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Comments 39201 to 39250:
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Albatross at 13:21 PM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Between Robert's post and the post by Tamino, Dr. Curry has again been shown to wrong (how many times has that happened now?). She was wrong in her claims about sea level, she was wrong in her claims about what decadal variability means for climate sensitivity, she was wrong about the implications of the Antarctic sea ice extent increasing slowly. It is quite obvious that Dr. Curry is doing whatever it takes to feed the beloved uncertainty monster that she recently conjured up;)
I hope that it is not lost on readers that Robert Way and Tamino have (unlike Dr. Curry) objectively analyzed the data. Robert's line plots, density plot and box and whisker plot demonstrate unequivocally that Dr. Curry's claims are simply and comppletely wrong. I would go further and argue that she was playing loose with the truth and facts in her testimony to Congress. She only has two options here-- either she is being disingenuous or she is not qualified to speak to the science of AGW.This sort of unprofessional conduct by Dr. Curry is completely unjustified, indefensible and reprehensible. I can't imagine why anyone with integrity or standards would even begin to try and defend Dr. Curry's unethical behaviour.
Another important result arising from this is that the IPCC tends to be, if anything, too conservative.
Moderator Response:[PS] This comment is on thin ice with respect to both inflammatory tone and accusations of deception. Let's keep this civil.
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Tom Curtis at 10:39 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard:
"I conclude that this article is mainly a promotional token for Cowtan & Way"
There is no warrant for the claim that this article is "a promotional token", which gives the appearance of disproof by slander. Robert Way cited 10 distinct data sets, only one of which is his own.
Of course, the statement may well be true. Willard may conclude whatever Willard likes, regardless of the merits of the case. In this case, however, Willard's conclusion reflects poorly on him.
Moderator Response:Before things go way offtopic with discussions of symantics and motivations which will be tedious for moderators, can I suggest instead Willard points to data that supports the Curry statement so that discussion can be more focussed on the science.
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Rob Honeycutt at 10:35 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard... First, not to nit-pick but these are "blog posts" rather than "op-eds." An Op-Ed would be something related to print media or an invited column from an invited outside person. Blog posts are usually owned by the blogger, or as with Robert, by someone who is a regular author of the blog.
That aside, as for "going a bridge too far," I don't agree. Look at Tamino's list of graphs from all the papers that are cited in the quote you provide from Curry. Even based on on the cited references you can't support the claim that the 1930's were warmer than the 2000's.
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Tom Curtis at 10:34 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard:
"Reading back that thread might show that the claim "there is no support for that [Judy's and the IPCC's] position" might be going a bridge too far, and has been offered by Rob Honeycutt as a proof by assertion."
Rather than a bridge to far, it is clear understatement. Every temperature record examined showing both 1930s and 2000s Arctic temperatures shows the later to be warmer than the former. Further, the only clear statement on the issue in the IPCC's supporting literature flatly contradicts their (and Curry's) claim.
Willard, condemning "proof by assertion" does not justify your attempting the same.
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Tom Curtis at 10:31 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
First, Tamino now has a follow up article on this issue.
In it he examines the temperature data presented in:
Polyakov et al (2003)
Wood and Overland (2010)
Yamanouchi (2011)
Fyfe et al (2013)
Johannessen (2004)
Bekryaev et al (2010)
He discusses these because they are the articles Curry cites in her defense. Tamino shows that none of them show temperatures in the 2000s as cold as those in the 1930s. That is, the literature Curry cites do not support her conclusion, and where they show both 1930s and 2000s temperatures, refute it.
In the list above, the bolded articles are also cited by the IPCC in the section quoted by Willard. It is far from clear that the articles cited by the IPCC are in support of the disputed claim. When making that claim, ie, that "Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s", they cite no literature in suport of the claim. Above (@1), Willard critiques the OP on the basis that there is no "... discussion of the rationale behind the IPCC's claim". In fact there is no discussion of the rationale behind the IPCC's claim in AR5 WG1. Criticizing Way for not reproducing or quoting what does not exist is bizarre. It shows that Willard has, at best, "phoned in" his initial critique,ie, that it is not based on an assessment of either the IPCC's discussion or of the literature.
I had expected better from Willard.
The IPCC also cites:
Ahlmann (1948)
Veryard (1963)
Hegerl (2007b)
Ahlmann and Veriyard are clearly too early to be relevant, not being able to compare 1930s even with 1990s temperatures - let alone those of the 2000s.
Hegerl et al (2007a) discusses attribution in relation to a reconstruction of NH temperatures from 30 to 90 degrees North, and contains no distinct discussion or representation of Arctic only temperatures. Further, the reconstruction terminates in 1990, making it irrelevant to the question at hand.
Hegerl et al (2007b) ie, AR4 WG1 Chapt 9 shows no pan-arctic temperatures, but those that it does show for individual Arctic areas show 1930s temperatures below temperatures in the 2000s.
Brohan et al (2006) introduces the HadCRUT3 which is superceded by HadCRUT4 which shows Arctic temperatures warmer in the 2000s than in the 1930s.
Bengtsson et al (2004) shows Arctic temperatures warmer than in the 1930s by the late 1990s, and does not show temperatures of the 2000s.
I do not have access to the full text of Grant et al (2009), but its abstract restricts its discussion entirely to the early twentieth century. That makes it unlikely that it will contradict what appears to be a concensus in the literature that actually discusses or shows a comparison between 1930s and 2000s Arctic temperatures. That is particularly the case as Grant et al (2009) share three coauthors with Bronniman et al (2012), including both Grant and Bronnimann.
Bronnimann et al (2012) conclude that:
"None of the data sets alone is sufficient for addressing long-term trends in the Arctic. However, knowing the shortcomings and differences, information can be gained even on trends from analysing all data sets individually and by combining the results (see also Thorne et al. 2010 for the value of multiple tropospheric temperature data sets). For instance, all data sets agree that the last two decades are unprecedented in the 20th century in terms of the magnitude of the warm anomaly in the lower troposphere.The rate of warming between the 1980s and present is also outstanding. The vertical structure of the trend shows a clear amplification of the recent trend at the surface in autumn to spring. During the ETCW, high temperature anomalies were also found at 700 hPa and above in winter. Although the data are more uncertain for the first half of the twentieth century, they clearly point to a smaller lapse rate compared to the recent warm period."
(My emphasis)
To summarize, the IPCC claim has no supporting evidence in any of their cited literature that I have been able to examine, and flatly contradicts all of the standard temperature records, and the only clear statement on the subject in the literature they cite.
I believe that shows Willard's critique to have been entirely baseless.
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willard at 09:52 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
> No, that is not what Dr Curry quoted.
Here is where Dr. Curry quoted what I said she quoted.
Following that op-ed published on January 27, 2014, there are some comments by Robert Way in the comment section, dated January 28, 2014 at 11:32 am, 11:57 am, 1:23 pm, 1:49 pm, and 4:34 pm.
My understanding is that Robert Way's op-ed has been published on January 28, 2014.
Reading back that thread might show that the claim "there is no support for that [Judy's and the IPCC's] position" might be going a bridge too far, and has been offered by Rob Honeycutt as a proof by assertion.
***
If we're supposed to evaluate the accuracy of the statement "Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s", a statement we can find in the IPCC documentation, then we wish to pay due diligence to what contains the IPCC documents and drop anything that has yet to appear there.
If what we want is to put emphasis on new, cutting-edge peer-review literature, then I suggest we clarify what kind of "Historical Perspective" is intended.
Moderator Response:[PS] fixed link.
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Rob Honeycutt at 09:37 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
I have to say, I find Dr Curry's response less than adequate. She's merely retreating to the idea that we can't really know if the temperature of the 1930's was warmer or not because the Arctic has poor coverage.
Once again, this completely contradicts the entire thesis of what she was presenting to the Senate committee! You can't claim on one hand, in front of elected officials and the general public, that AR5 actually reduces our certainty about AGW, and then turn around and claim in a blog post that the data are insuffient to even know.
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Rob Honeycutt at 09:23 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
And Tamino already has a response to Curry's response.
http://tamino.wordpress.com/2014/01/28/judith-curry-responds-sort-of/
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barry1487 at 09:14 AM on 29 January 2014Australia’s hottest year was no freak event: humans caused it
mchael sweet @ 45,
Climate change is projected to bring more water vapour but this is not uniform across the globe. Changes to the hydrological cycle vary by region. In Australia there has been increased precipitation in the North West, and decrease in the South West. Increasing drought is predicted for some regions but not for others. Rule of thumb is that wet regions will get wetter, and dry regions will get dryer. Tropical zones will see more rainfall and cloudiness, and the sub-tropics will become more arid. That's the general idea, though projections are not so spatially strict as this generalization, but the point is that climate change changes weather patterns n ways that are not uniform. Regional projections are less certain than global, so the comments here should be read with that in mind.
How this might change cloudiness (and solar exposure) nationally is less clear. Increased water vapour should increase cloudiness. Rainfall is projected to become less frequent but more intense in some parts of Australia, and there are seasonal differences. AR4 projections on precipitation in Australia are here.
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Charlie A at 09:01 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Judith Curry has a recent blogpost on this subject at http://judithcurry.com/2014/01/27/early-20th-century-arctic-warming/
Her original testimony can be found at http://www.epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=07472bb4-3eeb-42da-a49d-964165860275
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cpslashm at 08:34 AM on 29 January 2014It hasn't warmed since 1998
Tom Curtis @275, thanks for your response.
I was looking at the data from the opposite perspective: a sharp increase in energy going into melting ice from 2003. Is the trend real? Where is the extra energy coming from? What other part of the system is losing out? I am assuming that the bulk of the heat is being transported to the sea ice via the Arctic near-surface waters which then have less heat to pass up to the atmosphere. If this absorption of heat from Arctic waters by ice melt does not produce a corresponding loss of atmospheric heat input, I will have to look elsewhere.
The amount of heat melting Arctic sea ice per average year since 2003 is minor but enough to raise the temperature of the top three metres of the Arctic Ocean by 1 degree C. I have not yet found a correlation with sea ice area minima which would be the case if the melting were due mainly to a progressive loss of albedo. I am not convinced of the relevance of sea ice extent in this case.
To come back on topic, although minor compared to oceanic heat absorption, melting sea ice demonstrates that a lot of near-surface heating has been going on since 1998 which will not have contributed to a global surface temperature rise.
The advantage with my hypothesis is that it can be proved wrong within the next four years - I hope!
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Tom Curtis at 08:16 AM on 29 January 2014Real Skepticism About the New Marcott 'Hockey Stick'
Joe T @100, you have picked up on one of the most interesting and innovative features of Marcott's reconstruction. Instead of just making a central estimate of the temperature, and showing error bars, they varied the data based on the error margins of the original proxies. By doing this, they get statistical data on all the ways that the reconstruction could be wrong. From among all those variations, only 18% of ten year intervals are warmer than 2000-2009. Allowing for some inherent smoothing in the method, that becomes 28%. That does not mean that there were any decades warmer than 2000-2009 in the Holocene. The actual temperature record will approximate to one of their statistical variations of the data, their "realizations". It is, however, as likely to be a cold realization as a warm one. Because reconstructions can be wrong by being to warm, or to cold, with equal probability, the mean does not vary as much as the realizations can, and does not show the potential warmest years.
This explanation will be easier to understand if you actually see the realizations plotted with the mean:
The idea is that current temperatures, while much higher than the mean (black line), are not higher than about the warmest of the realizations in for any given decade about 18% of the time.
The net effect from this can be seen in Marcott's Fig 3:
The 2000-2009 temperatures, with an anomaly of about 0.4 C lies in the upper end of the distribution of realizaitons (solid black curve). These can then be compared with the expected temperatures from various IPCC AR4 scenarios. (The coloured curves represent alternative means of reconstruction, and can be ignored for this discussion.)
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A Historical Perspective on Arctic Warming: Part One
Curry has clearly made this claim, as per her testimony, stating:
Arctic surface temperature anomalies in the 1930’s were as large as the recent temperature anomalies.
That link would be good to add to the OP.
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Tom Curtis at 07:41 AM on 29 January 2014Australia’s hottest year was no freak event: humans caused it
Barry @43, thanks. I'll include that data in my analysis.
Michael Sweet @44 that is an obvious possibility, but is not obvious. First, if it were the case, 2013 would not be so (apparently) statistically unusual with respect to other years from 1990-2013 (3 sigma in two stations tested - I'll report on Australia wide in a day or so). Second, the trend in cloudiness is towards more cloud, not less, at least since 1957. That is the reverse of what we would expect if this were a feedback.
On theoretical grounds, the expectation is that when it is dry in warmed conditions, it will be dryer than it would have been under cooler conditions. That would translate into less cloud in warm dry conditions. Therefore there may be a feedback component in this, but it would be hard to argue for that from available data. Further, the feedback would also apply to naturally occuring warm dry conditions, suggesting Australia would have a higher probability of very warm years than standard deviations determined from normal years would suggest. Consequently, the idea that feedback is involved is refuted for a statistical trend; and equivacol if we consider its potential effect on exceptional years, whether those exceptional years are brought about by the combination of global warming plus natural variation, or natural variation alone.
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Rob Honeycutt at 07:40 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
In addition, Tamino notes that none of the data sets supports her position on this:
I’ve looked at a pretty large number of data sets. I defined the “Arctic” as the region from latitude 60N to the pole (as did Bengtsson et al.). Were temperature anomalies in the 1930s actually as large as those in the 1990s and 2000s?
Using the GISS LOTI (land+ocean temperature index), the answer is “No.” Using the GISS met-station data, the answer is “No.” Using the HadCRUT4 (land+ocean) data, the answer is “No.” Using the CRUTEM4 (land only) data, the answer is “No.” Using the NCDC land+ocean data, the answer is “No.” Using the NCDC land-only data, the answer is “No.” Using the Berekely data, the answer is “No.”
All those “No” answers aren’t close calls.
(My emphasis.)
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A Historical Perspective on Arctic Warming: Part One
willard - I believe that Robert Way has indeed presented the support for his disagreement with both Dr. Curry (who claims the Arctic anomalies were equal or greater than current Arctic anomalies) and the IPCC text. That support is the recorded temperature data, as in the GISS temps plotted by latitude:
Way doesn't have the responsibility of justifying the IPCC position, seeing as how he disagrees with it based on the data. As to providing the IPCC quote, that's in the opening post. It's not clear to me what you are asking for beyond that.
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Rob Honeycutt at 07:35 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard... No, that is not what Dr Curry quoted. That is the IPCC section she was quoting from. She actually only quotes the opening two sentences from that paragraph.
Curry's premise, if you'll recall, is that AR5 actually lessens the certainty on man-made global warming. Right? She is using (or attempting to use) that specific sentence "Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s" to support her thesis.
The problem is, while you can say Arctic temps were as high in the 1990's as they were in the 1930's, the error in the draft AR5 is in adding "and 2000's" to the sentence. There is no support for that position.
Willard, all you have to do is look at the data. None of the data sets supports the conclusion Curry is making. Tamino presents Johanessen because that is the only cited research that could possibly be used to support her position. But he shows she would be relying on out-of-date information to make such a claim.
Moderator Response:[KC] Accusation of dishonesty snipped.
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willard at 06:20 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Rob Honeycutt,
You say:
> [Tamino] explains the text from the IPCC is based on Johanessen et al. [...]
More exactly, Tamino claims that Johanessen & al is the only reference he could find that would substantiate Judy's claim. Only by considering that source does he raise concerns about the "2000s" mentioned by the IPCC. That Robert Way (not Dr., sorry about that) cites Tamino's reference does not substantiate what Tamino says: it simply repeats it.
Besides mentioning Gillett et al. (2008b), Wang et al. (2007), Shindell and Faluvegi (2009) and (Crook et al., 2011), and notwithstanding the model based attribution studies, here's the relevant paragraph quoted by Judy:
Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s. There is still considerable discussion of the ultimate causes of the warm temperature anomalies that occurred in the Arctic in the 1920s and 1930s (Ahlmann, 1948; Veryard, 1963; Hegerl et al., 2007a; Hegerl et al., 2007b). The early 20th century warm period, while reflected in the hemispheric average air temperature record (Brohan et al., 2006), did not appear consistently in the mid-latitudes nor on the Pacific side of the Arctic (Johannessen et al., 2004; Wood and Overland, 2010). Polyakov et al. (2003) argued that the Arctic air temperature records reflected a natural cycle of about 50–80 years. However, many authors (Bengtsson et al., 2004; Grant et al., 2009; Wood and Overland, 2010; Brönnimann et al., 2012) instead link the 1930s temperatures to internal variability in the North Atlantic atmospheric and ocean circulation as a single episode that was sustained by ocean and sea ice processes in the Arctic and north Atlantic. The Arctic wide temperature increases in the last decade contrast with the episodic regional increases in the early 20th century, suggesting that it is unlikely that recent increases are due to the same primary climate process as the early 20th century.
So again, I expect Skeptical Science to present what is in the litterature,
<snip>
Moderator Response:[PS] Please wind back the rhetoric and stick to the science. That means everyone.
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Rob Honeycutt at 05:06 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Magma... Please define for me what you mean by "squirrel" and please provide at least six citations (from sources I deem reasonable) proving the existence of said creature, and... Look, over there! It's a blimp!
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Magma at 04:48 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
@ Rob (#2, #4): it is well understood that the entire burden of proof, right down to providing exhaustive etymologies of technical terms and common English words, rests with those scientists who would infer any human role in climate change. Those who oppose that position, on the other hand, are allowed to say any old thing that pops into their heads. In such cases, asking for references is considered rude. I believe, but am not certain, that such commenters are also permitted to invoke the "Look, a squirrel!" rule at any point.
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JoeT at 03:49 AM on 29 January 2014Real Skepticism About the New Marcott 'Hockey Stick'
Sorry to break into the discussion. I have a fairly simple question that I'm hoping someone can straighten out for me. I just read the Marcott paper for the first time. If I look at Figure 2 of the original post or figure 1b of the Marcott paper, it looks to me like the peak of the instrumental temperature data is higher than the previous 11,300 years, even including the 1 sigma uncertainty. How do I reconcile that with the statement in the abstract that, "Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temerpature history." What am I missing?
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Composer99 at 03:47 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
willard,
Out of curiosity, why is that you refer to Robert Way as "Dr" even though - as his Skeptical Science author profile notes - he is a PhD student, but Dr Curry gets to be "Judy"?
Personal acquaintance, perhaps?
Moderator Response:[PS] Can all parties stick to the science please? (and leave out rhetoric).
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Rob Honeycutt at 03:28 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard... You should click the link over to Tamino's article. He explains the text from the IPCC is based on Johanessen et al. (2004, Tellus, 56A, 328–341), which this article cites, where the data ends at 1997.5. Someone of Dr Curry's "expertise" should have easily picked up on this. It is clearly an error in the draft version of AR5 that Judith was pouring over prior to her testimony. But rather than turning up the error she used the error to make a completely erroneous statement to the Senate committee.
I would also highly suggest you tone down your "I expect" comments. If you have questions, just ask.
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willard at 03:07 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
> The article is a response to Dr Curry's erroneous claims.
The explain the op-ed's kicker, Rob:
Based on the data presented above there is virtually no evidence that Arctic air temperatures were greater than present during any previous period of the last century. This is clearly a case where the IPCC should consider amending its text to provide a more accurate picture of Arctic temperature changes.
I expect Dr. Way to cite the relevant research behind the IPCC's "text".
I also expect Dr. Way to communicate his beef with its authors in another mean than an op-ed against Judy.
***
As an aside, it would be interesting to compare the citations provided in this op-ed and what we can find in Cowtan & Way, in press.
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Rob Honeycutt at 02:59 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
Willard... The article is a response to Dr Curry's erroneous claims. Would you expect Robert to not cite is own relevant research related to this issue? And, how is it a "promotional token" when there are at least six other citations in the piece?
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willard at 02:47 AM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
> During her most recent Senate testimony, Dr. Judith Curry (Georgia Tech) repeated one of the most common misconceptions found in the blogosphere, that the Arctic was warmer than present during the 1940s.
A quote might be needed, if only to see if Judy argues what "the contrarians argue", whoever they may be.
Some citations showing that what the contrarians argue can be reduced to the two claims in the text might be nice.
***
Furthermore, this article mentions "the contrarian view" and quotes the IPCC without presenting both viewpoints. All we see is a quote. No discussion of the rationale behind the IPCC's claim. Not even a citation.
In fact, we have no evidence of any effort to conciliate the author's opinion with the authors of the AR5, chapter 10.
***
I conclude that this article is mainly a promotional token for Cowtan & Way, in press, and expect better from a site that declares his intention "to explain what peer reviewed science has to say about global warming".
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Kevin C at 02:29 AM on 29 January 2014Cowtan and Way: Surface temperature data update
Temperature files contain 5 columns: date, temperature, total uncertainty (1σ), coverage uncertainty (1σ), ensemble uncertainty (1σ).
(From the series page, but I know from experience that it's easy to miss things like this.)
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chriskoz at 12:50 PM on 28 January 2014Cowtan and Way: Surface temperature data update
Kevin,
In your data, http://www-users.york.ac.uk/~kdc3/papers/coverage2013/had4_krig_v2_0_0.txt, you don't have the headings. I want to play it a bit in R but I need to understand the columns first. I'm guessing the column meaning:
column0 - time
column1 - dT based 1961-90
What are columns 2, 3 & 4? I could have guessed but I'd better ask.
Thanks, Chris.
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michael sweet at 12:31 PM on 28 January 2014Australia’s hottest year was no freak event: humans caused it
Bruiser and Tom,
How do you know that higher solar exposure is due to random fluxuations and is not a response to AGW forcing? Drought is predicted for Australia from AGW. Perhaps (most likely?) the high solar insulation in Australia is just a manifestation of AGW caused drought. Since we know all weather is affected by AGW, it seems to me that Bruiser must provide evidence to support his hypothesis that the higher solar exposure is random and not directly caused by AGW. I have not seen any data from Bruiser to support his hypothesis of random fluxuations. If the higher solar exposure persists in future years that would be evidence that it is caused by AGW (as a consequence of AGW caused drought) and not a random variation.
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barry1487 at 12:05 PM on 28 January 2014Australia’s hottest year was no freak event: humans caused it
Daytime cloudiness data at BoM website starts at 1957. Might be useful get a longer term estimate of solar exposure.
Thanks for the update and fair comments. Openly admitting doubts and errors and self-correcting are rare enough virutes in these debates.
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gws at 10:13 AM on 28 January 20142014 SkS Weekly News Roundup #4B
An then there was this interesting story in the NYT:
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Tom Curtis at 10:00 AM on 28 January 2014Australia’s hottest year was no freak event: humans caused it
Barry @41, a Watt equals one Joule per Second. The units for the solar exposure are in Megajoules per day per meter squared. Therefore multiplying by one million then dividing by 86,400 (24 x 60 x 60) converts to Watts per meter squared. I originally thought the units were Megajoules per annum per meter squared, and further divided by 365. Correcting for that error, the maximum possible forcing from solar exposure is then 21.8 W/m^2. That is the figure before correction for albedo, and for loss of greenhouse forcing due to reduced cloud cover and water vapour content in the atmosphere. It is, however, sufficiently large that I cannot argue for a small relative effect without quantifying those values as I did in my prior post.
Here is an albedo map for Australia:
The data is from Modis, and full global maps are available here.
It is hard to derive an exact value, but as yellow, which predominates, represents an albedo just greater than 0.3, and as orange to red areas (3.5-4) are more extensive than green areas (0.2-2.5), I think an average albedo of 0.3 for Australia is a conservative estimate. That reduces the transient forcing from the high solar exposure (low cloud cover) over Australia in 2013 to approximately 0.7 x 22, or to 15.4.
Further, the high solar exposure is due to low cloud cover, which reduces the greenhouse forcing due to clouds over Australia during that period. The solar exposure was 9.6% greater than normal. As the increased solar exposure was due to low cloud cover, that represents approximately a 9.6% reduction in cloud cover. Globally, single factor removal of clouds removes 14% of the total greenhouse effect, or 21.7 W/m^2. Therefore removal of 9.6% of clouds would remove 2.1 W/m^2 of the greenhouse effect. A similar reduction in WV content would remove just over twice that amount, but that does not allow for the overlap between WV and clouds. Single factor removal of Water Vapour and clouds at the same time removes 103.7 W/m^2 of forcing. Removing just 9.6% of that removes 10 W/m^2.
Combined, these two effects will bring the net transient forcing from increased solar exposure in 2013 to about 5 W/m^2. Clearly the error margins on this calculation are large. Without exact information on cloud content, water vapour, temperatures and access to a climate model, I do not think I can significantly lower them.
The final factor that comes into play is the lag in increase in temperature. It takes around 60 years for 66% of the final temperature response to a forcing to come into effect, and over 200 years for the full effect to be felt. Consequently a transient forcing over one year will not have the same temperature effect as a long term forcing that has been in existence for much of a century. The initial rise is rapid, however, especially over land. Therefore, while we would expect a transient forcing of 5 W/m^2 to not have had the same temperature response as a long term forcing of 5 W/m^2, it may have had the same, or greater response 2.3 W/m^2 (ie, the effective radiative forcing from anthropogenic activity).
The consequence of this is frustrating. Bruiser will not be convinced, and nor should he be convinced, by this that he is wrong in attributing most of the increased temperature to the high solar exposure. The error margins are too large. Neither should he be convinced from this that he is correct, for the same reason. I have tried to be conservative in my calculation, and to the extent that I have succeeded, that means it is more likely that the errors will have favoured his case rather than undermined it, and therefore, that an error free calculation would show his case to be wanting. Therefore I do not believe we can use direct calculation of the transient forcing to further the discussion (contrary to what I attempted).
This does not mean Bruiser should not be persuaded by the first part of my discussion (and by your comments). The fact is that the difference in temperature between years in the late twentieth and early twenty first century is much smaller than the difference in temperature between those years and years in the early twentieth century. That is not explicable in terms of solar exposure. It follows that while solar exposure is (very convincingly) the primary reason why 2013 was hot relative to 1990-2013, it is not the reason why 1990-2013 was hot relative to 1910-1939. Nevertheless, I would now like to analyze Australia's solar exposure data to determine if it has a trend; and what the relationship is between solar exposure and temperatures over recent years to strengthen (or refute) that case.
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Kevin C at 07:47 AM on 28 January 2014Cowtan and Way: Surface temperature data update
Actually BEST are doing monthly updates, although usually a month or two behind the others. I hadn't been picking them up for the trend calculator until a few weeks ago, which may have given the wrong impression.
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Andy Skuce at 06:24 AM on 28 January 2014Cowtan and Way: Surface temperature data update
There is a post by Stefan Rahmstorf just out at RealClimate. He compares Cowtan and Way's temperature series with GISS and NOAA NCDC as well as HadCRUT4. His ranking of the warmest years of C&W's series is based on their Version2 rather than the Hybrid method.
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CBDunkerson at 03:57 AM on 28 January 2014Cowtan and Way: Surface temperature data update
While it would be great to have additional papers which might make a 'splash' and help penetrate public consciousness, I can certainly appreciate your reluctance to put in that much extra effort.
Have you heard anything from people working on the other anomaly series as to whether they are considering implementing some of your adjustments? That would certainly also be a major accomplishment as the data from the large institutions will undoubtedly remain the most frequently referenced. That was one thing which bothered me about the 'BEST' project. They pulled in some additional data and introduced new analysis techniques which might be beneficial, but then they didn't continue projecting and none of the other data sets seem to have used anything from their study to improve results.
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Rob Honeycutt at 02:11 AM on 28 January 2014There's no correlation between CO2 and temperature
tkman0... Don't let Tom fool you with his humility. He is probably the best informed non-researcher I've ever had the pleasure to come across. While actual researchers are likely to have a deeper understanding of their own area of the science, Tom probably has the broadest knowledge of climate of anyone I've seen.
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Kevin C at 02:09 AM on 28 January 2014Cowtan and Way: Surface temperature data update
Ideally we'd write more papers. However, one of the main reasons for writing a paper in the first place was that it was the only way to draw the attention of the community to the problem. So to some extent if we can now communicate sufficiently well to the community through the project website and blogs then writing papers becomes less important.
Of course papers are important for the scientific record, but if the main temperature record providers update their work in response to the issues we raise it'll be recorded in their publications.
Doing a peer-reviewed paper in your spare time in someone else's field is a killer. We've probably got enough material (including unreleased results and work in progress) for at least another 2 papers, but I'm not sure I can face writing them.
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John Hartz at 02:02 AM on 28 January 2014It's cooling
tkman0: Suggest that you invite your friend to post his/her concerns here on SkS. there really is no need for you to play the role of middleman.
Moderator Response:[TD] But please inform your "friend" to keep each of his/her comments narrowly on one topic, to post each comment on an appropriately narrow thread, and to read the original post to which that thread is attached before writing the comment. I strongly suggest your friend not write any comments until after reading The Big Picture followed by The New Abridged Skeptical Science Reference Guide.
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CBDunkerson at 02:00 AM on 28 January 2014Cowtan and Way: Surface temperature data update
This is great stuff. As the uncertainty bands around the temperature anomaly series shrink, that may help make it easier to precisely identify the factors contributing to short term variations.
It seems like this is changing from a one time re-analysis of the anomaly data (ala the 'BEST' project) into a new ongoing data set. Are there likely to be additional papers published documenting the ongoing analysis and changes or will that information only be documented on the project website?
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barry1487 at 01:34 AM on 28 January 2014Australia’s hottest year was no freak event: humans caused it
Would you lay out the conversion/time in some detail when you post?
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Tom Curtis at 00:15 AM on 28 January 2014Australia’s hottest year was no freak event: humans caused it
Please note that I have reviewed my figures in construcing the graph @35 and detected an error, specifically I treated them as annual values when they should have been treated as annual averages of daily values. A apologize for that error. That means all of my post from the words "To try and resolve that question" is either false, or unsupported at the moment. I will try to extend my analysis to tackle the issue more accurately, but may take a day or so to do so. Once again, I apologize for the error.
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barry1487 at 23:29 PM on 27 January 2014Australia’s hottest year was no freak event: humans caused it
CB, I believe 2.3W/sq M refers to the accumulated anthropogenic forcing since 1750.
Bruiser, have you been skimming the replies to you?
Your argument that there have been hotter years with lower solar radiation whilst factual does nothing to prove your case. By your logic, temperatures should have increased every year since 1998 as the world has added billions of tons of Co2 since that time.
There is no logic to that point at all, it's merely an assertion to the inverse. No one is arguing that interannual variability (weather) is meant to cease when CO2 rises in the atmosphere. To the contrary, in his last post Tom said,
The idea is that there are many short term factors that influence annual temperatures. As a result temperatures may be warmer, or colder from year to year - but always within a limited range.
The point Tom and the authors are making is (in Tom's words);
...Long term factors, such as increased atmospheric forcing from CO2, however, can shift the mean of that range, allowing temperatures that we would never have seen otherwise.
Everyone is agreed here that annual temps will not monotonically respond to anthropogenic forcing. Solar exposure will have some impact, of course, even a major one in extreme years (high and low), but you are the only person trying to argue that this is the dominant factor, seemingly to advance the notion that last year's record-breaker was just a result of natural variability. But if 2013 solar exposure had an impact of 0.06 W/sq M above average, and accumulated anthropogenic forcing has had a long-term impact of 2.3 W/sq M, which is the greater contributor to the record temperature of the most recent year?
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CBDunkerson at 22:39 PM on 27 January 2014Australia’s hottest year was no freak event: humans caused it
bruiser, looking only at the CO2 increase from 2012 to 2013 deliberately ignores the vast majority of the warming caused by CO2. No one is claiming that the CO2 increase from that single year caused the recent high temperatures in Australia. That's a ridiculous straw man. Rather, the CO2 (and other greenhouse gas) increases over the past century plus have caused massive warming world-wide... without which the recent record high temperatures would not have occurred.
Tom Curtis's graph comparing the solar forcing for last year against the total accumulated CO2 forcing would be better if it instead showed the change in solar forcing over the same time frame as the CO2 change, but that data isn't available. However, based on what we know about variations in solar forcing in general, the total change in solar forcing would still be much smaller than the CO2 forcing.
If your claim that high solar irradiance last year was a primary cause of the observed high temperatures was valid then we should see similar changes in previous years of high and low solar irradiance... but barry has already demonstrated that this is not the case. Your hypothesis is contradicted by the evidence.
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bruiser at 20:38 PM on 27 January 2014Australia’s hottest year was no freak event: humans caused it
Tom, the increase in co2 concentrations between 2012 and 2013 are miniscule compared to the increase in solar radiatin. So far we have seen cold weather, storms, bushfires, decreasing Arctic Ice, increasing Antarctic sea ice, tornadoes, hurricanes and heat waves attributed to AGW. If 0.4 W/Sq M can cause the decline in Arctic ice, I am sure 2Mw/Sq M/day can push up Australian temperatures. Your argument that there have been hotter years with lower solar radiation whilst factual does nothing to prove your case. By your logic, temperatures should have increased every year since 1998 as the world has added billions of tons of Co2 since that time.
Cheers, Bruiser
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Tom Curtis at 14:02 PM on 27 January 2014Climate's changed before
tkman0 @393, given an interest in learning about global warming, I believe that the best approach is to start reading the history of the science. Here are some good resources from SkS:
Climate Science History Interactive Tool
Introducing the History of Climate Science
The History of Climate Science
Behind the Lines: Herschel's Discovery of Infrared
Two Centuries of Climate Science, Part 1, Part 2 and Part 3.
You should supplement reading those pages by targetted questions about aspects o the science discussed in the history that you do not understand. This will give you a far broader knowledge base than answering detailed questions in response to a denier. It will also show just how narrow is the focus, and how ignorant of the history of the discipline those deniers are when they start denying things proved decades, or even centuries ago.
Finally, I believe a good, clear explanation of the basic physics helps understand everything more clearly.
If you try to learn by debates with deniers, you will find they repeat previously refuted claims, contradict themselves and do not have a clear idea of the subject. Refuting them may be interesting the first time, but it will leave you with an unbalanced understanding of the science. As it is also the several thousandth time various of the people helping you have refuted those same points, a more sensible approach would be refreshing for them as well ;)
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Tom Curtis at 13:40 PM on 27 January 2014It's cooling
Out of interest, the difference between the video linked to by KR and the data in the graph I showed above is that the data above is pure thermometer based data. Because there were no meteorological stations in Antarctica in 1880 (and indeed, not till the 1950s), it is unable to show temperatures for that period and hence no trend from that period either. In contrast, KR's video appears to be a reanalysis product. With reanalysis, they feed actual observations into a climate computer so that the computer's output is constrained to match observations where they are available. They then allow the computer to fill in the missing data. The process is accurate to a fairly high standard, but not perfect (nothing in science is). I would trust it as as good a representation of the actual temperature trends in those areas we are likely to get. You should, however, be aware of the difference so you can answer sensible questions (how did they measure Antarctic temperatures in 1880) and stupid ones ("I did not know we had satellites in orbit in 1884"). For the last, check the Youtube comments, or alternatively keep a hold of your braincells, and don't.
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tkman0 at 13:32 PM on 27 January 2014It's cooling
@KR, they're private messages back and forth between us because we were causing a rucus on the forums. As to the website...you probably dont wana know, not really your typical website for every day use.
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DSL at 13:29 PM on 27 January 2014It's cooling
tkman0, there are a variety of tools available to look at such things. Here's GIS Land-Ocean Temperature Index (GIS L-OTI) for the last decade, and here's the main page for the tool.
Here's graphed data for three latitudinal bands. -
Tom Curtis at 13:28 PM on 27 January 2014It's cooling
tkman0 @204, looks pretty global to me:
The graphs of the trend in warming from 1880-2013. The upper graph shows the data by zone, while the lower shows the average for each latitude band. As you can see, the equator shows a trend of around 0.8 C over that period, or 0.06 C per decade. The band with lowest warming is at 60 degres South (0.02 C per decade). That is low relative to the average (0.07 C per decade) but it is still warming - not cooling.
I suspect your interlocuter's data only shows ocean temperature anomalies relative to some recent period, where the recent La Nina's have draged the equatorial trend down. They are, however, short term fluctuations, and if that is what they have done, they are cherry picking.
The data comes from the GISS website, and is very usefull for debunking denier claims. You absolutely should bookmark it if you are interested in the debate.
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It's cooling
tkman0 - Where is this discussion occurring?
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