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Rose and Curry Double Down on Global Warming Denial

Posted on 23 October 2012 by dana1981

David Rose and Judith Curry have doubled down on literal global warming denial, as they continue to deny that the planet is warming.  On 13 October 2012, Rose first published an article in the British newspaper the Mail on Sunday claiming that global warming stopped 16 years ago.  As we subsequently demonstrated, the article was riddled with errors, its main problem being in a false equivalence between rising global surface temperatures and global warming.  In reality a very small fraction of overall global warming goes into heating surface air temperatures, whereas over 90% goes into heating the oceans.  As we noted, Nuccitelli et al. (2012) had pre-bunked Rose's article by showing just days earlier that the overall heating of the planet has not slowed (Figure 1).

Fig 1Figure 1: Land, atmosphere, and ice heating (red), 0-700 meter ocean heat content increase (light blue), 700-2,000 meter OHC increase (dark blue).  From Nuccitelli et al. (2012).

Rather than acknowledge and correct their mistakes, Rose and Curry coordinated on a follow-up Mail on Sunday article published on 20 October 2012 (which Curry calls "well done") which repeated much of their previous misinformation and added a few new misconceptions for good measure.

Denying Climate Physics

The misconception that global warming has stopped is based on a lack of understanding of the physics of the global climate system.  When the Earth has an energy imbalance (more incoming than outgoing energy) as is currently the case (due to the increased greenhouse effect), the planet must warm in order to restore an overall energy balance.  Short-term effects can only stave off that warming for a short period of time.  Thus we know from basic physics that the current slowed rate of global surface warming cannot last indefinitely.

In this context, Rose quotes Curry making an argument that strains credulity:

"If we are currently in a plateau and possibly headed for cooling, then sometime in the middle of the century we would likely see another period with a large warming trend."

Given the large and growing global energy imbalance, it is simply not remotely plausible that the natural variability in the climate system could offset the inevitable global surface warming (let alone cause cooling) for another three decades.  As discussed below, even with virtually every major natural temperature influence aligning in the cooling direction over the past decade, surface temperatures have still warmed.

Physics will not be denied.

Denying Global Surface Warming via Cherrypicking

Rose's new article essentially doubles down on his original assertion that global surface temperatures have not warmed in 16 years, which he tries to defend with a new quote from Judith Curry:

"Nothing in the Met Office’s statement .  .  . effectively refutes Mr Rose’s argument that there has been no increase in the global average surface temperature for the past  16 years."

Curry's assertion is easily disproven by once again examining the Met Office statement:

"The linear trend from August 1997 (in the middle of an exceptionally strong El Nino) to August 2012 (coming at the tail end of a double-dip La Nina) is about 0.03°C/decade, amounting to a temperature increase of 0.05°C over that period, but equally we could calculate the linear trend from 1999, during the subsequent La Nina, and show a more substantial warming."

While 0.05°C is a small increase, and not statistically significant, the Met Office has nevertheless shown that average global surface temperatures most likely increased over the 15 (not 16) year period from August 1997 to August 2012.  Additionally, as statistician Tamino at the Open Mind blog put it, choosing mid-1997 as a starting point for this analyis is "not just cherry-picking, it’s championship cherry-picking."

"If [Rose] could prove, statistically, that the previous warming trend stopped (or even slowed) around that time, then choosing mid-1997 to start an analysis would be legitimate. But he can’t. Because it didn’t. And then of course there’s the pesky fact that he didn’t even try."

Tamino examines what the surface temperature data would have looked like had the 1975 to 1997 global surface temperature trend continued at the same rate from 1997 to 2012 (Figure 2).

pre 1997 trend extended

Figure 2: HadCRUT4 global surface temperature data from 1975 to mid-1997 fitted with a linear trend (blue), and from mid-1997 to mid-2012 with an extention of the same 1975 to 1997 trend (red).

What this figure shows is that in 1997-1998 there was a very strong El Niño event which caused a large short-term jump in global surface temperatures, which makes it possible to cherrypick start and end points to find whatever short-term trend one would like.  However, the long-term global surface warming trend has remained fairly steady.

It is true that over the past decade the rate of global surface warming has slowed.  As we noted in our response to Rose's previous article, this is precisely what we would expect to occur during a decade when aerosol emissions (which cause cooling by blocking sunlight) have risen, solar activity has been low, there has been a preponderance of La Niña events (which also cause short-term surface cooling), and heat has accumulated in the deep oceans.  However, the human-caused global surface warming signal is still peeking out from beneath these short-term cooling influences.  Unfortunately this is another fact which Curry and Rose deny in their new article.

Identifying the Human-Caused Global Surface Warming Trend

In a study last year, Foster and Rahmstorf (2011) attempted to measure the human-caused global surface warming signal by statistically removing the short-term influences of the El Niño Southern Oscillation (ENSO), changes in incoming solar radiation, and changes in volcanic activity.  Figure 3 shows the data before and after their analysis.

before/after filtering

Figure 3: Five temperature datasets (with a 12-month running average) before and after the statistical filtering of ENSO, solar activity, and volcanic activity by Foster and Rahmstorf (2011).

Thus Foster and Rahmstorf (2011) showed that beneath these short-term variations, the human-caused global surface warming signal has remained very steady.  However, Judith Curry apparently objects to this type of analysis.  According to Rose's new article,

"Prof Curry said that stripping out these phenomena made ‘no physical sense’. She added that natural phenomena and the CO2 greenhouse effect interact with each other, and cannot meaningfully be separated. It’s not just that the ‘cold mode’ has partly caused the plateau.

According to Prof Curry and others, the previous warm Pacific cycle and other natural factors, such as a high solar output, accounted for some of the warming seen before 1997..."

Frankly this is a rather bizarre and self-contradictory argument.  Curry first says that the temperature influences of ENSO and CO2 cannot be separated (which is incorrect - that is exactly what the Foster and Rahmstorf analysis did), and then she confidently claims that ENSO caused some of the pre-1997 warming.  Which is it - can natural and human factors be separated or not?

The answer is that Curry's second statement is mostly correct.  There were more El Niño events than La Niñas in the 1990s, and vice-versa in the 2000s (however, it is not true that solar activity was particularly high prior to 1997).  There was also some global brightening in the 1990s and global dimming in the 2000s due to changes in human aerosol emissions and global cloud cover.

In short, factors other than human greenhouse gas emissions amplified the observed surface warming in the 1990s and dampened it in the 2000s.  Foster and Rahmstorf showed that when we filter these influences out, the underlying human-caused surface warming trend has been very steady.  We just happen to be in the midst of a period when virtually all natural effects are acting in the cooling direction.  Despite all of the cooling effects discussed above, average surface temperatures have continued to rise slowly, which is a testament to the strength of the human-caused surface warming trend.

Denying Ocean Warming

In his new article, Rose does finally acknowledge the warming of the oceans illustrated in Figure 1, but only long enough to deny it.

"Other scientists say that heat has somehow been absorbed by the waters deep in the oceans. However, the evidence for this is contested, and there are no historical records with which to compare recent deepwater readings."

The ocean heat content data used by Nuccitelli et al. (2012) in Figure 1 originate from Levitus et al. (2012).  It is certainly true that ocean heat content measurements in the past are sparser than measurements today, but Rose is incorrect to claim that there are no historical records.  Past ocean heat content measurements were obtained from bathythermographs - instruments which have a temperature sensor and are thrown overboard from ships to record pressure and temperature changes as they drop through the water.  Levitus et al. showed the uncertainty range in the ocean heat content data over time (vertical red lines in Figure 4).

levitus OHC

Figure 4: Time series for the World Ocean of ocean heat content (1022 J) for the 0-2000m (red) and 700-2000m (black) layers based on running pentadal (five-year) analyses. Reference period is 1955-2006. Each pentadal estimate is plotted at the midpoint of the 5-year period. The vertical bars represent +/- 2 times the standard error of the mean (S.E.) about the pentadal estimate for the 0-2000m estimates and the grey-shaded area represent +/- 2*S.E. about the pentadal estimate for the 700-2000m estimates. The blue bar chart at the bottom represents the percentage of one-degree squares (globally) that have at least four pentadal one-degree square anomaly values used in their computation at 700m depth. Blue line is the same as for the bar chart but for 2000m depth.  From Levitus et al. (2012)

As Figure 4 shows, there is of course more uncertainty in the past ocean heat content measurements than the more recent data, but the rapid increase in ocean heat content is nevertheless very clear and much larger than the margin of error.  The oceans and planet as a whole have warmed an immense amount, with the equivalent energy of 2 Hiroshima atomic bomb detonations accumulating in the world's oceans every second since 1961, and 3 detonations per second over the past decade.  This is the immense global warming that Rose and Curry are denying.

Misunderstanding Climate Models

Curry and Rose continue to misunderstand climate model projections in their latest article.

"The 2007 Fourth Assessment Report of the UN Inter-governmental Panel on Climate Change (IPCC) said: ‘For the next two decades, a warming of about 0.2 degrees Celsius per decade is projected for a range of emission scenarios’ – a prediction it said was solid because this rate of increase was already being observed.

But while CO2 levels have continued to rise since 1997, warming has paused. This leads Prof Curry to say the IPCC’s models are ‘incomplete’, because they do not adequately account for natural factors..."

As we noted in our respose to Rose's previous article, the 0.2°C per decade surface warming projection from the IPCC is the average of all of their model simulations (a.k.a. the multi-model mean), which is why the IPCC used language like "about 0.2°C".  The model runs in which natural effects had a short-term warming influence over the next decade or two simulated more than 0.2°C per decade surface warming, while the model runs in which natural effects had a short-term cooling influence simulated less than 0.2°C per decade surface warming.

We currently cannot predict oceanic cycles like ENSO very far in advance;  thus, some model simulations contain a short-term warming influence from these sorts of natural cycles, and others contain an associated short-term cooling influence.  When the model runs are all averaged together, those natural warming and cooling effects average out.  Thus the 0.2°C per decade multi-model mean projection does not include ENSO effects. 

If there are more El Niño events over a given decade, as in the 1990s, the surface warming will probably be larger than the expected 0.2°C, and if there are more La Niñas, as in the 2000s, the surface warming will probably be less than 0.2°C.  In both cases that is precisely what we observed, and Rose is therefore wrong to suggest that climate models are unreliable based on the slower surface warming over the past decade.  Quite obviously there is no such thing as a perfect model, but global climate models are very useful tools which have made some accurate predictions thus far.

Future Global Warming

Rose also misrepresents the IPCC  and underestimates future global surface warming.

"For the world to be two degrees warmer in 2100 than it is now – as the IPCC has predicted – warming would not only have to restart but also proceed much faster than it has before."

In reality the IPCC produces a range of global surface warming projections based on a number of different emissions scenarios.  The amount of warming between now and 2100 ranges anywhere from about 1°C to 6°C (grey bars in the right margin of Figure 5).

Figure 5: Global surface temperature projections for IPCC Scenarios. Shading denotes the ±1 standard deviation range of individual model annual averages. The orange line is  constant CO2 concentrations at year 2000 values. The grey bars at right indicate the best estimate (solid line within each bar) and the likely range.  (Source: IPCC).

Limiting global surface warming over the next 90 years to 2°C, which would blow past the internationally-accepted 'danger limit', would require humans to follow one of the IPCC scenarios in which we significantly reduce our greenhouse gas emissions.  A continued business-as-usual path (roughly Scenario A2) will result in 3 to 4°C warming between now and 2100.  The only way we can avoid accelerating global warming is to take major steps to reduce human greenhouse gas emissions.

Current vs. Medieval Warmth

Rose also briefly mentions two recent studies which he purports show that the Medieval Warm Period (MWP) was warmer than today.  This is a misrepresenation of both studies, neither of which are global or even full northern hemisphere temperature reconstructions, and which do not include the rapid surface warming over the past ~40 years shown in Figures 2 and 3 above.

Rose is also undermining his own argument that future global warming is of little concern, because if the MWP were particularly hot, it would mean that the climate is very variable and sensitive to changes in the global energy imbalance.  Future global warming will only be small if the climate has a low sensitivity to changes like increasing solar activity or atmospheric greenhouse gas levels.  By arguing for a hot MWP, Rose is scoring an own goal - he is arguing with himself.

Summary of Rose and Curry Denial

To sum up, rather than admit the errors they made in their first Mail on Sunday article, Rose and Curry have doubled down on their previous mistakes and added a few new ones.

  • They continue to ignore that the 90+% of global warming that has gone into heating the oceans has not slowed or "paused", as most recently illustrated in Nuccitelli et al. (2012).
  • They fail to understand the fundamental physics of the climate system - that when there is a global energy imbalance, warming is an inevitable response, and natural variations in the climate system can only offset that warming for so long.
  • They continue to cherrypick convenient dates in their surface temperature data analysis.
  • They claim that natural temperature influences like ENSO are responsible for some of the global surface warming in the 1990s (which is true), but deny that they are responsible for the slowed rate of surface warming in the 2000s (which is also true).
  • They deny the existence of historical ocean heat content measurements.
  • They misunderstand and thus misrepresent global climate model simulations.
  • As a result of these errors, they wrongly downplay future global warming.
  • Rose also scores an own goal by essentially arguing for large future warming by claiming the MWP was hot, which would suggest the climate is sensitive to changes in the Earth's energy imbalance.

Overall Rose and Curry would do well to learn from the many critiques of their erroneous analyses rather than doubling down on their errors and continuing to propagate misinformation in the process.

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Comments 1 to 50 out of 56:

  1. well done, dana! Now let's see how long it takes Wattsy and his minions to completely screw this all up....a very valuable reference guide to yet another denialoshpere tour de farce.
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  2. Thanks vrooomie. It's worth noting that Watts immediately and uncritically reposted both error-riddled Rose/Curry articles.
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  3. The amount of attention Rose's first article has kicked up in the deniosphere has been particularly frustrating. I imagine this second article will do little but add fuel to the fire, error-ridden as it was. The full explination of all the ways in which the first article was incorrect, especially the energy imbalance the influences of el nino, la nina and aerosols, seem to be above the heads of a fair few that I have gotten into debates with over the course of the last week. It appears as is very clear depictions of the ocean heat storage and how blatantly cherry-picked the August 1997 date is (I made use of best-fit lines from August 1996, 97, and 98 showing the discrepency of 97) are the most effective methods of showing that the article is error prone, and work to more complicated explinations from there. Also, thanks for pointing out the 15 (not 16) part. I'm still trying to figure out where the 16 figure came from, and I'm just accrediting it to terrible math at this point
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  4. DMCarey @3 - the 16 simply came from Rose's article headline. January 1997 to August 2012 would at least be approaching 16 years, but Rose cherrypicked August 1997 as his starting point, which makes it 15 years. I'm not sure why he didn't just say 15, unless he simply got the arithmetic wrong. Or maybe it was to make it sound bigger than his previous 'no statistically significant warming in 15 years' claim. Who knows. There's so much wrong with his articles that it's hard to keep track of it all. This post got rather long and I still didn't cover all the errors in his second article.
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  5. Excellent summary, Dana. Well done. Just one question: Mr Rose may well not understand what he is writing about but, is it really credible to suggest that Dr Curry does not understand everything you have explained here? If she does not understand it all then she should perhaps not be in her job. If she does understand it then she would appear to be disputing it because she does not want it to be true (a.k.a. "the motivated rejection of science"). I am very disappointed that the Met Office has declined to lodge a formal complaint about Rose (especially since he has the audacity to repeat his misinformation). I think it would be very unwise of anyone to think that these serial deniers can just be ignored. Given that our governments will only act if their electorates demand that they act, anything that perpetuates ignorance, uncertainty, doubt and/or conspiracy theory is very dangerous indeed. Therefore, all those that understand what is going on need to ensure that their political representatives demand that our governments do the right thing.
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  6. Dana, Nice job, as usual. Curry remains a mystery. Have you asked the Mail if they are willing to publish this rebuttal, even if it has to be a shorter version?
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  7. Martin @5 - I think Curry focuses far too much on short-term variability and as a result loses sight of the forest for the trees. As for why she does that, answering that question would require me to try and ascertain her motivation, which would violate the SkS comment policy. Overall I agree with mike roddy that she's something of a mystery, and it's hard to figure out why she seems determined to miss the big picture. mike @6 - no, I haven't contacted the Mail. I rather doubt they would be at all interested in publishing this material. I get the impression they're not very interested in being perceived as a reputable newspaper - sort of the Fox News of British tabloids as I understand it.
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  8. Dana (@4)... Rose had to say 16 years because he did an article in January this year that said there's been no warming for 15 years.
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  9. Nice post Dana. In my opinion, when errors are pointed out to someone (especially a scientist) and instead of acknowledging them and correcting them, they double down, then they are in the realm of actively misinforming people. Not to mention deluding themselves. It is amusing, the "skeptics" (and in that faux skeptic group I now include Judith Curry) can't seem to decide if they love or hate the 0-2000 m ocean heat content data. This issue once again highlights the internal inconsistencies and lack of coherence in the "arguments" put forward by "skeptics".
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  10. Re #6,#7 on the Daily Mail reputation: IDK, it may be that there are different camps within the company, or that the editors are indiscriminate. For instance, here is an article where a different writer got it mostly correct. Climate change 'will reduce bio-diversity because global warming is happening too fast for animals' That does not mean that Dana's assessment about the company not caring is wrong, but it does leave open the possibility that there is more going on there that may appear at first glance. Rose himself is a different story; willful ignorance, deliberate misrepresentation, in combination with wishful thinking seems to be his mode. What I found disheartening was that the highest N ranked comments were in the wishful thinking camp.
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  11. I always thought it was somewhat ironic that there is overlap between the set of people who want to claim that the CRU data are not reliable because of 'climategate', and the set of people who rely exclusively on the HADCRU data sets to try to show that there has been no warming.
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  12. Dana, a slam-dunk follow-up exposé of David Rose’s dismal attempt to cover his tracks. With voluminous amounts of scientific research and evidence on human’s causal link to global warming, it’s a great wonder that Judith Curry and her merry band of contrarian scientists have not been able to gasp that they are on the wrong side of the argument – but there you go.
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  13. As much as I respect this posting and appreciate the focus on actual science it appears to me to be a comparison of healthy apples and lingerie. Dana articulates the science and shows Rose's article is both misleading and unsupported by available metrics. Rose on the other hand is trying to manipulate with emotion and does so with the expectation that the details of science will fly past his readers and the bulk of society. Dana is speaking clearly and uses graphs and graphics that help to establish the reality of the science while Rose is using vague generalities that depended on the ignorance of society when it comes to the language of science. This double-down is just more wordsmith Three Card Monte used to confuse. Rose is not going to address the questions regarding the metrics or his interpolation because for his audience it will not matter or make any sense. He wants to establish a more populist tone while staying clear of the gobbledegoo of academic palaver. -I mean after all aren't all scientist and elites just a bunch of egg-heads who think they know more than us working people? It was cold this morning, AGW my ass!- sarc Think of the two of them as new car salesmen. Dana stress fuel economy standards and safety features while Rose keeps telling us how "sexy" the car is. Market research tells us that more people care about getting laid then they do about seat belts. Until we can stop this sophistry in it's tracks and hold media outlets to the flames of informational integrity we are going to be bloodied over and over again in a war of words we can't win because we don't sell "sexy".
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  14. What flames, YD? I'm highly doubtful of any mode of accountability being exercised.
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  15. I'd suggest an investigative reporter sit down with the editorial board and challenge their decision in posting and supporting this tripe. I'd suggest letters to the NY Times be sent that ask questions of the Mail Online's editorial board. Ask the NYT why they aren't asking these questions. I'd suggest this be taken to a wider audience, one that is less concerned over the details of the article Rose wrote and is more concerned with the lack of editorial honesty and objectivity. Enlist the Guardian in asking these questions. But then I do have to agree and express being equally doubtful; doubtful that these kind of manipulative articles will be replaced by objective journalism, doubtful that our current energy programs will be replaced by more progressive programs that alter the trajectory of emissions, and doubtful a more insightful and caring society will rise from the ashes of what we currently call civilization. Animals do what animals do, we just do it with better hair and whiter teeth.
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  16. In HadCRUT4, analysis and critique I used both GISTEMP and UAH to show that the lack of polar coverage in the HadCRUT datasets caused coverage bias in the resulting temperature estimates. The impact was a warm bias around 1998, declining to a cool bias more recently, hence creating a plateau. The combination of this effect and the shift from El Nino to La Nina are sufficient to explain all of the recent apparent slowdown in warming. My latest project is to allow anyone to calculate the instrumental temperature record in their web browser, using their choice of data and methods. This allows a check of my claim above. Here is a sneak preview. First, the CRU and HadSST2 data using the HadCRUT method (note we are not even using HadSST3, so this is more akin to HadCRUT 3 than 4): Note the poor coverage in the mini maps. Now, the same data and calculation, but allowing each station to influence a 1200km radius, weighted by distance, like GISTEMP. Despite the ENSO shift, we still see rather more warming over the Rose/Curry period. The results show exactly the same thing as my previous analysis. Is the 1200km method used by GISTEMP valid? Yes, and you can prove it experimentally. I used cross validation to see which method suffers most bias if additional regions of the planet are omitted. The 1200km method is less biassed.
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    Moderator Response: [DB] Fixed image widths.
  17. sorry, off topic joke, but them denialistas must be quite thick and short for all this "doubling down", I've never understood the phrase but imagining a cardboard Curry in 16-folded layers suddenly made this one clear for me. :-D. Fold the cardboard ad and go.
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  18. jyyh, the term 'doubling down' comes from the card game blackjack. Basically, you make an initial bet upon receiving your hand and then have an option to double that bet (i.e. "double down") after receiving the first additional card. The intent is thus that, rather than changing course after seeing the reaction to the first article (corresponding to seeing the first additional card in the game), Curry and Rose are going even further in pushing their position (corresponding to doubling their bet).
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  19. How long before the Daily Mail joins the ranks of The News of The World, The BBC and The Mirror in the ongoing media scandals across the UK?
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  20. My cynicism having been said, it does seem like a fish-in-a-barrel opportunity for investigative reporters. People who can't be ignored need to start naming names--calling people out. The PBS piece is presumably a start, but of course PBS is a propaganda tool for those freakish liberals (no matter - when Romney arrives, Elmo dies). The target audience is willfully immune to many of the organizations that might produce such investigative pieces. Well shucks, I'm back to cynicism.
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  21. David Rose is only a conduit. His 2 recent articles (and likely many of his previous) are largely sourced from or written by David Whitehouse of the Global Warming Policy Foundation. Rose's latest effort bears an uncanny resemblance to a Whitehouse article that appeared on the GWPF website on the 15 October called 'The Mail on Sunday and the Met Office' (I won't link). Similarly, Rose's original 13 October article is based on a David Whitehouse cherry-picking exercise published by GWPF on 10 October called 'An Updated Hadcrut4 – And Some Surprises' (not currently available on the GWPF website - undergoing redesign – but can be found on other denier sites). Sad to see a once respected investigative journalist reduced to repeating the one-sided propaganda of Nigel Lawson’s 'sceptic' think-tank. Curry is only in there only to add a bit of credibility. When it comes to climate change The Mail have ceded a large degree of editorial control to the GWPF. Occassionally some reasonable climate change articles do appear in the Mail, but generally the articles are heavily weighted towards repeating the GWPF line.
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  22. The personal connections and overlaps between top people at the Mail, the GWPF and UKIP are an open secret. Like-minded chaps who will recreate the Tory party as it ought to be and save England and the Union. While denying AGW, which seems to be a sine qua non with the far-right. It could be 40 years ago, in Heath's days. Most amusing to watch.
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  23. Kevin C, thanks for that comparison. I've read a couple of articles on behaviors of complex systems that have tipping points. (Don't confuse me with someone with any expertise on the subject.) One of the common characteristics as a tipping point was approached is that the variation decreased. Imagine a marble in a bowl (embedded in some multidimensional, irregular surface), with some internal, inherent movement of the bowl, plus an external force on the marble. (Maybe it is a bearing and there is an electromagnetic of increasing strength nearby.) As the mean location of the marble moves further up the side of the bowl, the variance of its movement decreases. Basically, it is progressively harder to push it up the side of the bowl for both the internal and external forces, and the external force keeps it from going down the side very much. Until, the marble goes over the lip and heads toward the nearest other local minimum that represents the next region of relative stability. I've no doubt that the HADCRUT data sets have an inherent bias, but I have a nagging worry in the back of the head that this period of high temps with little increase, and no decrease despite there having been La Nina and low TSI conditions, is consistent with the earth coming to the edge of a local minimum. Lord_sidcup, what you said is very consistent with the observed bias of the people who choose to read the Daily Mail. Birds of a feather and all that. OT, thanks for the heads-up on the PBS Frontline piece.
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  24. Chris G: Check out the first paper in New Research #42 - model shoing increased winter negative AO. There also an older paper on colder boreal winters which Tamino has posted about very recently. The recent cold winters certainly seem to be tied up with the warm Arctic, and are dragging HadCRUT down because it misses the Arctic. However as far as I understand (which is no more than you when it come to models), I think they are the result of us just having undergone a change in the Arctic, rather than approaching one. Of course the knock-on effect on the Arctic may trigger other unforseen changes, but I wouldn't even attempt to guess what they might be.
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  25. There's a real classic 'sceptic' feel to this whole thing: - take a marginally valid point of scientific discussion - exaggerate it and draw absurd, unjustifiable conclusions from it - when people challenge these ludicrous exaggerations accuse them of ignoring the issue, circling the wagons, not saying what you want them to say in the way you want them to What disgusts me is that Judith Curry doesn't just buy in to this, she is a prime force driving it.
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  26. DSL@20: "No matter how cynical you get, it's *impossible* to keep up." Lily Tomlin, from "The Search for Signs Of Intelliegent Life in The Universe." >;-D
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  27. Well from this graph (Figure 3) it’s pretty obvious that global warming stopped in 1996 1997 1998. Never mind, I just realized I had my head tilted 20 degrees…. Thanx, Tamino and Skeptical Science. Cross Posted...
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  28. OPa@25 "- take a marginally valid point of scientific discussion" "- exaggerate it and draw absurd, unjustifiable conclusions from it" For the typical individual who didn't: go to university, study statistics, work in research, read peer review journals, or ponder the complexities of any thing more involved the a cricket score these statements are met with a blank expression and a "so what". AGW as an issue of science is generally accepted within the science community and the data that serves as evidence for this position, though it is complex, is not confusing for those who have studied the science and understand the nature of natural systems. Now how many people in the general population are going to be able to fit in this niche of comprehension? For every Einstein there is a soccer stadium full of halfwit hooligans swilling beer and screaming at men kicking a ball. Taking a marginal point and spinning it into a unjustifiable conclusion is as easy as selling lotto tickets to the delusional.
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  29. Thanks for another great post, Dana. I am constantly baffled by the deliberate obtuseness of people who argue for low climate sensitivity and a warm MWP. Own goal indeed.
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  30. lord_sidcup @21 Off topic, but I suspect someone has been reading Wodehouse as well as Whitehouse. Odd choice, that.
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  31. The following post by John Brookes at Tamino's nicely exposes (from a slightly different angle) the game being played by the disingenuous likes of Curry and Rose et al. (my bolding): "My suggestion is that we insist that “No significant warming since xxxx” should always have to use 1995 as the starting date, as I’m sure we all recall when Phil Jones was forced to concede that there had not been statistically significant since 1995. It was good enough for the “skeptics” then. It should be good enough for them now." So the fake skeptics have again shifted the goal posts and 1997 becomes the new cherry-pick. They can play this disingenuous game indefinitely.....but not if we hold them to 1995, for example. Has anyone asked Curry why she supports the use of 1997 as a start date versus 1995 when using the HadCRUT data?
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  32. Kevin @16, Great work! Very interesting.
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  33. Skepticalscience trend calculator has zero within the confidence interval from 1995 using HadCRUT4. Tamino suggested a while ago that given the noise and the trend, 17 years is around the threshold at which we should always (95%) see a significant positive trend in the surface data. Combined, it suggests that the past 17 years has been unusually noisy.
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  34. Tristan @33, Here are the full set of statistics for the period 1995 through 2012 for HadCRUT4: Trend: 0.097 ±0.113 °C/decade (2σ) β=0.0097464 σw=0.0016980 ν=11.093 σc=σw√ν=0.0056555 What is interesting is the trend for the UAH satellite data run by "skeptics" Drs. Roy Spencer and John Christy, their data show the strongest warming of all the products for 1995-2012: Trend: 0.121 ±0.191 °C/decade (2σ) β=0.012135 σw=0.0023288 ν=16.855 σc=σw√ν=0.0095612 One has to wonder why the "skeptics" are using the surface temperature data from a group that they continuously accuse of "fudging" the data, when they can use a "superior" (as claimed by "skeptics") product generated by "skeptics"? Well, the answer to that is very easy..... ;)
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  35. Just so I didn't completely waste my time, I am reposting a comment I made to the online version of this Mail story which they have not posted. I think analogies such as these are useful because the general public are too easy too fool with the disinformation that Rose keeps churning out. The video mentioned is that: "Nasa video shows Earth's changing temperature from 1880 to present" which to us appears so clear... _________________________________________ "The video shows the true situation better than any words. It blindingly obviously shows that although global surface temperatures vary a lot year to year and country to country, over decades, the overall warming trend is clearly visible, most dramatically in the Arctic region. It clearly shows the big problem with David Rose's cherry picked start dates that badly misrepresent the true situation. Imagine, Mr Rose, you are on a beach at a place with a high tidal range. As the waves break 40 feet up and down the beach over one minute you are constantly pointing out when the water goes down the beach and biasing your trend lines to claim that the tide is going out - meanwhile the tide is actually slowly coming up at half an inch a minute. You are suggesting there is no danger but if you stay where you are on the beach, you will drown - and everybody else too. Natural climate variation is big like waves but CYCLIC. Global warming is small, like the tides but cumulatively more dangerous"
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  36. Tristan: Absolutely correct. However... The trend uncertainty is valid only under the assumption than the underlying model - linear increase plus autocorrelated noise - is valid. Now that's probably not a bad assumption for greenhouse-forced warming over a short period with no volcanoes. However, if we take into account that there has been a transition in where the warming occurs from somewhere which is covered by HadCRUT4 to somewhere that isn't, it becomes problematic. Because GISTEMP largely remediates the coverage issue, the results from GISTEMP are a bit more robust (assuming you start after the end of the Pinatubo dip).
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  37. Kevin It's a fool's game anyway. The only reason we're having to explain a 'lack of warming' is because the 'skeptics' are fixated on a short, contextless range of data. Once all is accounted for, it seems like the atmosphere is being pushed along at 1.8-2C/century. In 10-20 years when sulfates start to dip, we'll learn what a hot year is.
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  38. Seems a lot of to do about nothing. 1) It seems in paragraph 3 you acknowledge global warming has stopped. (you say slowed but for all practical and statistical purposes it has stopped). You said: "the current slowed rate of global surface warming". .03 warming per decade is as good as stopped (at least temporarily) 2) You also acknowledge that it is due to aerosols produced by China burning coal in a rapid industrialization. Not only is that in conflict with your claim the heat is going into the ocean, but it in fact means the heat is not even entering the planet in the first place due to manmade emissions. I think that means its stopped too. 3) Finally the claim the heat is in the oceans seems to defy physics. Heat rises in both water and the atmosphere. Its basic physics. So if you claim it is entering the ocean I think you need to explain, via some physics, why its allegedly coming out more slowly and not warming the atmosphere in accordance with the basic physics it normally does. I have built passive solar space heating systems using water as a heat storage medium. I have yet to notice the system just mysteriously slowing down. La Ninas and El Ninos is kind of a folklore type explanation so thats not adequate. La Ninas appear to be upwellings of cold water from the bottom of the ocean, but it seems it needs to actually represent ocean cooling as the upwelling water needs to be replaced by water via downwelling, and warm water does not downwell. The AMO shows the main downwelling zones being near the poles where water is being cooled so basic physics suggests that the cold upwelling La Nina water is being replaced by colder water and El Nino must generally be a time of low rates of downwelling cold water. That would at minimum likely be the null hypothesis unless I am missing something. Don't take any of the above as an argument against CO2 being a greenhouse gas. It just seems its not the only thing that controls temperatures of the surface.
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  39. Bill, I'm sure you're going to get an earful, and I hope you come back after you do get your earful. I hope you listen to criticisms of your comment, because that comment contains a number of very irritating "smudges." The line in paragraph three says, "current slowed rate of global surface warming." You say it says,"you acknowledge global warming has stopped." This is the kind of imprecision that paid "skeptics" produce as a matter of course, because they know their audiences aren't going to understand the distinction. Note that the troposphere/surface makes up all of what, 5% of the Earth's surface-ocean-atmosphere system thermal capacity. If you say that AGW has stopped because 5% of the system has experienced a slower rate of warming (using the least representative surface temp analysis) even though the other 95% is rolling along as predicted (or even more strongly than predicted), pardon me if I laugh in your face -- unless, of course, you honestly didn't realize the globe consists of more than the simple surface temp (minus poles for Hadley (GISS is a significant .146C per decade over 1996-2011, the last 16 whole years)). Note also that 2-3% of the additional energy is going into global ice mass loss, and that loss has accelerated over the "haitus" period of surface temp. As for the oceans, see (and reply to) the Levitus piece, this article, and SoD's pieces.
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  40. Billhunter, You characterisation of El Nino-Southern Oscillation (ENSO) as folklore cannot be more incorrect. Of all the modes of variability on longer timescales (> 1 year), it is probably the most well understood. The heat transfer between atmosphere and the ocean depends crucially on the the temperature difference between air and sea surface, and it is not always true that the ocean warms the air. If you cool the ocean surface sufficiently ( e.g. during La Nina years), the heat can be transferred from the air to the ocean, leading to a drop in global temperature. You said:
    La Ninas appear to be upwellings of cold water from the bottom of the ocean, but it seems it needs to actually represent ocean cooling as the upwelling water needs to be replaced by water via downwelling, and warm water does not downwell.
    In the pacific there is constant upwelling on the eastern end due to the trade winds. It is more accurate to think of La Nina as years with stronger than normal upwelling, and El Nino as years with weaker upwelling. It is also incorrect to state that ocean must cool during La Nina years: it is true that the ocean surface cools, but the overall heat content of the entire ocean is largely unchanged. Warm water can in fact downwell. What you are thinking of is likely up/downwelling due to density/buoyancy changes. However the upwelling/downwelling in the ENSO is driven not by density, but by surface wind.
    The AMO shows the main downwelling zones being near the poles where water is being cooled so basic physics suggests...
    What you are describing here is called "deep water formation". This is a density driven process, so it is not helpful at all to think about ENSO in terms of deep water formation, as the physics is completely different.
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  41. Bill, Before you can say "Finally the claim the heat is in the oceans seems to defy physics. Heat rises in both water and the atmosphere. " you need to understand basic Physics and Chemistry. Fresh water is most dense at 4C. 0C water floats on top of 4C water. This is related to the obvious fact that ice floats. In sea water the situation is more complicated. The density is a function of the salinity and the temperature. Since, as was pointed out above, the circulation of the oceans is partly driven by wind, if the salinity and temperature of the surface changes it is basic physics that the bottom water will be affected also. Do you think the catastrophic ice loss in the Arctic changed the salinity at all? If the water column increases in temperature by 0.1C that is a lot of heat. Please review your basic physics before you give others lectures. You will come across much better if you ask questions instead of giving lectures. How can warmer water sink? would be appropriate.
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  42. I appreciate the reasonable comments from most. It seems that the primary argument here is that heat is sinking in the oceans. I am not arguing that heat cannot sink via wind and tides (thats what the mixing layer is dominated by). But that alone is insufficient to explain the missing heat. I am not lecturing anybody either, merely pointing out that heat rises in both liquid and gaseous mediums of unchanging chemical composition. If heat is sinking into the ocean it should be broadly supported by science and clearly that's not the case. Cherry picking which scientists we choose to believe about what is going on in the system seems rather overwrought, which was basically my claim of a lot of to do about nothing. I am just a member of the public that has been regaled for over a decade from numerous institutions offering up warming atmosphere temperatures as evidence of global warming. Now that the popular and primary evidence no longer supports the case, no one is going to convince the public that Curry is wrong without actually demonstrating the heat is sinking into the ocean as the idea runs contrary to our empirical sensibility. One might start by explaining why the average temperature the ocean is so much below that of the average temperature of the surface. Should not heat coming from both directions warm the ocean? We have intense heat at the core of the planet very slowly conducting to the surface. If we dig a hole in the ground the average depth of the ocean 3,000 meters it gets warmer. We also have a greenhouse effect that makes the surface about 10degrees warmer than the average temperature of the ocean. So obviously there must be an explanation for why the ocean is not isothermal. Downwelling of super cooled water is one theory some scientists have proposed. One might assume that process has some variability to it. But what we are seeing concurrent with the loss of ice is more cold upwelling not less. Thus increasing the strength of the arctic halocline by melting ice would seem to be an explanation that adds to the problem rather than provides an explanation. Occam's razor suggests more downwelling of supercooled water. I am not saying thats a fact that simply the answer that best reflects our understanding. Throwing salinity in is a lot like throwing convection into the greenhouse effect argument. One cannot pick and choose what he wants to ignore. . . .I agree with that. But thats the challenge of those who pretend to understand climate, not the public. One explanation is perhaps the loss of multiyear ice and the distribution of surface waters world wide has weakened the arctic halocline either on average or regionally say at places of higher rates of downwelling. Not saying thats so, but some cohesive explanation is very much needed for increased upwelling of cold water. But I am getting too much into the weeds. This is the job for climate models to explain. A lot less certainty about whats happening would much more accurately reflect the need for additional knowledge. Seems to me that's what Curry has been saying since day one. So to be clear I am not giving a science lecture but I am open to one.
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  43. IanC at 01:31 AM on 29 October, 2012 "Billhunter, You characterisation of El Nino-Southern Oscillation (ENSO) as folklore cannot be more incorrect. Of all the modes of variability on longer timescales (> 1 year), it is probably the most well understood." Wow! Most well understood! ENSO prediction in at least the 5 years I have been monitoring it is abysmal. 3 months ago a fairly decent El Nino was projected for right now. The two models controlled by Jim Hansen GISS an Cola CCSM something have hands down the worst record of the lot. Usually predictions in the short run are fairly decent like over the first 3 months or so. Beyond that success tails off dramatically. The ENSO forecast system only goes out 8 months. If thats the best climate stuff we have, we don't have much climate prediction ability. To carry on a bit, prediction is aided some by the fact its an oscillation. So some predictibility arises from that. It is also appearing that the Pacific oscillation may have some effect on the mix of El Nino and La Nina, though it seems few know enough to incorporate in their models. Some models are doing much better than others. It might be worthwhile to look at why.
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    Moderator Response: [DB] Please take any further discussion of models to the appropriate page.
  44. Bill, Understanding and predictability are completely different. You can have the most sophisticated model that includes all the relevant physics (i.e. 100% understanding), yet have dismal predictability because you have insufficiently good initial data. The difficulty with forecasting ENSO is that it is effectively a long term weather forecast for the ocean, and it suffers from sensitivity to initial conditions the same way a weather model does. Let's not get side tracked by predictability and finish the original discussion My points are 1) Ocean can warm or cool the atmosphere. It depends on the surface temperature. 2) Your objection pt 3 in #38 is likely due to an incomplete understanding of oceanic dynamics. Warm water can downwell if you apply a wind forcing.
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  45. Bill, The graph in the OP shows measured increase in heat content of the deep ocean. This is not theoretical heat, it is measured heat. Your "Occam's razor suggests more downwelling of supercooled water" is simply uninformed speculation. Please provide a citation of your speculation. What scientists have measured is increased temperatures in the deep ocean. The ocean circulation is well understood by scientists. You are getting information from uninformed sources. The average surface temperature of the ocean is higher than the air above it. The ocean warms the air in the majority of the world. This is because the sun shines on the ocean and warms it. In locations like the Arctic, cold water sinks so the deep ocean is cold. As the Arctic warms the sinking water has increased in temperature. This increase has been measured. Because the sinking water is now warmer than it was in the past the deep ocean is warming. This is measured data. The heat coming from the Earths core is measured and is much smaller (orders of magnitude) than the heat retained by greenhouse gasses. It has no significant effect on climate. The difficulty scientists have predicting weather,like El Nino, is a completely different situation to long range climate forecasts. Hansen does not do weather forecasts. He occasionally speculates on what he thinks El Nino will do, but it is not his area of expertise. Read the links in the OP if you want to see the data. Making up explanations off the cuff does not go over well on a scientific blog.
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  46. Bill @38 "If heat is sinking into the ocean it should be broadly supported by science and clearly that's not the case. " You do realize that if your supposition was correct, there would never be an Arctic ice cap in the first place? You seem to be missing that essential (and peculiar quality of water, that it expands as it cools (after it reaches 4C), and it is that change in density that allows for the counter-intuitive downwelling of warmer water. The point that michael sweet makes is also pertinent "The average surface temperature of the ocean is higher than the air above it." That is average temperature over both day and night ... air and surface cool much more quickly than water does. It is one of the reasons we have such a great climate in California ... since we get the cold Alaska current running offshore, we get much cooler nights than the East Coast does with the Gulf Stream.
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  47. Old Mole thanks for your comments. I agree my comments do not have anything to do with convection near the poles. But I have never seen 4c water off California's coast, much less seen it pushing any water under it. I have to assume it doesn't happen at the equator either. And yes I agree living at the coast in southern California is great, cool summers and balmy winters thanks to the California current. When I said the average temperature of the ocean is around 5C or less, I was not talking about the surface which might be 17C. There must be sufficient downwelling of water colder than 5C to maintain it at that average temperature as the surface is constantly conducting heat downwards and the ocean floor is conducting heat up into a cold ocean. Downwelling of water warmer than 5c will not maintain the ocean at 5C. So that implies that the ocean has overridden all or part of the greenhouse effect as far as its average temperature is concerned. Unusual upwelling at the equator over time could be indicative of a natural variation on this on going negative feedback process. A possible mechanism is ice retreat. If the ice edge moves north its fairly reasonable to assume the downwelling zones will also move north. If they move north they will have a larger area where it will be cold enough to downwell. Obviously a larger Arctic halocline would offset that in some way, but is there any evidence the halocline is increasing in size? I guess that's a possibility but that merely adds to the problem of figuring where the additional upwelling cold water that has dominated the last decade is coming from. I think we can assume some of it comes from the ongoing negative feedback process that keeps our oceans cold. . . .on average. I recall Jim Hansen back in 2000 declaring that El Ninos were the new normal. Since then there has been an expectation of repetitions of 1998. But what we see is just the opposite. An emerging La Nina dominance not seen for quite a while. Unfortunately most of the measures of the ocean are in the upper 700 meters. (-snip-). 700 meters represents the warmest 18.5% of the ocean. If upwelling and downwelling is concentrated in limited areas it makes sense that downwelling conduction could have warmed the ocean between 700 meters and the bottom of the mixing zone (or even maybe deeper) from recent ocean surface warming even while the ocean cooled overall and provided additional cold water for the surface. Let me be clear. I am not saying thats the case. I am saying that contrary to Michael Sweet's statement that the science is mixed on deep ocean warming or cooling. It has in fact not been measured. (-snip-). Bottom line is the ocean is not a good explanation for the missing heat. Most studies of OHC come up way short. That spawned the idea that the heat was migrating below our measurements. But no mechanism for that has been proposed and ocean surface warming has been lagging so its not likely conduction from the mixing layer of the ocean which has also experienced a slowing in warming. But we know less about the bottom of the ocean than we do the surface of planet Mars. In the interest of full disclosure I am an ocean guy so I want to see more funding for research in the oceans.
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    Moderator Response: [DB] Intimations of impropriety snipped. Let me be clear: Please re-read the Comments Policy. Subsequent comments constructed as this one will be summarily deleted in their entirety. Please also note that unsupported assertions, as you make, that have been debunked on multiple occasions constitute sloganeering, itself another Comments Policy violation.
  48. Dana another great post. Keep up the great work. I thought I should let you know that I wrote my own post regarding Rose's meme over at my little I mention it because after I finished with what I wanted to say - I posted this article. You know, to follow up with plenty of serious resources. So a big Tip Of The Hat for SkepticalScience's generous sharing and reposting policy.
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  49. Billhunter It [deep ocean warming] has in fact not been measured.
    Johnson GC et al. (2006) Recent western South Atlantic bottom water warming Geophys. Res. Lett. 33, L14614 Abstract: Potential temperature differences are computed from hydrographic sections transiting the western basins of the South Atlantic Ocean from 60 degrees S to the equator in 2005/ 2003 and 1989/1995. While warming is observed throughout much of the water column, the most statistically significant warming is about + 0.04 degrees C in the bottom 1500 dbar of the Brazil Basin, with similar ( but less statistically significant) warming signals in the abyssal Argentine Basin and Scotia Sea. These abyssal waters of Antarctic origin spread northward in the South Atlantic. The observed abyssal Argentine Basin warming is of a similar magnitude to that previously reported between 1980 and 1989. The Brazil Basin abyssal warming is similar in size to and consistent in timing with previously reported changes in abyssal southern inflow and northern outflow. The temperature changes reported here, if they were to hold throughout the abyssal world ocean, would contribute substantially to global ocean heat budgets. Johnson GC et al. (2007) Recent bottom water warming in the Pacific Ocean J. Climate 20, 5365-5375. Abstract: Decadal changes of abyssal temperature in the Pacific Ocean are analyzed using high-quality, full-depth hydrographic sections, each occupied at least twice between 1984 and 2006. The deep warming found over this time period agrees with previous analyses. The analysis presented here suggests it may have occurred after 1991, at least in the North Pacific. Mean temperature changes for the three zonal and three meridional hydrographic sections analyzed here exhibit abyssal warming often significantly different from zero at 95% confidence limits for this time period. Warming rates are generally larger to the south, and smaller to the north. This pattern is consistent with changes being attenuated with distance from the source of bottom water for the Pacific Ocean, which enters the main deep basins of this ocean southeast of New Zealand. Rough estimates of the change in ocean heat content suggest that the abyssal warming may amount to a significant fraction of upper World Ocean heat gain over the past few decades. Johnson GC (2008) Warming and Freshening in the Abyssal Southeastern Indian Ocean J. Climate 21, 5351-5363. Abstract: Warming and freshening of abyssal waters in the eastern Indian Ocean between 1994/95 and 2007 are quantified using data from two closely sampled high-quality occupations of a hydrographic section extending from Antarctica northward to the equator. These changes are limited to abyssal waters in the Princess Elizabeth Trough and the Australian-Antarctic Basin, with little abyssal change evident north of the Southeast Indian Ridge. As in previous studies, significant cooling and freshening is observed in the bottom potential temperature-salinity relations in these two southern basins. In addition, analysis on pressure surfaces shows abyssal warming of about 0.05 degrees C and freshening of about 0.01 Practical Salinity Scale 1978 (PSS-78) in the Princess Elizabeth Trough, and warming of 0.1 degrees C with freshening of about 0.005 in the abyssal Australian-Antarctic Basin. These 12-yr differences are statistically significant from zero at 95% confidence intervals over the bottom few to several hundred decibars of the water column in both deep basins. Both warming and freshening reduce the density of seawater, contributing to the vertical expansion of the water column. The changes below 3000 dbar in these basins suggest local contributions approaching 1 and 4 cm of sea level rise, respectively. Transient tracer data from the 2007 occupation qualitatively suggest that the abyssal waters in the two southern basins exhibiting changes have significant components that have been exposed to the ocean surface within the last few decades, whereas north of the Southeast Indian Ridge, where changes are not found, the component of abyssal waters that have undergone such ventilation is much reduced. Ozaki H et al. (2009) Long-term bottom water warming in the north Ross Sea J. Oceanograph. 65, 235-244. Abstract: We measured potential temperature, salinity, and dissolved oxygen profiles from the surface to the bottom at two locations in the north Ross Sea (65.2A degrees S, 174.2A degrees E and 67.2A degrees S, 172.7A degrees W) in December 2004. Comparison of our data with previous results from the same region reveals an increase in potential temperature and decreases in salinity and dissolved oxygen concentration in the bottom layer (deeper than 3000 m) over the past four decades. The changes were significantly different from the analytical precisions. Detailed investigation of the temperature, salinity, dissolved oxygen and sigma (3) value distributions and the bottom water flow in the north Ross Sea suggests a long-term change in water mass mixing balance. That is to say, it is speculated that the influence of cool, saline, high-oxygen bottom water (high-salinity Ross Sea Bottom Water) formed in the southwestern Ross Sea has possibly been decreased, while the influences of relatively warmer and fresher bottom water (low-salinity Ross Sea Bottom Water) and the Ad,lie Land Bottom Water coming from the Australia-Antarctic Basin have increased. The possible impact of global warming on ocean circulation needs much more investigation. Johnson GC et al. (2009) Deep Caribbean Sea warming Deep Sea Research. 1 –Oceanograph. Res. 56, 827-834. Abstract: Data collected from hydrographic stations occupied within the Venezuelan and Columbian basins of the Caribbean Sea from 1922 through 2003 are analyzed to study the decadal variability of deep temperature in the region. The analysis focuses on waters below the 1815-m sill depth of the Anegada-Jungfern Passage. Relatively dense waters (compared to those in the deep Caribbean) from the North Atlantic spill over this sill to ventilate the deep Caribbean Sea. Deep warming at a rate of over 0.01 degrees C decade(-1) below this sill depth appears to have commenced in the 1970s after a period of relatively constant deep Caribbean Sea temperatures extending at least as far back as the 1920s. Conductivity-temperature-depth station data from World Ocean Circulation Experiment Section A22 along 66 degrees W taken in 1997 and again in 2003 provide an especially precise, albeit geographically limited, estimate of this warming over that 6-year period. They also suggest a small (0.001 PSS-78, about the size of expected measurement biases) deep freshening. The warming is about 10 times larger than the size of geothermal heating in the region, and is of the same magnitude as the average global upper-ocean heat uptake over a recent 50-year period. Together with the freshening, the warming contributes about 0.012 m decade(-1) of sea level rise in portions of the Caribbean Sea with bottom depths around 5000 m. Johnson GC (2008) Reduced Antarctic meridional overturning circulation reaches the North Atlantic Ocean Geophys. Res. Lett. 35, L22601 Abstract: Potential temperature differences are computed from hydrographic sections transiting the western basins of the South Atlantic Ocean from 60 degrees S to the equator in 2005/ 2003 and 1989/1995. While warming is observed throughout much of the water column, the most statistically significant warming is about + 0.04 degrees C in the bottom 1500 dbar of the Brazil Basin, with similar ( but less statistically significant) warming signals in the abyssal Argentine Basin and Scotia Sea. These abyssal waters of Antarctic origin spread northward in the South Atlantic. The observed abyssal Argentine Basin warming is of a similar magnitude to that previously reported between 1980 and 1989. The Brazil Basin abyssal warming is similar in size to and consistent in timing with previously reported changes in abyssal southern inflow and northern outflow. The temperature changes reported here, if they were to hold throughout the abyssal world ocean, would contribute substantially to global ocean heat budgets. Fukasawa, Masao, et al. "Bottom water warming in the North Pacific Ocean." Nature 427.6977 (2004): 825-827. Observations of changes in the properties of ocean waters have been restricted to surface1 or intermediate-depth waters2, 3, because the detection of change in bottom water is extremely difficult owing to the small magnitude of the expected signals. Nevertheless, temporal changes in the properties of such deep waters across an ocean basin are of particular interest, as they can be used to constrain the transport of water at the bottom of the ocean and to detect changes in the global thermohaline circulation. Here we present a comparison of a trans-Pacific survey completed in 1985 (refs 4, 5) and its repetition in 1999 (ref. 6). We find that the deepest waters of the North Pacific Ocean have warmed significantly across the entire width of the ocean basin. Our observations imply that changes in water properties are now detectable in water masses that have long been insulated from heat exchange with the atmosphere. Kawano, Takeshi, et al. "Bottom water warming along the pathway of Lower Circumpolar Deep Water in the Pacific Ocean." Geophysical research letters 33.23 (2006): L23613. Repeat trans-Pacific hydrographic observations along the pathway of Lower Circumpolar Deep Water (LCDW) reveal that bottom water has warmed by about 0.005 to 0.01°C in recent decades. The warming is probably not from direct heating of LCDW, but is manifest as a decrease of the coldest component of LCDW evident at each hydrographic section. This result is consistent with numerical model results of warming associated with decreased bottom water formation rates around Antarctica.
    Etc. For some reason there's a widely held wrong belief that we know nothing of abyssal temperatures.
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  50. Doug thanks for you comments. (-SNIP-)
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    Moderator Response: (Rob P) - The cornerstone of this site is peer-reviewed science. Time to start backing up some of your inventive claims with some peer-reviewed literature.

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