Skeptical Science Comments

Comment on 2013 SkS News Bulletin #12: The Consensus Project

John Hartz

miffedmax:

No surprise there given how Deniersville is merely an echo-cahmber, full of sound and fury, and signifying vitually nothing.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Longhornmaniac8

Great work, SkS team!

One complaint I have (or perhaps just missed) is a relative lack of discussion of the No Position papers and their self-ratings.

You mentioned at the end of page 4:

"Among self-rated papers not expressing a position on AGW in the abstract, 53.8% were self-rated as endorsing the consensus."

What about the other 46.2%? Needless to say, it would somewhat undermine your conclusion if of the No Position papers that were self-reviewed, the entire remainder rejected the consensus. Now, I'm 99.9% sure that wasn't the case, but unless I missed it, I don't see any further discussion of the self-reviews of the No Position papers.

Could an author perhaps provide some additional insight to go along with that 53.8% figure? Of the remainder, what percentage self-identified as "rejecting" the consensus, and what percentage self-identified as "no position."

Comment on 2013 SkS News Bulletin #12: The Consensus Project

gws

The Financial Times link seems already behind a paywall, at least when accessed from here (Norway)

Comment on 2013 SkS News Bulletin #12: The Consensus Project

miffedmax

I haven't done a thorough search, but it sure seems a lot of the denier blogs closed their comment sections immediately after challenging the 97% claim on pretty much the same grounds as fretslider.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

dana1981

Note that I tweaked the first sentence a bit to add some precision.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

DSL

herrhund: "Why are the CERN physicists focusing on cosmic rays when it is correct what Jim Eager said about that there are no theories supported by the full body of evidence?"

Herrhund, the cosmic ray theory is not a comprehensive theory of climate change. It is not an alternative to the theory of anthropogenic global warming. If Svensmark turned out to be right about cloud seeding, CO2 would not suddenly stop absorbing/emitting radiation at various pressure-broadened bands in the thermal infrared range. You also fail to understand what's working against Svensmark. That, in fact, strongly suggests that you're not concerned with scientific progress but rather finding anything (no matter how collectively incoherent) that supports your current understanding of the world.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

DSL

Otiose: "It's very possible in a decade or two science historians will cite this paper as an example during the period in question measuring the degree to which politization was successful in defending a parituclar view or set of views in the climate field and not a measure of the validity of the science."

Yes, Otiose, it is possible. Now, tell me how probable it is, and give me the evidence upon which you base your answer.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

John Hartz

The fact that two-thirds of the 12,000 papers reviewed did not explcitly mention endorse "climate change" or "global warming" completely undercuts the denier meme that scientists have adopted pro-AGW positions in order to feed at an imaginary grant trough.

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

MA Rodger

With my memories of the heavy-going I encountered discussing the more straightforward issues raised in part 1 of this post, this second part would appear a nightmare.

One of the areas I consider worthy of discussion is the reconstruction of the past AMO. Tom Curtis has already addressed some aspects of this up-thread.

The existence of an AMO prior to the industrial age would give much credence to the Tung & Zhou 2013 thesis. But I find the offered analysis, the statistical significance identified between CET & Mann et al 1998 RPC#5 data, to be less than convincing. The wavelet analysis on CET will yield a 50-80 year signal of some sort, just as the Mann et al filtering will yield a 50-90 year signal. And as there are such signals existing in synchronisation in both the AMO & the CET for the last 130 years, it would take very little for them to stay in synchrony for a further 200 years into the past. So why is this 50-80 year cycle in CET more than just a form of cherry-picking?

Mann et al 1998 is not the only extended AMO reconstruction. Gray et al 2004 present an AMO reconstruction 1567-1990 which certainly looks more convincing that Mann et al 1998 when compared to Enfield et al 2001. Gray et al 2004 was noted within Tung & Chou 2013 but not seriously considered for analysis. And Gray et al 2004 shows nothing convincing by way of a periodic AMO that could be resulting from natural variation.

For illustration, I have plotted the Enfield, Mann & Gray AMO series here.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

Say we wanted to introduce a new brand of cat food, "Vibrizzae", and for our advertising campaign, we conducted a survey to find out whether cats preferred our catfood over that of our competitors. So we found twenty households with cats, and asked their owners to put out a bowl of Vibrizzae and a bowl of MouseChunkz for each cat at noon and then return an hour later to see which had been eaten. Eight cats were found to have eaten the Vibrizzae, two had eaten the MouseChunkz and 10 had not touched either (perhaps they were having a nap, or had gone outside hunting, or just weren't hungry). So how could we present our results? The cats that didn't eat either catfood don't really tell us anything about the cat's food preferences, so the obvious thing to analyse the food preferences of the cats that actually ate some of the catfood. We could then reasonably claim "eight out of ten owners, that expressed a preference, said their cats preferred Vibrizzae"; sound familiar?

Now the Vibrizzae Corporation could have said that "40% of owners said their cats preferred Vibrizzae", but that is clearly only a lower bound on the proportion of cats that preferred Vibrizzae as it implicitly assumes that the 50% of cats that didn't eat anything would have eaten MouseChunkz had they eaten anything. Now if you were the CEO of MouseChunkz inc. I can see why you would argue that Vibrizzae should choose the latter advertising slogan, but would that have been fair or reasonable? No, of course not, it would clearly be a daft request, and the CEO of the Vibrizzae Corporation would laugh his arse off if the CEO of MouseChunkz inc had made any request of the sort.

In case anybody has missed the analogy, the skeptics that are claiming that there is not a 97% concensus are making the same argument as the CEO of MouseChunkz inc. and their argument is about as sensible. "In our survey 97 out of 100 papers who expressed a preference, said their scientists preferred anthropogenic climate change" is essentially what the survey says.

Of course, like all analogies, you can almost guarantee that someone will extend it beyond reason to avoid the basic point being made, but at the very least it establishes a precedent for the calculation used. ;o)

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Otiose

It's very possible in a decade or two science historians will cite this paper as an example during the period in question measuring the degree to which politization was successful in defending a parituclar view or set of views in the climate field and not a measure of the validity of the science.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund - "What I am trying to say here is, that throwing around with headlines like '97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature' is not accurate since they are missing all literature in other languages than English, as well as all research papers which are not using the exact key words."

Indeed, some skeptic papers were missed by those by criteria. But for those same reasons, so were many papers supporting the consensus. This is a sampling procedure, looking at a representative subpopulation and extrapolating to the whole, with small uncertainties due to sample size and how representative a slice of the population was examined.

12,000 papers is a huge sample - political studies with +/-3% accuracy are commonly done with <1000 samples. And I would opine that 'global warming' and 'global climate change' will produce a quite representative slice.

This is a percentage study of a population to measure consensus - and given the data, it's missed some 44 consensus papers for every single skeptic paper not collected by the search criteria. Whether or not it collected your favorite (individual) paper(s) is irrelevant; your argument is invalid.

Comment on Measure the climate consensus yourself with our Interactive Rating System

Tom Curtis

Kevin C @12, well picked. The "missing" paper from an "e" search turns out to be:

Agricultural Impacts Of Global Warming - Discussion

Authors: Innes, R; Kane, S (1995)
Journal: American Journal Of Agricultural Economics
Category: No Abstract
Endorsement Level: 4. No Position

Comment on 2013 SkS News Bulletin #12: The Consensus Project

Dikran Marsupial

I have also deleted my responses to fretsliders deleted posts. If fretslider wishes to discuss the issue in a less argumentative manner, I would be happy to start again from a clean slate.

Comment on Measure the climate consensus yourself with our Interactive Rating System

Kevin C

I can't imagine an abstract with no e's, unless someone was having a bet. A paper with no abstract and no e's in the title might be the case.

Comment on 2013 SkS News Bulletin #12: The Consensus Project

John Hartz

fretslider:

Many of your recent posts are in violation of the following part of the SkS Comments Policy. As such, they have been deleted.

Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.

Comment on Measure the climate consensus yourself with our Interactive Rating System

Tom Curtis

JosHaq @10, not knowing how to search for wildcards, I merely searched for "e" with essentially the same results (12279 total abstracts). The difference between that and the 12,465 papers recovered by the ISI search according to the paper would indeed be the 186 non-peer reviewed papers. (Or at least that seems very likely.) I have no explanation for the difference between the wildcard search and my "e" search (unless there is an abstract with no "e"s), nor why the difference in the total papers between search engine and paper.

Comment on 2013 SkS News Bulletin #12: The Consensus Project

Tom Curtis

fretslider @8:

To believe means "to accept something as true". So according to you, athiests accept nothing as true. (I wonder if you accept it as true that atheists accept nothing as true? Or was that merely a convenient lie that you did not believe.) Anyway, however much that idiocy may be true of you, it is not true of atheists in general - so don't slander us with your ill concieved misunderstandings.

Comment on 2013 SkS News Bulletin #12: The Consensus Project

Tom Curtis

fretslider, you are not being imaginative enough. Consider the paper, "First evidence of Late Carnian radiolarians from the Izmir–Ankara suture complex, central Sakarya, Turkey: implications for the opening age of the Izmir–Ankara branch of Neo-Tethys". It neither directly nor indirectly affirms that humans are causing climate change, and wasn't even included in the survey. Against the backdrop of all scientific publications, papers actually discussing the issue of whether humans have caused global warming are distinctly less than 1%; and hence the 97% of papers discussing the issue who affirm that humans are in fact causing global warming are also less than one percent. There is no limit to how much you can pad the statistics to avoid an uncomfortable truth. You can include newspaper articles as well. Or add in right wing think tank press releases. But no matter how you pad and how you evade, it will still be true that:

97% of scientific papers that discuss the issue affirm that global warming is caused by humans.

The evident desperation of deniers to conceal that fact shows just how strongly they rely on subterfuge to make their case.

Comment on Measure the climate consensus yourself with our Interactive Rating System

JosHag

@Tom Curtis #9, the total number of papers in the search option is 12280 (enter SQL wildcard % at 'Search Term') and before I start a search it says that 12,464 papers are present. So, you are probably right that (almost) all the papers have been retained in the database. The difference between the two numbers is 184, almost the same as the 186 you mention. A coincidence?

Comment on 2013 SkS News Bulletin #12: The Consensus Project

jyyh

fretslider - it seems you're the sort who thinks if one forgets gravity one can fly. Thus, you might also believe the rocks have a mind which is constantly thinking of gravity. This is an interesting belief system, but please talk about this somewhere else, do you know a forum for pantheism which would be in my opinion a more proper place to discuss your beliefs about rocks whichi have not stated anything to you unless you hear them speak? (possible ad hom - delete if required)

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Tom Curtis

herrhund, two can play that game.

"Sensitivity of a global climate model to an increase of CO2 concentration in the atmosphere" by Manabe and Stouffer (1980) was not included because it was published too early for the survey, even though it clearly affirms anthropogenic global warming (IMO).

"Thermohaline Circulation, the Achilles Heel of Our Climate System: Will Man-Made CO2 Upset the Current Balance?" by Broecker (1997) was also excluded due to lacking the correct search terms although it also affirms AGW.

By its nature, not survey of the contents of scientific papers can be expected to be exhaustive; but any large survey is likely to be representative unless it uses biased search terms. This survey did not.

Of course, you can disprove my assumption that the survey was not biased by its search terms by conducting several different surveys of comparable size using distinct (and independent) search terms; or by one very large survey using a random selection of articles from the entire scientific corpus. But just identifying single papers that were not included proves nothing. For all you know, for each "skeptical" paper not included, there are 100 affirming papers that were not included and of which you are unaware.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund, yes, please do research, but bear in mind that it is generally best to do the research before posting.

Asking whether the database contains all debunkings is yet another attempt at rhetorical evasion on your part. It is irrelevant to the purpose of a study whether the paper is a debunking or not, so there is no need for me to check. The point was that there are plenty of non-skeptic papers that are not included due to the choice of keywords as well, that you were not taking into account. Pointing out the debunking papers was just an easy way of demonstrating that this is the case.

Comment on Measure the climate consensus yourself with our Interactive Rating System

Tom Curtis

JosHag @8, the total number of endorsement papers on the database exceeds the numbers mentioned in the paper as well. Combined there is an excess of 335 papers. Interestingly in the consensus project paper, it says:

"The ISI search generated 12 465 papers. Eliminating papers that were not peer-reviewed (186), not climate-related (288) or without an abstract (47) reduced the analysis to 11 944 papers written by 29 083 authors and published in 1980 journals."

There were a total of 335 "not climate-related" and "no abstract" papers, suggesting these have been retained in the data base we are searching.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Well, okay I will leave - doing some research though.

I don't know if you notices, English is not my first language so yes indeed, sometimes I oversee text which is not written in my mother language for some reason.

However, it does not change the facts I pointed out. And you did not answer my question since you expected me to check my sources too, I thought you checked yours in case some of them were debunked.

Comment on 2013 SkS News Bulletin #12: The Consensus Project

fretslider

97% sounds very impressive.

Yet why did the original press release say: "From the 11 994 papers, 32.6 per cent endorsed AGW, 66.4 per cent stated no position on AGW, 0.7 per cent rejected AGW and in 0.3 per cent of papers, the authors said the cause of global warming was uncertain."

How did you get from 32.6% to 97%

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund, stop playing games, I was merely pointing out your lack of self skepticism. The debunkings I mentioned were clearly listed on the web page that you yourself provided, but you failed to mention them. This means that either you saw them and chose not to mention them (which would be dishonest) or that you stopped looking when you found the evidence that supported your argument and didn't bother to check it out (which would suggest that it is you that is biased). Being charitable, I shall assume it is the latter.

Comment on 2013 SkS News Bulletin #12: The Consensus Project

jyyh

Congratulations, it was nice being a part of the initial information gathering phase. Very clever of you to make it a sort of game among the site. :-). I never imagined seeking contact info from thailand in thai language, contact info of female scientists who have published only by their maiden name, or trying to find contact info from indian (or US) nuclear facility, let alone among the russian academics. I will probably remember the game long afterwards. Did you ever find out which T.Hong (or what the name was in the chinese universities) made which paper??

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Did you check all papers which count to the 32% with position on AGW if they got debunked somehow?

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

Herrhund, your argument is incorrect, unless you have some reason to suggest that English speaking scientists are more biased in favour of AGW than against. You have provided precisely zero evidence to support that contention. Similarly the exact choice of keyword is irrelevant unless you can show that the particular keywords used were biased towards AGW. It is not feasible to surver every single paper ever published, so we have to have some method of generating a representative sample. Pointing out skeptic papers that were missed is not evidence of bias, especially if your examples includes papers that were debunked in the peer reviewed litterature and the debunkings are not in the database either!

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund, there are also many papers not included in the project beacuse of missing keywords that do at least implicitly supprt AGW, I know this because I am one of the authors of one such paper! Pointing out skeptic papers that were not included does not establish there was a bias unless you can show that it disproportionately favours mainstream over skeptic papers. So please stop disrupting the discussion until you can do so.

Note that in the particular case of the Svensmark and Friis-Christensen paper, there is clearly no bias as the database doesn't contain the article by Gierens and Ponater that debunks Svensmark and Friis-Christensen either. Or the one by Jorgenson and Hansen. Funny you didn't mention that (it isn't difficult to check whether comments papers are published pointing out the flaws in existing papers).

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

What I am trying to say here is, that throwing around with headlines like '97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature' is not accurate since they are missing all literature in other languages than English, as well as all research papers which are not using the exact key words. And I can bring up tones of research papers like that - all peer reviewed.
Fine, there is a lot of evidence that the climate change is driven by humans - there is also a lot of evidence that support other hypothesis and theories. There is also something like False consensus effect. existing.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Another study that is not included in the consensus project because of missing key words in the abstract:

'Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships'

(Henrik Svensmark, Eigil Friis-Christensen
Solar-Terrestrial Physics Division, Danish Meteorological Institute, Lyngbyvej 100, DK-2100; published 1997)

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund, your evasion is transparent. You have made it abundently clear that you are unwilling to discuss the information the CLOUD project has published, which is a fairly good indication that either you know it doesn't really support your argument or that you don't actually know what it says and are just playing rhetorical games to avoid the fact that those who reject the existence of AGW are only a tiny minority within the scientific community - which is the topic of the discussion.

The CLOUD people were making the same kinds of noises to the general public before the last publication, but the science itself turned out to be a damp squib. I wish they were right, it would be great news, but I am rational enough to know that is highly likely to be wishfull thinking.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Dikran,

the last publication from the cloud project is from august 2011
http://cloud.web.cern.ch/cloud/People/Publications.html

If you would understand German, the interview link I posted is from may 10th with the leading researcher of the cloud project. He is saying that they are going to release new research results, LATER this year - and it is going to be interesting.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund the CLOUD project has published the results of some of their work already, so there is no problem in discussing it. The fact is that it doesn't support your argument and that you simply don't want to discuss it, that is not the same as not being able to discuss it.

I suspect that there are very few following the discussion that would fall for such transparent evasion as introducing an item to support your argument and then saying we can't discuss it because it hasn't been publsihed yet!

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Well, I think nobody can talk about the cloud project in detail since the results are not released yet - I read an interview with the research team and at the moment the results are being checked and will be presented as soon as they are excepted.

http://science.orf.at/stories/1717291/

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

herrhund - the CLOUD project at CERN is a bad example for your argument, there results are interesting, but don't actually support a strong link between cosmic rays and climate. This was something that was pretty well known already, but it does show that governments are happy to fund climate skeptic scientists if the quality of the proposed experiments was high (which AFAICS they were - the results provided so far have been interesting, but not for the reasons the skeptics hoped).

As for the paper in German, I suspect the reason it wasn't included is that it clearly isn't a journal paper. The fact it was published in January of this year is another good reason.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Another example of a research paper, that could not find a way in this study because it is German.
http://wkserv.met.fu-berlin.de/Beilagen/2013/SO%2001-13%20Klimawandel%20Europa.pdf

This paper shows for example a significant correlation between the middle temperature in Europe and the number of sunspots since 1672.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

Why are the CERN physicists focusing on cosmic rays when it is correct what Jim Eager said about that there are no theories supported by the full body of evidence?

The cloud experiment is going to release their research results this year, but here is some information for now:
http://home.web.cern.ch/about/experiments/cloud

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

"Jim Eager at 07:14 AM on 18 May, 2013
Herrhund wrote: "there are other theories"

Except that there are no other theories.

There are several hypotheses, most of which have already been disproven, such as "it's the sun," or shown to be insignificant, such as cosmic rays, but none have risen to the level of being a cohesive theory supported by the full body of evidence."

What about papers done in other languages than English?

Or paper which are about that exact topic but not having the key words in their abstract?

An example: 'Impact of galactic cosmic rays on Earth’s atmosphere and human health' A.Singh, D. Siingh, R. Singh;
The abstract of this paper does not use the key words - so I believe this research paper was not included. Just naming one example of a research paper that is ignored by this study.

Comment on Measure the climate consensus yourself with our Interactive Rating System

JosHag

Thanks a lot for the search possibility.
I tried to check the total number of papers in Endorsement Level '8. Undecided', but got no matches. Endorsement Level 4 'No position' gives 8269 which is much higher than the 7930 mentioned in the Cook et al paper.
Are the level 8 papers per accident incorporated in the level 4 papers?

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

Dikran Marsupial

Dr Tung writes: "That model spread is rather large. If you are satisfied with that, that is fine with me."

The model spread is indeed large, the key question is whether there is a good reason to suppose that the spread should be smaller, and you so far have provided no evidence or argument to suggest that it should. Of course we want the projection to have as great a certainty as possible, so none of us are "satisfied" with the spread and why climate modelling groups are working hard to improve their models.

"And I am not sure how the models can be made to do it since we do not know the initial condition in the ocean sublayer well in 1850-1870 (the time these model simulations start)."

That is the entire point of using a Monte Carlo simulation. We can't predict chaotic phenomenon, but we can simulate them, so that is what we do and the spread of the model is an indication of what is plausible given what we know about the underlying physics.

"My comments about the CMIP3 model underpredicting the warming should not be taken as a criticism of the models"

In that case, I think you need to be more careful in how you express yourself as there are those in the public debate on climate that are likely to use your words to argue that the models are flawed. The statement however is still wrong - the models DON'T underpredict the warming, the ensemble mean IS NOT a hindcast of the observed climate change, only the forced component. The enembles hindcast of the actual climate is that it lies somewhere in the spread of the model runs, which indeed it does, so the models DO NOT underpredict the warming. I'm sorry to go on about this, but this is a fundamental point in understanding what the model ensemble actually says.

"One could take the point of view that the internal variability is just climate noise, and that the difference from any such unpredictable (by models) internal variability should be considered as "insignificant" (p595 of AR4) (post 33 here)"

It is only insignificant for the purposes of deciding whether the models do what they are intended to do correctly, which is to hindcast/project the forced component of the climate change.

"This is in essence a statement that we will ignore internal variabilities just because we have not found a way to simulate it using the current generation of models."

This is a deeply unfair and uncharitable characterisation of a community of hard working scientists. In making policy for (in)action on fossil fuel use, the key question is what is the effect of fossil fuel emissions on future climate. The answer to this question depends only on the forced component of climate change. This means the modellers are giving the direct answer to the question posed. They are not ignoring internal variabilities, far from it, the spread of the model runs is a good way of characterising the plausible effects of internal variability (according to our current understanding of the physics).

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

nealjking

#102, grindupBaker:

Real science often progresses in ways that seem not to have been the most straightforward, from a backwards-looking perspective. The development of quantum mechanics was far weirder than that of the framework for climate science, yet that was done in thirty years. If you look at the book by Archer & Pierrehumbert that I mentioned before, you can see how the picture fell into place.

Comment on The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

John Mason

Agnostic #26 -

The variability of sea levels back then (and for much of the time leading up to the Pleistocene Transition) was no more than +/- 70 metres. That means that in cold cycles it only got cold enough, in the worst cases, for enough land ice to form to drop sea levels some 70m and rise them back up by the same amount during the warm cycles when it melted. Quite a difference from the 125m associated with the Last Glacial Maximum!

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Kevin C

grindupBaker: Yes. While fundamental controller for the climate of any body with an atmophere has always been top-of-atmosphere energy balance, we've been stuck with surface temperatures because that's all we've got for all most of the period of interest. The start dates for various records look something like this:

10,000-1,000BP: Global prooxy record
~1700: Regional instrumental record
~1850-1880: Global instrumental record
~1950?: Energy content from reanalysis
~1990s: Energy content from observations

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

Philippe Chantreau

This has been a most interesting, truly scientific debate, all too rare on blogs. I can think only of RC as another place where such discussions could happen .Not surprisingly, there is no noise about it in the denialosphere.

I understood a couple of years ago that this was the direction where SkS was heading and thus stepped down as a moderator, as I did not have the time to participate at that level, nor to qualify myself in order to do so. I think KR is pretty close to the point where he could put together his own paper. Not to put pressure on anybody :-) but it would certainly be a useful elaboration on Dr Tung's published work and in the interest of continued scientific debate and fostered understanding...

Comment on Measure the climate consensus yourself with our Interactive Rating System

Chris G

Only done a handful, but surprisingly, also 100% in agreement. Hard do find something to quibble about.

Good job.

To observe the obvious, there's quite a lot of buzz on this. One thing I noticed was that the people attacking the article, are mostly not really attacking the article; they are attacking the secondary sources reporting on the article, on points that are addressed in the article itself. And, they are reduced to quibbling over semantics without at all touching the observation that researchers rejecting AGW are a very, very small minority.

The "Peer review process was corrupted" zombie appears to be a bit more animated than normal. Yeah, either there has been a multi-national, multi-decade, coordinated effort to keep dissenting views from being published (nevermind the fame that could be had for successfully overturning established science, and being the journal in which it was published), or it is very difficult to write a dissenting article without the article containing egregious flaws.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

grindupBaker

I think it's unfortunate that scientists didn't put this forward 40 years ago or whatever as "Global Warming" being an increase in the ocean heat content and hold hard onto that through the decades before discussing all these complex, though important, matters of climate change, global average surface temperature anomalies and so on. They've confused the heck out of the general public by pretty much stating it backwards.

Comment on The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

Tom Curtis

Agnostic @26:

1) Keeping CO2 to 450 ppmv peak concentration requires reducing CO2 emissions linearly to zero emissions in 2050. It is technically and economically feasible to do. There is, however, substantial doubt as to whether it is politically feasible, ie, whether the nations of the world can be persuaded to agree to and then impliment such a program.

2) With a 450 ppmv peak concentration the natural draw down of CO2 will reduce the CO2 concentration to about 365 ppmv over 200 to 400 years. (My earlier lower estimate was in error, for which I apologize.) With an Earth System Climate Sensitivity of 4 C per doubling of CO2, that works out to a long term temperature increase of 1.5 C above the preindustrial average. That is comparable to the 1.4 C transient climate response to 450 ppmv. The net effect is that tempeartures will stay approximately constant with zero net emissions because the slow feedbacks will be countered by the gradual decline in CO2 levels from natural uptake.

3) This optimistic scenario depends essentially on our in fact reducing net anthropogenic emissions to zero in the short term, and maintaining them at zero of slightly negative values in the long term. It is optimistic only in the sense that if we make a concerted effort to tackle climate change, we can limit the disaster to levels comparable to previous experience (ie, somewhere between the economic impact of the 1970s oil shock and a permanent great depression). Absent that effort the impact will be equivalent to a permanent great depression or worse.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

paulhtremblay

Otiose: You claim "The funding for climate science has been channeled by many governments since at least the early 90's (especially true in Europe) specifically towards those scientists concerned about climate i.e. probably already predisposed towards concluding that humans were the cause if not the primary cause."

This claims is illogical for a number of reasons. First, you offer no evidence that in fact scientists who choose to study climate are predisposed to concluding that humans cause warming. It can just as well be that people who study the climate see the evidence and come to the same conclusion that CO2 causes warming, the way a biologist concudes humans evolved from other species.

Further, you don't show that publishing papers questioning AGW would ruin a scientist's career. In fact, good research that overturn the consensus would make that scientists a rock star among his peers, a true innovator.

But more importantly, the whole idea that funding somehow causes bias shoud be dismissed out of hand. If we want to accept your argument, then we should also reject any biologists' claims about evolution, or any medical research--after all, most of such research comes from the government. Do engineers have a bias that objects fall at 32 ft/sec squared because they attend publich universities, funded by the government? Likewise, if a car company invents a super effecient car that gets 200 miles to the gallon, and produces the car so that everyone can test it, does that mean we shoudn't believe the car gets 200 miles to the gallon because the funding came from a car company? At the same time, if a private organization which is agains global warming funds scientists who truly produce papers overturning the consensus, do we accept thier finiing or reject them because of the funding?

Given your logic, we should not conduct any inquiry, but should act like medieval thinkers, identifying ourselves with tribes, and dismiss the ideas of other tribes not our own.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

KeenOn350

Kudos to the whole SkS team for this effort

DaveW

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

Looking into this subject a bit further, I would like to point out Ting et al 2009, Forced and Internal Twentieth-Century SST Trends in the North Atlantic as a recent work that summarizes a great deal.

This paper examines the various components in the AMO using Empirical Orthogonal Function (EOF) analysis, which is a principal components analysis including both time and spatial patterns. They find that EOF analysis supports detrending North Atlantic sea surface temperatures using either global sea surface temperatures (SSTs) or global mean temperature, not a linear detrending, as linear detrending aliases external forcing into the AMO index.

FIG. 2. (a) The linear trend (solid black line) and detrended NASSTI (shaded). (b) NASSTI regressed onto the global mean SST (SSTg regression, solid black line) and the difference between the observed NASSTI shown in Fig. 1 and the SSTg regression (shaded). (c) NASSTI regressed onto the global mean surface temperature (Tg regression, solid black line) and the difference between the observed NASSTI shown in Fig. 1 and the Tg regression (shaded).

This supports works such as Trenberth and Shea 2006, with rather more numeric backing; the first EOF component dominating:

This ï¬rst EOF explains 55%–72% of the total model variance except the GISS-EH model, which only explains 37%. However, the second mode explains only 3%–6% in all models. This indicates that on decadal time scales, the externally forced variability can be represented rather decisively by a single, globally synchronous pattern.

Note that the mid-century AMO is supported as a real, internal variation - but at end of the 20^th century a linear detrended AMO is heavily aliasing global warming. This indicates that, rather than the AMO presently being at a peak influence and perhaps about to decline, it instead has the possibility of rising over the next few decades increasing North Atlantic temperatures above that driven by external forcings - whether the AMO increases or reverses in the near future will have a significant effect on Atlantic region temperatures. And the late 20th century AMO influence is actually quite small.

I would be very interested in what external forcing vs. internal variation analysis would conclude regressing against a more accurate AMO index. But I repeat that a linear detrending is inappropriate, aliases the global warming signal, and (in context with respect to the Tung et al paper) linear detrending leads to a significant underestimation of external forcings.

Comment on The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

KeenOn350

Excellent summary of the work by Brigham-Grette et al - and encouraging to see some learning happening in the comments section. Thanks, John

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

DSL

Otiose, you're asking me to believe that the science is not progressive. Climate science doesn't work as you imply. It as an interdisciplinary, highly integrated, and dynamic area of research. Findings that throw doubt on fundamental understandings must explain why existing research is wrong.

Btw, your reference to the "rejected" science in the "climategate" emails works against your implied claim of fraud. If you can defend Soon & Balinuas (2003), then by all means do so, and that will get Chris Di Frietas off the hook for his years of "pal review" in the service of the Canadian group Friends of Science (an Orwellian use if there ever was one). Doing so will also reveal that the editors that resigned in protest over the publication of S&B did so based on their misinterpretation of the science.

Good luck on that.

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

KK Tung

I am trying to catch up with the replies after a busy week.

Some of the comments concern my statement that I thought there was a systematic underprediction of the observed rate of warming in the early twentieth century by the CMIP3 models. Opinions were expressed that statistically they agree within two standard deviations of the model spread. That model spread is rather large. If you are satisfied with that, that is fine with me. To me I see that the multimodel mean produced only 50% of the observed warming during the first half of the 20th century. Our proposal was that that 50% was caused by an internal variability (viz the AMO). We do not expect the ensemble mean to contain this internal variability. And I am not sure how the models can be made to do it since we do not know the initial condition in the ocean sublayer well in 1850-1870 (the time these model simulations start).

I agree entirely with Bob Loblaw in post 39. The observed climate is one realization of many possible climates. It is important to point out that one realization should in principle contain a particular phase and amplitude of the AMOC, an internal variability. There was a warm phase in the first half of the twentieth century. It is not reasonable to expect the model ensemble to produce it. Also, even if we use a single model realization, that realization may contain a different AMOC phase. My comments about the CMIP3 model underpredicting the warming should not be taken as a criticism of the models; they are expected to robustly generate only the forced solution. But the point remains that there is another part that is important but was not simulated.

One could take the point of view that the internal variability is just climate noise, and that the difference from any such unpredictable (by models) internal variability should be considered as "insignificant" (p595 of AR4) (post 33 here). This is in essence a statement that we will ignore internal variabilities just because we have not found a way to simulate it using the current generation of models.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

John Hartz

@otiose #93:

You assert,

"Finally, for a few decades it's been common knowledge that any scientist who was known to be contrary to the emerging "consensus" had something less than a snowball's chance in hell of getting hired into the faculty of a major university."

Where exactly does this "common knowledge" come from?

'

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

yocta

Is this an appropriate analogy?

Lets suppose 100 medical science papers were searched for the words lung cancer?

Now if 100 abstracts were returned and (Using Kevin C's approach):
Address the question, smoking is a cause of lung cancer (32.6%)
Address the question, don't know the answer (0.4%)
Address the question, smoking not a cause of lung cancer (0.7%)
Don't address the question (66.4%)

It would be silly based on these responses to even argue that 66% of scientists consider smoking not a cause of lung cancer.

(obviously there are other causes for lung cancer...but this was a back of an envelope kind of thing)

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years?

KK Tung

I am glad that it (inserting a figure) works this time!

This figure was done following Bart Verheggen's prescription of removing the usual solar, ENSO and volcano influences, but not the AMO or anthropogenic influence, because we don't know what the latter is.

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years?

KK Tung

Could someone tell me how to insert a figure into the comment the correct way? Thanks.

Also in reply to post 53: "The Lean and Rind analyses would make me think there would not be a substial influence of such cyclical behavior, but that's worth investigating with newer data". This was done with the old and also with the new data. See my post above. The point is: if you just look at the anthropogenic response from the assumed regressor, it would show accelerated warming after 1978. But the residue has a negative trend after 1978. When that negative trend is added back to the regressed response, the combination becomes more linear.

Here is another try for post 54 with a pdf figure:

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

nealjking

Otiose,

Science is conducted by human beings, and is heir to the weaknesses of human beings.

Nonetheless, science has managed to overcome the confines of Galilean/Newtonian mechanics to understand relativity; the confines of "realism" to create quantum mechanics; and many other discoveries and inventions that were originally undreamt of.

The way science is done in climate studies, including control of access to publication of articles, is not different from the way it is done in other sciences.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

nealjking

#89: grindupBaker at 07:40 AM on 18 May, 2013

A very good collection of papers on the topic is:

The Warming Papers: The Scientific Foundation for the Climate Change Forecast,

by David Archer and Raymond Pierrehumbert

It's not a cheap book; you might be able to find it at a local library.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

otiose, government funding is spent on plenty of climate skeptics, for instance Roy Spencer, who apparently gets all his funding from government sources and Henrik Svensmark, who according to his book "the Chilling Stars" appears to have much less trouble getting government funds than most. Or the CLOUD project at CERN, 12 million euro is a lot of money. Just because skeptics say they can't get funding, or get their papers published, doesn't mean it is actually true.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Otiose

Nice study. However, there are several factors that are not included in the scope of the study that undermine its target conclusion and these relate to what's not in the papers reviewd.

The funding for climate science has been channeled by many governments since at least the early 90's (especially true in Europe) specifically towards those scientists concerned about climate i.e. probably already predisposed towards concluding that humans were the cause if not the primary cause. That would bias the pool of potential papers as scientists not interested global warming itself or of a contrary opinion would not get the funding. Other scientists in order to get funding would be incentivized (need to eat, career advancement, desire to support families, etc.) to slant their work in the preferred direction.

Moreover we know from the email release that there were important journals in the field that simply refused to accept the work of known skeptics. Another factor tending to bias the pool.

And then the peer groups selected to review submitted papers tended to be skeptical (and not in an ironic sense) toward the qualifiations and work product of any scientist who didn't lean heavily towards the conclusion that humans were the primary cause of global warming (or indeed that it exists today and did in the past). Yet another hurdle for contrary concluding papers to get through.

Finally, for a few decades it's been common knowledge that any scientist who was known to be contrary to the emerging "consensus" had something less than a snowball's chance in hell of getting hired into the faculty of a major university.

So while the study sounds good there are several factors that undermine the touted conclusion. There were at least the above factors that would tend to encourage the consensus that emerged within the published papers that had nothing to do with the underlying validity of the science or what was or was not going on within climate and had everything to do with subtle and not so subtle intimidation of one form or another targeted towards those in the field who did not conform to the party line.

Comment on The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

Agnostic

John Mason – What an excellent article. Just how high was Pliocene and early Pleistocene average sea level compared the present?

Tom Curtis @13 expresses an optimistic view that by curbing CO2 emissions to 450 ppm (can we?) average global surface temperature will not exceed 2ºC above the pre-industrial by 2100.

I wish!

It might be, if we ignore the effects of slow feedbacks such as accelerating loss of albedo and permafrost, carbon emissions in the Arctic and increasing ocean heat content. Unfortunately we can not. Nor can we assume that CO2 concentration will not exceed 450 ppm by 2050, let alone 2100.

In the absence of enforceable national emissions targets it seems unlikely, unless there are remarkable technological developments enabling affordable carbon capture and sequestration or cheaper electricity generation from renewable sources.

Present rates of anthropogenic CO2 emissions are over 2 ppm/annum and accelerating making it very likely that concentration of 450 ppm will be reached by 2040. Emissions will continue thereafter reaching 560 ppm by 2100, resulting in average global surface temperature of around 3ºC.

It seems likely that anthropogenic emissions and those caused by slow feedbacks will result in considerably more than 560 ppm CO2 equivelant by 2100 with average global surface temperature of around 4ºC above the pre-industrial.

We should all hope that science and technology will reduce this possibility over the next 50 years. I believe they will. However there is shrinkingly little possibility that average global surface temperature of over 3ºC above the pre-industrial can be avoided this century.

Comment on Measure the climate consensus yourself with our Interactive Rating System

adelady

Hard to categorise? Yup. I studiously kept on checking that I was doing the ratings correctly. And worried that I was getting it wrong in some way or another. Now I've checked mine against the project and every single ratings number I gave was the same as theirs.

But the categories? Not hopelessly jumbled, but distinctly unwonderful in places. I'll now be using my previous scores to inform my future categorisations.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

grindupBaker @89 In addition to Tom's answer, generally if you send an email to the corresponding author of the paper, they will be only too happy to send you a pre-print of the paper (if it isn't already self-archived on-line somewhere). This is something that most journals are comfortable with (there is an on-line database somewhere listing the practices of most journals); indeed in the old days when you published a paper in a journal they would send you a couple of dozen free paper copies of your masterpiece (as it appears in the journal) for just that purpose (which then sit in your filing cabinet for several years untill your office becomes terminally full and you put them in the recycling bin).

There is nothing that us scientists like more than to hear that someone actually wants to read our papers! ;o)

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years?

KK Tung

In reply to posts 52 and 53 by Bart Verheggen: Your suggestions are fair. Our work were actually following ideas similar to your suggestions.

(1) We did not assume linearity for anthropogenic forcing. In the post we used a number of nonlinear anthropogenic indices.

(2) "Another approach would be to rather than using a questionnnable (see my previous commment) estimate of the AMO as a predictor in the regression analysis, see if there is a AMO-type (or other cyclical) signal is left over in the adjkusted temperature, after having corrected for the better known influences (solar, ENSO, volcanic, anthropogenic)." This was what we did in Zhou and Tung (2013). After we accounted for your suggested better known influences, the blue line in the figure was what remains, and it shows an AMO like signal.

[image snipped]

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Tom Curtis

I don't think people are giving Herhund's arguments the seriousness they deserve. Afterall, consider one of the "neutral" papers I rated yesterday. Surely it is obvious that if a paper on "Environmental Assessment Of Supercritical Water Oxidation And Other Sewage Sludge Handling Options" does not explicitly state that "Humans have caused more than 50% of global warming since 1950" then the authors must disagree with that proposition. Isn't it? Afterall, that is just part of the general maxim that "Silence is disagreement"

/sarc

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Tom Curtis

grindupBaker @89, subscriptions to most scientific journals includes access to articles from prior issues on the web. Articles from periods prior to when web publication became common may not be included in this.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Tom Curtis

william @90, I'll bite. Just how often has the past consensus of a mature science (one with more than a million man hours of scientific research behind it) been wrong? I can only think of one instance (continental drift) and in that instance the alternative theory presented at the time was also wrong, but when a correct theory was presented it was rapidly adopted as the consensus view.

People often forget how few were the number of scientists before the twentieth century, and how limited their resources. For example, science courses (other than Mathematics) did not even exist at Cambridge University until 1851. With the small number of scientists in the past, and their limited resources, it took time to falsify promising theories. Further, most "examples" of theories that have been overturned are like Newton's theory of motion in which the overturning theory predicts the same results as the original theory withing the range of conditions in which the first theory was tested. Even today, NASA uses Newtonian theories of motion to work out the orbits of satellites and interplanetary missions.

In fact, if the history of science teaches us anything, it teaches us that once a scientific theory commands a consensus with in an area of detailed observation, any future theory will predict the same observational consequences within the resolution of current observations. So unless the CO2 concentration exceeds that of Venus, or drops near zero (the range of current observations), the history of science suggests that if any theory replaces AGW it also will predict a CO2/temperature linkage.

Further, people often forget (if they ever knew) the real bite of the argument from scientific consensus. The scientists are the experts, where an expert is somebody who knows enough about a subject not to make dunderhead mistakes. If there is a scientific consensus, then that means the vast majority of people who will not make silly mistakes accept the theory (and the exceptions all have known, strong ideological agendas, like Fred Singer who turned down a job offer from the White House because it would not allow him enough influence on policy). That means it is extraordinarilly unlikely that there is any obvious error in the theory of AGW, while obvious errors in alternative theories abound.

However, this is beside the point. Climate change deniers frequently argue that there is no scientific consensus on climate change. The need to. If they do not accept that false belief they are forced to explain why so many people who know far more about the evidence then they do, and typically are far more intelligent, accept a theory while they reject it. This article, and the paper it reports on merely shows that frequent denier claim. The frenzy with which the paper has been attacked by climate change deniers shows they know what is at stake. If this paper becomes well known and accepted, their most powerfull (and falacious) argument - that there is no scientific concensus so therefore the evidence must not be conclusive- is false.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

grindupBaker

I might find some hours to study next winter if I don't lose interest. Can anybody inform how I get 100 or so of the most informative prior peer-reviewed papers without paying $32 each ? Does a magazine subscription somewhere include some back issues ?

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Dikran Marsupial

William the existence of a concensus is not scientific evidence of anthropogenic climate change (and nobody is claiming it is), the consensus is a result of the scientific evidence of anthropogenic climate change.

AFAICS the purpose of the study is to demonstrate the disconect between the public/political perception of the science of climate change and the scientific perception of the science of climate change. The scientists are able to weigh the evidence for themselves, but what about the general public? Who should they trust? I would suggest that mainstream scientific opinion is the most rational option (as the "outliers" are in fact very rare*), and this paper communicates very clearly where mainstream scientific opinion lies, and how few papers there are that actually challenge the mainstream view.

*It is true that occasionally there is a Gallileo who overturns the scientific orthodoxy, but there are many more scientists you never get to hear of who challenge the scientific mainstream and are simply mistaken. Gallileos are vanishingly rare in the population of scientists, academics that have merely "gone emeritus" are not. If someone thinks the scientific mainstream is wrong on AGW, the odds are not in their favour. I wish they were.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

John Hartz

Herrhund:

Your recent posts are in violation of the following part of the SkS Comments Policy. As such, they have been deleted.

Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Jim Eager

Herrhund wrote: "there are other theories"

Except that there are no other theories.

None. Zip. Nada.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Rob Honeycutt

herrhund... Would you prefer that we merely use the phrase "0.7% of the published research found to reject anthropogenic climate change?"

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Kevin C

herrhund:

How many of the 66,4% address the topic and expressed no position on AGW?

None. See table 3 in the paper. The papers in the 66.4% are in that class because they didn't address the question. There are 4 categories in table 3:

Address the question, humans causing most of GW (32.6%)
Address the question, don't know the answer (0.4%)
Address the question, humans not causing most of GW (0.7%)
Don't address the question (66.4%)

Among papers which addressed the question the consusus view is 97%. You can't classify the consensus among papers which don't address the question because they don't address the question.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

william

I have not doubt that climate change is happening and none that we are causing it but consenses is a pretty weak argument for anything scientific considering how often in the past the outlier has been correct and the crowd, wrong. Better we just look at the overwhelming evidence in it's own right rather than using an argument that is of such questionable value.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

John Hartz

Here's the best one sentence description of the paper that I have come across.

An analysis of 4,000 abstracts of peer-reviewed articles on the topic of global warming and climate change has revealed an overwhelming consensus among climate scientists that recent warming is human-caused.

Source: There Is Scientific Consensus On Anthropogenic Climate Change Among Climate Scientists

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Kevin C

Yes exactly.

Just having 'global warming' in the title does not mean a paper addresses the question of whether human activity has been the dominant cause of recent warming. Here are some examples:

1. A paper on measuring the warming signal might say nothing about the cause.

2. A paper looking at the impact of global warming on animal habitats may say nothing about rate or cause.

3. A paper on adapting societies to deal with global warming does not address the issue either.

You'll find thousands like this. All of these are classified as 'no postion' because they don't address the question. These are distinct from papers which try to address the question and are undecided on the answer.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Kevin C

herrhund: If you go to the TCP site and rate a few papers yourself, you will find the answer to your question.

The survey is trying to assess the consensus on whether humans have caused the bulk of recent warming. The fact that a paper takes 'no position' does not imply that the the authors failed to reach a conclusion on this question. The majority of the papers involved simply didn't address the question. Go and read some of the abstracts and you will see for yourself.

If you want to know what proportion of papers accept, reject or are undecided on a question, you have to count papers which address that question. Throwing in a load of papers which do not address the question in order to distort the statistics would be nonsensical.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

BWTrainer

@83 - Most of the papers were not attempting to come to such a conclusion, so their "failure" to do so is not surprising.

Anyone who reads the entirety of the sutdy available for free, or this article, or one of several other articles about the study, will be left with no confusion as to the conclusions.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

VictorVenema

I presume you will have to do this type of study every year as soon people will have forgotten it again and will again think that scientists think the same as their libertarian neighbour.

For a follow-up study it may be nice to study abstracts from climate journals. That way you are sure the studied sample is not biased by first searching for key words. I expect no difference, but it would be nice to be sure. I would advocate to ask an experienced bibliographical researcher to organize the study.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

herrhund

"A new survey of over 12,000 peer-reviewed climate science papers by our citizen science team at Skeptical Science has found a 97% consensus in the peer-reviewed literature that humans are causing global warming"

This is a false statement.

66,4% of the abstracts expressed NO POSITION on AGW, wich means just 32,6% endorsed AGW and then out of that 32,6% - 97,1% come to the conclusion that the climate is human driven.
So just, 32% of 11 000 implicate AGW
Which also means that most of the papers did not come to the conclusion on AGW
"We ï¬nd that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming"

Comment on It hasn't warmed since 1998

DSL

To further Dikran's point, consider the trend of 1992-2007. Using Had4, the trend is 0.3C per decade. That's approaching double the expected rate of warming. According to your logic, climate scientists should have declared that they had seriously underestimated the rate of warming. No. It's a short-term trend. And it's a cherry-pick. And it covers half of your 16-year period. You can try to reconcile all that, or you could actually engage a critical thinking process and try to understand the forces at work that create the state of the surface temp -- like scientists do.

One more thing, Warren: when you say "no warming" you immediately reveal yourself to be ignorant about the science. You complained about the accuracy of the survey titling. Now you want a free pass for using an insignificant portion of the thermal capacity of the climate system (the troposphere) to represent the whole shebang. Ignoring OHC is deceptive . . . or ignorant. Your response will determine my choice.

Comment on Measure the climate consensus yourself with our Interactive Rating System

jdixon1980

Love it, love the ongoing improvements.

A suggestion - how about a category for articles relating to the effects of factors other than GHG emissions on climate? I came across an article on clouds that was hard to categorize.

Another abstract was an environmental impact study of engineered water recirculation for fish farming, and one of the impacts was "GWP (global warming potential)." I wasn't sure if it was safe to assume that the GWP was due to GHG emissions related to generating the mechanical power to recirculate the water, or if it could be something else like albedo or CO2 uptake effects of tinkering with bodies of water and/or land. (I suppose if it were CO2 uptake effects, that would be an implicit endorsement of AGW, because if CO2 uptake affects climate, than so do emissions.)

Another possible article topic that could be hard to categorize would be climate effects of sulfate/aerosol emissions (as by-products as opposed to deliberate geoengineering, which would fit nicely in mitigation).

I suppose the best place for this type of article right now is "methods," in the sense of the category description "basic climate science not included in the other categories." But using "methods" as a catch-all category in this manner might obscure the statistics about articles that really get into the nitty-gritty details of data selection, gathering, and analysis.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Rob Honeycutt

Warren... Think of it this way. The paper set out to better understand the level of consensus on AGW in the published literature. Right? We rated 12,000 peer reviewed papers. From that research we found a 97% consensus that humans are responsible for global warming.

That is what the paper is about. That is what the research found.

The alternative presentation you could make is: The paper set out to better understand the level of consensus on AGW in the published literature. We rated 12,000 papers and found that 32% accept it. 66% show no position. And 0.7% reject AGW.

Take your pick.

Comment on It hasn't warmed since 1998

Dikran Marsupial

Warren, well worth reading the Guardian's reporting on James Hansen's BBC R4 comments this mornng (here), in particular:

Prof Hansen, speaking to BBC Radio 4's Today programme, rejected both arguments. "In the last decade it has warmed only a tenth of a degree compared to two-tenths of a degree in the preceeding decade, but that's just natural variability. There is no reason to be surprised by that at all," he said. "If you look over a 30-40 year period the expected warming is two-tenths of a degree per decade, but that doesn't mean each decade is going to warm two-tenths of a degree: there is too much natural variability."

Comment on It hasn't warmed since 1998

Warren Hindmarsh - I've discussed this particular topic with Werner Brozek at some length, for example at Spencers blog. You, unfortunately, appear to have some of the same misconceptions regarding statistical significance - it's possible to cherry-pick an interval that shows any conclusion you wish, as long as you avoid using all of the data. But short periods are not statistically significant, there is insufficient data to make a claim one way or another.

As I have mentioned before on these threads:

For any of the instrumental series, over any time span ending in the present:

There is no period where warming is invalidated, against a null hypothesis of no warming.
Against a null hypothesis of the long term warming trend, there is no period where a "no warming" hypothesis is validated. None.
Over any period with enough data to show statistical significance, that data shows a statistically significant warming trend.

Claims otherwise, such as your repetitions of 'skeptics' elsewhere, are demonstrably wrong.

Comment on It hasn't warmed since 1998

Dikran Marsupial

Warren, firstly your posts on SkS have demonstrated an argumentative rhetorical tone. This is not conducive to discussion of science and is likely to irritate the other participants in the discussion, which reflects more badly on you than on anyone else. Please give it a rest.

So "What is wrong with the graph?"

(i) It is an example of cherry picking start and end dates. If you have a time series with an upward trend that is small in comparison to the magnitude of the noise, then it isn't surprising that you can choose start and end points where the noise temporarily masks the trend. However that doesn't mean the trend has gone away. This can be easily demonstrated by constructing a synthetic time series with an upward trend (so you know it is there by construction) and observing that you can still cherry pick periods where this trend is masked.

(ii) Trends are not measured by noting the difference in temperature at the start point and the endpoint as this is to sensitive to the noise to have any statistical meaning. Instead scientists use least-squares linear trends, often adjusted to take account of the autocorrelation.

(iii) The anlaysis makes no mention of statistical significance, nor of the statistical power of the test (which is very important if you want to claim that there has been no warming since 1998, I'd be happy to explain this in more detail when you respond to my post).

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

jdixon1980

Will there be a follow-up article comparing the results of the public survey of abstracts to those of the SkS team and the self-rating authors?

Comment on It hasn't warmed since 1998

Robert Murphy

"What's wrong with this graph"?

It's mislabeled. WATTS and company can't add - that's 15 years, not 16. It's also been shifted - the real data on that is from August 1997 to August 2012, not the beginning of 1997 and the end of 2012. Also, the values have been altered. The first one should be less than .5*C and the last higher. It's been fudged, in other words.

"The Hadley Centre/CRU records show no warming for 18 years (v.3"

False. v.3 shows about .14*C of warming over that period globally.

"or 19 years (v.4),"

Even more false. The trend is bigger with v.4 - about .17*C of warming over the last 18 years and about .2*C over the last 19.

"and the RSS satellite dataset shows no warming for 23 years"

Spectacularly incorrect. RSS shows about .28*C of warming over the last 23 years.

"h/t to Werner Brozek for determining these values"

Hat tip for feeding you false data? Seriously? Where's your skepticism?

"temps have been rising slowly since the middle ages"

So, you're a LIA denier too?

"sorry gotta go catch ya later"

Ah, hit and run. Next time, why not come back with correct info?

Comment on It hasn't warmed since 1998

CBDunkerson

Warren Hindmarsh wrote: "what is wrong with this graph"

Read up on 'cherry picking'... that is, deliberately choosing a time period which shows the result you want despite the fact that longer and/or shorter time periods show results contradicting your claim.

Also: "temps have been rising slowly since the middle ages"

Not according to any historical temperature study I am aware of. Indeed, temperatures were slowly falling for thousands of years, including both before and after the 'middle ages', until the modern greenhouse warming surge.

Finally: "but for the last 17yrs or so [temps] have stablized"

Again, 'cherry picking'... not only of the time period, but also which temps. Ocean temps have certainly not 'stabilized' over the past 17 years.

You obviously didn't even bother to read the post above. Maybe try that before making arguments which it has already disproved.

Comment on A Detailed Look at Renewable Baseload Energy

CBDunkerson

JvD, no SkS is not here creating a false impression. As you concede, it is possible to achieve global 100% renewable energy... with current technology. It would just be very expensive. If you read the post above you will see that it does not advocate 100% renewable power with current technology, but rather "within the next few decades" and "by 2020 or 2030". Ergo, no it is not ignoring the cost factors.

As I said upthread, I think there will be a transition period over the next few decades where natural gas and existing nuclear play a role. After that the buildout of the grid and storage combined with falling costs will lead to 100% renewables.

Comment on It hasn't warmed since 1998

Tom Curtis

A third question:

Isn't it misleading to say that a period with a positive tempertature trend (ie, temperatures are rising) shows no warming?

Please note that "no warming" does not mean the same thing as "the warming is not statistically significant".

Comment on It hasn't warmed since 1998

Warren Hindmarsh

sorry Dipal have to go right now

The graph is from

The Hadley Centre/CRU records show no warming for 18 years (v.3) or 19 years (v.4), and the RSS satellite dataset shows no warming for 23 years (h/t to Werner Brozek for determining these values).

Comment on It hasn't warmed since 1998

Tom Curtis

Warren Hindmarsh, two questions:

Did temperature rise or stand still over the course of the twentieth century?

If the warming rate over a given period is greater than in a period over which temperatures are known to rise, is it correct to say that temperatures are not rising?

Comment on Measure the climate consensus yourself with our Interactive Rating System

Tom Curtis

Alexandre @3, I had the same problem but fixed it by reducing the zoom back to 100%. You may need to go a little lower.

Comment on Measure the climate consensus yourself with our Interactive Rating System

Alexandre

I had some trouble using it. When I moused over the 4th or 5th paper title, the abstract would appear so far up in the page that it did not appear in my screen.

I use Google Chrome 26.0.1410.64 m

Comment on It hasn't warmed since 1998

Warren Hindmarsh

what is wrong with this graph

Comment on Measure the climate consensus yourself with our Interactive Rating System

adelady

Oh my.

That's a terrible idea. I could get addicted to such a "game". (I find myself having to do _this_ lot of ratings so I can move to the next page just to see what the next interesting/ odd/ peculiar/ fascinating assortment of papers is going to be. The occasional downright weird item is just the cherry on the sundae.)

Comment on It hasn't warmed since 1998

Warren Hindmarsh

Hi dikran

where is the global warming :)

Comment on A Detailed Look at Renewable Baseload Energy

Tom Curtis

JvD @417, SkS is most definitely not being misleading on this issue, a point you have already tacitly acknowledged @407 when you wrote:

"Yes renewables can be used. But the difficulty is great."

You are not disputing a matter of technical feasibility, but only of economic cost. It may be true that the economic cost of an all renewables energy economy is to great to maintain continued economic growth, but it is not so high that such a conversion would bring down our civilization. Ergo it is even economically feasible to have a global renewable energy only economy. Beyond that I don't care provided that any nuclear power satisfies the conditions I specified above, and that renewables are a significant portion of any energy mix.

Finally, I do not agree that a full renewable economy can only be achieved with "extreme difficulty". Assuming that to be the case depends on assuming an technical difficulties with nuclear power will be quickly and cheaply resolved, while any technical difficulties with renewables are intractable. I don't believe in begging the question in so blatant a manner.

Comment on The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.

K.a.r.S.t.e.N

KK Tung @10:

I am referring to forcing from tropospheric (anthropogenic) and stratospheric (volcanic) aerosols likewise. They have an impact on both, the AMOC and the AMO. Sure, the response of the AMOC to external forcing is slower and hence harder to identify, but neither AMOC nor AMO are independent of it. I agree that the AMO is influenced by the AMOC (how can it not). The exact linkage is still under debate. However, I strongly disagree with your reply to Kevin C in post 8 and your notion that a volcanic impact on the AMO is unlikely. Let me try to convince you.

In your paper, you wrote: “The 20-y small dip in temperature near 1810 coincides with the solar Dalton Minimum, but is probably caused by a negative excursion of the AMO. The rising AMO cycle in the first half of the 19th century produced a warming, despite the eruption of Tambora (1815), the largest in the past four centuries.”

The problem is that we have a strong volcanic eruption in 1809 (unknown tropical eruption; see Cole-Dai et al. 2009 or Arfeuille et al. 2013), followed by the 1815 Tambora eruption (strongest eruption in the last centuries). Hence I have no doubt whatsoever as to what the reason of the negative AMO excursion is. It’s entirely attributable to these two strong eruptions. The surface air temperature over the Atlantic-Arctic boundary in your Fig.3C perfectly matches the timing of these eruptions. If we go on to the 1830s, we see the next dip which perfectly matches with the Babuyan Claro eruption (1831) and the next very strong eruption at Cosiguina in 1835. The dip around 1860 is stronger than one would expect from the amplitude of the corresponding eruption recorded in 1861, only to have a clear signal for the Krakatau eruption in 1883 again. Note that the exact magnitude of the volcanic forcing differs between different estimates. I plotted the older dust veil index (DVI) and the newer ice core index (ICI) from Crowley and Unterman 2012 for the time period 1750-2000 in order to illustrate my point.

Moreover, I consider it very likely that volcanic eruptions do have a measurable effect also on the AMOC. Gleckler et al. 2006 and Stenchikov et al. 2009 demonstrate that a persistent deep ocean signal emerges after strong volcanic eruptions. Therefore, most of the time the climate system is not in an equilibrium state as it takes several centuries to get rid of any remaining signal from volcanic eruptions. As soon as there is a lull in volcanic activity, the climate system warms in order to restore equilibrium. I don’t know how strong this warming signal is, but it definitely plays a role in post-volcanic periods such as that between 1910-1940. I agree with Tom Curtis (post 40), that this period saw some additional warming in the North Atlantic region due to increasing black carbon forcing (while anthropogenic sulfate forcing was barely rising during that very time). The external forcing impact on the AMOC is also widely discussed in the literature, with numerous suggestions as to what mechanisms could be at play. I would like to point at a very recent paper by Menary et al. 2013 or another one by Iwi et al. 2012. It goes without saying that undoubtedly internal AMOC variability exists undoubtedly. The review paper by Kuhlbrodt et al. 2007 gave a good overview.

Similar to what Kevin C did (see post 21), I recently developed my own two-box EBM model which accounts for volcanic eruptions at two time-scales: A fast surface temperature response which more or less coincides with the stratospheric AOD evolution, and a slow response which accounts for the deep-ocean signal as shown for the Tambora and the Pinatubo eruptions in Stenchikov et al. 2009. In addition, instead of using the GISS forcing (which I personally consider not very accurate regarding the tropospheric aerosol forcing) I used the forcing time series for sulfate and black carbon aerosols presented in Skeie et al. 2011. The resulting forcing function (nudged towards NH conditions) for the 1750-2010 period looks like this (I can provide more details upon request):

Not only are the volcanic spikes easy to identify, but also becomes their long-term effect noticeable. I am not claiming that this is the real volcanic fingerprint which we find in the observations, but it indicates where we might have to look for a forced disturbance in the thermohaline circulation, may it be the AMOC or ENSO/PDO. Let’s compare the forcing function with the NH instrumental observations and reconstructions:

Note that the temperature response in Europe as represented by the Berkeley Best data and Baur temperature series (both are comparable with the AMO temperature trends) is not always in phase with the rest of the NH. In fact, there is reason to think that the NAO response to volcanic eruptions is preferably positive. Fischer et al. 2007 have a good discussion on that. Assuming that the NAO and the AMO mutually influence each other, stochastic multi-annual or decadal variations as a result are all but surprising. Even in the absence of NAO-like atmospheric variability, Deser et al. 2010 brilliantly illustrate how white noise from pure random atmospheric heat flux variations turns into (oceanic) red noise. The time scale of the resulting SST fluctuations depends on the ocean mixed-layer height. It is interesting to note that the mixed-layer depth of the North Atlantic is comparably high, particularly in winter, which can easily explain the high standard deviation of its SSTs. The same is true for large portions of the North Pacific.

This brings me to DelSole et al. 2011, which you cited in your response. Likewise, they identified these very regions as most variable. However, I can’t see how the “projection” of the observed temperatures onto this pattern removes the problem of unreliable model forcing. As can be seen from my best-guess forcing assumption for the NH (which includes aerosol indirect effects, which most models omit altogether), the real forcing has likely been considerably more variable than assumed in your analysis as well as in their analysis (which is based in the forcings of the models used). This can also be illustrated by looking at the NH/SH inter-hemispheric temperature trend. Not only does it differ considerably, but also is the NH instrumental record strongly correlated with the anthropogenic sulfur emissions, which is almost certainly not a mystic coincidence.

Many other issues regarding the robustness of your results have been raised in the discussion already. I agree with Tom Curtis (post 11/15) on the magnitude of the AMO signal in the NH temperature variance, which I believe your method terribly deflates, as well as on the consistency and significance of the oscillation in the data (post 15/20), which I believe you have not demonstrated. Conservation of energy is another is another big problem (see e.g. KR in post 14) which you have so far failed to address properly.

Finally, let me show you what happens if we extend the forcing time series back in time and keep comparing it with paleo-reconstructions. With a low-pass filter it looks like this:

From a NH point of view, the AMO plays a minor role as far as the temperature evolution is concerned. Not to mention global temperatures. The AMOC is important on longer time scales, typically in response to slow changes in external forcing. On shorter time-scales, AMOC changes can have strong regional impacts. The AMOC shutdown in the context of the 8.2ka event as the prime example for its response to strong fresh water pulses.

Comment on Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature

Warren Hindmarsh

Tom I must admit I had difficulty making sense of the self rated section I can now see how the self rated respondents had a 62.7 % acknowledgement.

they contacted 8,500 authors 1,200 responded and reviewed 2,100 97% of which agreed with AGW