Basically, you asking me the equivalent of, “How do you engineer?” “How do you make a guitar?” “How do you find a new theory?”
Correct! That is exactly the kind of question I am asking. I have no reluctance in “accepting” your points #1 & #2. But having “accepted” them, what do I have? Damn little.
Let’s turn it around for a moment, and pretend you asked me about guitar-making. I could say that 1) every guitar design is different, because it attempts to meet specific needs either of an individual player or of an anticipated class of players, and 2) guitar design must follow a set of specific principles (which I would list, but won’t here for brevity), mostly to do with the physics of vibrating bodies.
And you “accept” that. But you still don’t even know–from my explanation at least–that most guitars are primarily made of wood. You don’t know what I mean by “the physics of vibrating bodies,” at least not in any specific way. And you have no idea what sorts of operations, materials, or skills are needed. In short, you don’t have a clue how to tell a luthier from a Lothario. (Not that those are necessarily exclusive classes…!)
That’s pretty much how I’ve felt after receiving one of your standard issue responses.
So, what could you do differently?
You could, to propose 5 (non-exhaustive) strategies:
1) Cite examples. (You actually do this sometimes, but usually separately from the exchanges I’ve been talking about.) I get that solutions will be site-specific, but that idea is much ‘richer’ cognitively if I have learned about a few different instances, and had the chance to compare and contrast what people have done. So, who’s exemplifying sustainability/simplification/renewable ag today in the Middle East? North America? Southern Europe? East Asia? What are the commonalities, and what are the local adaptations?
2) Explore the principles in practice. This is basically using examples, too, but is carried forward in a more specific, focused way. Returning to the guitar example, I could tell you about the principle that guitars primarily use string length to control pitch: the shorter the string, the higher the pitch. I could tell you that guitars “quantize” pitch by the use of wire “frets” placed transversely across the neck–a linked picture would be good here–and that the ear’s sensitivity to small variations in pitch implies that a very high standard of accuracy is needed in the correct placing of fretwires, if one is to build a guitar that will play acceptably in tune.
(Et cetera, as desired. But now you know about one specific principle, and about what it implies operationally for a guitar maker.)
3) Personalize. Who are notable people involved in the space? Even data nerds care about people, and remember notable ones, which in turn helps them remember, understand, and contextualize the ideas or practices associated with those people.
4) Give bibiliography! Where can I access more information? (I have a whole file of stuff Scott Strough has linked on regenerative ag, for example. There could be another one for your info.)
5) Teach the controversy–whatever it is. (I don’t know what it is, but there’s got to be one.) What are people struggling to figure out in this space? What are they saying, and where can I tap into that conversation? (C.f., points #3 & #4.)
You want us to accept simplification as the necessary solution to the climate crisis. It’s not too much to ask, IMO, that you take the trouble to teach a bit. If you really think simplification is that important, why not take that trouble, eh? Students are asking… can you step up and meet us where we are, and not just insult us for not being where you think we should be?
You’re right that these papers are scientifically negligible. That’s why, for instance, the Stallinga paper you mention was published in an open access journal, probably without any real review process. But here are some comments on points in the abstract:
The effect of this gas in the atmosphere itself was already determined as being of little importance based on empirical analysis.
By whom? There’s no citation, which there should be, even in an abstract. And in fact this bald statement flies in the face of a massive body of literature, which should have been addressed as well. Shoddy scholarship.
In a new approach, the atmosphere is solved by taking both radiative as well as thermodynamic processes into account. The model fully fits the empirical data and an analytical equation is given for the atmospheric behavior.
Ah, a model has been constructed! The devil is always in the details, of course, which aren’t given in the abstract. But again, this particular model is set against a great many other incompatible models which have proven to have considerable predictive value.
Upper limits are found for the greenhouse effect ranging from zero to a couple of mK per ppm CO2.
So, let’s plug in “a couple of mK per ppm CO2.” (Note that he’s apparently modeling climate response to CO2 as linear, whereas everybody else says it’s a log function, but let that go. Maybe he’s limiting the range involved and approximating.)
Anyway, CO2 concentrations have risen from 280 ppm to 410, which would be a rise of 130 ppm. If we take “a couple” to mean “two,” then the upper range of expected temperature rise per this paper would be 0.26 C since pre-Industrial. Because of the log aspect, expected temperature responses are usually defined in terms of doublings. So, should CO2 double, that would obviously be a rise of 280 ppm, and the expected temperature response (per Stallinga) would then be 0.56. How does that compare with orthodox expectations?
The radiative forcing due to doubling CO2 from the pre-industrial 280 ppm is approximately 3.7 Watt per square meter (W/m2). This energy inbalance would eventually result in roughly 1 °C of global warming in the absence of feedbacks.
So, Stallinga purports to reduce expected warming by a factor of somewhere between 44% and 100%. Not an impressive constraint, even if you take everything at face value. (It’s not clear to me from the abstract whether Stallinga’s approach would fold in feedbacks to date or not. And why “upper limits”, plural?)
It is shown that it cannot explain the observed correlation of carbon dioxide and surface temperature. This correlation, however, is readily explained by Henry’s Law (outgassing of oceans), with other phenomena insignificant.
Epic fail! Here Stallinga tries to account for the correlation between warming and CO2 by reversing causation: it’s not (he says) that CO2 warms, it’s that warming releases CO2 from the ocean. There’s truth in that latter assertion, of course: that’s thought to be a major piece of the cycles of glaciation and deglaciation seen throughout the span of the Quaternary period.
But the problem is that we know from isotopic studies, accounting studies of the carbon cycle, and from the observed loss of atmospheric oxygen that the source of the increased carbon in the atmosphere is not the oceans, it’s primarily the combustion of fossil fuels. Had Stallinga read the literature adequately, he would have known that. (And maybe he did, but chose to ignore the issue?)
Finally, while the greenhouse effect can thus, in a rudimentary way, explain the behavior of the atmosphere of Earth, it fails describing other atmospheres such as that of Mars.
Dude needs an editor; if you say “finally” it really should be your final point–but he goes on to add a “moreover” and then yet another “finally.” But I digress…
Again, Stallinga should review the literature. James Hansen cut his astrophysical teeth studying planetary atmospheres, particularly Venus and Mars.
Moreover, looking at three cities in Spain, it is found that radiation balances only cannot explain the temperature of these cities.
Could that be because circulatory changes in the atmosphere matter, too? Wow, revolutionary thought! Frankly, I’m amazed that Stallinga or anyone else would write something quite that dumb.
Finally, three data sets with different time scales (60 years, 600 thousand years, and 650 million years) show markedly different behavior, something that is inexplicable in the framework of the greenhouse theory.
Gee, you think that circulation and albedo might have been a tad different?
As to “markedly different” behavior between the timescales of 60 years and 600,000 years, well, it’s really too vague to know what he means here. But given that climate is normed out over 30 year spans, it’s quite evident that you wouldn’t expect the same variability over just 60 that you would over 600,000! (And in fact, there’s quite a number of glaciations and deglaciations that have happened over the last 600 millennia.) That said, the correlation between CO2 and global temperature *does* appear to hold in a broadly similar way over both time spans.
Polar Flyersays
Moderators, Regarding post #87 by “Killian,” I am really saddened to see that it met your standards. I made a serious and deeply skeptical, but polite and earnest, attempt to engage with “Killian” to better understand his position. In return he has done nothing but overtly insult me. That sort of experience doesn’t really help me find the sort of quality intellectual discussion I have come to hope for at RealClimate. I’m going to exercise my prerogative to ignore his future posts because he has clearly disengaged from civility, and I urge you to hold him (and the rest of us) to a higher standard. Thanks.
Killiansays
Re #101 Kevin McKinney said Killina, please teach me permacuture for free.
Killian says: No. Take a course, or at least read books on the topic. Not only will I not teach you for free, I certainly *can’t* do it within the confines of this blog.
There are lots of books and related books.
Read one. Or, if you’re serious about solutions, I’ll do a deeply discounted course with you online – but not here.
Killiansays
Re #103 Polar Flyer said I made a serious and ****deeply skeptical,**** but polite and earnest
Deeply skeptical but earnest? Laughable.
You were ddeply insulting and got zero insults in return. Your thin skin and lack of language skills is your problem.
attempt to engage with “Killian” to better understand his position.
Again, deeply skeptical. Save it for fools who believe such B.S.
overtly insult me.
There were zero insults in that post. This is also not one: You intellectual accuity is quite low if you believe you were insulted in the first response. That’s an analysis based on the fact you conflate terse or even coarse with insults.
That sort of experience doesn’t really help me find the sort of quality intellectual discussion I have come to hope for at RealClimate.
Then don’t insult the people you are asking favors of.
I’m going to exercise my prerogative to ignore his future posts because he has clearly disengaged from civility, and I urge you to hold him (and the rest of us) to a higher standard. Thanks.
If they did, both of your posts would have been boreholed.
nigeljsays
Al Bundy @94, I’m a bit more conservative on the climate sensitivity issue. I predicted at least 15 years ago that climate sensitivity would turn out to be medium, but that this level of warming would cause greater changes to the biosphere and cryosphere than anticipated including about 2 metres of sea level rise per century very possible worst case. Didn’t post it on this website. Just an educated guess based on a whole lot of things adding together.
The evidence is still on my side. The modelling finding high climate senstivity is still well in the minority of studies, according to something sid posted a while back. Although the fact that its at least possible is enough reason to strongly mitigate the problem.
nigeljsays
Polar Flyer “Moderators, Regarding post #87 by “Killian,” I am really saddened to see that it met your standards. ”
I agree. His rhetoric, tone and ideas are way below acceptable standard.
Killian says: No. Take a course, or at least read books on the topic. Not only will I not teach you for free, I certainly *can’t* do it within the confines of this blog.
There are lots of books and related books.
Read one.
Wow. So simplification is the hope of humankind, the essential pathway to salvation, and we have the One Great Guru of it here… but the oracle is “read a book.”
Great One, may I humbly inquire if you had a particular book in mind?
Your question about discrepancies in the reporting of the recent record temperature at Marambio Base, Antarctica, I must admit, initially provoked the internal question “How the hell would I know who’s wrong?”
Scientists at an Argentine research base measured a temperature of 18.3 degrees Celsius (nearly 65 degrees Fahrenheit) Feb. 6 on a peninsula that juts out from Antarctica toward the southern tip of South America. The previous record there was 17.5 degrees celsius (63.5 degrees Fahrenheit) in March 2015.
The source you linked was a standard-issue automated ‘weather data for everywhere’ webpage. The version I saw is in Fahrenheit, presumably because I’m looking at it from the US, but gave in the “High & Low Weather Summary for the Past Weeks” section a Feb. 6 high of 60F, achieved at 3 PM on that date. 60 F is roughly 15.55 C, close to your given value of 15.
Just below the Summary box, your website says this:
Note: Actual official high and low records may vary slightly from our data, if they occured [sic] in-between our weather recording intervals…
Looking at the box, all the records reported occurred at either 3 AM or 3 PM. So, evidently the “intervals” are 12 hours long. Thus, it’s quite likely that the discrepancy arises because the high of 18.3 C occurred at some other time of day.
(Probably the high occurred later in the afternoon or in early evening, since Marambio, at ~64 S, is actually a sub-Antarctic locale, outside the Antarctic Circle, and does experience nocturnal twilight on Feb. 6, with sunset coming at 9:31 PM. The highest temperatures usually lag solar noon–at Marambio, 1 PM–by several hours, assuming other conditions remain similar.)
So I think that’s the answer to your query. Neither source was “wrong;” they were just not talking about the same time of day.
As to the record itself, note that official extremes take a lot of vetting:
Last week, researchers from Brazil claimed to have measured temperatures of 20.75 degrees Celsius on an island off the peninsula — beating the record for the entire Antarctic region of 19.8 Celsius in January 1982.
Fowler said both of the new measurements would need to be transmitted to Prof. Randall Cerveny, a researcher at Arizona State University who examines reported temperature records for WMO.
Cerveny then shares the data with a wider group of scientists who “will carefully evaluate the available evidence (including comparisons to surrounding stations) and debate the merits and problems of the observation,” said Fowler.
The evaluation normally takes six to nine months, after which Cerveny would “formally either accept or reject the potential extreme,” giving official WMO approval to the new record, he said.
Keith Woollardsays
Curious about people’s thoughts on temperature data being reported as midpoint of min/max. Statistically this is a pretty meaningless number. I understand the history and obviously we need to retain old records, but surely with AWS, moving forward we should be analysing daily mean temperature. This will give a much better correlation to the energy increase within the system. It will also mean surface records will more closely match satellite data.
Is there any other scientific field that relies on mid-range as a measure?
Al Bundysays
Some good news for once. It seems fossils are spewing more methane than previously thought. This reduces the estimate for natural emissions, which indicates that natural systems aren’t in the middle of a methane tipping point.
zebrasays
#110 Keith Woolard,
Interesting point, but it isn’t clear why e.g. hourly averaging over the course of a day is particularly more significant in terms of system energy.
Why not each hour over the course of a year? Why not daily lows and daily highs independently? And so on.
It depends on the question we are trying to answer, and usually in physics we are looking to characterize more variables rather than mush them all together “statistically”. That’s how we discover new phenomena, right?
But I would be interested in hearing your reasoning on the energy question.
zebrasays
#103 Polar Flyer,
It sounds like you would appreciate a post by Gavin a few months ago:
Unfortunately, most of the people making most of the comments here are not motivated by the desire to engage in a scientific discussion/debate/dialogue as suggested in that post.
If you follow along, you will see varying degrees of what I call “column-inch addiction”…this is a place where one can be “published”, for free, without peer review.
For my part, I would like to see more “lurkers” or “visitors” like yourself contributing, but I understand the reluctance when your input is buried under multiple, long, repetitive and unconstructive comments.
We seem to be in agreement about the merits of wind-generated electricity, but please feel free to pick a fight with me on something. (I will win the argument, of course, but be reasonably polite in doing so. ;-) )
AB: Yep. It ain’t like any of us did the math and modelling needed to make a legitimate forecast. We’re all talking through our hats and expressing our feelings. Mrkia is a climate optimist, you’re a middle of the roader, and I tend towards climate pessimism. Regardless of how it turns out the ‘winner’ deserves all the adulation of someone who picked the ‘right’ number to bet on in roulette.
The real measure of capability is being of sound enough mind to know that our pontifications are akin to waving a wooden sword. It’s pathetic when somebody starts believing his weapon is superior to the sharpest steel.
As for climate sensitivity, a 3C sensitivity can be worse than a 4C sensitivity if the planetary system spews more carbon in reaction to a doubling of CO2. If 280 to 560 via our emissions gets the planet to re-double to 1120, that 3C becomes an effective sensitivity of 6C. Nature bats last and it is foolish to assume she’ll strike out.
Susan Andersonsays
News broke yesterday about a report challenging Francis/Vavrus and the wavy jetstream, and since I’m technically challenged I’d like to know if anyone can help evaluate it. https://twitter.com/polar_james/status/1230488969403682816
In the Twitter stream, they specifically say they are challenging Francis/Vavrus. Does the red X mean they acknowledge it is getting wavier – those emojis are not optimal communication vehicles!
Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves
Russell Blackport* and James A. Screen – Science Advances 19 Feb 2020: Vol. 6, no. 8 https://advances.sciencemag.org/content/6/8/eaay2880
Abstract: Whether Arctic amplification has contributed to a wavier circulation and more frequent extreme weather in midlatitudes remains an open question. For two to three decades starting from the mid-1980s, accelerated Arctic warming and a reduced meridional near-surface temperature gradient coincided with a wavier circulation. However, waviness remains largely unchanged in model simulations featuring strong Arctic amplification. Here, we show that the previously reported trend toward a wavier circulation during autumn and winter has reversed in recent years, despite continued Arctic amplification, resulting in negligible multidecadal trends. Models capture the observed correspondence between a reduced temperature gradient and increased waviness on interannual to decadal time scales. However, model experiments in which a reduced temperature gradient is imposed do not feature increased wave amplitude. Our results strongly suggest that the observed and simulated covariability between waviness and temperature gradients on interannual to decadal time scales does not represent a forced response to Arctic amplification.
The most recent publication with Francis I could find was this: Warm Arctic episodes linked with increased frequency of extreme winter weather in the United States – Judah Cohen, Karl Pfeiffer & Jennifer A. Francis – Nature Communications volume 9, Article number: 869 (2018)
Abstract: Recent boreal winters have exhibited a large-scale seesaw temperature pattern characterized by an unusually warm Arctic and cold continents. Whether there is any physical link between Arctic variability and Northern Hemisphere (NH) extreme weather is an active area of research. Using a recently developed index of severe winter weather, we show that the occurrence of severe winter weather in the United States is significantly related to anomalies in pan-Arctic geopotential heights and temperatures. As the Arctic transitions from a relatively cold state to a warmer one, the frequency of severe winter weather in mid-latitudes increases through the transition. However, this relationship is strongest in the eastern US and mixed to even opposite along the western US. We also show that during mid-winter to late-winter of recent decades, when the Arctic warming trend is greatest and extends into the upper troposphere and lower stratosphere, severe winter weather—including both cold spells and heavy snows—became more frequent in the eastern United States.
Interesting query about use of mid-range temps. I’ve had a conversation or maybe 2 with denialati who tried to make it an issue, but without much success IMO.
FWIW, I don’t see it as problematic in terms of extant analyses. (Though that could be an ‘unknown unknown.’) But who knows what might turn up if someone studied high-frequency temperature variability using that’s AWS data you refer to?
As to other applications, my only thought is that this mid-range measure is very closely related to the hoary old statistical ‘median’, even if the calculation is a little different in method.
nigeljsays
Robert @118, regarding “science wanna be-papers” and denialist science in general. I read an article some time ago, cant find it now but the essence of it was a couple of journalists went under cover as fossil fuels people or business lobbyists, something like that, and penetrated the Heartland Institute looking for expert opinions downplaying climate change. They were basically told “tell us what you want the science to say and well get it done, it will cost this much…”.
nigeljsays
Al Bundy @116, agree overall. However I’m a natural born pessimist and doomer, probably way more so than you. One of my favourite novels was the Stand by Steven King. And the world needs clever pessimists to counter the eternal optimists who often inhabit fairy land, the Pollyannas and glass half full characters, who can get a bit irritating.
But too much pessimism (and reliance on intuition) has its obvious downsides. I understand my excessive tendencies towards pessimism (enough people have pointed them out to me), and so I try to keep a level head and look hard at data, and avoid confirmation bias etc. I try to manage my own biases. Hence I often end up towards the centre, but not always.
I’m curious though, KW claims it is commonly used, but I personally have never seen it used. Any citations?
zebrasays
#117 Susan Anderson,
Susan, I got the impression a while back that Francis has backed off a “simplistic” analysis on this issue…and that applies to others as well, I think.
The idea that reducing the temperature gradient will have an easily characterized effect on the Coriolis mechanism ignores the physical complexity of the polar system. Could the jet stream get wavier?…sure. But when you look at all the inputs, like the increased energy of geographically distinct adjacent ocean and atmospheric systems, the causal narrative gets murky.
So, this particular analysis isn’t as big a deal as it may sound. It all depends on how granular your choice of data is; read both things you quoted carefully and you will see that we are nowhere near a resolution of what is going on.
Al Bundysays
BPL: A mean is a meaningless number?
AB: I wouldn’t call the average of two data the mean of all data (and yes, you didn’t do that). 3AM and 3PM (or high/low) seems sparse to me.
He was being hyperbolic but I’m intrigued with his question. That said, stuff smooths. 730 measurements over a year is not just meaningful but solid.
But yeah, I’ll join the whine about wanting hourly data. Which begs the question: how often are measurements made and how automated and consistent across the world are said measurements? I’m curious, not concerned.
Ray Ladburysays
The questions of whether the averaged extrema of temperature approximate a mean and whether it is a more or less meaningful statistic than mean, median or mode is an interesting one. Of course, it depends on how the temperatures are distributed over the course of a day. In some ways, the midpoint between max and min might be a more meaningful measure of climate change than the mean, since we expect greenhouse gasses to limit cooling at night. The mean might not be as sensitive.
It would be interesting to see the range as well (max – min)
John Pollacksays
Susan @117 The new Blackport/Screen paper looks sound to me. I agree with Zebra that this wouldn’t be a big deal, except that the Francis/Vavrus hypothesis has been jumped on and hyped up as the explanation for recent harsh winters in parts of the norther midlatitudes, with the expectation that the trend would continue as polar amplification and sea-ice melt intensify.
Among the important points that the authors make are that overall waviness is not increasing, especially if you use a longer time period than 30 years. This is unsurprising to me, since there were also periods of enhanced waviness in the 1930s and 1970s, which cannot be attributed to either sea ice disappearance or polar amplification.
There are a lot of ways to measure waviness, not all consistent.
Climate model waviness trends are in reasonable agreement with observed long-term trends, and do not show a statistically robust increase (or decrease) in waviness. This is important, because the atmosphere/ocean system has a lot of different ways of arranging energy exchange. Since there are a lot of things happening simultaneously in the real world, modeling can help examine underlying causes.
The picture is quite different when it comes to short term trends of a few years up to around a decade. In shorter periods, there is a fairly clear correlation between increased waviness and warmer arctic and colder midlatitude autumn and winter. However, Blackport/Screen suggest that Francis/Vavrus have their causality reversed. It is the increased waviness, which happens mostly for other reasons, which reduces the polar to midlatitude temperature contrast.
Killiansays
Who knew mainstream economists could come to their senses? Existential risk to humanity, even! And things could get worse than worst IPCC scenarios? 8.5, you’re a piker! LOL…
With a grain of salt in some respects, but also not to be dismissed.
Killian says: No. Take a course, or at least read books on the topic. Not only will I not teach you for free, I certainly *can’t* do it within the confines of this blog.
There are lots of books and related books.
Read one.
Wow. So simplification is the hope of humankind, the essential pathway to salvation, and we have the One Great Guru of it here… but the oracle is “read a book.”
Great One, may I humbly inquire if you had a particular book in mind?
Don’t be a shithead.
You don’t understand the magnitude of what you’re asking for.
You are seriously acting as if you haven’t already been given what you are asking for?
Which brings us back to, you don’t understand what you’re asking for.
Finally, you need to read the book that works for *you*. There are many different books and styles of books. I can guess what might resonate with you, but it’s only a guess. That’s why *you* should google them, read some excerpts, read some reviews, choose.
Why in the world do you need the function of googling explained to you at your age?
If you want ME to inform you, pay me. Or do you do what you do for free? Hmmm?
But what’s really confusing is I have discussed
* any number of principles here, and their applications
* the process I suggest for beginning simplicity wherever you are
* why principles are the key
* why starting from Nature, even to design in a citym is vital
* the myriad non-permaculture concepts and ideas that shape my thinking
and many other things that you want to pretend have not already been given you and everyone else here. You’ve been given *more* than an Intro to Permaculture course and pretend you haven’t… and have certainly not paid me for it.
BPL: If you take two numbers, add them, and divide by two, what you get is a mean. If you take the mid-point between two numbers, it is equivalent to the arithmetic mean. Try some examples and see.
Bob Loblawsays
Re: daily temperature = (max+min)/2
This is indeed a common method, and is endorsed by the Word Meteorological Organization. This is, I think,a portion of an older document, but you can see it in section 4.8.5:
For decades, temperatures were recorded manually with simple max/min thermometers, read once or twice per day. Many volunteer stations still work this way.
In the U.S., the change in timing of the “once per day” standard is the origin of the “time of day correction” in historical records. The effects are well documented. (Of course, to the rabid contrarian, to not make the correction means climatologists are using “bad data”. To make the correction, climatologists are “fudging the data”. Anything to discredit the science.)
At “synoptic” stations, manual readings were recorded more often – usually hourly, but only reported in the international real-time communication systems on a three- or six-hour basis. For consistency with other stations and the historical record, (max+min/2 was often used for daily temperature, though.
With modern automated systems, hourly reporting is common, and met services are moving towards minutely reporting (although dissemination to the entire world in real time is mostly still on an hourly basis).
For the latest set of normals (due for the period 1991-2020), the WMO is leaving it up to national agencies to decide how to calculate daily temperature:
“Deadly “day-night hot extremes” are increasing across the northern hemisphere due to climate change, a new study finds. And the number of people exposed to such events, also known as “compound hot extremes”, is likely to increase “several-fold” as temperatures continue to climb in the coming decades, the study authors tell Carbon Brief…”
Polar Flyersays
#107 nigelj – Thank you for the solidarity on that point.
#113 zebra – Gavin’s post which you referenced was definitely worth re-reading, thank you. I’ll try to come up with something to argue with you :)
Keith Woollardsays
I am really surprised that I need to explain my #110 any further. I would have thought anyone making intelligent regular posts or comments here would understand straight away (Gavin??)
For starters, AWS systems typically measure >= 1s sample rate, and report 60s interval. It would be trivial to start providing daily mean using the 60s data. I have no idea how far back that data is recorded, but moving forward is not issue.
Secondly, (and here comes early high school maths) there are three common “averages”
1) Mean – the most common and what most people think of when you say average. Ideal for “normal-ish” distributions. Also ideal if you wanted to calculate total heat content of a constantly varying system
2) mode – most common – self explanatory but not very useful for us here.
3) median, middle value when you count from each end. Ideal for distributions that have a long variable tail, particularly with a variable sampling. i.e. house prices where once every few months a house is sold that is 20 times the mean.
Then there is a fourth, rarely used, meaningless number – the midpoint of min and max. If we used that, the average rate of pay in the USA would be something like $4,000,000/hr.
The only time that a daily temperature record could be accurately represented by mid-range was if the temperature change was perfectly sinusoidal. Go and have a look at any daily temperature record and see what the shape is. Or look at this one https://photos.app.goo.gl/Ee8N1fEe6n7y48mQ6
In this, the arithmetic mean is 29.65, whilst the mid-range is 31.85
This is one example and I have I don’t care which way it is different, but it is different and that is due to the flawed statistics we have been relying on for many years. Using extrema only can only reduce the signal quality by applying undue emphasis to outlying values.
Mr. Know It Allsays
110 – Keith Wollard
“..I understand the history and obviously we need to retain old records, but surely with AWS, moving forward we should be analysing daily mean temperature. This will give a much better correlation to the energy increase within the system…”
You cannot calculate the energy in air with just temperature. You have to know the humidity as well. For example, the enthalpy of air at 80 F, and 30% RH (0.0066 lb H2O/lb dry air) is ~ 26.4 BTU/lb dry air; but at 80 F and 60% RH (0.0132 lb H2O/lb dry air) is ~ 33.6 BTU/lb dry air. That’s a big difference. {I read those off of a psychrometric chart, but an online enthalpy calculator could give more precise numbers.}
Scientists can say all day that the energy can be calculated based on temperature, but engineers who build things that must meet process requirements specified by paying clients know that is not so. ;)
Also, taking only 2 readings per day could result in significant error – at a particular time of day a reflection of the sun, etc could skew a reading significantly. Thus, you are correct, 2 readings per day IS meaningless.
“You cannot calculate the energy in air with just temperature. You have to know the humidity as well.”
Partially correct – you also have to know the pressure (density). The enthalpy values given in examples above are at standard atmospheric pressure of 29.92 in. Hg., and will change if pressure changes due to, for example, being at higher altitude. ;)
120 – nigelj
“…They were basically told “tell us what you want the science to say and well get it done, it will cost this much…”.”
Works the same on the other side – everyone has their price.
Al Bundysays
Mrkia: everyone has their price.
AB: Bernie doesn’t. I don’t. Lots of others here don’t. Are you saying that you’d do something truly evil for a big personal payday?
nigeljsays
Mr KIA @136, no everyone doesn’t have their price. There are things I simply wont do not for any amount of money.
And what governmnet in their right mind is going to pay a scientist millions of dollars to make up a climate catastrophe? Nobody is going to do this. Governments have enough problems to worry about already, and any money they gain through carbon taxes ends up in renewable energy etc, and is time limited by the nature of the climate problem. It doesn’t really benefit them or increase their power significantly.
And even if governments paid some scientist handsomely to publish a study making outrageously exaggerated claims, it would be shot down in flames so would be a pointless exercise. Even warmists delight in shooting each others studies down.
And you need evidence not innuendo. You have no evidence, the journalists I mentioned got their evidence.
Critical thinking man. Not your strong suit :)
nigeljsays
Killian @128
“You don’t understand the magnitude of what you’re asking for.”
He was asking for a suggestion on a good book on permaculture, not a dissertation on the nature of the universe, or a loan of a million dollars. Jesus wept. I dont know whether to laugh or cry reading your stuff.
zebrasays
#134 Keith Woolard,
“I am really surprised”
I’m not surprised at all… that you still haven’t answered the relevant question.
You said: “This will give a much better correlation to the energy increase within the system.”
Why??? How would this give a “better correlation” with the energy increase in the global climate system?
As I said originally, given that we have have lots of data and lots of computing power, I would expect that we could gain far more information by refining our study… looking at minima alone, for example. Why would we want to destroy information by averaging?
KIA 135: You cannot calculate the energy in air with just temperature.
BPL: You can come damn close, since the mean volume fraction of water vapor in the atmosphere is 0.4%. That means a constant-pressure specific heat capacity of 1,010 J/K/kg instead of 1,004. Big whoop.
Maybe someone can find a 30-year plot for mins and maxes in some locale or region or whatever… not to be all Victor-like, but a visualization might be nice. However, here we can see that both min and max have increased.
So, if we are looking at climate, there’s no particular reason even to find the mean of those two values, much less some arbitrary data-interval-averaging…hour, half-hour, minutes, seconds…what would be the point? We see that there is regional variation, as expected, and energy is increasing, as expected.
A classic case of failure to agree on what the question is…what physics are we trying to quantify/evaluate… before disagreeing about the statistical methodology.
Al Bundysays
BPL: If you take two numbers, add them, and divide by two, what you get is a mean.
AB: Please don’t channel a doofus. As anyone with a brain would know he was talking about way more than two data. Our group’s discussion has naturally accepted hourly as the key.
Seriously, you didn’t just suffer a stroke, right? So I can only conclude that you’re being a shit head.
Guest (O.)says
This is, how (animated) graphics on scenarios can look like, and I enjoyed playing with it:
Prof. Jason Box
@climate_ice
Sutton, R. (2019) Climate science needs to take risk assessment much more seriously. Bulletin of the American Meteorological Society, 100 (9). pp. 1637-1642. ISSN 0003-0007 doi: https://doi.org/10.1175/BAMS-D
In climate risk assessment, don’t think about likelihood, think about impact. #IPCC has made too much emphasis on likelihood and too little on impact. – R.T. Sutton
This is *exactly* the point I have been making. And it has to be tied to extremes, the events that destroy/alter/trip tipping points, not averages and trends. Those give us directionality, extremes give us the risk boundaries.
This is a point I have been pounding on, and pounding climate scientists about, for YEARS. I have begged and pleaded for them to shift to a long-tail risk framing of the Climate Crisis to absolutely no avail.
About. Goddamned. Time.
Seriously, if I keep getting there before you do, maybe you (collectively) should… freaking…. listen… to… thinking… that…. is…. outside… *your*… collective… box.
We are now well into the period when the maxiumum daily Arctic Sea Ice Extent can appear for the year (or more correct “has appeared in past years”) – 21 Feb to 31 Mar.
This year, 2020 is so far struggling to stay within the Top Ten ‘least icy maximum SIE’. That is, in NSIDC it sits 10th ‘least icy’ at 15.00 M sq km. In JAXA (which has SIE which is slightly less smoothed) it is still sitting in 8th having not managed to top 2019 or 2005. With this exception the Top Ten ‘least icy maximum SIE’ are in identical order, with 2014 sitting currently in 11th in both. (In JAXA, 2020 woud need to find an extra 0.222 M sq km to drop to 11th ‘least icy’. In NSIDC it would need another increase to just 0.007 M sq km above the max seen a couple of days back.)
The NSIDC version of ‘least icy maximum SIE’ run as follows:-
1st … … 2017 … … 14.45 M sq km
2nd … … 2018 … … 14.50 M sq km
3rd … … 2015 … … 14.55 M sq km
4th … … 2016 … … 14.57 M sq km
5th … … 2011 … … 14.70 M sq km
6th … … 2006 … … 14.78 M sq km
7th … … 2007 … … 14.84 M sq km
8th … … 2019 … … 14.88 M sq km
9th … … 2005 … … 14.99 M sq km
10th … … 2020 … … 15.00 M sq km
11th … … 2014 … … 15.01 M sq km
12th … … 2009 … … 15.20 M sq km
Dan H.says
zebra@142,
Your link does not quite say that. It implicitly states that mins have increased since the early 1900s, while the maxes have increased since the mid 1960s. Assuming that heat waves and cold waves can be correlated with max and mins.
nigeljsays
AB @146 Mrkia: Scientists can say all day that the energy can be calculated based on temperature, but engineer…..AB: don’t understand that on a global level relative humidity is essentially a constant?
Remember climate change is causing absolute humidity to increase, although not enough to have much effect on the changing energy content of the atmosphere. Humidity is just too small a number.
Killian, #90–
Correct! That is exactly the kind of question I am asking. I have no reluctance in “accepting” your points #1 & #2. But having “accepted” them, what do I have? Damn little.
Let’s turn it around for a moment, and pretend you asked me about guitar-making. I could say that 1) every guitar design is different, because it attempts to meet specific needs either of an individual player or of an anticipated class of players, and 2) guitar design must follow a set of specific principles (which I would list, but won’t here for brevity), mostly to do with the physics of vibrating bodies.
And you “accept” that. But you still don’t even know–from my explanation at least–that most guitars are primarily made of wood. You don’t know what I mean by “the physics of vibrating bodies,” at least not in any specific way. And you have no idea what sorts of operations, materials, or skills are needed. In short, you don’t have a clue how to tell a luthier from a Lothario. (Not that those are necessarily exclusive classes…!)
That’s pretty much how I’ve felt after receiving one of your standard issue responses.
So, what could you do differently?
You could, to propose 5 (non-exhaustive) strategies:
1) Cite examples. (You actually do this sometimes, but usually separately from the exchanges I’ve been talking about.) I get that solutions will be site-specific, but that idea is much ‘richer’ cognitively if I have learned about a few different instances, and had the chance to compare and contrast what people have done. So, who’s exemplifying sustainability/simplification/renewable ag today in the Middle East? North America? Southern Europe? East Asia? What are the commonalities, and what are the local adaptations?
For instance, here’s a place I’m interested in:
https://www.themountainrlc.org/many-hands-peace-farm
2) Explore the principles in practice. This is basically using examples, too, but is carried forward in a more specific, focused way. Returning to the guitar example, I could tell you about the principle that guitars primarily use string length to control pitch: the shorter the string, the higher the pitch. I could tell you that guitars “quantize” pitch by the use of wire “frets” placed transversely across the neck–a linked picture would be good here–and that the ear’s sensitivity to small variations in pitch implies that a very high standard of accuracy is needed in the correct placing of fretwires, if one is to build a guitar that will play acceptably in tune.
(Et cetera, as desired. But now you know about one specific principle, and about what it implies operationally for a guitar maker.)
3) Personalize. Who are notable people involved in the space? Even data nerds care about people, and remember notable ones, which in turn helps them remember, understand, and contextualize the ideas or practices associated with those people.
Say, just for example, Linda Manzer:
https://manzer.com/news/
4) Give bibiliography! Where can I access more information? (I have a whole file of stuff Scott Strough has linked on regenerative ag, for example. There could be another one for your info.)
5) Teach the controversy–whatever it is. (I don’t know what it is, but there’s got to be one.) What are people struggling to figure out in this space? What are they saying, and where can I tap into that conversation? (C.f., points #3 & #4.)
You want us to accept simplification as the necessary solution to the climate crisis. It’s not too much to ask, IMO, that you take the trouble to teach a bit. If you really think simplification is that important, why not take that trouble, eh? Students are asking… can you step up and meet us where we are, and not just insult us for not being where you think we should be?
#86, Robert–
You’re right that these papers are scientifically negligible. That’s why, for instance, the Stallinga paper you mention was published in an open access journal, probably without any real review process. But here are some comments on points in the abstract:
By whom? There’s no citation, which there should be, even in an abstract. And in fact this bald statement flies in the face of a massive body of literature, which should have been addressed as well. Shoddy scholarship.
Ah, a model has been constructed! The devil is always in the details, of course, which aren’t given in the abstract. But again, this particular model is set against a great many other incompatible models which have proven to have considerable predictive value.
So, let’s plug in “a couple of mK per ppm CO2.” (Note that he’s apparently modeling climate response to CO2 as linear, whereas everybody else says it’s a log function, but let that go. Maybe he’s limiting the range involved and approximating.)
Anyway, CO2 concentrations have risen from 280 ppm to 410, which would be a rise of 130 ppm. If we take “a couple” to mean “two,” then the upper range of expected temperature rise per this paper would be 0.26 C since pre-Industrial. Because of the log aspect, expected temperature responses are usually defined in terms of doublings. So, should CO2 double, that would obviously be a rise of 280 ppm, and the expected temperature response (per Stallinga) would then be 0.56. How does that compare with orthodox expectations?
So, Stallinga purports to reduce expected warming by a factor of somewhere between 44% and 100%. Not an impressive constraint, even if you take everything at face value. (It’s not clear to me from the abstract whether Stallinga’s approach would fold in feedbacks to date or not. And why “upper limits”, plural?)
Epic fail! Here Stallinga tries to account for the correlation between warming and CO2 by reversing causation: it’s not (he says) that CO2 warms, it’s that warming releases CO2 from the ocean. There’s truth in that latter assertion, of course: that’s thought to be a major piece of the cycles of glaciation and deglaciation seen throughout the span of the Quaternary period.
But the problem is that we know from isotopic studies, accounting studies of the carbon cycle, and from the observed loss of atmospheric oxygen that the source of the increased carbon in the atmosphere is not the oceans, it’s primarily the combustion of fossil fuels. Had Stallinga read the literature adequately, he would have known that. (And maybe he did, but chose to ignore the issue?)
Dude needs an editor; if you say “finally” it really should be your final point–but he goes on to add a “moreover” and then yet another “finally.” But I digress…
Again, Stallinga should review the literature. James Hansen cut his astrophysical teeth studying planetary atmospheres, particularly Venus and Mars.
Could that be because circulatory changes in the atmosphere matter, too? Wow, revolutionary thought! Frankly, I’m amazed that Stallinga or anyone else would write something quite that dumb.
Here’s a map of the world 650 million years ago:
https://i.pinimg.com/736x/40/09/c4/4009c4c4d2c87cf1c7d670b8a5370815.jpg
Gee, you think that circulation and albedo might have been a tad different?
As to “markedly different” behavior between the timescales of 60 years and 600,000 years, well, it’s really too vague to know what he means here. But given that climate is normed out over 30 year spans, it’s quite evident that you wouldn’t expect the same variability over just 60 that you would over 600,000! (And in fact, there’s quite a number of glaciations and deglaciations that have happened over the last 600 millennia.) That said, the correlation between CO2 and global temperature *does* appear to hold in a broadly similar way over both time spans.
Moderators, Regarding post #87 by “Killian,” I am really saddened to see that it met your standards. I made a serious and deeply skeptical, but polite and earnest, attempt to engage with “Killian” to better understand his position. In return he has done nothing but overtly insult me. That sort of experience doesn’t really help me find the sort of quality intellectual discussion I have come to hope for at RealClimate. I’m going to exercise my prerogative to ignore his future posts because he has clearly disengaged from civility, and I urge you to hold him (and the rest of us) to a higher standard. Thanks.
Re #101 Kevin McKinney said Killina, please teach me permacuture for free.
Killian says: No. Take a course, or at least read books on the topic. Not only will I not teach you for free, I certainly *can’t* do it within the confines of this blog.
There are lots of books and related books.
Read one. Or, if you’re serious about solutions, I’ll do a deeply discounted course with you online – but not here.
Re #103 Polar Flyer said I made a serious and ****deeply skeptical,**** but polite and earnest
Deeply skeptical but earnest? Laughable.
You were ddeply insulting and got zero insults in return. Your thin skin and lack of language skills is your problem.
attempt to engage with “Killian” to better understand his position.
Again, deeply skeptical. Save it for fools who believe such B.S.
overtly insult me.
There were zero insults in that post. This is also not one: You intellectual accuity is quite low if you believe you were insulted in the first response. That’s an analysis based on the fact you conflate terse or even coarse with insults.
That sort of experience doesn’t really help me find the sort of quality intellectual discussion I have come to hope for at RealClimate.
Then don’t insult the people you are asking favors of.
I’m going to exercise my prerogative to ignore his future posts because he has clearly disengaged from civility, and I urge you to hold him (and the rest of us) to a higher standard. Thanks.
If they did, both of your posts would have been boreholed.
Al Bundy @94, I’m a bit more conservative on the climate sensitivity issue. I predicted at least 15 years ago that climate sensitivity would turn out to be medium, but that this level of warming would cause greater changes to the biosphere and cryosphere than anticipated including about 2 metres of sea level rise per century very possible worst case. Didn’t post it on this website. Just an educated guess based on a whole lot of things adding together.
The evidence is still on my side. The modelling finding high climate senstivity is still well in the minority of studies, according to something sid posted a while back. Although the fact that its at least possible is enough reason to strongly mitigate the problem.
Polar Flyer “Moderators, Regarding post #87 by “Killian,” I am really saddened to see that it met your standards. ”
I agree. His rhetoric, tone and ideas are way below acceptable standard.
Killian, #104–
Wow. So simplification is the hope of humankind, the essential pathway to salvation, and we have the One Great Guru of it here… but the oracle is “read a book.”
Great One, may I humbly inquire if you had a particular book in mind?
Martin Smith, #99–
Your question about discrepancies in the reporting of the recent record temperature at Marambio Base, Antarctica, I must admit, initially provoked the internal question “How the hell would I know who’s wrong?”
But then curiosity kicked in.
Per AP:
The source you linked was a standard-issue automated ‘weather data for everywhere’ webpage. The version I saw is in Fahrenheit, presumably because I’m looking at it from the US, but gave in the “High & Low Weather Summary for the Past Weeks” section a Feb. 6 high of 60F, achieved at 3 PM on that date. 60 F is roughly 15.55 C, close to your given value of 15.
Just below the Summary box, your website says this:
Looking at the box, all the records reported occurred at either 3 AM or 3 PM. So, evidently the “intervals” are 12 hours long. Thus, it’s quite likely that the discrepancy arises because the high of 18.3 C occurred at some other time of day.
(Probably the high occurred later in the afternoon or in early evening, since Marambio, at ~64 S, is actually a sub-Antarctic locale, outside the Antarctic Circle, and does experience nocturnal twilight on Feb. 6, with sunset coming at 9:31 PM. The highest temperatures usually lag solar noon–at Marambio, 1 PM–by several hours, assuming other conditions remain similar.)
So I think that’s the answer to your query. Neither source was “wrong;” they were just not talking about the same time of day.
As to the record itself, note that official extremes take a lot of vetting:
Curious about people’s thoughts on temperature data being reported as midpoint of min/max. Statistically this is a pretty meaningless number. I understand the history and obviously we need to retain old records, but surely with AWS, moving forward we should be analysing daily mean temperature. This will give a much better correlation to the energy increase within the system. It will also mean surface records will more closely match satellite data.
Is there any other scientific field that relies on mid-range as a measure?
Some good news for once. It seems fossils are spewing more methane than previously thought. This reduces the estimate for natural emissions, which indicates that natural systems aren’t in the middle of a methane tipping point.
#110 Keith Woolard,
Interesting point, but it isn’t clear why e.g. hourly averaging over the course of a day is particularly more significant in terms of system energy.
Why not each hour over the course of a year? Why not daily lows and daily highs independently? And so on.
It depends on the question we are trying to answer, and usually in physics we are looking to characterize more variables rather than mush them all together “statistically”. That’s how we discover new phenomena, right?
But I would be interested in hearing your reasoning on the energy question.
#103 Polar Flyer,
It sounds like you would appreciate a post by Gavin a few months ago:
https://www.realclimate.org/index.php/archives/2019/08/just-the-facts/
Unfortunately, most of the people making most of the comments here are not motivated by the desire to engage in a scientific discussion/debate/dialogue as suggested in that post.
If you follow along, you will see varying degrees of what I call “column-inch addiction”…this is a place where one can be “published”, for free, without peer review.
For my part, I would like to see more “lurkers” or “visitors” like yourself contributing, but I understand the reluctance when your input is buried under multiple, long, repetitive and unconstructive comments.
We seem to be in agreement about the merits of wind-generated electricity, but please feel free to pick a fight with me on something. (I will win the argument, of course, but be reasonably polite in doing so. ;-) )
KW 110: Curious about people’s thoughts on temperature data being reported as midpoint of min/max. Statistically this is a pretty meaningless number.
BPL: A mean is a meaningless number? Are you sure you’re clear on what “meaningless” means?
High CO2 favors growth of toxic cyanobacteria over algae and diatoms.
https://phys.org/news/2020-02-cyanobacteria-problems-worsen-carbon.html
Nigelj: I predicted…just an educated guess…
AB: Yep. It ain’t like any of us did the math and modelling needed to make a legitimate forecast. We’re all talking through our hats and expressing our feelings. Mrkia is a climate optimist, you’re a middle of the roader, and I tend towards climate pessimism. Regardless of how it turns out the ‘winner’ deserves all the adulation of someone who picked the ‘right’ number to bet on in roulette.
The real measure of capability is being of sound enough mind to know that our pontifications are akin to waving a wooden sword. It’s pathetic when somebody starts believing his weapon is superior to the sharpest steel.
As for climate sensitivity, a 3C sensitivity can be worse than a 4C sensitivity if the planetary system spews more carbon in reaction to a doubling of CO2. If 280 to 560 via our emissions gets the planet to re-double to 1120, that 3C becomes an effective sensitivity of 6C. Nature bats last and it is foolish to assume she’ll strike out.
News broke yesterday about a report challenging Francis/Vavrus and the wavy jetstream, and since I’m technically challenged I’d like to know if anyone can help evaluate it.
https://twitter.com/polar_james/status/1230488969403682816
In the Twitter stream, they specifically say they are challenging Francis/Vavrus. Does the red X mean they acknowledge it is getting wavier – those emojis are not optimal communication vehicles!
Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves
Russell Blackport* and James A. Screen – Science Advances 19 Feb 2020: Vol. 6, no. 8
https://advances.sciencemag.org/content/6/8/eaay2880
Abstract: Whether Arctic amplification has contributed to a wavier circulation and more frequent extreme weather in midlatitudes remains an open question. For two to three decades starting from the mid-1980s, accelerated Arctic warming and a reduced meridional near-surface temperature gradient coincided with a wavier circulation. However, waviness remains largely unchanged in model simulations featuring strong Arctic amplification. Here, we show that the previously reported trend toward a wavier circulation during autumn and winter has reversed in recent years, despite continued Arctic amplification, resulting in negligible multidecadal trends. Models capture the observed correspondence between a reduced temperature gradient and increased waviness on interannual to decadal time scales. However, model experiments in which a reduced temperature gradient is imposed do not feature increased wave amplitude. Our results strongly suggest that the observed and simulated covariability between waviness and temperature gradients on interannual to decadal time scales does not represent a forced response to Arctic amplification.
The most recent publication with Francis I could find was this:
Warm Arctic episodes linked with increased frequency of extreme winter weather in the United States – Judah Cohen, Karl Pfeiffer & Jennifer A. Francis – Nature Communications volume 9, Article number: 869 (2018)
Abstract: Recent boreal winters have exhibited a large-scale seesaw temperature pattern characterized by an unusually warm Arctic and cold continents. Whether there is any physical link between Arctic variability and Northern Hemisphere (NH) extreme weather is an active area of research. Using a recently developed index of severe winter weather, we show that the occurrence of severe winter weather in the United States is significantly related to anomalies in pan-Arctic geopotential heights and temperatures. As the Arctic transitions from a relatively cold state to a warmer one, the frequency of severe winter weather in mid-latitudes increases through the transition. However, this relationship is strongest in the eastern US and mixed to even opposite along the western US. We also show that during mid-winter to late-winter of recent decades, when the Arctic warming trend is greatest and extends into the upper troposphere and lower stratosphere, severe winter weather—including both cold spells and heavy snows—became more frequent in the eastern United States.
# 100, MA Rodger
# 102, Kevin McKinney //
Many thanks for your informative reviews.
Valuable confirmative support in various discussions when these “science wanna be-papers” pops up.
KW, #110–
Interesting query about use of mid-range temps. I’ve had a conversation or maybe 2 with denialati who tried to make it an issue, but without much success IMO.
FWIW, I don’t see it as problematic in terms of extant analyses. (Though that could be an ‘unknown unknown.’) But who knows what might turn up if someone studied high-frequency temperature variability using that’s AWS data you refer to?
As to other applications, my only thought is that this mid-range measure is very closely related to the hoary old statistical ‘median’, even if the calculation is a little different in method.
Robert @118, regarding “science wanna be-papers” and denialist science in general. I read an article some time ago, cant find it now but the essence of it was a couple of journalists went under cover as fossil fuels people or business lobbyists, something like that, and penetrated the Heartland Institute looking for expert opinions downplaying climate change. They were basically told “tell us what you want the science to say and well get it done, it will cost this much…”.
Al Bundy @116, agree overall. However I’m a natural born pessimist and doomer, probably way more so than you. One of my favourite novels was the Stand by Steven King. And the world needs clever pessimists to counter the eternal optimists who often inhabit fairy land, the Pollyannas and glass half full characters, who can get a bit irritating.
But too much pessimism (and reliance on intuition) has its obvious downsides. I understand my excessive tendencies towards pessimism (enough people have pointed them out to me), and so I try to keep a level head and look hard at data, and avoid confirmation bias etc. I try to manage my own biases. Hence I often end up towards the centre, but not always.
KW at 110, BPL at 114:
For a discussion of the mid-range as an estimator, see https://en.wikipedia.org/wiki/Mid-range. It’s definitely not a mean. And sometimes it is useful.
I’m curious though, KW claims it is commonly used, but I personally have never seen it used. Any citations?
#117 Susan Anderson,
Susan, I got the impression a while back that Francis has backed off a “simplistic” analysis on this issue…and that applies to others as well, I think.
The idea that reducing the temperature gradient will have an easily characterized effect on the Coriolis mechanism ignores the physical complexity of the polar system. Could the jet stream get wavier?…sure. But when you look at all the inputs, like the increased energy of geographically distinct adjacent ocean and atmospheric systems, the causal narrative gets murky.
So, this particular analysis isn’t as big a deal as it may sound. It all depends on how granular your choice of data is; read both things you quoted carefully and you will see that we are nowhere near a resolution of what is going on.
BPL: A mean is a meaningless number?
AB: I wouldn’t call the average of two data the mean of all data (and yes, you didn’t do that). 3AM and 3PM (or high/low) seems sparse to me.
He was being hyperbolic but I’m intrigued with his question. That said, stuff smooths. 730 measurements over a year is not just meaningful but solid.
But yeah, I’ll join the whine about wanting hourly data. Which begs the question: how often are measurements made and how automated and consistent across the world are said measurements? I’m curious, not concerned.
The questions of whether the averaged extrema of temperature approximate a mean and whether it is a more or less meaningful statistic than mean, median or mode is an interesting one. Of course, it depends on how the temperatures are distributed over the course of a day. In some ways, the midpoint between max and min might be a more meaningful measure of climate change than the mean, since we expect greenhouse gasses to limit cooling at night. The mean might not be as sensitive.
It would be interesting to see the range as well (max – min)
Susan @117 The new Blackport/Screen paper looks sound to me. I agree with Zebra that this wouldn’t be a big deal, except that the Francis/Vavrus hypothesis has been jumped on and hyped up as the explanation for recent harsh winters in parts of the norther midlatitudes, with the expectation that the trend would continue as polar amplification and sea-ice melt intensify.
Among the important points that the authors make are that overall waviness is not increasing, especially if you use a longer time period than 30 years. This is unsurprising to me, since there were also periods of enhanced waviness in the 1930s and 1970s, which cannot be attributed to either sea ice disappearance or polar amplification.
There are a lot of ways to measure waviness, not all consistent.
Climate model waviness trends are in reasonable agreement with observed long-term trends, and do not show a statistically robust increase (or decrease) in waviness. This is important, because the atmosphere/ocean system has a lot of different ways of arranging energy exchange. Since there are a lot of things happening simultaneously in the real world, modeling can help examine underlying causes.
The picture is quite different when it comes to short term trends of a few years up to around a decade. In shorter periods, there is a fairly clear correlation between increased waviness and warmer arctic and colder midlatitude autumn and winter. However, Blackport/Screen suggest that Francis/Vavrus have their causality reversed. It is the increased waviness, which happens mostly for other reasons, which reduces the polar to midlatitude temperature contrast.
Who knew mainstream economists could come to their senses? Existential risk to humanity, even! And things could get worse than worst IPCC scenarios? 8.5, you’re a piker! LOL…
With a grain of salt in some respects, but also not to be dismissed.
https://www.theguardian.com/environment/2020/feb/21/jp-morgan-economists-warn-climate-crisis-threat-human-race?CMP=Share_iOSApp_Other
Re #108 Kevin McKinney said Killian, #104–
Killian says: No. Take a course, or at least read books on the topic. Not only will I not teach you for free, I certainly *can’t* do it within the confines of this blog.
There are lots of books and related books.
Read one.
Wow. So simplification is the hope of humankind, the essential pathway to salvation, and we have the One Great Guru of it here… but the oracle is “read a book.”
Great One, may I humbly inquire if you had a particular book in mind?
Don’t be a shithead.
You don’t understand the magnitude of what you’re asking for.
You are seriously acting as if you haven’t already been given what you are asking for?
Which brings us back to, you don’t understand what you’re asking for.
Finally, you need to read the book that works for *you*. There are many different books and styles of books. I can guess what might resonate with you, but it’s only a guess. That’s why *you* should google them, read some excerpts, read some reviews, choose.
Why in the world do you need the function of googling explained to you at your age?
If you want ME to inform you, pay me. Or do you do what you do for free? Hmmm?
But what’s really confusing is I have discussed
* any number of principles here, and their applications
* the process I suggest for beginning simplicity wherever you are
* why principles are the key
* why starting from Nature, even to design in a citym is vital
* the myriad non-permaculture concepts and ideas that shape my thinking
and many other things that you want to pretend have not already been given you and everyone else here. You’ve been given *more* than an Intro to Permaculture course and pretend you haven’t… and have certainly not paid me for it.
Sometimes you’re as maddening as the anklebiters.
Natural methane emissions roughly 1/10 as much as previously estimated; implications for impact of human efforts to reduce anthropogenic emissions.
https://phys.org/news/2020-02-methane-emitted-humans-vastly-underestimated.html
jb 122: It’s definitely not a mean.
BPL: If you take two numbers, add them, and divide by two, what you get is a mean. If you take the mid-point between two numbers, it is equivalent to the arithmetic mean. Try some examples and see.
Re: daily temperature = (max+min)/2
This is indeed a common method, and is endorsed by the Word Meteorological Organization. This is, I think,a portion of an older document, but you can see it in section 4.8.5:
http://www.wmo.int/pages/prog/wcp/ccl/guide/documents/Normals-Guide-to-Climate-190116_en.pdf
For decades, temperatures were recorded manually with simple max/min thermometers, read once or twice per day. Many volunteer stations still work this way.
In the U.S., the change in timing of the “once per day” standard is the origin of the “time of day correction” in historical records. The effects are well documented. (Of course, to the rabid contrarian, to not make the correction means climatologists are using “bad data”. To make the correction, climatologists are “fudging the data”. Anything to discredit the science.)
At “synoptic” stations, manual readings were recorded more often – usually hourly, but only reported in the international real-time communication systems on a three- or six-hour basis. For consistency with other stations and the historical record, (max+min/2 was often used for daily temperature, though.
With modern automated systems, hourly reporting is common, and met services are moving towards minutely reporting (although dissemination to the entire world in real time is mostly still on an hourly basis).
For the latest set of normals (due for the period 1991-2020), the WMO is leaving it up to national agencies to decide how to calculate daily temperature:
https://library.wmo.int/doc_num.php?explnum_id=4166
https://www.carbonbrief.org/climate-change-driving-surge-in-day-night-hot-extremes-in-northern-hemisphere
“Deadly “day-night hot extremes” are increasing across the northern hemisphere due to climate change, a new study finds. And the number of people exposed to such events, also known as “compound hot extremes”, is likely to increase “several-fold” as temperatures continue to climb in the coming decades, the study authors tell Carbon Brief…”
#107 nigelj – Thank you for the solidarity on that point.
#113 zebra – Gavin’s post which you referenced was definitely worth re-reading, thank you. I’ll try to come up with something to argue with you :)
I am really surprised that I need to explain my #110 any further. I would have thought anyone making intelligent regular posts or comments here would understand straight away (Gavin??)
For starters, AWS systems typically measure >= 1s sample rate, and report 60s interval. It would be trivial to start providing daily mean using the 60s data. I have no idea how far back that data is recorded, but moving forward is not issue.
Secondly, (and here comes early high school maths) there are three common “averages”
1) Mean – the most common and what most people think of when you say average. Ideal for “normal-ish” distributions. Also ideal if you wanted to calculate total heat content of a constantly varying system
2) mode – most common – self explanatory but not very useful for us here.
3) median, middle value when you count from each end. Ideal for distributions that have a long variable tail, particularly with a variable sampling. i.e. house prices where once every few months a house is sold that is 20 times the mean.
Then there is a fourth, rarely used, meaningless number – the midpoint of min and max. If we used that, the average rate of pay in the USA would be something like $4,000,000/hr.
The only time that a daily temperature record could be accurately represented by mid-range was if the temperature change was perfectly sinusoidal. Go and have a look at any daily temperature record and see what the shape is. Or look at this one
https://photos.app.goo.gl/Ee8N1fEe6n7y48mQ6
In this, the arithmetic mean is 29.65, whilst the mid-range is 31.85
This is one example and I have I don’t care which way it is different, but it is different and that is due to the flawed statistics we have been relying on for many years. Using extrema only can only reduce the signal quality by applying undue emphasis to outlying values.
110 – Keith Wollard
“..I understand the history and obviously we need to retain old records, but surely with AWS, moving forward we should be analysing daily mean temperature. This will give a much better correlation to the energy increase within the system…”
You cannot calculate the energy in air with just temperature. You have to know the humidity as well. For example, the enthalpy of air at 80 F, and 30% RH (0.0066 lb H2O/lb dry air) is ~ 26.4 BTU/lb dry air; but at 80 F and 60% RH (0.0132 lb H2O/lb dry air) is ~ 33.6 BTU/lb dry air. That’s a big difference. {I read those off of a psychrometric chart, but an online enthalpy calculator could give more precise numbers.}
Scientists can say all day that the energy can be calculated based on temperature, but engineers who build things that must meet process requirements specified by paying clients know that is not so. ;)
Also, taking only 2 readings per day could result in significant error – at a particular time of day a reflection of the sun, etc could skew a reading significantly. Thus, you are correct, 2 readings per day IS meaningless.
The ice machine is working as designed:
https://www.wunderground.com/forecast/ca/resolute?cm_ven=localwx_10day
MKIA above:
“You cannot calculate the energy in air with just temperature. You have to know the humidity as well.”
Partially correct – you also have to know the pressure (density). The enthalpy values given in examples above are at standard atmospheric pressure of 29.92 in. Hg., and will change if pressure changes due to, for example, being at higher altitude. ;)
120 – nigelj
“…They were basically told “tell us what you want the science to say and well get it done, it will cost this much…”.”
Works the same on the other side – everyone has their price.
Mrkia: everyone has their price.
AB: Bernie doesn’t. I don’t. Lots of others here don’t. Are you saying that you’d do something truly evil for a big personal payday?
Mr KIA @136, no everyone doesn’t have their price. There are things I simply wont do not for any amount of money.
And what governmnet in their right mind is going to pay a scientist millions of dollars to make up a climate catastrophe? Nobody is going to do this. Governments have enough problems to worry about already, and any money they gain through carbon taxes ends up in renewable energy etc, and is time limited by the nature of the climate problem. It doesn’t really benefit them or increase their power significantly.
And even if governments paid some scientist handsomely to publish a study making outrageously exaggerated claims, it would be shot down in flames so would be a pointless exercise. Even warmists delight in shooting each others studies down.
And you need evidence not innuendo. You have no evidence, the journalists I mentioned got their evidence.
Critical thinking man. Not your strong suit :)
Killian @128
“You don’t understand the magnitude of what you’re asking for.”
He was asking for a suggestion on a good book on permaculture, not a dissertation on the nature of the universe, or a loan of a million dollars. Jesus wept. I dont know whether to laugh or cry reading your stuff.
#134 Keith Woolard,
“I am really surprised”
I’m not surprised at all… that you still haven’t answered the relevant question.
You said: “This will give a much better correlation to the energy increase within the system.”
Why??? How would this give a “better correlation” with the energy increase in the global climate system?
As I said originally, given that we have have lots of data and lots of computing power, I would expect that we could gain far more information by refining our study… looking at minima alone, for example. Why would we want to destroy information by averaging?
KIA 135: You cannot calculate the energy in air with just temperature.
BPL: You can come damn close, since the mean volume fraction of water vapor in the atmosphere is 0.4%. That means a constant-pressure specific heat capacity of 1,010 J/K/kg instead of 1,004. Big whoop.
More on Max and Min,
A quick search came up with this:
https://science2017.globalchange.gov/chapter/6/
(table 6.1)
Maybe someone can find a 30-year plot for mins and maxes in some locale or region or whatever… not to be all Victor-like, but a visualization might be nice. However, here we can see that both min and max have increased.
So, if we are looking at climate, there’s no particular reason even to find the mean of those two values, much less some arbitrary data-interval-averaging…hour, half-hour, minutes, seconds…what would be the point? We see that there is regional variation, as expected, and energy is increasing, as expected.
A classic case of failure to agree on what the question is…what physics are we trying to quantify/evaluate… before disagreeing about the statistical methodology.
BPL: If you take two numbers, add them, and divide by two, what you get is a mean.
AB: Please don’t channel a doofus. As anyone with a brain would know he was talking about way more than two data. Our group’s discussion has naturally accepted hourly as the key.
Seriously, you didn’t just suffer a stroke, right? So I can only conclude that you’re being a shit head.
This is, how (animated) graphics on scenarios can look like, and I enjoyed playing with it:
Intended Nationally Determined Contributions (INDCs) & Scenarios
https://www.pik-potsdam.de/paris-reality-check/indcs-scenarios/
IMHO this is well done :-)
Also look at the scenario explorer!
https://www.pik-potsdam.de/paris-reality-check/ar5-scenario-explorer/
Mrkia: Scientists can say all day that the energy can be calculated based on temperature, but engineers
AB: don’t understand that on a global level relative humidity is essentially a constant?
Tweet:https://twitter.com/climate_ice/status/1232244513642614786
Prof. Jason Box
@climate_ice
Sutton, R. (2019) Climate science needs to take risk assessment much more seriously. Bulletin of the American Meteorological Society, 100 (9). pp. 1637-1642. ISSN 0003-0007 doi: https://doi.org/10.1175/BAMS-D
Paper: https://journals.ametsoc.org/doi/10.1175/BAMS-D-18-0280.1
This is *exactly* the point I have been making. And it has to be tied to extremes, the events that destroy/alter/trip tipping points, not averages and trends. Those give us directionality, extremes give us the risk boundaries.
This is a point I have been pounding on, and pounding climate scientists about, for YEARS. I have begged and pleaded for them to shift to a long-tail risk framing of the Climate Crisis to absolutely no avail.
About. Goddamned. Time.
Seriously, if I keep getting there before you do, maybe you (collectively) should… freaking…. listen… to… thinking… that…. is…. outside… *your*… collective… box.
We are now well into the period when the maxiumum daily Arctic Sea Ice Extent can appear for the year (or more correct “has appeared in past years”) – 21 Feb to 31 Mar.
This year, 2020 is so far struggling to stay within the Top Ten ‘least icy maximum SIE’. That is, in NSIDC it sits 10th ‘least icy’ at 15.00 M sq km. In JAXA (which has SIE which is slightly less smoothed) it is still sitting in 8th having not managed to top 2019 or 2005. With this exception the Top Ten ‘least icy maximum SIE’ are in identical order, with 2014 sitting currently in 11th in both. (In JAXA, 2020 woud need to find an extra 0.222 M sq km to drop to 11th ‘least icy’. In NSIDC it would need another increase to just 0.007 M sq km above the max seen a couple of days back.)
The NSIDC version of ‘least icy maximum SIE’ run as follows:-
1st … … 2017 … … 14.45 M sq km
2nd … … 2018 … … 14.50 M sq km
3rd … … 2015 … … 14.55 M sq km
4th … … 2016 … … 14.57 M sq km
5th … … 2011 … … 14.70 M sq km
6th … … 2006 … … 14.78 M sq km
7th … … 2007 … … 14.84 M sq km
8th … … 2019 … … 14.88 M sq km
9th … … 2005 … … 14.99 M sq km
10th … … 2020 … … 15.00 M sq km
11th … … 2014 … … 15.01 M sq km
12th … … 2009 … … 15.20 M sq km
zebra@142,
Your link does not quite say that. It implicitly states that mins have increased since the early 1900s, while the maxes have increased since the mid 1960s. Assuming that heat waves and cold waves can be correlated with max and mins.
AB @146 Mrkia: Scientists can say all day that the energy can be calculated based on temperature, but engineer…..AB: don’t understand that on a global level relative humidity is essentially a constant?
Remember climate change is causing absolute humidity to increase, although not enough to have much effect on the changing energy content of the atmosphere. Humidity is just too small a number.