original post, and the comments to both it and your two posts, and address the issue of the detrending that is done in deriving the AMO.
This is not quibbling about definitions of words. The distinction between "observations" and "interpretations" is essential. You are attempting to explain temperatures using temperatures, which seems unsupportable - it involves a circularity that is hidden because you appear to be forgetting that AMO is not an observation. -
HJones at 03:13 AM on 22 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
@ Kevin C 165,
Unless you know that the first 100 are representative of the 300, you can't make any comment on the 300. You can't assume anything. For all you know in your example is that right handed pirates hear better, so came forth with their reply before the left handed pirates did, or conversely, the left handed pirates hear better and come forward right away, and there is only three of them in total.
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CBDunkerson at 02:10 AM on 22 May 2013A Detailed Look at Renewable Baseload Energy
JvD, did you stop reading after the part of my message you quoted or did you just decide to repeat the same false claims anyway?
You do realize that no matter how many times you claim that this page (or my response) is misleading because it says renewables will be cost effective "in no short order" or that "money is no object" the actual page itself will always still say;
"However, detailed computer simulations, backed up by real-world experience with wind power, demonstrate that a transition to 100% energy production from renewable sources is possible within the next few decades."
and
"In Part II of the study, J&D examine the variability of WWS energy, and the costs of their proposal. J&D project that when accounting for the costs associated with air pollution and climate change, all the WWS technologies they consider will be cheaper than conventional energy sources (including coal) by 2020 or 2030, and in fact onshore wind is already cheaper."
Right? So no matter how many times you claim, "SkS ignores this [cost] question", it will never be true.
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miffedmax at 01:47 AM on 22 May 2013Has the rate of surface warming changed? 16 years revisited
No, no, no. This isn't how the game is played. If some of your evidence is incorrect, you don't withdraw it, you shout it louder.
(I am on a Heartland-friendly site, aren't I?)Moderator Response:[RH] Changed all caps to bold. (Per commenting policies.)
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Dikran Marsupial at 01:40 AM on 22 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Prof. Tung, I don't think we are wasting our time either. It is unfortunate that misunderstandings ocurr sometimes, but we wouldn't be so thorough in trying to get to the bottom of them if we didn't think understanding the science properly was important.
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BillEverett at 20:10 PM on 21 May 2013Help close the consensus gap using social media
Will the consensus project website be made available in different languages (similarly to some of the SkS material)?
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JvD at 19:20 PM on 21 May 2013A Detailed Look at Renewable Baseload Energy
"As you concede, it is possible to achieve global 100% renewable energy... with current technology. It would just be very expensive."
If money is no object, anything is possible, obviously. This does not add understanding. The impression people are going to take home from SkS's various webpages on renewables is that renewables will 'plausibly' replace fossil fuels in no short order. This is a patently false and dangerous impression which directly harms the fight to stop AGW, by fostering complacency and motivating people like the German's to recklessly trash their own high-quality nuclear energy sector.
It may be worthwhile to look at the case of the Ozone Hole problem of the last century. Scientists discovered that popular chemicals used at the time as refrigerants for cooling applicatios were causing massive damage to the ozone layers. Therefore, policy was phased in to eliminate the use of these chemicals. Slowly, these are being phased out which has cause the ozone hole to stop expanding. (it has yet to start shrinking BTW).
Now, the interesting thing about the Ozone Hole problem was that the cost of switching to non-ozone depleting refrigerants was only a few percent compared to BAU. But even these few percentage point costs required global cooperation and law-making in order to realise the necessary switch.
Now, a project to make renewables cover for baseload would require backup, storage and renewables build out, which would increase the cost of baseload electricity generation by at least 100% in the best case, and possibly up to 500% or more (f.e. when considering countries like France who currently have 80% nuclear electricity costing about 3 ct/kWh.)
Considering how slow and difficult it has been to *begin* solving the ozone hole problem - which after all involved adding only a few percentage point costs to refrigeration by switching to chemicals that were only a tiny bit more expensive - how "plausible" is it really that we will switch tot non-co2 emitting energy generators that will cost from 100% to more than 500% more than current?
This question is the interesting question to tackle. It is not interesting to conclude that renewable energy can meet baseload as long as money is no object. That is elementary. The question is whether it is able to do it when money is an object. What if people and competitive economies demand that the cost of energy does not rise more than a few percent over baseline? What then? SkS ignores this question and thereby fosters complacency IMHO.
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Rob Painting at 18:16 PM on 21 May 2013Another Piece of the Global Warming Puzzle - More Efficient Ocean Heat Uptake
Dissident - that's not how the ocean circulation works. During La Nina-dominant (negative Pacific Decdal Oscillation [PDO]) global weather, such as that since the mid 90's, tropical easterly trades winds intensify. The mid-latitude ocean gyres spin faster and, due to convergence in the centre of the gyres, Ekman pumping (the downward transport of heat) is stronger. Stronger downward transport of water mass must be balanced by upwelling somewhere else, and this occurs in regions of divergence (Ekman suction) - along the equatorward travelling arms of the gyres, and along the equator itself. In the Pacific Southern Hemisphere this region of upwelling occurs along the coast of South America - the Humboldt Current.
So what we would expect to happen, during La Nina-dominant (negative PDO) global weather, is a stronger Humboldt Current and more productive fisheries there as nutrients, which support phytoplankton blooms, are sucked up from the deep. A weakening of the easterly trade winds will not only reduce the heat going into the deep ocean and lead to greater surface ocean warming, but it will weaken the Humboldt Current, weaken Ekman suction, and the fishery will not be as productive because of diminished nutrient availability.
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JasonB at 17:54 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
What makes you think I took offence? Surprised, maybe, that people post without reading first, but not offended.
As I said in the earlier comment I pointed you to, there's nothing "special" about the 12,000 papers that were manually rated. They are simply what was left after applying the earlier filters. Manual rating was required to filter out the irrelevant papers from that set in order to arrive at what was actually desired, namely, the set of papers that were relevant to the question at hand, which was to determine the percentage of papers in the scientific literature that endorsed the consensus position that "human activity is causing global warming" vs the percentage of papers in said literature that rejected that position. The size of that set of papers with respect to the size of set of papers that required manual rating is mildly interesting but irrelevant. After all, with sufficient effort, they could have simply manually checked all scientific papers during that period, which should not have changed the relevant percentages but which would have reduced the percentages you're interested in to minuscule values. The purpose of the filtering was to make the problem tractable, that's all.
Note that I am not an author of the paper. I, like many others, participated in the online rating exercise announced here a few weeks ago to get a taste of what was involved. I suggest you have a go, because by doing so you'll quickly realise the true nature of the papers that end up being rated neutral and why they don't make statements about the cause of global warming, contrary to your current expectations, but you'll need to try the more recently announced exercise instead, which appears to be very similar, because the former has already closed.
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Dikran Marsupial at 17:30 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Using the search facility on TCP for papers on "downscaling" gives
0 papers that explicity endorses and quantifies AGW as 50+%
6 that explicitly endorses but does not quantify or minimise
35 that implicitly endorses but does not minimise
46 that take no position
0 that implicity minimise or reject AGW
0 that explicitly minimises or rejects AGW but does not quantify
0 that explicitly minimises/rejects AGW at less than 50%
0 that are undecided
Which is pretty much what you would expect if you knew that downscaling was an area of research in climate change that had relatively little to do with attribution, and that scientists tend only to draw conclusions on issues that are directly addressed by the paper. I suspect the paper I co-authored would have been rated as "no postion" or "implicitly endorses but does not minimise", and three of my co-authors are from the Climatic Research Unit at UEA. You have a mistaken view of the motivations of scientists, scientific publications are generally rather understated. -
JasonB at 17:24 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
barry,
The proposition put to the authors in the email is "that human activity (i.e., anthropogenic greenhouse gases) is causing global warming (e.g., the increase in temperature)", as you quoted. They were asked to assign the level of endorsement of their paper to the proposition that human activity is causing global warming. If you read the description of each level you'll see that the difference between 1, 2, and 3 is not how strongly they agree with that proposition, nor what percentage of human involvement there is, but rather the manner in which that endorsement was expressed.
In other words, it is not that level 1 is "I am absolutely certain that humans are responsible for > 50%" and level 3 is "I'm reasonably sure that humans are responsible for > 50%" (i.e. degree of confidence), or that level 1 is "Humans are responsible for > 50%" and level 3 is "Humans are responsible for > 10%" (i.e. degree of responsibility), but rather than level 1 is explicitly stating the percentage of human responsibility and it is greater than 50% while level 3 is implicitly assuming human responsibility.
Now it's possible that different people have different interpretations of the phrase "is causing", but to me it implies it is the major component, i.e. > 50%, and the authors of 97.2% of the papers with a position on AGW responded to the proposition that human activity is causing global warming by saying their paper endorsed that proposition, either by explicity quantifying the degree of human involvement, by explicitly stating that humans are causing global warming, or by implying that humans are causing global warming.
If they felt their paper disagreed with that proposition, then levels 5, 6, and 7 were available for them to show how it expressed that disagreement.
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engineer8516 at 17:18 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
@ Kevin...You didn't understand my post at all. I don't disagree with the 97% number. It's like voting if people don't vote they're not part of the total so u use the subset that actually voted. But that's not my point. Please read my comment 162 to understand what I'm talking about. Whatever, it was just my opinion on the topic anyway.
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Dikran Marsupial at 17:12 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Engineer wrote "Why? If those papers are on the topic of climate change ... and the authors support AGW, then I would expect them to mention human CO2 emissions"
I can give you an example with which I am familiar. I have done some work on statistical downscaling (essentially trying to work out how climate change will effect sub-regional scale climate from the larger scale climate projections provided by GCMs). As this only looks at the statistical relationships between large scale and sub-regional climate it is pretty much independent of the cause of the climate change. This means that there is no specific need to take a stance on the cause of the climate change as it isn't directly relevant to the methods described in the paper. Some papers do mention emissions scenarios (IIRC the paper I authored [which isn't in the survey] does, but I can't remember if it explicitly attributes any proportion of climate change to anthropogenic emissions), and some don't, basically at the author sees fit.
Something worth bearing in mind is that scientific papers are generally written for other scientists, not for the general public,and they definitely are not generally written to resolve common myths in climate blogs (although there are exceptions). As a result, they tend not to state the bleedin' obvious, and they tend not to draw conclusions on topics that are not directly supported by the evidence presented in the paper. In the case of a downscaling paper, the results basically show how well you can predict historical local climate from supra-regional climate, so it doesn't in itself say anything about the cause of climate change, even though the authors fully agree with the mainstream position on attribution.
Essentially, not all papers on climate change are on the question of what causes how much of it, so not all papers explicitly make a statement on attribution.
I look forward to your answer to Cap'n Bluetooth's conundrum ;o)
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barry1487 at 17:02 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Thanks to Tom.
Re-reading the thread at Lucia's, I see Zeke Hausfather reads the ratings much as I did, and I know he's no dummy. So if he did, and I did (and some others at Lucia's), how many original authors did?
Regarding Tom' points, if original Authors believed that options 2, 3, 5 and 6 were not related to >/<50% influence, but qualitative statements, then that may have a significant impact on results expected under the rubric given here. Almost everyone agrees, including the (better-informed) skeptics, that AGW is real and happening. This is the public perception that John Cook has stated he is combatting with this paper - that AGW is real and happening, which public announcements may also have confused me and others as to what the consensus position is that the paper is investigating.
A concise statement in the abstract of what the "consensus position" is as investigated by the paper would have obviated a considerable amount of confusion.
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Kevin C at 16:37 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Captain Bluetooth is also confused about the consensus
Arg, me hearties, I've been learnin' me numbers. Need to divvy up the booty fair 'n square. Burden of bein' a cap'n, an all.
A week past I got cut in a fight with Leftie Jake. So I got to wonderin', what proportion of sailor dogs is right handed?
So I calls the crew on deck, all three 'undred men, and I asks 'em "Which hand do you dogs like to use yer cutlass in?".
Ninety seven of them says "Right". Two says "Left". Roberts says "Both", the blaggard.
The other two hundred? They're cussin' me and yelling "I've only got one 'and". Except for two-hooks Jim who fixes me a stare that's blacker 'n pitch.
So this is what's puzzlin' me. Is the proportion of sailor dogs that's likely right 'anded 97% (ninety seven of an 'undred), or 32% (ninety seven of three 'undred).
Engineer: Can you explain Captain Bluetooth's confusion?
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sidd at 14:53 PM on 21 May 20132013 SkS Weekly News Roundup #20B
Before expressing strong opinions on the Cheung(2013) paper, one might want to read it ?
1)Impact of increasing fish exploitation:
In the quote below, LME = Large Marine Ecosystem and MTC = Mean Temperature of Catch
"Second, fishing efforts in many LMEs have been increasing con-
tinuously since the 1970s. This coincided with increases in SST, result-
ing in strong correlation between changes in SST and fishing effort in
some LMEs. However, there is no evidence that fishing systematically
alters MTC. Specifically, significant but weak relationships between
maximum body size (positively related to vulnerability to fishing, in
general) and the temperature preference of exploited species is found
in only 19 LMEs, with the majority (13) of them showing a positive
relationship, suggesting that the increasing MTC trend was not a result
of the depletion of large fish by fishing that was reported by many
fisheries (Supplementary Information)."2)"What species will move to the warmest waters? To where will the coldest water species migrate?"
None and nowhere. See Figure 1 (which is available at no charge, as is the Supplementary information). The red curves in the panel on the left show local extinction.
sidd
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Tom Curtis at 14:30 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Barry, very briefly (and for the last time for a while):
1) Lucia's argument that the IPCC consensus in 1990 was not that greater than 50% of warming due to anthropogenic factors is valid. The concensus position has evolved over time, a factor not properly recognized in the concensus project. How significant is that? Well, using the figures from Carrick's "scrape" of the data, I excluded all affirmations prior to 2001 but did not exclude any rejections. The result: Affirmations are 97.5% of the sum of all rejections and 2001 to 2011 affirmations. So, even if we exclude all affirmations prior to 2001 because the consensus position was not as well developed then, the result still stands.
2) Further, I also tried excluding all implicit affirmations (but no rejections) from the result. The result is that affirmations are still >80% of the sum of affirmations and rejections in all years, and average 95.35% of the sum of affirmations and rejections in all years. It cannot seriously be believed that 100% of implicit ratings are false positives, even on the stricter criterion that the projects participants believed applied (and rated according to). But even on that absurd assumption it makes nearly no difference to the result.
3) You are correct that authors may have used a less strict interpretation of the criteria than the abstract ratings. If true, however, it would merely partially explain why author ratings rated the papers as far more supportive of the concensus, and would have no implications about the validity of the abstract ratings.
So, even allowing absurd amounts of credence to the arguments of Mosher and Lucia, the actual impact on the result is minimal. Lucia keeps on saying she will get around to producing numbers to analyze her intuitions. Frankly, if she were serious she would not blog on the subject until she produced those numbers. I believe she relies on the fact that gullible people will accept her mere pointing to a possible flaw as thereby establishing a fatal flaw in the paper. In reality, however, she is at best nitpicking.
Finally, you can find out all the numbers you need for your own analysis by going to the searchable database and searching each distinct category (by year, rating and topic) with the search term "i". It takes about half an hour to get full tables of the data.
Bye now for a month or so.
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engineer8516 at 14:16 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
that's why I thought the 97% consensus was overemphasized.
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engineer8516 at 14:06 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
@ Jason B.
Climate change is a sensitive topic and proponents of AGW do mostly support drastic cuts in emissions. I don't know why you took offense to that statement.
Anyway, 7,930 papers (66%) had No AGW position. 1,339 of these were then self rated and of the 1,339 36% were self-rated as no position on AGW. Since you worked on the paper...How many of the No AGW Position papers and self rated No AGW Position were on the topic of climate change?
You're wondering why I consider the overall percentage number to be relevant. It is interesting that 66% of the overall 12,000 and 35% of the 2,142 respondents had no stated AGW position in their paper. Why? If those papers are on the topic of climate change (I don't know if they are that's why I asked the above question) and the authors support AGW, then I would expect them to mention human CO2 emissions because a) humans are driving climate change through emissions and b) we're running out of time and scientists have to convince governments that humans are behind climate change so we don't kill ourselves.
and reason number 2 doesn't cut it for me. " 2) frankly, every scientist doing climate research knows humans are causing global warming. There's no longer a need to state something so obvious. For example, would you expect every geological paper to note in its abstract that the Earth is a spherical body that orbits the sun?" The paper itself and the UIC survey cited above refute this. I doubt you can find a geologist that doesn't believe that the Earth is a spherical body orbiting the sun. just my 2 cents.
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barry1487 at 13:58 PM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
KR and Jason,
"Two comments, with the understanding that the "concensus on AGW" means AGW as the dominant force behind global warming:"
"If the abstract says anything that can be interpreted as "human activity is <50% responsible for global warming" it would have automatically shunted it into category 5, 6, or 7"
It seems I have been labouring under a misapprehension, then. But I wonder if I am alone in that. The email sent to original authors makes no mention of the consensus being about degree of warming. The Endorsement statement in the email only mention humans contributing, not being a primary source.
Endorsement: The second drop down indicates the level of endorsement for the proposition that human activity (i.e., anthropogenic greenhouse gases) is causing global warming (e.g., the increase in temperature). Note: we are not asking about your personal opinion but whether each specific paper endorses or rejects (whether explicitly or implicitly) that humans cause global warming:
Then they get the 7 rating options, 2 of which are quantified, and the other 5 are qualified. The Author reading the email it must infer that all 7 ratings are under the rubric of >/<50% human influence, rather than (as I did) view the remaining 5 ratings as qualitative, rather than quantitative options. Scientists must make an assumption about that because it is not expressly stated, and in the manner that it is stated in the email, it does not mention degree of human influence at all.
Neither is it in the abstract of the paper. In fact, apart from options 1) and 7), only one sentence of the paper does mention degree of human influence, in the last sentence of the introduction. I find this confusing. The abstract mentions of the consensus position infers a simple accept/reject AGW. Eg,
"Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming."
Throughout the paper, apart from the one sentence in the intro, the values are tied to the phrase "the consensus" or similar.
Read straight, this could easily include a human contribution of less than 50%, and options 2, 3, 5 and 6, are qualitative options, and nothing to do with >/<50% hmuan contribution. IE, If an abstract seems to minimize the importance of the human contribution and gives no qantification, then it is rated 5 or 6, and if it emphasises the importance of the human contribution, but does not quantify, then it should be rated 2 or 3. (It's a shame a breakdown of ratings results is not included in the study/supplementary)
My concern now is, that with different interpretations of the consensus statement (and different scientific societies and position statements also word the consensus differently, some only going as far as saying that human activity is contributing to global warming), the original Authors may have rated as I did, applying to all but options 1 and 7 a qualitative interpretation of abstracts.
Possibly I am just ignorant or not too bright. They said so at Lucia's, where I have been arguing, against them there, that the 97% result has come from a simple accept/reject AGW. I really do find it incredible that 97% of abstracts endorse >50% human influence, implicatively or otherwise.
BTW, are any of the authors commenting here? It would be great if they did and identified themselves (unless they prefer anonymity), so that they could clear up misunderstandings.
Hey, John Cook, come straighten us out.
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JasonB at 11:12 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Dr Tung,
We are all wasting our time here.
On the contrary, this latest exchange has definitely cleared up some confusion that I, and apparently many others, had about your position. You may feel that the meaning was clear but by continuing to use a word that carries a different meaning to that which you were apparently trying to express, it made it difficult for others to discern.
So this has certainly been productive and should move the discussion forward.
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JasonB at 11:00 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
engineer,
just my 2 cents.
I'd be asking for my money back.
Perhaps you haven't seen my earlier comment, among many others' comments that already addressed this point? Perhaps you can explain why a number that would be invariant regardless of how many irrelevant papers are considered is less important than a number that can be changed at will simply by adding more papers to the set of papers that must be manually considered?
To me, it seems illogical to include papers that are irrelevant to determining the question at hand but I look forward to your explanation.
Especially since the keyword searches used to find the papers, "global warming" and "global climate change," are sensitive topics with proponents pushing for drastic emission reductions.
Are they? Tell me, what topics should researchers use who are simply reporting on some scientific results so they can avoid these "sensitive topics" with unnamed "proponents"? That's what all the papers I looked at were doing, and, as I've mentioned before, all the "neutrals" I saw clearly accepted global warming was occurring (and were reporting on some aspect of the consequences), it's just that they didn't mention the cause of it in their abstracts. Since they did give any indication on the cause, they were irrelevant to the question at hand, just as the vast majority of papers published in the scientific literature. Should they be included in the total too, so the two percentages become ~0% and ~0% (while still maintaining the same ratio)? Or should we focus on the papers that actually have a bearing on the question at hand?
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ColorMeSkeptical at 10:54 AM on 21 May 2013CRU tampered with temperature data
Ummm... How can "Climate Change Email Review" perform an "independent" review that "proves" CRU was hiding nothing when CRU a) refused to release its data, deleting it in the end with the (-snip-) justification that they "lacked disk space" and b) refused to release their source code for independent analysis? How is "refusing to release for truly independent review by any interested party" different from "hiding"?
Moderator Response:[DB] Inflammatory snipped. Note that the Muir Russell Commission performed their independent audit and replication of CRU data sans any source code in a mere 2 days, saying in typical reserved fashion that 'any competent researcher could have done similarly'.
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Rob Honeycutt at 10:54 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
engineer @ 157... Well, no one ignored the "no position" papers. It's discussed quite extensively in the paper.
You're not noting the fact that, when the scientists rated their own papers, that 66% dropped to 35%, yet the consensus figure of papers that state a position stayed nearly the same. That, in and of itself, suggests a level of robustness to the conclusions.
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KK Tung at 10:45 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to post 70 and 71: I may have used the word "underpredict" and "discrepancy" incorrectly, but the meaning was clear because I elaborated many times and in different ways what I meant. It was even clear from my first mention that I was using the ensemble mean as the prediction of the forced response only. But you keep repeating an erroneous interpretation of what I said, as using the ensemble mean as a prediction of forced response plus internal variability. I never said that. In fact I kept saying the opposite. We are all wasting our time here.
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JasonB at 10:43 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
barry,
Further to KR's comment, the reason I mentioned the 5, 6, and 7 categories was because each cateogory must be considered in the context of all the others. If the abstract says anything that can be interpreted as "human activity is <50% responsible for global warming" it would have automatically shunted it into category 5, 6, or 7, whether it was implying it, stating it, or exlicitly quantifying it.
And if it did not go either way, then it was neutral.
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Roger D at 10:19 AM on 21 May 20132013 SkS Weekly News Roundup #20B
William - OK, fish leaving one area for another with a more suitable water temperature may not be as "serious" as overfishing now. Maybe climate change is miniscule in impact in comparison to overfishing now, but it is a warning that this will be a worsening problem to life as normal. In addition to overfishing, pollution, ocean acidification that may all get worse now we see there is this new and likely growing impact that will probably be a negative. What species will move to the warmest waters? To where will the coldest water species migrate?
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engineer8516 at 09:57 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
First, I would like to commend you guys for putting the time and effort to do this. However, I think the 97% consesus is misleading.
The article states, "We found that about two-thirds of papers didn't express a position on the subject in the abstract, which confirms that we were conservative in our initial abstract ratings."
Thus, the 97% consensus is only for the papers that expressed a position on the topic of AGW. Therefore, out of the total sample size of 12,000, the number of papers that expressed support of AGW in their abstract was actually 32% . And 1% expressed disagreement or uncertainty with AGW. Thus, 67% of the abstracts didn't have a position.
The article further states,
"This result isn't surprising for two reasons: 1) most journals have strict word limits for their abstracts, and 2) frankly, every scientist doing climate research knows humans are causing global warming. There's no longer a need to state something so obvious. For example, would you expect every geological paper to note in its abstract that the Earth is a spherical body that orbits the sun?"
While the first one is true, it still doesn't tell us the author's position. The actual authors may or may not support AGW or maybe unsure. The second one looks like a personal opinion.
It seems illogical to just ignore the 67% of papers that didn't express an opinion in their abstracts. Especially since the keyword searches used to find the papers, "global warming" and "global climate change," are sensitive topics with proponents pushing for drastic emission reductions.
Also that UIC paper that is cited asked 2 questions in its online survey.
"1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?
2. Do you think human activity is a significant contributing factor in changing mean global temperatures?"
76 out of 79 climate scientists answered risen to question 1. The 97% consensus comes from the 75 out of 77 climate scientists that responded yes to question 2. But question 2 is subjective because it doesn't state what % is considered siginificant. Significant could be 10%, 20%, 50%, etc of observed warming. just my 2 cents.
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Bob Loblaw at 08:28 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Another thought just popped in. You (Dr. Tung) said:
" Could it be the word "under predict", which to me just means that the model warming is less than the observed warming. I did not attach any value judgement to it."
The problem is that "under predict" is a value judgment. Just as "discrepancy" is. A non judgmental wording would be "the numbers are not the same".
Part of my science training was the importance of making clear distinctions amongst "observations", "interpretations", and "conclusions". Not only is "under predict" not an observation, it is not even an interpretation - it is a conclusion.
And we're "nit-picky" not because we're at Skeptical Science - we're nit-picky because that is what scientists do...
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Bob Loblaw at 08:17 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Busy, so not much time to comment, but I want to stress Dikran's comment in #67, and put it more bluntly:
The model ensemble mean can't be used as a prediction of forced response plus internal variability, and thus is can't "under predict". Regardless of what label you put on it, I think you are over-interpreting the difference.
Also as Dikran points out: you need to get back to the points people have raised about the circularity of the argument. I think that your repeated "under predict" type vocabulary underlies a lack of realization that that you have potentially serious issues related to your methodology. You are interpreting things in a fashion that is not supported by either the evidence or your discussion, but you don't seem to be able to step back and realize that there is an implicit assumption in your work that is not jsutified (and is leading you in the wrong direction).
...back to reader mode...
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John Hartz at 08:01 AM on 21 May 2013Who is Paying for Global Warming?
Also see Who's Paying the Price for Global Warming? a 60 second podcast by David Biello, Scientific American, May 19, 2013.
BTW, Biello's answer to the question posed:
U.S. taxpayers have so far borne the brunt of climate change costs
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dagold at 06:41 AM on 21 May 2013Help close the consensus gap using social media
Hey, Alexandre: Yes, sometimes I think it is necessary to 'leap ahead' and at least put the 'picture' out there of what we want to help bring about. Not in any way, shape or form to compare anything I do or say or write to MLK, but his 'I have a Dream' speech sort of did that.
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Rob Honeycutt at 06:16 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
KR... Well, you know, they don't have much room to play with at 0.7% of the research. ;-)
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Eyal Morag at 05:59 AM on 21 May 2013Was Greenland really green in the past?
The Saga of Erik the Red - Icelandic Saga Database
1880, English, transl. J. Sephton, from the original 'Eiríks saga rauða'.Now, afterwards, during the summer, he proceeded to Iceland, and came to Breidafjordr (Broadfirth). This winter he was with Ingolf, at Holmlatr (Island-litter). During the spring, Thorgest and he fought, and Eirik met with defeat. After that they were reconciled. In the summer Eirik went to live in the land which he had discovered, and which he called Greenland, "Because," said he, "men will desire much the more to go there if the land has a good name."
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Alexandre at 05:41 AM on 21 May 2013Help close the consensus gap using social media
dagold at 05:22 AM on 21 May, 2013
Not likely, I know, but I wish there were more people dreaming of the right things...
Already liked on Facebook.
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dagold at 05:23 AM on 21 May 2013Help close the consensus gap using social media
Okay- think I got the hyper-link inserted now:
www.huffingtonpost.com/davidgoldstein/a-daughters-tears_b_3287465.html?utm_hp_ref=climate-change
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dagold at 05:22 AM on 21 May 2013Help close the consensus gap using social media
Well, here is my latest Huffington Post article with my attempt to generate climate awareness. It is the complete text of the dramatic climate policy speech we all want Obama to make. It's gotten some buzz in the climate world and I am hoping folks will share it enough so that it comes to the attention of Pres. Obama himself. Here it is: http://www.huffingtonpost.com/davidgoldstein/a-daughters-tears_b_3287465.html?utm_hp_ref=climate-change
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Rob Painting at 05:06 AM on 21 May 20132013 SkS Weekly News Roundup #20B
William - actual research demonstrates that the effect of ocean warming on fish stocks is significant. I don't think that anyone here disputes that overfishing is a huge concern - many species are heading toward collapse. These pressures are not mutually exclusive.
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rockytom at 04:38 AM on 21 May 20132013 SkS Weekly News Roundup #20B
#5. From Peru
It may be that the authors used a non-permafrost area to conduct their experiment. Their abstract doesn't mention permafrost (I haven't read the whole article). The main concern about the warming Arctic is the release of methane from thawing permafrost and not the release of carbon from non-permafrost soils over a 20-year period. Maybe someone who has read the whole article can elucidate.
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Dikran Marsupial at 04:35 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
I'm sorry Dr Tung, but there were no accusations of your motives, in fact I clearly stated "I did not mean to imply that your comments were deliberately unfair".
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MP3CE at 04:25 AM on 21 May 2013Help close the consensus gap using social media
I think SkS does this job very good. Perhaps the issue of polluting without paying a price to it should be compared to avoiding taxation at the expense of others, but again, I am not sure about public perception of this as some people do think that avoiding taxation is good and not a cheating on others.
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KK Tung at 04:17 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Replying to post 67 by Dikran: Your comment is well taken. I had suspected that all these accusations of my motives may be due to a word that I used. Instead of the word "underpredict" I should have used a longer phrase "a difference and the difference is negative when taken as the model ensemble mean minus the observation". I will try to be more careful commenting on this site and not use short-hand words. Often when I was busy or in a noisy environment trying to reply using my ipad I tend to write tersely, and it has not worked here.
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Dissident at 04:11 AM on 21 May 2013Another Piece of the Global Warming Puzzle - More Efficient Ocean Heat Uptake
I'm not sure whether this is off topic, but I have read in other threads that there is less cold water plunging to the ocean floor around Antarctica (and presumably the Arctic too) due to the sea water becoming less saline due to increased precipitation and melting polar ice. In the Arctic that can result in a weaker gulf stream in the North Atlantic, while in the southern ocean, would the same mechanism increase the flow of water into the Humboldt current (what doesn't plunge down has to go somewhere) - behaviour of both currents are different due to land mass distribution.
I think the increase in water 'available' for the Humboldt current would automatically make it stronger, would that be a reasonable hypothesis? If that current is stronger, wouldn't the likelihood of La Niña be increased, with an associated increase of polar water migrating to the tropical Pacific, which would affect the amount of heat absorbed by the Pacific?
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Alexandre at 04:00 AM on 21 May 2013Help close the consensus gap using social media
For some time now I'm convinced this issue needs a more skillful aproach - PR wise.
Documents like that joint statement from academies of science are not nearly enough to reach the broader audience. Only a few climate geeks get to read it.
Simple and direct messages are much more suitable for this kind of task. If you could get the endorsement of a few top-rank climate research insitutions, it could be even better (GISS? NOAA? Hadley Center?). I don't think it's beyond the reach of the SkS community.
This project is definetely a step in the right direction. I wish you success.
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william5331 at 03:35 AM on 21 May 20132013 SkS Weekly News Roundup #20B
If the snow pack is melting in the Rockies, providing the water too early for agriculture, they better start encouraging the spread of the Canadian Beaver. They serve the same purpose as glaciers in shifting water from winter to summer, mitigating floods and eliminating catastrophic low water. Read Three Against the Wilderness by Eric Collier to see just how effective beavers were in 1948 when the reverse happen. There was a very heavy snow pack and a much delayed spring. When it came, the floods were incredible and the Frazer Valley Delta by Vancouver had huge floods. Only on Meldrum Creek where Eric had brought back the beavers from near extinction, were the waters held and released slowly.
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william5331 at 03:23 AM on 21 May 20132013 SkS Weekly News Roundup #20B
Trying to blame climate change for a change in fish catches is like when the Canadians tried to blame the seals for the decline of fish on the Grand Banks. (read Sea of Slaughter by Farley Mowat). Yes there may be an effect but it is miniscule in relation to the destruction we have wrought on the fisheries stocks by our amazingly stupid fisheries policies. In the future, climate may be the overwhelming factor but at present it is us.
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Dikran Marsupial at 02:30 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Dear Prof Tung, "underpredict" and "discrepancy" are both words that carry a strong implication that two things should be the same, but aren't.
As we agree, the ensemble mean is an estimate of only the forced response. This means that it is not itself a prediction of observed temperatures. Therefore it is unfair to say that the ensemble mean underpredicts something that it does not actually attempt to predict.
The collins dictionary says this about the word "discrepancy":
"Discrepancy is sometimes wrongly used where disparity is meant. A discrepancy exists between things which ought to be the same; it can be small but is usually significant. A disparity is a large difference between measurable things such as age, rank, or wages"
Now if you had said there was a difference rather than a discrepancy, your statements would have been far less of an issue.
Note this is not nitpicking. There are many skeptical arguments used to criticise models that explicitly or implicitly are based on the assumption that the observations should lie close to the ensemble mean (which would seem reasonable to most, but which we would I hope agree is incorrect). Sometimes these arguments even make it through into publciations in peer reviewed journals, for example Douglass et al (2008). When discussing science for the general public, especially on a contentious subject, such as climate change, it is very important to make sure that ones choice of words is correct and does not propogate misunderstandings.
I offer this in the hope that we can return to the substantive issue, which is the circularity of the proposed method.
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KR at 02:16 AM on 21 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
barry - Two comments, with the understanding that the "concensus on AGW" means AGW as the dominant force behind global warming:
First: The title is part of the definition of the categories, as viewed by both raters and authors. And category 2 "Explicit endorsement without quantification" is just that, endorsement of the AGW consensus. If a paper treats AGW as not the dominant influence, it's not endorsing the consensus, and shouldn't be rated as Category 2. Ratings are not just off the description (a refinement), but also the category title itself. And somehow, I cannot see an author whose paper rates AGW as a minority influence would voluntarily rate it as explicitly endorsing the consensus.
Second: Category 3, "Implicit Endorsement: Implies humans are causing global warming. E.g., research assumes greenhouse gas emissions cause warming without explicitly stating humans are the cause", is a clear endorsement of human caused global warming if you understand that greenhouse gas emissions are caused by humans.
Therefore, unless there is a statement in the abstract or paper that increases in GHGs such as CO2 are from natural causes, rather than anthropogenic (very much a minority view), this is indeed an endorsement of the consensus. Because, quite frankly, the evidence for human driven increases in CO2, CFCs, and the feedback from water vapor is overwhelming.
---
What is most amazing to me in these discussions (here and on sites like the Blackboard) is the push for one-sided filtering: that papers categorized as rejections are always rejections, but that somehow papers categorized as endorsements are not always endorsements. That seems overwhelmingly biased to me...
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KK Tung at 02:05 AM on 21 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to post 63 and post 65 by JasonB: you and others are asking a different question and a different test than the point I was trying to make. The question you asked was if I claim that the model is in error in under predicting the observed warming what statistical test do I have to prove it. The standard test, which many of you are alluding to, is to test if the mean of all the ensemble members is different from the observation by seeing if it is within two standard deviations of the variance created by the ensemble members. If so then I cannot claim that the model is in error because the difference is random climate noise. My question was different, it concerns forced response vs unforced response. I used the model ensemble mean to approximate the forced response. If I see the forced response is lower than the observation, which contains both forced and unforced internal variability, I tentatively attribute the difference to internal variability that is not and should not be in the ensemble mean. It is tentative because there were not enough ensemble members from any modeling group in CMIP3. I see it happen systematically in most models we looked at with more attention paid to models we trust. I mentioned it previously as an revelation to me, a thought process that is often necessary in science, not a proof in mathematics. You may have a different thought process for discovery. I know of mathematicians who do not proceed to solve for the solution to a partial differential equation until they could prove that the existence and uniqueness of the potential solution.
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