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Comments 38951 to 39000:
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gws at 00:41 AM on 31 January 2014Methane emissions from oil & gas development
Informative story on NPR this morning:
Much of North Dakota's Natural Gas is going up in Flames
Situation is similar in Texas.
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barry1487 at 21:54 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
chris & Glenn,
While ENSO maybe the primary factor in ocean/atmosphere heat flux, it is not the only mechanism. Trenberth's paper is trying to resolve the energy budget on interannual scale, but I am interested in decadal trends. (I'm not sure if the paper says that they are better resolved or not) There has been much discussion attributing the 'pause' in surface temps since the turn of the millenium to accelerated uptake of energy in the oceans. This would seem to be corroborated in the OHC data since the turn of the millenium. So I looked further back to see if that kind of correlation was evident, using OHC as the pacemaker.
For periods when there was a clear linear trend change in OHC (0-700 & 0-2000), there seems to be an inverse correlation with surface temperatures. I added a few more trend lines to surface data here.
The first 2 trendlines are sub-decadal and should be ignored (although they fit my hypothesis) , but the following 3 are decadal periods with distinct trends. ENSO is not factored because it is a component of total OHC.
The three decadal surface temp trends behave as I imagine for periods when OHC rises quickly or is flattish. OHC has a steep warming trend 1969 - 1979 (incl), has a much lower trend 1980 - 1990, and a steep trend again 2000 - 2014. Surface trend for those periods are, inversely, flattish, steeply warming, and flattish again. IIRC, long-term volcanic forcing is negligible, and solar influence is not a major factor (15% on decadal time scales according to Trenberth). I didn't attempt to run a trend for 1990 - 2000, as OHC trend for that period was hard to read.
I don't know if there may be something to accounting for surface/ocean trends on decadal scales, but I was interested in the possibility in light of the recent 'haiatus' in surface temperatures. From Trenberth's paper:
Several runs with the model under future emissions scenarios where the radiative imbalance is known exactly and a distinct energy imbalance at TOA was occurring nonetheless featured several stases in surface temperatures for more than a decade. Examination of the energy flows during such intervals for all ensemble members reveals a consistent picture. The net radiation at the TOA (RT) was on the order of 1 W m-‐2 into the climate system, yet there was a stasis in warming at the surface. Examination of the changes in OHC showed clearly that this was the main sink. Indeed, the full depth OHC continued relentlessly upwards with no hesitation at all. Hence the missing heat was being deposited mainly below 700m depth....
Consistent with prevailing theories on the 'pause'?
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chriskoz at 19:56 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
wwsyim@5,
No, we haven't "overlooked" the role of submarine volcanic eruptions.
The 'heat' of underwater volcanic eruptions you're presumably refering to, is part of earth's geothermal etnergy. The total geothermal energy was mesured as 0.1W/m2, which is much less than current toa imbalance. You can read about it, e.g. here:
What might be causing the imbalance? Might it be heat flowing from within the Earth? Apparently not. Pollack et al 1993 estimated total geothermal heat flows from within the Earth at 44.2 trillion Watts. This is only around 1/6th of the observed heat build-up
Out of that 0.1W/m2, volcanoes are only a part. Your volcanoes (underrwater) are still ~3/4 of total volcanoes on the globe. So I can confidently say that the heat of your volcanoes is at least 10 times smaller than the heat retained due to TOA imbalance. To have a little bit of understanding about the enormity of TOA imbalance, you can read further therin:It [imbalance] would now take all of 100 minutes to boil Sydney harbour dry
Any of your volcanoes would be able to do it? It would be an enormous volcano that no one has seen yet... Of course, one can find & claim that that some specific eruption warmed ocean water by several degrees and caused change of currents and that may have even contributed to the reversal of ENSO oscillations. But it's going to be only local and minor event. Globally, the biggest factor is imbalance due to GHG.
The "natural" CO2 emissions from all volcanoes are 100times smaller than human emissions, as you can read here. So the volcanic CO2 is also a minor factor.
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Rob Painting at 17:10 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
wwsyim - the global oceans are warming from the top down. There are many other lines of evidence, but this alone precludes submarine volcanoes as a culprit.
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wwsyim at 16:22 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
Submarine volcanic eruptions have always been an episodic natural contributor to ocean warming. For example the El Hierro submarine volcanic eruption in the Canary Archipelago, off the northwest African coast from October 2011 to March 2012.
How can we distinguish between ocean warming due to natural and anthropogenic causes? - or have we entirely overlooked the role of submarine volcanic eruptions.
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Glenn Tamblyn at 16:16 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
barry @1
Actually from your graph, 0-700 and 0-2000 OHC seems to have moved in lock-step from 57 - 83 with a blip around 75. Implying no long term heating in 700-2000. Then from 83-86 0-2000 rose faster implying heating in 700-2000. Then from 86 to 94 0-2000 matched 0-100 so no warming od 700-2000. Then from 94 onwards 700-2000 started warming continuously.
Perhaps 700-2000 actually started warming around 83 onwards with something suspending that from 86 to 94.
And what could cause these sorts of fluctuations? Winds. Increased winds in the tropics and mid latitudes can 'spin up' the mid-ocean gyres, increasing the rate at which water gets pumped down to mid depths through Ekman pumping, taking heat from the surface with it.
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R. Gates at 15:23 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
I think this general analysis is right on target and the "pause" in the accumulation of energy in the Earth climate system is indeed an illusion. Tropospheric sensible heat is a poor proxy for measuring the energy gain in the Earth system. It is only a partially good proxy over the longest time frames. The Earth climate system continues to gain energy from the geologically rapid build up of GH gases caused by human activity.
Having said all this however, let me correct what I think is a basic thermodynamic error that many make when saying the "heat is going into the oceans" from anthropogenic global warming. By a very very big margin, the net flow of latent and sensible heat is from ocean to atmosphere on a global basis. The atmosphere simply does not heat the ocean-- quite the opposite. What increasing GH gases do is alter the rate of energy flow from ocean to atmosphere to space. The oceans gain energy because this flow is reduced. Much of this addition energy in the ocean is advected to the poles (especially the north pole, due to the hemispheric energy flux differences). Thus we see much if the sea ice decline actually occuring from ice being melted from the bottom From warmer water. Thus, a slightly warmer atmosphere acts like a control knob to create a much warmer ocean and even faster warming polar region.
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chriskoz at 12:45 PM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
barry@1,
If you think about the fact that OHC trend is responsible for over 90% of warming due to TOA imbalance, you may reasonably expect the surface T changes (where only 3% of that imbalance energy goes) will not be very well correlated. It's hard to establish precise correlation from when other factors (volcanoe aerosols, sun's variability) are coming into play and influence TOA balance.
However your remark:
the cursory implication is that warming slows or stops at the surface for periods that OHC rises quickly
can be interpreted as an indication of LaNina conditions (ENSO minus zero) that may have prevailed during your periods. You would have to consider other effects (volcanoes & sun variability) to establish your correlation.
Trenberth et al. (2014) cited in the article is an excelent analysis of OHC/ENSO and TOA imbalance that may help you.
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barry1487 at 11:30 AM on 30 January 2014Warming oceans consistent with rising sea level & global energy imbalance
OHC trend was also relatively strong between 1969 - 1979, similar to the period since 2000.
For both periods HadCRUt4 shows flattish surface trends.
It's just two periods, but the cursory implication is that warming slows or stops at the surface for periods that OHC rises quickly. Is there a long-term correlation, and does anyone know of published literature on this?
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VictorVenema at 11:22 AM on 30 January 2014A Historical Perspective on Arctic Warming: Part One
It could be that the IPCC was right, but Curry was wrong. There is namely an important sentence missing from Curry’s quote h/t Steve Bloom:
“A question as recently as six years ago was whether the recent Arctic warming and sea ice loss was unique in the instrumental record and whether the observed trend would continue (Serreze et al., 2007).”
In other words, the IPCC was describing the way science saw the situation 6 years ago. Six years makes quite a difference as the temperature increase was strong the last few years. For more details see my blog.
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A Historical Perspective on Arctic Warming: Part One
These sea ice maps from 1938 (the summer with least sea ice during the ECWP) and the record year 2012 confirms what the temperature records say about the Arctic, namely that the warming around 1930-1940 was not comparable to the warming we see today.
And even if it was, it’s worth noting that the areas north of 60°N and 70°N cover no more than about 7% and 3% of the Earths surface, respectively. A significant warming here could easily be offset by an insignificant cooling in the rest of the world without affecting the global temperature.
Source: Danish Meteorological Institute (DMI) and NSIDC.
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A Historical Perspective on Arctic Warming: Part One
An update on my previous post - Dr. Curry's Georgia Tech publication list shows about 154 titles, meaning that just under 1/3 (45) concern the Arctic. Again, she should know what she is talking about, making her Congressional testimony puzzling.
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A Historical Perspective on Arctic Warming: Part One
A quick look at Dr. Currys publication history shows two instances of 'Antarctic', and 45 of 'Arctic '. Only 5 on 'temperature', however (note: her publications go back to 1983, well over 100 listed). She appears to know a lot about the Arctic.
Given that publication history and the existing Arctic data, these postions in her testimony seem quite out of place.
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CBDunkerson at 05:42 AM on 30 January 2014A Historical Perspective on Arctic Warming: Part One
Albatross raises an interesting point. Curry has an extensive publication history... but I can't recall having seen her publish any peer reviewed 'research' on her climate denial talking points.
Her participation in the 'BEST' study would have been a perfect example... except that it wound up showing that her claims were false... and then, of course, she disavowed it.
Has she published 'denial research' that I have missed? Her claims on scientists (including her own BEST study) 'hiding the decline' were particularly egregious... yet she made her 'case' entirely in the field of 'journalism' rather than science.
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tkman0 at 04:03 AM on 30 January 2014A Historical Perspective on Arctic Warming: Part One
Thats a great Idea ^^
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Philippe Chantreau at 03:33 AM on 30 January 2014A Historical Perspective on Arctic Warming: Part One
Very good point Albatross, Willard's playing on words does not fool anyone. Curry's testimony in Congress had little more value than that of Monckton. Robert Way is one of many regular contributors to SkS who can claim publication in a serious journal. It is one more in a list that is becoming significant and continues to grow. I'm not sure if this is the right thread but I would like to propose a new tab on the upper left of the home page: "SkS authors/contributors climate science articles." Anyone else thinks it's a good idea? I'm not suggesting competiton with RC but something that would allow newcomers to see that this site is not to be given the same weight as clowns like Goddard or other internet junk...
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JoeT at 14:01 PM on 29 January 2014Real Skepticism About the New Marcott 'Hockey Stick'
Hey Tom, thanks very much for a very cogent explanation. I appreciate it.
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Albatross at 13:28 PM on 29 January 2014A Historical Perspective on Arctic Warming: Part One
To be fair, I am going to issue a challenge to Dr. Curry. If Dr. Curry honestly believes that her opinions have scientific merit and/or are novel, then I challenge her to publish (as sole author) a paper on each one of her claims made to Congress in a reputable peer-reviewed journal such as Quarterly Journal of the Royal Meteorological Society, Journal of Climate, or Climate Dynamics, or International Journal of Climatology or Geophysical Research letters.
Cowtan and Way did so.... -
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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