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Tropical Thermostats and Global Warming
Tom Curtis - The 'thermostat' hypothesis has been seriously proposed in the literature, as per Lindzen's Iris papers; and as noted in this discussion it has been shown to be false. It just doesn't hold up under examination, under the data.
But as with the ongoing Lindzen papers (repeating the same claims while ignoring published rebuttals) and with hobbyists like Eschenbach at WUWT, it appears to be (IMO) attractive as some kind of magical counteraction to AGW, something that absolves us of any responsibility to change. And as such I expect that this mythical thermostat will continue to be invoked by those in denial, or who are relatively uninformed about the science.
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Tom Curtis at 00:11 AM on 19 March 2014Tropical Thermostats and Global Warming
KR, the ridiculousness of the "hard limit" theory as an argument against climate change is multiple. It is not supported by the basic data. It has no physical basis. It contradicts the fact that higher SST determined in the past by proxies as you note, including some as high as 40 C. It is accepted, therefore, not on any scientific basis, but out of desperation to believe that global warming cannot be harmfull. The problem is, it fails even that purpose.
Taking Palau as an example, the average SST in the warmest month in Palau is 29.2 C. The rise in SST expected at Palau in the warm scenario is 2.5 C. Consequently, with current predictions of global warming, in a BAU scenario we expect ocean temperatures in the Pacific Warm Pool to rise to 31.7 C, ie, below the "wall". That is, still below any reasonable estimate of the "wall". So even if this absurd hypothesis were true, it might possibly limit warming a little next century, but this century it is irrelevant anyway.
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Tropical Thermostats and Global Warming
I would note that tropical sea surface temperatures are considered to have been rather higher during the Eemian, which is in and of itself sufficient data to disprove a 'thermostat' hypothesis.
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Jim Hunt at 22:44 PM on 18 March 2014The Extraordinary UK Winter of 2013-14: a Timeline of Watery Chaos
My latest musings on this topic, including the latest from both the Met Office and the NOAA, and some pictures of the after effects here in Soggy SW England:
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DSL at 13:28 PM on 18 March 2014Tropical Thermostats and Global Warming
When does the magical cooling mechanism kick in? Does it automatically occur regardless of what Hadley and Walker circulation are doing to cloudiness? I note that in, for example, Palau, rainfall shows a pretty flat trend despite temp rising (Figs. 10.3 & 10.4).
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michael sweet at 12:34 PM on 18 March 2014Tropical Thermostats and Global Warming
Russ,
There are now approximately 13 posts relating to the land temperatures at Kritimati island. You brought up this subject as your primary argument to support your wild claim that there is a "wall" to surface sea temperatures. You have provided no reason why the land temperature at Kritimati Island would relate to the sea temperature in the Pacific Warm Pool 3,000 miles away, or even why any current land temperature would relate to a future maximum sea temperature even if it was nearby. The thermal mass of the ocean controls the land temperatures of very small, low islands like Kritimati and Tarawa except for rare occasions like the calms Tom described. You have provided no additional data or citations to support your wild claim. The moderator has to ask what your point is. Tom has provided copious data showing current sea temperatures are frequently over 31C and as high as 35C. What is the point of your argument about Kritimati Island land temperatures? How does it relate to your wild claim of a "wall" in sea temperatures?
Perhaps I should have said that you were in violation of the policy against excessive repetition instead of sloganeering, I see the moderator has warned you again. Please address the points of fact that you have previously ignored instead of making useless rhetorical points.
Why do you bother posting here when you apparently have no interest in the data or peer reviewed reports?
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Tom Curtis at 12:26 PM on 18 March 20142014 SkS Weekly News Roundup #7
Russ R @89:
1) Your hypothesis is that high temperatures will automatically result in high humidity. A failure of that connection is further refutation of that hypothesis, not justification for ignoring the data.
2) The data you presented does not show a "remarkably consistent upper boundary". It shows a distribution, with daily maximum temperatures ranging between 18 C and 27 C. The mean is close to 29 C, with a standard deviation around 1- 2 C. To show "a remarkably consistent upper boundary" you need to show the actual statistical distribution, and show that it has a sharp cut off. You have not even made an attempt at that. Nor have you defined the supposed "upper boundary" to even know whether it lies at 1 or 2 standard deviations from the mean. Rather, you have hedged your claim to make it unfalsifiable. When it was found that you had not hedged it enough, you provided ad hoc reasons to ignore contrary data. And now, you use an arbitrary binning method to ignore the fact that the data do not show a consistent upper limit at all. The only trope of pseudo-science your missing is the conspiracy theory.
3) You introduced Tarawa, not me. If you objected to the data, you should have mentioned that before detailed analysis showed it did not support your opinion. It is very revealing, however, that you consider the data source suitable when it supports your views, but unsuitable when it does not.
4) The Red Sea also shows temperatures comfortably above you supposed upper limit. It is over 100 km wide at nearly all points, and has an average depth of 490 meters. Therefore if the supposed mechanism of your upper limit worked, it would work in the Red Sea. But yet again, we will find, any data that falsifies your views will be excluded by you as irrelevant on specious grounds.
Russ R @93:
"Dikran Marsupial @91,
"Now if you were genuinely interested in scientific discussion, you would admit that your assertion was incorrect, and possibly revise it."
Very well, you've made your case. I accept that I was incorrect..."
Yet still no apology for the false accusation of cherry picking.
Well, who cares anymore. Russ has so trashed his intellectual reputation that I see no point in further discussion with him regardless of any apology or lack of it. As the good book says, "Do not cast your pearls before swine."
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Tom Curtis at 11:58 AM on 18 March 20142014 SkS Weekly News Roundup #7
I have posted a comment on the thread suggested by KR. I have looked at Eschenbach's data, for at least he provided some (unlike Russ). I show from that data that it contradicts, rather than supports, Eschenbach's hypothesis, both because it shows a more poorly defined upper limit on temperatures in warm months than in cooler months; and because large scale statistical features of the data that Eschenbach attributes attempt to explain in light of his hypothesis, which therefore would be evidence for his hypothesis, are in fact a consequence of the actual pattern of insolation found in the tropics (which is not what is often naively supposed to be the case). As those patterns have a sufficient explanation in facts that are both well established by theory and observation, they are not evidence of some hypothetical alternative explanation.
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Tom Curtis at 11:52 AM on 18 March 2014Tropical Thermostats and Global Warming
Following on from a discussion elsewhere, I would like to discuss Willis Eschenbach's hypothesis, in that he at least presents what at first glance looks like evidence for his hypothesis. The evidence is scattered through three posts at WUWT, and shows that SST above 30 C are uncommon. Eschenbach argues that because those temperatures are uncommon, there is a "hard limit" on ocean temperatures, slightly above 30 C.
Eschenbach's hypothesis faces an immediate hurdle in that his own data refutes it. Here is his plot of "all" NH Argo surface temperatures (Fig 2, AOTM):
The "all" is dubious in that there are far to few data points for "all" ARGO NH surface temperature records, and it is likely that Eschenbach has used a random sample of the data to make distributions clearer. Regardless of that point, however, it is very clear from the graph that there is not a hard limit at 30-32 C. Several temperatures are recorded above those values, and some very far above those values. This is most clear in 2012 which shows a cluster of data points above 35 C. Further, the period of peak temperature does not show a well defined limit. Indeed, the upper limit on temperatures is less well defined in the warm months than in the cool months, the opposite of what we would expect if there were indeed a "hard limit".
What we would expect with a genuine "hard limit" can be seen by comparing the NH warm temperatures with the lower range of the SH cool temperatures (Fig 2, Notes 2):
You can clearly see a hard limit in low temperatures slightly below 0 C, representing the freezing point of sea water. The key feature is that the lower limit of temperatures is far more sharp ly defined in the cool months than in the warm months. That is in strong contrast to the upper temperature limit, which is more sharply defined in cool months than in warm months, a feature which by itself refutes Eschenbach's hypothesis.
At this point I will make a short logical excursion. As everyone knows, there is a "hard limit" on liquid water temperatures at 0 C, ie, the freezing point. Despite that, the hard limit in sea water is obviously less than 0 C. The reason is that increased salinity reduces the freezing point. Therefore, the "hard limit" is only a hard limit under a certain set of condition. If you change those conditions, you also change the "hard limit". It follows that even had Eschenbach been able to demonstrate a hard limit, he would not have demonstrated that Sea Surface Temperatures would not rise above that limit in the future, under different conditions. Of course, that is a point purely of logical interest in that Eschenbach has not demonstrated a "hard limit" to begin with.
Returning to Eschenbach's evidence, he presents more evidence that he supposes supports a hard limit. Specifically, he shows that the closer to the equator, the smaller the annual variation in temperatures (Fig 3, AOTM):
He says of this graph,
"As you can see, the warm parts of the yearly cycle have their high points cropped off flat, with the amount cropped increasing with increasing average temperatures."
That, however, is not what you see at all. Rather, at the warmest times of the year, the upper limit of temperatures are least well defined. If anything, at that time you have a spike in temperatures.
I suspect the misdescription is because Eschenbach reffers to the guassians rather than the data. He expects the Gaussians to show a series of sine waves, with those closer to the equator being warmer than those further away. He thus interprets the actual series of successively smaller amplitude sine waves with the upper cycle nearly coinciding in values as the top of the cycles having been truncated.
Unfortunately for his hypothesis, there is a well known phenomenon in nature that shows a similar pattern to his Gausians, ie, the daily TOA insolation relative to latitude:
(Source)
You will notice the near constancy of insolation at the equator, and also that insolation at 20 degrees North is higher in the summer than it is at any time on the equator. The reason for that is that, at 20 degrees North, when the sun is directly overhead, the days are longer than they are when the sun is directly overhead on the equator. And with a longer day, and the same peak forcing we expect higher SST, which is what we see. Curiously Eschenbach draws attention to the fact that the peak temperatures are found not at the equator, but between 15 and 30 degrees North, in the Summer. But given the insolation data, that is just what we would predict. So also, given the insolation data, would we predict that peak summer temperatures through out the tropics and near tropics would match or exceed peak equatorial temperatures, and that the closer the equator, the less variation in SST.
Eschenbach also draws attention to the shape of the Gaussians (shown in Fig 6), noting in particular that "...summer high temperature comes to a point, while the winter low is rounded". But again, however, he needs search no further for an explanation than the insolation pattern:
I mentioned in my introduction that Eschenback presents data that "...at first glance looks like evidence for his hypothesis". It should not be plain, however, that it is onlyh at a first, and superficial glance that that is true. His most convincing evidence turns out to be a direct consequene of the patterns of insolation at, or near the equator. The more direct evidence is seen to contradict his claim of a hard limit, showing as it does a less defined limit to temperatures in the warmest months - the exact opposite of what is required by his hypothesis. It is only by maintaining a superficial glance, and by not paying attention to actual forcings that his hypothesis appears to have any support at all.
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Russ R. at 09:47 AM on 18 March 20142014 SkS Weekly News Roundup #7
KR@92,
Thanks for the link. As I promised to michael sweet, I will "put it to rest" here, and take any further "thermostat" arguments to that thread.
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Russ R. at 09:32 AM on 18 March 20142014 SkS Weekly News Roundup #7
Dikran Marsupial @91,
"Now if you were genuinely interested in scientific discussion, you would admit that your assertion was incorrect, and possibly revise it."
Very well, you've made your case. I accept that I was incorrect and in light of the data, will revise my argument from "never" to "less than 0.1% of the time".
Moderator Response:[JH] You have reverted to your snarky persona. If you continue down this path, there will be consequences.
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Michael Whittemore at 01:37 AM on 18 March 20142014 SkS Weekly Digest #11
It is really good to see politicians using skeptical science to communicate climate change. I wouldn't be surprised if they start funding the site one day.
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2014 SkS Weekly News Roundup #7
Russ R. - I believe that the thread on Tropical Thermostats and Global Warming would the most relevant discussion, where Chris Colose states that:
...there is no compelling physical justification to suggest that the tropical sea surface temperatures must be pegged at some maximum value independent of the forcing, or that clouds/evaporation must act as some sort of tropical regulation mechanism.
I suggest taking further discussion of any 'thermostat' hypothesis there.
Moderator Response:[JH] Thank you for ferreting out the Chris Colose article. I also agree that any further discussion of Russ R's assertion about sea surface temperatures take place on its comment thread.
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Dikran Marsupial at 01:14 AM on 18 March 20142014 SkS Weekly News Roundup #7
RussR wrote " Sea surface temperatures never get above ~30C because thunderstorms (or occasionally tropical cyclones) limit further temperature increases and bring temperatures back down."
and later complained
RussR wrote "The data I presented covered 14.2 years or around 5187 days... you're pointing to 2 of those days. I'm pointing to the other 5185 days (99.96% of the data record) which show a remarkably consistent upper boundary."
You made an assertion, if you say that something can't happen, then pointing out a single occasion on which it did happen is not a cherry pick, it is a counter example that proves your assertion to be incorrect. Now if you were genuinely interested in scientific discussion, you would admit that your assertion was incorrect, and possibly revise it. Instead you have attempted to bluster your way out of it by accusing Tom of cherry picking. Sorry, I am not impressed, you are just continuing your trollish behaviour demonstrated earlier in the thread. If you want to retain a shred of credibility, then just man up and admit your assertion was incorrect.
Moderator Response:[JH] It is also incumbent upon Russ R to provide references to published and peer-reviewed scientific papers which support his assertion.
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Russ R. at 00:00 AM on 18 March 20142014 SkS Weekly News Roundup #7
michael sweet,
Allow me to refer you to the definition of "sloganeering" the comments policy:
- No sloganeering. Comments consisting of simple assertion of a myth already debunked by one of the main articles, and which contain no relevant counter argument or evidence from the peer reviewed literature constitutes trolling rather than genuine discussion. As such they will be deleted. If you think our debunking of one of those myths is in error, you are welcome to discuss that on the relevant thread, provided you give substantial reasons for believing the debunking is in error. It is asked that you do not clutter up threads by responding to comments that consist just of slogans.
If you would kindly point me to the main article that "debunks" my argument, then I'll put it to rest.
Moderator Response:[JH] What exactly is your "argument"?
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Russ R. at 23:54 PM on 17 March 20142014 SkS Weekly News Roundup #7
Tom Curtis @87 & @88,
- If your record day in Kirimati in 2010 had "very low humidity" why would it be in any way relevant to my argument about the convective behaviour of water vapour?
- The data I presented covered 14.2 years or around 5187 days... you're pointing to 2 of those days. I'm pointing to the other 5185 days (99.96% of the data record) which show a remarkably consistent upper boundary. (Where I come from, when you present an argument, but your data actually makes the exact opposite case, we call that an own goal.)
- Tarawa's weather station is located at an Bonriki International Airport. I'll leave it to you to ponder what an asphalt covered airstrip might do to daily max temperature readings.
- Pointing at the Persian Gulf SST as refuting evidence of how water vapor behaves in the tropics is a bit curious since the Persian Gulf is not in the tropics, its humidity is often negligible, and its geography as a body of water is analagous to that of an inflatible wading pool in a parking lot.
And yes, I'm still calling your October 26, 2010 Kirimati high temperature an "egregious cherry-pick"... the data are in plain view above.
Moderator Response:[JH] You are now skating on the thin ice of excessive repetition which is banned by the SkS Comments Policy.
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Kevin C at 21:48 PM on 17 March 20142014 SkS Weekly News Roundup #11
Oh yes, I read that the same way.
For me the huge surprise about the Shindell paper is that no-one spotted the issue before, given that its fingerprints are all over the hemispheric temperature record, and as you point out they are all over AR4 as well.
I keep asking myself whether I would have spotted it if climate were my day job. I suspect not - often the obvious is not obvious until someone points it out.
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Timothy Chase at 18:26 PM on 17 March 20142014 SkS Weekly News Roundup #11
Kevin C, re Otto... Looking at the article, the only point at which they acknowledge the distinction between direct and effective radiative forcing is at the end of the last paragraph:
Most of the climate models of the CMIP5 ensemble are, however, consistent with the observations used here in terms of both ECS and TCR. We note, too, that caution is required in interpreting any short period, especially a recent one for which details of forcing and energy storage inventories are still relatively unsettled: both could make significant changes to the energy budget. The estimates of the effective radiative forcing by aerosols in particular vary strongly between model-based studies and satellite data. The satellite data are still subject to biases and provide only relatively weak constraints (see Supplementary Section S2 for a sensitivity study).
Otto, Alexander, et al. "Energy budget constraints on climate response." Nature Geoscience (2013).
It seems clear that they are acknowledging the "effective radiative forcing by aerosols" as an issue that is not specifically dealt with in their paper, but which they or others may wish to turn their attention to at some later point. Incidentally, Drew Shindell is listed as one of the authors of Otto et al. (2013).
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Timothy Chase at 17:57 PM on 17 March 20142014 SkS Weekly News Roundup #11
Kevin C re radiative forcing... I don't which usage the authors of the different papers are employing. It really isn't my area of expertise.
However, until someone specifies otherwise, by "climate sensitivity" I would assume they mean Charney, not transient or earth system sensitivity, and by the same token, I would assume that by "radiative forcing" they mean direct radiative forcing, not effective. "Effective radiative forcing" is a derivative, more specialized concept. In this context, "direct" denotes primary usage, "effective" secondary. In the case of "climate sensitivity" refering to Charney it is more simply a matter of historical accident and common usage.
Or at least that is my best guess, not being as familiar with the literature as I might like.
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Kevin C at 16:39 PM on 17 March 20142014 SkS Weekly News Roundup #11
Thanks Timothy - didn't realise this was already present in the definitions of efficacy. The thing I haven't checked is whether papers like Otto et all are using direct or effective radiative forcing estimates - have you looked at this?
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Tom Curtis at 16:21 PM on 17 March 20142014 SkS Weekly Digest #11
wideEyedPupil @1, I have responded on a more appropriate thread.
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Tom Curtis at 16:20 PM on 17 March 2014Sea level rise predictions are exaggerated
Elsewhere wideEyedPupil comments:
"Interested in comment from scientists on the Media watch story "AN ALARMING STORY" on 10 March about sea level rise, describing reportage of a 6 metre sea-level rise as alramist because they omitted the 4014 prediction-come-trueth date."
The Media Watch (ABC, Australia) show has several problems, but arguably that is not one of them. As can be seen from the main post above, expected sea level rises by the end of this century vary from 0.57 to 1.1 meters, depending on the scenario, with confidence intervals of 0.81 to 1.65 meters for the warmest scenario (table 1). Those values are from a single study, and are higher than the IPCC values, who give a likely range of 0.45 - 0.82 meters for the warmest scenario by 2081-2100. That is, its upper 66% confidence range almost coincides with the lower 95% confidence range of the study above. I have heard several times that scientist making emperical projections of sea level rise think the IPCC relied to heavilly on models, and gave too low a value, but only a few expect sea level rises above 2 meters as even an upper bound. Those few (best typified by Hansen), argue not that very high sea level rises are likely, but that they are possible, and sufficiently probable that they should be taken into account in establishing climate policy. For what it is worth, I disagree with those very few, but several SkS regulars agree with them.
Given that background, it is at minimum careless sensationalism to not mention the timescale involved, particularly given that a more or less specific time was given the the paper being reported on.
Having said that, the Media Watch article is rife with inaccuracies itself. To start with (and most germaine), the two thousand year interval in the study was chosen as a period in which equilibrium will have been reached. That means they are predicting the sea level rise will be reached by 4014 AD, but do not specify that it will not be reached before than. Potentially much before them. In fact, while I consider it unlikely that the full sea level rise will be reached by 2100, it is certainly possible that it could be reached by 2500, and probable that it will reached by 3000 AD. Indeed, technically the article does not preclude Hansen's worst fears being realized, and the full sea level rise being reached in as little as 150 to 200 years. So, if leaving out the date is careless sensationalism, not specifying that the paper is stating the latest possible date for the realization of sea level rise must be considered careless soft pedalling of a real threat.
Even worse, is Media Watch's describing a 6.9 Meter rise in Sea Level as "a worst case scenario". In fact, the paper in question mentions the number 6.9 exactly once. In table 1 it shows as the median (not worst case) percentage of the current population displaced by sea level rise with a temperature of 3 C (again, not the worst case examined). So it is neither a worst case, nor even a value for sea level rise.
The actual values for sea level rise used in the paper comes from another paper from the same authors plus others. That paper indicates a median sea level rise of 2.3 Meters per degree C increase in temperature. It does not specify the error, but it is shown in figure Figure 2 E:
The worst temperature case looked at in the original paper is a 5 C rise, and as can be seen, even with a 4 C rise, the worst case (95%) at even 4 C is well above 12 meters. Even the median case at 5 C is an 11.5 meter sea level rise, so that Media Watch has stated as a worst case a value 40% less than the median value of the highest temperature examined.
What is worse is that while 5 C is at the upper end of the likely range (66% confidence interval) for BAU (RCP 8.5) as given by the IPCC, that is just for warming until 2100. By 2400 warming could procede well beyond that point so that 5 C may be the worst case examined, but it is not by any stretch of the imagination a worse case scenario.
Consequently, while Media Watch's limited point is fair, in making it they have made far worse errors in the opposite direction - errors that in fact contradict the study they are reporting on rather than merely eliding ambiguous information.
(Having looked at this, I will be notifying Media Watch of these issues.)
Moderator Response:[RH] Tweaked image width.
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chriskoz at 15:52 PM on 17 March 20142014 SkS Weekly Digest #11
wideEyedPupil@1,
Weekly Digest is the right place to raise any topic, so you don't need to be appologetic. However, this site is dedicated to discuss the science, not the primitive junk alarmism of the story you are pointing. It's a waste of time to dsicuss such junk so I bet no one will care.
The only exempt from this story worth discussing here is:
Yes, we’re talking [...] 2000 years away.
By which time the world could have far worse things to worry about.
(i.e. climate change impacts on industrial civilisation's tourism and entertainment industry in this case) but of course the assertion is lost (left unpursued) among junk.
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wideEyedPupil at 12:19 PM on 17 March 20142014 SkS Weekly Digest #11
Interested in comment from scientists on the Media watch story "AN ALARMING STORY" on 10 March about sea level rise, describing reportage of a 6 metre sea-level rise as alramist because they omitted the 4014 prediction-come-trueth date.
Apart from completely ignoring the issue of the climatic tipping points (methane burps in polar regions etc) for such an occurance potentially being yesterday, tomorrow or in the next couple of decades, the certainty of 2000 years for 6m seemed a little over-cofident to me as a lay follower of claimte science (having passed my Climate Change Conversations introduction to CC course on Coursera last year ;-] run by UBC)
http://www.abc.net.au/mediawatch/transcripts/s3960467.htm
Anyone care to discuss. I don't think it's possible for me to create my own thread on SkS hence this thread hyjack, apologies if I've broken etique.
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Klapper at 12:00 PM on 17 March 2014Global warming not slowing - it's speeding up
"In 2013 the Earth’s oceans accumulated energy at a rate of 12 Hiroshima atomic bombs per second"
An utterly irrelevant metric. From a dataset downloaded from this link:
...you can see that the delta ZJs for the world ocean between 1959 and 1960 are -8.7 - (-5.5) = 3.2ZJs or approximately 16 Hiroshima's per second. Please check my math, but even if it is wrong, the use of one year's data to show how serious global warming is verges on the absurd.
Moderator Response:[RH] Hotlinked URL that was breaking page formatting.
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Timothy Chase at 11:10 AM on 17 March 20142014 SkS Weekly News Roundup #11
Kevin C. wrote:
The quote you picked up refers to the Shindell paper. Shindell doesn't contest the lower aerosol forcing, but points out that the lower forcing is countered by the fact that the aerosols are being emitted in regions where they have a greater impact on temperature, which has the same impact on global mean temperatures as if the aerosol effect were stronger again.
From what I can see, Shindell is simply applying the concept of climate efficacy to industrial aerosols.
In the fourth IPCC assessment, efficacy is defined:
Efficacy (E) is defined as the ratio of the climate sensitivity parameter for a given forcing agent (λi) to the climate sensitivity parameter for CO2 changes, that is, Ei = λi / λCO2 (Joshi et al., 2003; Hansen and Nazarenko, 2004). Efficacy can then be used to define an effective RF (= EiRFi) (Joshi et al., 2003; Hansen et al., 2005).
Climate Change 2007: Working Group I: The Physical Science Basis
2.8.5 Efficacy and Effective Radiative Forcing
https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5.htmlThe reason why different forcings have different efficacies is largely a matter of how the forcing is spatially distributed:
The efficacy primarily depends on the spatial structure of the forcings and the way they project onto the various different feedback mechanisms (Boer and Yu, 2003b).
Climate Change 2007: Working Group I: The Physical Science Basis
2.8.5.1 Generic Understanding
https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5-1.htmlLatitude is particularly important:
Nearly all studies that examine it find that high-latitude forcings have higher efficacies than tropical forcings.
ibid.
... and this is precisely what Shindell has keyed in on with respect to anthropogenic reflective aerosols.
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Tom Curtis at 07:48 AM on 17 March 20142014 SkS Weekly News Roundup #7
For the record, Tarawa has a minimum recent recorded temperature of 14 C, and several in the vicinity of 17C. I therefore have no grounds to reject the 13 C recorded in Kirimati as spurious. The 2 C and 0 C, on the other hand, are suspicious, having no analogue temperatures in nearby stations, nor any ready explanation (that I can think of).
Also, as an addendum to my prior post - the 2010 record temperature at Kirimati coincides with a day with zero cloud cover, very low humidity, and very low wind speeds - a combination that supports my hypothesis as to the cause, and that it is not spurious.
A further addendum - Russ R has not shifted the grounds of criticizing that falsifying data. He is no longer claiming a cherry pick as such, but has not apologized for his unwarranted accusation.
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Tom Curtis at 07:35 AM on 17 March 20142014 SkS Weekly News Roundup #7
Russ R @86, the possibility that the reading was spurious occurred to me when I first saw it. However, to accept it as spurious we need to also treat the similar reading in 2005 as spurious, and the (at least) two readings of 40 C at Tarawa as spurious. In fact, for Tarawa, the highest recorded temperatures by month are:
Jan: 38 C
Feb: 34 C
Mar: 40 C
April: 34 C
May: 33 C
June: 38 C
July: 34 C
Aug: 34 C
Sep: 37C
Oct: 34 C
Nov: 34 C
Dec: 40 C
That's five out of twelve monthly records you will want to elliminate as spurious, plus two from Kirimati. You realy don't like data that contradicts your claims. Do you?
Further, all that is required for a very high land temperature on Kirrimati or Tarawa is a very still day, such that air over land has longer to heat up and ocean water warms rapidly at the surface due to decreased wind driven mixing (and lagoon water even more so due to shallow depth). I wonder, how could an Island that lies in the Inter Tropical Conergence Zone experience a day or two with little or no wind?
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Kevin C at 05:29 AM on 17 March 20142014 SkS Weekly News Roundup #11
Wili: The new scientist article is right, but there are several things going on at once.
Recent studies have generally show a reduced aerosol cooling effect. Which means a stronger total forcing. However to explain recent climate change from a stronger forcing means a lower sensitivity. So on the one hand we expect greater forcing, and on the other lower sensitivity. If aerosols were expected to grow in proportion to ghgs then projections would be unaffected.
However all the RCP scenarios show reduced aerosol emissions in the future, so the lower sensitivity leads to lower warming projections.
The quote you picked up refers to the Shindell paper. Shindell doesn't contest the lower aerosol forcing, but points out that the lower forcing is countered by the fact that the aerosols are being emitted in regions where they have a greater impact on temperature, which has the same impact on global mean temperatures as if the aerosol effect were stronger again.
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michael sweet at 01:58 AM on 17 March 20142014 SkS Weekly News Roundup #7
Following one of Tom's links I found this graph:
original site Interestingly, Russ's temperature graph was just above it (Russ does not link data).
Kiritimati is located just above the "d" in Trade Winds, approximately 3,000 miles from the warm pool. Tarawa is just below the "K" in Kirabati, approximately 500 miles from the warm pool and 1000 miles from the center of the warm pool. I note that the warm pool is not near any continents. Russ is trying to support his wild claim that ocean temperatures are limited by using data 3,000 miles from the hot locations of the Pacific ocean. It is impossible to support Russ's wild claim using this data. Data from warm areas must be used. Tom's explaination that the temperature is stable from thermal mass and current mixing completely explains the ocean temperatures at Kiritimati.
The temperatures Russ is currently arguing over are land temperatures. It is difficult to understand how land temperatures could possibly relate to a "wall" for ocean temperatures. It wastes our time when Russ makes these distracting arguments for arguments sake.
Russ has provided no citations to support his wild claim that ocean temperatures are limited. This would be in the peer reviewed literature if it was even a remote possibility. It is a waste of time for Russ to cite land temperatures 3,000 miles from the hottest ocean to support his wild claim.
It is sloganeering to continue to post unsupported arguments. At a scientific blog peer reviewed data is required. Russ should be required to support his arguments like everyone else.
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wili at 01:33 AM on 17 March 20142014 SkS Weekly News Roundup #11
Thanks for that explanation, link, and graph (and for ignoring my bone-headed punctuation and spelling errors!). If I can try your patience a bit further, what do those watts per meter squared measurments translate into in terms of degress C of warming that aerosols are responsible for temporarily blocking?
So given that Schmidt paper, am I right that the "How Much Hotter..." article was wrong when they said: "the latest findings show that the cooling effect of aerosol pollution from factories and fires has been underestimated." Do you suppose that they were unaware of that article and were just looking at earlier articles that showed an increased effect of aerosols? -
2014 SkS Weekly News Roundup #11
Have experienced the same problem as shoyemore, but it seems to be working now. Hopefully I’ll soon be able to update the Norwegian translation of The Big Picture.
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Russ R. at 01:16 AM on 17 March 20142014 SkS Weekly News Roundup #7
Tom Curtis,
Do you honestly believe that the 37C measurement you're pointing to is any more accurate or reliable than the 13C outlier in 2007 or the 2C reading in 2006?
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Micawber at 23:31 PM on 16 March 2014Global warming not slowing - it's speeding up
This excellent post points to a fundamental shift in global warming from the trivial 7% in air to the majority 93% in oceans. Indeed is heat captured over 70% of earth’s surface that includes the 8.5% in shelf seas <200m where most impacts are found.
Climatologists deal in anomalies in 30-year records as James Wright pointed out. Moreover, they rely on records collected by others and never go to sea to collect verification ground truth data. Their data at the surface are not to ocean standards that require >3,000 times more accuracy to account for the higher heat capacity (specific heat seawater: air). Moreover, salinity in the ocean surface has never been routinely collected. Seawater density is critically important because fresh warm water floats over saltier cool water.
The Levitus et al (2012) data incorporates the unverified SST data from 1955-1995 that has only sparse coverage as they show in their paper. It has only complete surface temperature coverage over rough degree grid where surface data is averaged over the top 100m from 1995.
The conclusion, that Earth is warming faster than ever before, is very securely based on ocean data. The huge heat capacity smoothes out the great swings in heating and cooling observed on land and in air. Moreover, as James states the main factor is greenhouse gas heat imbalance at the top of the atmosphere.
However, the 93% in the oceans is trapped by the almost completely unstudied top 2m of the ocean as was pointed out in a recent discussion paper (http://www.ocean-sci-discuss.net/11/C54/2014/osd-11-C54-2014-supplement.pdf).
Using rare daily timeseries, the authors quantify ocean warming as currently more than 1ºC in twenty years. This is strong confirmation of dangerously accelerating global warming.
Moreover, it is based on real ground truth data un-modified by models or statistics. They go on to show the post-1986 accelerated temperature rise coincides with a rapid decline in solar radiation. I suppose these are two hockey sticks in opposite directions. This strongly suggests that greenhouse gas contribution to heat imbalance now outweighs not only volcanic variations but also variations in solar activity from the Maunder Minimum to the modern 20th Solar High.
It also suggests that it masks all the global ocean indices such as ENSO, PDO, and NAO that are known to depend on the 22y Hale Cycle and the more familiar 11.6y sunspot cycles. This suggests that predictions, based on atmospheric statistical assumptions, of changes of El Nino/La Nina are unlikely to be accurate. ENSO cycles in the 21st century have been far less predictable. The ocean warming due to greenhouse gases is a good physics-based reason for the observed changes.
It will be very difficult to change climate deniers opinions.
As Alistair Fraser pointed out on his website on Bad Science “Be very, very careful what you put into that head, because you will never, ever get it out.” Thomas Cardinal Wolsey, (1471-1530). (A. B. Fraser, (http://www.ems.psu.edu/~fraser/BadScience.html)
Fraser also pointed out that evaporation does not depend on relative humidity as assumed in many ocean models, but on sea surface temperature. In practice that means evaporation increases by 7% per degree rise in temperature (Precipitation rises by 2-3%). The presence of air is not relevant to vapour pressure that determines evaporation (http://fermi.jhuapl.edu/people/babin/vapor/index.html).
The Matthews and Matthews (2014) discussion confirms and quantifies James Wright’s alarming findings. They present the first measurement of evaporation free from precipitation. They show evaporation and heat sequestration is critically dependent on salinity. The north Pacific ocean heat is trapped in the top 2m and is twice that of the southern ocean with salinity >35.5‰ (the authors use parts per thousand as appropriate at the surface). Moreover, they show from long-timeseries data that North Atlantic/Arctic heating has been buffered by basal icemelt in three phases. The post-1986 accelerating temperature rise they suggest is due to decreasing amounts of floating ice.
Indeed, they suggest, on the basis of real ground truth data and basic physics, that the warming will continue as long as we have the top of the atmosphere heat imbalance. It is not enough to stop adding greenhouse gases. Climatologists assume that if you do that, the heat balance will eventually be restored by back radiation. However, there is no back radiation from 2m below the sea surface. They point out that hurricanes can draw cooling water from below if they linger long enough. It is the storm’s speed over the ground that determines whether it grows into Hurricane Force 5 (fast moving), or is downgraded to tropical storm (slow moving). That could account for the first hurricanes seen in UK this spring.
Pacific warm pools have seen sustained temperatures of 32ºF from more normal 28ºC. That implies an increase in evaporation and precipitation of almost 30% above long-term averages. This is the likely explanation for excess precipitation in 2011 over SE Asia, Australia and S America that lowered global sealevels by 3mm. It could also explain why container shipping companies in the western Pacific now use two Beaufort classes above Hurricane force 12 to describe Pacific Typhoons.
James, you have presented a fundamental shift in our understanding of global warming.
There needs to be a major shift in funding to focus on the top 2m of ocean.
Unfortunately, the manned weatherships and other monitoring programs were discontinued just before the rapid warming began. Manned weatherships would have been very useful for seeing first hand what is really happening. They could be quickly deployed to help aircraft or ships in distress. Even if the aircraft turned off its tracking devices, I suspect weatherships could track them.
Manned ocean programs have been savagely cut in the everywhere including UK, US and Canada.
We need to lobby to get funding restored to counter the devastating cuts shown in this video:
Silence of the Labs http://www.youtube.com/watch?v=Ms45N_mc50Y.
Congratulations! You have made a major contribution to science of importance to all mankind. SKS has a great record in countering false arguments and bad science. You now have the mother of all battles to fight. No one has argued that we must actually reduce greenhouse gases to former stable levels. But that is what is demanded if ocean warming and acidification is to managed and mitigated. -
shoyemore at 21:27 PM on 16 March 20142014 SkS Weekly News Roundup #11
Is anyone else having trouble with their login?
My (perfect valid (I thought) password no longer works.
On asking, I got sent another one, but the message seems to mean this is happening often.
Moderator Response:[DB] Check your email.
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DMarshall at 19:52 PM on 16 March 201430 US Senators Speak Up4Climate Science
Bernie Sanders not only made the "97% consensus argument" but alluded to the links between denialism of tobacco as a carcinogen & that of AGW.
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Bjorn10256 at 18:41 PM on 16 March 201430 US Senators Speak Up4Climate Science
For iPad and Android use the app "Photon". A web browser/flash player which allows you to watch Flash.
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Wol at 15:51 PM on 16 March 201430 US Senators Speak Up4Climate Science
>>It's probably a Flash problem, a "feature" of iPads. The video works on a PC in all browsers.<<
Didn't work for me either, on a PC.
However, I was not logged on: when I did log on it worked eventually, after I had refreshed it and clicked several times on the various "play" arrows. -
Steve L at 14:31 PM on 16 March 20142014 SkS Weekly News Roundup #11
The Lawrence Torcello article on criminal negligence of the climate confusionists -- amusing to see commenters still obsessing about Mike Mann and "hide the decline". More relevantly, I think it would be very instructive to compare/contrast the criminality of fake climate skeptics to that of the tobacco producers who downplayed health risks and have been sued.
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wili at 10:21 AM on 16 March 20142014 SkS Weekly News Roundup #11
From the "How Much Hotter..." article: "the latest findings show that the cooling effect of aerosol pollution from factories and fires has been underestimated"
I was under the impression the recent studies had actually shown that the cooling effect of aerosols had been _over_ -estimated, not underestimated. Am I missing something here. There was now study linked in the original article to support this contention.
Moderator Response:(Rob P) - there have been a number of research papers that have suggested global dimming in the early 21st century. For example - see this SkS post: Global Dimming in the Hottest Decade.
But more recently see Schmidt et al (2014), and note this image from their paper:
Reduced solar radiation, volcanic and industrial pollution aerosols appear to have contributed to a smaller-than-expected net forcing of the climate. Still an area of large uncertainty I'm afraid.
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Global warming not slowing - it's speeding up
Timothy Chase @ 36. Thanks again - lots of interesting reading there.
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Tom Curtis at 08:08 AM on 16 March 20142014 SkS Weekly News Roundup #7
Russ R @82, I find it seriously offensive that mister "only studies which find low climate sensitivity are valid" should accuse me of cherry picking.
In this case, you are claiming that there is a wall on ocean temperatures at, or about 30 C. As already explained, that tropical ocean temperatures are very stable is hardly surprising. They are ocean temperatures, with a large thermal mass. They are tropical temperatures, with near contant insolation over the year. And they are smoothed (mixed) both vertically across the thermocline, and laterally by both currents and wind so that large excursions are unlikely. That smoothing was not enough for you. You presented as evidence of the "wall" data that was a multi-annual montly average. That is, you presented as evidence of an upper limit on temperatures data that had any excursions beyond that limit smoothed out.
As to my purported cherry pick, to falsify the claim that a temperture series never exceeds 32 C, I need present only one example of a record above 32 C. That you then accuse me of "cherry picking" because I focus on an instance that falsifies your claim shows cutzpah, I'll grant you. It does not show intellectual integrity. In fact it shows rather the opposite, in that you gloss over the fact that my supposedly "cherry picked" example is not the only example of such a high temperature in the data shown, or even the highest shown (see also 2005 which has a day with a maximum temperture higher than 37 C). It also glosses over the fact that I pointed to two monthly records for a nearby station of 40 C, and to the highest recorded SST which is well in excess of your "wall".
If you are going to accuse me of cherry picking for pointing to instances that falsify your claims, this discussion is over. If you want it to continue, I expect an apology. If that is not forthcoming, I have done more than enough to show that on the science of climate change you are ignorant, and in fact dismiss any data you find inconvenient from consideration.
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michael sweet at 08:01 AM on 16 March 20142014 SkS Weekly News Roundup #7
While we are on the subject of "egregious cherry pick"s, I wonder why we are using sea temperatures from a Central Pacific island to illustrate maximun sea temperatures? Kirimati is one of the farthest east islands in the Pacific. Everyone knows that the highest temperatures in the Pacific are always in the Western Pacific. The trade winds push the hottest water west. The claim that it is desirable to get away from continental effects is not sufficient to choose an area strongly affected by upwelled cold water coming from the coast of South America. A location where sea temperatures are not artificialy lowered would be a much better location to use for this example. November in Rabul is already 30.2 average and 31.2 maximum.
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Timothy Chase at 05:03 AM on 16 March 2014Global warming not slowing - it's speeding up
BC, I have little doubt Rob Painting has more background in this area than I do, and would defer to him in this.
Personally, while I was aware of the existence of the gyres, I thought of their motion as being principally horizontal and hadn't considered their vertical effects. However, it makes sense that they would involve that as well, similar to hurricanes, the latter of which involve a vertical pumping action and are responsible for some of the poleward circulation of heat in both the atmosphere and ocean.
However, what I was refering to in terms of "quasi-stability" was simply the tendency of the system to chaotically move about a mean state where the mean state itself remains unchanged and the system has no overall trend. In this sense, I was refering to the system's tendency to regress towards the mean. When a trend is involved you would have regression towards the trend.
But typically the term gets used in climatology to refer to the tendency of the system to remain within any one of several states that are "stable" for only a finite time, typically according to a characteristic time scale. With ENSO the quasi-stable states would be the El Nino, La Nina and neutral states. Other oscillations may have only positive and negative quasi-stable states.
There is however one point that I would like to touch on, a potential misunderstanding, basically where I speak of constructive and destructive interference between ENSO, PDO and IPO. When one looks at how they overlap, one possibility that suggests itself is that they are essentially independent of one another, independent modes that are superimposed and simply additive in their effects.
However, one indication that this is not the case is that a correlation with lag-time exists between El Ninos and the the positive phase of PDO. The positive phase of PDO will often follow an El Nino within a matter of three to six months, thus the El Nino appears to act as a trigger for the PDO flipping states. The reason, it would seem, is that their existence and consequent interaction involves various feedbacks.
Anyway, you might find some value in a comment I made in an earlier thread several years ago that goes into things in more detail. It includes both references and links. Frankly, I do a better job there than I would be capable of at present without more review. However, at one point it refers to a piece by Atmoz that has since been taken down. This is still in the Wayback Machine.
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Russ R. at 02:23 AM on 16 March 20142014 SkS Weekly News Roundup #7
Tom Curtis @81,
No need to apologize for the tardy response.
What you should, however, be apologizing for is what amounts to the most egregious cherry pick I've ever seen.
You showed a daily high temperature at Kirimati on Oct 26, 2010 of 37C as evidence to counter my "wall" argument about tropical ocean temperatures.
Without further comment, here are the full daily records at that station back to 2000:
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014 (ytd)
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Global warming not slowing - it's speeding up
Timothy Chase at 32 and Moderator comment at 30. Thanks for the detailed response. It's obviously more complicated than I thought and pretty interesting too. What I hadn't realised was the idea of the quasi-stability with heat going in to oceans (IPO negative, La Nina) having to balance heat going out of oceans (IPO positive, El Nino) over time. That makes sense.
One further question/comment about 32. You mention the thermohaline effects but not the subtropical ocean gyres - see comment 34 from Rob Painting, who did a post on this topic a few months ago. I suspect I had this in mind when I made my comment at 30. Would this heat transfer and the strong warming of the 0-2000m layer be why the stability you mentioned is only quasi?
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Rob Painting at 16:13 PM on 15 March 2014Global warming not slowing - it's speeding up
Barry - I think that pretty much sums up contrarians - they're not really interested in science, i.e. how the physical world really works, but simply jump from dataset to dataset in order to affirm their wishful thinking. As you point out, ocean heat content is a classic example - all the contrarians thought it the greatest thing since sliced bread when the 0-700 metre layer exhibited cooling in the mid 2000's.
Since then we've discovered that that was largely due to more heat being pumped down into the deep ocean via the subtropical ocean gyres, and that the 0-2000 metre layer has been warming strongly. With a longer record we have more confidence that the trend is robust, but contrarians have abandoned the ocean heat content data because it doesn't affirm what they'd like to believe. Hardly a surprise.
.....Meanwhile back in the real world the Earth continues to build up heat, and a return to the positive phase of the IPO (strong surface warming) draws ever closer.......
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barry1487 at 15:37 PM on 15 March 2014Global warming not slowing - it's speeding up
Re OHC, I remembered that 5 or 6 years ago (or more) RP Snr was consistently saying that ocean heat content is a much better metric to measure global warming than surface temps (I agree). Around that time he was pointing out that OHC for 2003 - 2006 had not risen, and prior warming was not homogenous across the oceans. A few years later with more data, and we see OHC has continued to increase, so I wondered how RP Snr had interpreted that. I found a post citing him at WUWT, where he advises that the problematic OHC data is not robust enough to rely on.
I haven't followed RPS as much as I used, but I long respected him for being a qualified alternative voice on climate science, whether or not I agreed with him. Do I have the narrative right, here? Did he really promote OHC as the best metric, then use it to emphasise little or no warming (or cooling), and then when warming continued called the data into question?
Good post, BTW. Thanks.
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Tom Curtis at 10:53 AM on 15 March 20142014 SkS Weekly News Roundup #7
Russ R @78 & 79, first, sorry for my very tardy response.
Second, thankyou for your agreement that the WV feedback increases in strength with rising temperature. As we are near a minimum for the ice albedo feedback, the implication is that we are at, or near a minimum climate sensitivity with respect to the current configuration of continents, and that increasing temperatures will increase climate sensitivity rather than decrease it.
Having said that, your agreement seems half hearted. You go on to say:
"I don't think it requires anything more than simple assertion to argue that the addition of heat to surface water causes it to evaporate, and rise, and then subsequently condense, and fall back to the surface."
Actually, that does require more than assertion. The tendency of rising water vapour to condense is a function of temperature. In an isothermal atmosphere, it would not condense as it rises, and as I recently learned, an atmosphere without greenhouse gases would be isothermal (or an immeasurably close approximation to isothermal). What you think you can claim by simple assertion is a contingent fact, depending on empirical conditions.
What is worse, it as a drastic oversimplification. As I have already discussed the potential impact of cloud top height, you know that your "simple assertion" glosses over a lot of relevant detail that can change the conclusions you seek. Another example is cloud droplet size. In optically thick clouds, increasing cloud droplet size decreases albedo. With more water vapour in the air, cloud droplet size is likely to increase (a fact evident everyday with the large, heavy droplets of rain found in the tropics). Consequently warming air will likely reduce cloud albedo per unit area, but may increase cloud area. You seem to be prepared to "simply assert" that the former effect is irrelevant, and only the later need be considered. Certainly you "rebutted" evidence that warmer temperatures will increase the GHE of clouds by your "simple assertion".
Frankly, in the face of these and other complexities, your simple assertion has all the logical elegance, and persuasiveness of (snip)
You also simply asserted that "... vertical heat transfer can occur by convection in addition to radiation,which your response ignores", which is odd given that none of my points relied on denying or ignoring that, and one (increased cloud height with increased temperature) directly relied on the fact that heat can be transferred by convection.
Your last simple assertion was that "...in any tropical ocean location, the surface temperature after an afternoon rainfall is lower, not higher, than before". That may be true, or not. I have seen, and you have provided no data on that fact. It is probable, IMO, in that tropical rainfall tends to start around 2-3 pm (ie, once the day starts cooling), and finish one to two hours later. Your imputation that the cooling is due to the rainfall is, therefore, very dubious. Rather, on nearly all afternoons in the marine tropics, it cools in the afternoon after about 1-2 pm, and that cooling may well result in precipitation. (I notice that you are carefull to cherry pick your assertion by limiting it to afternoon rainfall. Morning rainfall, I am sure, is accompanied on most occassions by a warming with time.)
Moving on, you continue to attempt to defend your claim of a wall in sea surface temperatures. This time you do so by showing that if you average an unspecified number of years data of averages of approximately 30 days data (monthly averages) the temperatures do not show extremes. That was, of course, obvious from the moment you took averages.
If instead of looking at averages, you look at daily temperatures you find things are more variable:
In this case, the daily temperatures are for 2010, Kiritimati, Kirribati. For Tarrawa, Kirribati, temperatures have reached as high as 40 C, both in March and December. What is more, maximum (and average) temperatures in Kirribati have been increasing. In the case of maximum temperatures, they have increased by 0.18 C per decade since 1950, or by 1.1 C over that period. Neither local maximum temperature records, nor the increase over time seem aware of the wall you are so confident in.
There are good physical reasons to think the very high maximum temperatures occassionally experienced in Kirribati are not perfectly reflected in SST. Indeed, had they been, they would have broken the world record SST of 36.67 C (Persian Gulf). But that record itself shows your wall to not exist. Likewise the higher SST in past eras determined by proxies show the wall to not exist. The "wall" is a figment of the imagination, having no physical basis, and stands refuted by actual temperature records from instruments and proxies.
Perhaps you will not shift the wall up to 36 C. If so, you will make the fallacy of the reasoning behind the wall plain to all. For any set of circumstances, there must be some SST which is not in fact exceded. What that temperature is is a function of the particular circumstances. The existence of a de facto limit in no way proves that it is an absolute limit, such that if circumstances change it will not be exceeded. Treating it as such is simple a non sequitor.
(More later)
Moderator Response:[PS] snipped portion unlikely to promote constructive debate,
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Pete Wirfs at 10:26 AM on 15 March 2014A Hack By Any Other Name — Part 5
Same here.
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