Arguments
Recent Comments
Prev 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 Next
Comments 1651 to 1700:
-
One Planet Only Forever at 04:24 AM on 5 September 2023Climate Confusion
Markp,
Your comment @40 contains the following helpful point: "In fact, one of our first mirror test sites was either on or adjacent to a local airport's land and their permission was required, and it was given."
This is helpful because it appears to establish that, along with your earlier mention of being very familiar with 'climate related finance', you appear to be 'invested' in a 'mirroring enterprise'.
Mirrors may be a helpful measure, along with other actions that increase the reflection of sunlight, to reduce the current degree of human impacts on global warming. They could be a part of the broad diversity of helpful actions. But they are unlikely to be 'the primary solution'.
Project Drawdown (at drawdown.org) developed by Paul Hawkin (author of The Ecology of Commerce) is an informative resource. It lists and evaluates climate impact reduction solutions. In their words "Project Drawdown’s world-class network of scientists, researchers, and fellows has characterized a set of 93 technologies and practices that together can dramatically reduce concentrations of greenhouse gases in the atmosphere." But their list of solutions includes helpful actions that do not reduce ghgs like the one they evaluated that seems close to your 'mirror' application - Green and Cool Roofs (Linked to Project Drawdown).
Maybe you should get in touch with Project Drawdown to get your idea added to their list of evaluated solutions.
However, I am pretty sure about what the primary solution is. And it is not covered by Project Drawdown. It is not a 'new idea'. It requires nothing new to be built. And it requires no alteration of any developed activities. It is:
Reduced Consumption - especially by the people who have over-developed levels of consumption (who consume 'beyond necessary consumption') - especially the reduction of types of consumption that are ultimately undeniably unsustainable like fossil fuel use (which cannot be continued to be 'enjoyed by everyone' centuries into the future even if there were no harmful impacts).
-
Rob Honeycutt at 04:19 AM on 5 September 2023Climate Confusion
Markp... When I say "new tech" what I'm alluding to is new materials. Replacements for cobalt. Potential for, say, solid state batteries. New methods and materials for the production of solar panels.
You can fall off your chair all day long, but people are continually working on better ways to generate energy. There is no lack of ingenuity being applied to these problems.
I think this illustrates the potential problem with your evaluation of the issue. If you look at any of this as steady state and extrapolated forward from there, you're inevitably going to end up with a doomsday scenario. But, as I've stated from the start, things are happening. Smart people have been working hard on these issues for decades and it's bearing fruit. The IPCC's work has been instrumental in keeping that ball moving forward though international agreements.
The task remains nothing less than Herculean, but it is wholly inaccurate to suggest that nothing has happened.
I tend to harp on this issue quite a lot because I believe rhetoric suggesting nothing has happened leads people to give up, right when we need people to understand that real progress is being made.
-
Markp at 02:58 AM on 5 September 2023Climate Confusion
Rob, I missed your bullets on how we can achieve net zero by 2050. Are you talking about these?
>A lot is happening toward decarbonization
>Decarbonization needs to happen faster
>We know a hell of a lot more about the climate than we did decades ago
>We have a good chance of getting to net zero by ~2050
>Once we get to net zero, warming is expected stop
>There are going to be increasing impacts in the coming decades
>The sooner we get to net zero the better off we are
>There is going to be a longer, more difficult task of getting fully to zero emissions which will take some decades moreBecause if you are, I fail to see how there explain how might be able to reach net zero by 2050!
As for the real problem of materials, I'm trying not to fall off my chair at your comment about new tech. We are talking about replacing FF. What new tech is on the market, or coming, that will replace FF and fill the huge gaps expected from wind and solar?
-
Rob Honeycutt at 02:28 AM on 5 September 2023Climate Confusion
Markp... "When I asked you how you thought this could be done, I asked for a few bullets."
And when I gave you bullet points you challenged me to provide sources. Which I did.
I'll read the Michaux's paper but I think this is an old discussion point about necessary resources for the technologies, whether it be lithium or cobalt or whatever. The good thing is, there is a near constant stream of new technologies coming to market all the time now. People have understood resource constraints and view it as both necessary areas for development and potential market opportunities.
-
Markp at 01:01 AM on 5 September 2023Climate Confusion
Eclectic, thanks. I always find it odd that people will say that such -and-such a solution will be "a hard sell" when we've arguably got no alternative other than extinction. This is not a "sale" the way one buys a new car and wants it a Honda to be perfect or they'll buy a Mercedes (or whatever). There are no perfect solutions here.
I think people who grumble at windmills but accept that they produce energy, will just as easily accept mirrors (which a tiny percentage of the public would ever see as they may indeed occuppy mainly relatively lonely parts of the world) knowing that they are keeping life on Earth possible.
Farmers will be happy to be able to increase their yields and actually grow and water their crops, which the way things are going, is getting really difficult. The cost will likely be born by the governments, as they will probably be tied to "offsetting" schemes (tax write-offs or direct subsidies).
Mirrors do not bother pilots or birds (the first thoughts of many). In fact, one of our first mirror test sites was either on or adjacent to a local airport's land and their permission was required, and it was given. There are some physics needed to explain why a mirror field does not affect pilots but I'm not prepared to offer them.
-
Markp at 00:47 AM on 5 September 2023Climate Confusion
Rob, thanks for the chart, but merely looking at a cost comparison between FF and renewables overlooks a lot. Have you seen Michaux's paper on this? You can find it here. It's a large report but worth looking at.
The report is called "Assessment of the Extra Capacity Required of Alternative Energy Electrical Power Systems to Completely Replace Fossil Fuels." One of his conclusions is that the amount of metals required far outstrips current reserves to build the needed infrastructure for the first generation of such a "transition" only (1st generation needs to be mined because until it's been built there is little to recycle). He writes: "Current expectations are that global industrial businesses will replace a complex industrial energy ecosystem that took more than a century to build. The current system was built with the support of the highest calorifically dense source of energy the world has ever known (oil), in cheap abundant quantities, with easily available credit, and seemingly unlimited mineral resources. The replacement needs to be done at a time when there is comparatively very expensive energy, a fragile finance system saturated in debt, not enough minerals, and an unprecedented world population, embedded in a deteriorating natural environment. Most challenging of all, this has to be done within a few decades. It is the author’s opinion, based on the new calculations presented here, that this will likely not go fully to as planned."
So even if wind and solar energy is cheaper than FF, we may not be able to replace FF with them, even if the IPCC says "we MUST."
Thanks also for the IEA link to "Net Zero Emissions by 2050" but this is a big paper. When I asked you how you thought this could be done, I asked for a few bullets. I will have a look at the paper, but my fear is that, as Simon Michaux's has pointed out, a lot of the "plans" for a better climate future have, amazingly, been made without consideration for the reality of time, energy, resources, etc. So they contain bold statements about what MUST be done, as if saying it is all that's needed. Like I said, I'll look at it but I'm not going to be surprised if I don't find a realistic assessment.
-
Eclectic at 05:50 AM on 4 September 2023Climate Confusion
Markp , thank you for a tad more detail on your "suspended mirrors" in post 34 paragraph 9 (please consider numbering your paragraphs & subsections, as per Congressional law-makers ).
Perhaps SkepticalScience has a suitable thread for such discussion?
Overall, mirrors wil be a hard sell to farmers, and to aircraft pilots who will have their own professional objections.
Also a hard sell to the general public (such as me) who might grumble at the "visual pollution" of fields of wind-turbines and fields of solar panels ~ but who recognize the immediate benefit of cheap low-pollution electricity on top of the long-term environmental benefits. A field of raised & suspended mirrors . . . not so much.
Markp , as a financier of sorts, you will have considered not only the per-square-kilometer levelized costing of mirrors, but also the opportunity cost. Opportunity cost analysis would be interesting, indeed.
-
Bob Loblaw at 05:24 AM on 4 September 2023Climate Confusion
Markp:
I am also not going t try to wade through a long post, either. I will respond to one small portion. You state, with respect to models:
And as my primary experience (nearly 30 years now) has been in the financial arena for many "quant" strategies where, in that industry it is painfully common to see wonderful quant investment funds with great backtested results finally have some real money thrown at them and start a live track record, only to see the live returns look nothing like the lovely return characteristics of those backtests, I confess a lot of my skepticism comes from just that type of environment.
All I will say is that climate models likely bear very little resemblance to the sort of models you run into in financial topics. For one, climate models have an awful lot of physics in them. They are not pure statistical models (although statistical models do get used in climatology). The laws of physics put some pretty strong constraints on how climate models behave.
-
Rob Honeycutt at 04:33 AM on 4 September 2023Climate Confusion
Markp... I'll also add this report from the IEA on the chances for net zero by 2050:
Net Zero Emissions by 2050 Scenario (NZE)
"There are many possible paths to achieve net zero CO2 emissions globally by 2050 and many uncertainties that could affect any of them; the NZE Scenario is therefore a path, not the path to net zero emissions."
-
Rob Honeycutt at 04:09 AM on 4 September 2023Climate Confusion
Markp... The conversation gets unweildy when you do such long posts. Can you please try to engage in a bit more editing to get your comments better focused? I think it would improve the value of this exchange.
I'm only going to address your first observation here: "'A lot is happening towards decarbonization' is vague enough to require examples to qualify the statement."
I'm sure there is a better thread for this but, if the mods will allow, I'll just post a response here for now.
First is the mere fact that onshore wind and solar are now cheaper than FF sources. This is relatively recent yet is already starting to show benefits in the energy marketplace.
The result of this is now renewable energy is scaling exponentially.
Bear in mind, this is still the early phase of exponential growth, so the true effects of that growth are going to be realized out past 2030-2050.
In the latest EIA LCOE (levelized cost of energy) reports they're now including battery storage technologies because those costs are now falling in line with peaker plants.
So, to try to somewhat tether this to the topic at hand, these technologies are the product of decades of very hard, complex work done by a lot of very smart people. These are the fruits of those efforts. This is why I say, while there are still many large and looming challenges, there is a lot of positive change afoot that should not be ignored.
These advances are very likely a product of the sorts of communications and political engagement done over the years by the IPCC and various resulting international agreements. It would have been unlikely any of these advancements would have occurred with out the IPCC's work.
These are the kinds of advancements that have to occur in order to get to net zero and then eventually zero carbon emissions by 2050 and after.
-
Markp at 22:43 PM on 3 September 2023Climate Confusion
For Rob: I know I have not provided much data to back what I've been saying, but that's mainly because I was going on the assumption that you may already be aware of the data that could support me. In other words, I don't think what I've said is uncontroversial from a data point of view, but I do accept that it might be controversial from the point of view of making those holding a mainstream view (and I know that's vague) uncomfortable.
I disagree with little of what you say about climate in this last post. From your list of 8 items, only 1,4 and 5 are problematic in my view. Unfortunately, those few items are weighty:
"A lot is happening towards decarbonization" is vague enough to require examples to qualify the statement. There has definitely been a lot of talk about decarbonization, but as 2022 saw global emissions hit a new high of 36.8 Gt, according to the IEA's report "CO2 Emissions in 2022" one has to ask what decarbonization achievements, what action, in place of mere talk, can we point to. Renewable energy production plus use of EVs, heat pumps and who knows what else saved about 550 Mt. Fine. But this growth rate (growth of renewable contribution) won't hold up. So when you say "a lot" is happening, what's that really mean? And could you give just a few bullets on how you think we'll achieve net zero by 2050?
I'm also curious to know how much your vision of "net" zero relies on offsetting schemes, because I don't trust them and fear that they are being relied on too much for comfort.
As for what happens to the rising temperatures in a net zero 2050, we'll have to wait and see.
I'm certainly with you on breaching 2C by 2050, but since I've got little hope we'll be anything close to net zero by then (for whatever net zero is actually worth as long as we've got all the offestting nonsense thrown in there) it looks worse to me than to you.
Finally, and to change the subject a bit, I think the talk about models went too far. I'm not saying models are bad, just that they're being relied on too heavily in certain important cases. And as my primary experience (nearly 30 years now) has been in the financial arena for many "quant" strategies where, in that industry it is painfully common to see wonderful quant investment funds with great backtested results finally have some real money thrown at them and start a live track record, only to see the live returns look nothing like the lovely return characteristics of those backtests, I confess a lot of my skepticism comes from just that type of environment. Still, when we continually see news reports with headlines running "Researchers present shocking new data that climate change is happening much faster than expected" and the previous expectation was based on models, I don't feel at all surprised. I've just had a look at the "myths" section of Skeptical Science specifically at the models myth and I also see there that most of the argument seems to be toward trying to convince climate deniers who say models are all wrong that GW is real. That's clearly not me.
For Eclectic: I don't think I've written too much, do you? I know people these days don't like to read anything longer than a twitter post, but I don't think your assessment here is fair. I've tried to keep it short, in fact. Like I said, I assumed, and maybe wrongly(?), that you folks had a decent understanding of the data already, and could follow commentary like mine that took a broader look at things rather than fussing over citations and decimal points because I'm not claiming anything that boils down to a disagreement over small measurements but has been more about one's basic orientation: some of you seem to be wearing rose-colored glasses in my view, like too many people are.
As for the mirror concept, if the goal were to limit global temperature rise to 2C by 2100 we would need about twice the surface area of the contiguous USA. Although these reflectors would be useful in many instances, like on rooftops, parks, outdoor markets, reservoirs, etc., the main idea is for them to be used in agricultural settings because there's a lot of agricultural land, and because the reflectors would bring both local benefits to the crops by cooling, saving water and increasing yield, and contribute to global cooling. How to do that on a large scale is a problem that needs to be worked out. Any cropland managed by tractors and other large machines would either need to involve reflectors that would be removed from time to time for those machines to do their work, which wouldn't be easy, or they'd need to be placed so as not to interfere with those machines, perhaps by having them suspended vertically alongside crops rather than horizontally over them. And of cource, horizontal coverage would not involve blocking all available sunlight as to choke off photosynthesis, but as most crops can thrive with up to 30% shading, it would be placed intermittently. Anyway, this is the rough idea. Reflectors made from PET and aluminum cans from landfill provide more than enough for this level of scale, but other reflector constructions/materials could pop up as well. If you feel this isn't the type of detail you'd like to see, I'm not allowed to offer more. Not to protect technology or profits, because this comes from a nonprofit, but simply because I'm not authorized. As some of you know, the science takes time. We're working on it.
If that surface area seems "too big" as in "nobody will go for that" I can certainly feel that, but what choice have we got? The Earth is big. We can do it. We've got 4 million miles of roads in the USA. When cars first got started, nobody would have thought that possible. All of our climate "solutions" are by nature on a grand scale. Nothing to do about that as far as I know. And why people might balk at lots of mirrors/reflectors when they seem to think DAC (or your solution of choice) can clean (enough of) the entire atmosphere, I'm stumped.
-
BaerbelW at 18:19 PM on 3 September 2023It's freaking cold!
Please note: the basic version of this rebuttal has been updated on September 3, 2023 and now includes an "at a glance“ section at the top. To learn more about these updates and how you can help with evaluating their effectiveness, please check out the accompanying blog post @ https://sks.to/at-a-glance
-
Eclectic at 10:08 AM on 3 September 2023Climate Confusion
Rob Honeycutt @32 :
Well stated.
......................................
Markp @31 (and prior) :
There is a danger zone, in posting, when an increasing word-count tends to cause a loss of focus. Just as a 10-minute sermon does better than a 45-minute sermon.
Worse ~ as verbiage increases, some cracks may start to appear in the messaging. And the naive reader (such as me) begins to identify contradictions :- This part looks Extinction-Rebellion-ish . . . That part looks Denial-ish . . . Here is some disingenuous arguing . . . There is a practical impossibility . . . and so on.
It all leaves a feeling that one is looking at a mask ~ with another mask beneath that ~ and perhaps a third mask underneath that. It erodes confidence in the candor of the commenter ~ and the naive reader starts to look under bridges for those mythical inhabitants.
Overall, it is best to avoid anything suggestive of smoke & mirrors. Practicality should be King. And speaking of mirrors, Markp, you have not yet provided a practical outline of your "mirror solution" ; an outline which is at least back-of-envelope in quantification.
-
Rob Honeycutt at 09:22 AM on 3 September 2023Climate Confusion
Markp...
It's a little difficult to cut through your tone to get to a substantive discussion. I read a lot of frantic hand-waving but not much in the way of data or linked citations needed to evaluate the position you're putting forth.
All I'm left with is restating what I've already said.
- A lot is happening toward decarbonization
- Decarbonization needs to happen faster
- We know a hell of a lot more about the climate than we did decades ago
- We have a good chance of getting to net zero by ~2050
- Once we get to net zero, warming is expected stop
- There are going to be increasing impacts in the coming decades
- The sooner we get to net zero the better off we are
- There is going to be a longer, more difficult task of getting fully to zero emissions which will take some decades more
We could rant all day long about what actions should have been taken and when they should have happened, but that changes nothing. We are where we are. People are working hard on the problem.
I would add here, the basic premise of the 2°C limit is, we know with a reasonable degree of certainty that the last interglacial reached about 2°C over the modern Holocene preindustrial temperature without setting off any spiraling amplification effects. And 1.5°C has been set forth as a modern safe limit to try to stay under.
We are almost certainly going to break 1.5°C. As I understand it, we'll probably also breach 2°C by ~2050 but global temperature will settle back down below that. I think the question becomes, how resilient is human civilization going to be, and how resilient are natural systems going to be.
-
Markp at 05:22 AM on 3 September 2023Climate Confusion
Hello
No, I'm not at all advocating that individuals adjusting their lifestyles are the answer, far from it (I'm surprised to hear this from you!), but it is something that must be done. Average people pushing the politicians and business leaders to act is necessary as well, because as we can see, without that they'll continue making targets and holding discussions that don't get us anywhere.
This is going to come down to us agreeing to disagree, I guess, for example regarding the IPCC and all the supposed "progress" we've made. I know that most people in climate science (scientists and others) think like you, that a lot has been done, etc. I just don't buy it. We've certainly managed to elevate the overall knowledge of GW among everyone - people from all walks of life (not with the honesty and clarity that is needed in my opinion, but...). But that has not translated into the kind of action we need by a LONG shot. It's politics and it's scientific reticence (i.e. David Spratt) and many other reasons, but it's there, staring us all in the face. Maybe I'm just speaking here to the optimists, 45-years of experience or not. I don't know. But if you think you shouldn't take me seriously because of my attitude towards models re "the end of temp rise" I'll just reiterate that it's not just me but people like James Hansen who have expressed those opinions. Just look at his latest tidbit: "Equilibrium Warming = Committed Warming?" where he writes in the 4th paragraph: "...climate science should be focused on data. That's the way science is supposed to work. However [the] IPCC is focused on models. Not just global climate models, but models that feed the models, eg. Integrated Assessment Models that provide scenarios for future GHG levels...sometimes the models contain hocus-pocus. As we mention in our current paper, they can assume, in effect, that 'a miracle will occur.'" And as you know, he's not the only one to criticise the overreliance on models. I'm assuming you are all familiar with Spratt and Dunlop's "What Lies Beneath."?
At the end of the day, scientists are no different from anyone else in this world where we all have to struggle for survival and protect our jobs and reputations and do things we have to do but may not believe in. Research isn't done for fun or for pure curiosity unless one bankrolls one's own laboratory, which few do. It's done to support the money, make a product, build a name for oneself, etc.
So people like (unnamed) set up for-profit companies as sidelines in addition to their responsibilities with their universities and, look what he just did: sold Carbon Engineering for over $1B. Nice. Ka-ching. You can't sell simple solutions for that kind of money, can you? And Climeworks, when are they going to have an IPO and cash-out, for worthless DAC? And this is all because the IPCC said "We MUST do this!"
An extremely important statement from the foreward of "What Lies Beneath" is from Hans Joachim Schellnhuber, professor of theoretical physics, etc., long list of credentials, when he said we are running out of time and so "...it is all the more important to listen to non-mainstream voices who do understand the issues and are less hesitant to cry wolf [than for example those scientists working with the IPCC]".
I work with those non-mainstream scientists because they are the ones who seem to be cutting through the BS towards real solutions that give us more than hopium.
Let me just ask you, and I am trying to be fair to the scientists in climate, generally speaking, because I imagine the vast majority are really doing their best. They aren't free to do what they might if they weren't trapped in the system we all are trapped in. (I know one who is a physicist but works with the IPCC on policy and he told me once "You have to trust your institutions, Mark"!!! Really. I trust the post office to deliver a letter. I don't trust politicians to solve global disasters that require those in power taking home less money.) But let me ask: if scientists really have been trying as hard as they could for decades now to come up with ways to stop rising heat and protect life on Earth as fast as possible, why has nobody else but a man who left his academic career at Harvard behind in order to found a nonprofit been able to come up with the solution staring us each in the face every morning when we brush our teeth, involving mirrors? Could it maybe have anything to do with the fact that it is just not very sexy? Honestly, I cannot understand or explain it any other way. And I've seen big-wig scientists in the climate sphere hear of this and say "where's your peer-reviewed research?" instead of just turning their brains on and thinking about the idea first. "Hey, makes sense, pretty obvious, actually...could be some complications, but overall, interesting idea..." (Kudos to Eclectic on this one) No, instead they just wanted research to back up the idea that ice will melt in a hot frying pan.
Well...would have been more fun over a beer. Take care.
-
Eclectic at 04:29 AM on 3 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Bigoilbob @59 :
Yes, very likely that is the ultimate aim of Dr Frank's mathematical contortions ~ to declare all the data to be "unevaluable". That is the desired end-point of the exercise.
Tragic, to have years of effort devoted to "proving" that the mountain of evidence of AGW . . . is non-existent and meaningless. This is the fall-back position of many Denialists ~ though most use a shotgun of poor reasonings, rather than the single bullet approach favored by Dr Frank.
-
bigoilbob at 23:29 PM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Dr. Frank not only mixes up evaluations of systemic v random error, but asserts - with no justification - that the extremely statistically durable trends we've found with GAT, sea level, ice melt, etc. have been constructed from systemic errors that, if accounted for, would invalidate them. He has several papers treating these mixes of errors, that all conclude that the trend under discussion is bogus. Again, without even attempts to re-evaluate the data using the "larger" error bounds, and of course also with no treatment of the correlation of these systemic errors. In other words, he ends these papers by throwing up his hands and declaring the data "unevaluable" with zilch for backup.
-
Bob Loblaw at 08:40 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
ICU: I think you posted comment 56 while I was preparing comment 57.
In the OP, the MANOBS chart of temperature correction is an excellent example of systematic error in a temperature sensor - and how to account for it. Here it is again, for convenience.
If this correction is ignored, we see that there is an additional uncertainty of up to 0.2C in the readings - with the exact value depending on temperature. Since each thermometer is calibrated against a better temperatuer sensor (in a lab), we can adjust the reading based on that known systematic error.
But error is not uncertainty... but even if we do not know the error, we can account for any fixed error (e.g., Mean Bias Error) by subtracting each individual reading from the mean (i.e, an anomaly). That fixed error is non-random, so it is present in every reading in the same amount - even if we do not know that amount.
Let me try with a simple equation set: (I know, not that math $#!^ again).
T1true = T1reading + error1
T2true = T2reading + error2
Since we don't know the error (we never can, because anything we compare our reading to also has errors), the unknown is an uncertainty. If error1 and error2 are independent, then all the "combined in quadrature" equations that Pat Frank uses are applicable.
But what if they are related? In the simple case, where the error is completely systematic and fixed (the MBE describes it all), then error1 = error2. In that case when we do T2reading - T1reading, [error2 - error1] = 0, and we get exactly the correct answer for T2true-T1true, even though we have uncertainty in each individual reading.
Comments 49 and 50 demonstrate this using real data. The errors are not purely MBE, but correcting for MBE on a monthly basis greatly reduces the uncertainty.
Much of the literature that Pat Frank references, related to different ventilation shields, different measurement systems, changes in station locations etc., is designed specifically to ferret out the MBE and other systematic errors in temperature measurements. Once that systematic error is identified, it is accounted for through the process of homogenization.
Pat Frank has no idea how any of this actually works.
-
Bob Loblaw at 08:11 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
ICU: I mentioned the randomness issue briefly above, in the blog post and in comments. He makes the argument for non-randomness saying he finds a non-normal distribution. I point out in comment 46 that he is wrong: you can have non-normal, but still random, distributions.
And he keeps using equations to combine uncertainties that require independence of the variances, which is contrary to his claim of non-randomness. And he uses a multiplier of 1.96 to get 2-sigma from 1-sigma, even though he says that distributions are non-normal.
In the NoTricksZone post, he argues that covariance is not relevant (in fact, that statistics equations combining variances) are not relevant because uncertainty is different from statistics. So he dismisses the equations I have present in the OP - in spite of the fact that they are listed in Wikipedia's "Propagation of Uncertainty" section. Yet covariance is the key concept that needs to be included when things are not random.
In comment 21, bdgwx provided a link to JCGM 100:288, which is basically the same as the 1995 ISO Guide to Uncertainty in Measurement. Section 5.2 talks about Correlated input quantities. If you look at section 5.2.1 on page 33, it says (emphasis added):
Equation (10) and those derived from it such as Equations (11a) and (12) are valid only if the input quantities X are independent or uncorrelated (the random variables, not the physical quantities that are assumed to be invariants — see 4.1.1, Note 1). If some of the Xi are significantly correlated, the correlations must be taken into account.
The internal inconsistencies in Pat Frank's work are numerous and critical. It's not random, but you don't need to use equations that are designed for correlated inputs. It's not normally-distributed, but you can still get to 95% confidence levels by using the proportions from a normal curve and 1-sigma/2-sigma ratios.
He's picking equations and terms from a buffet based on taste, having no idea how any of the dishes are made, and claiming that he can cook better than anyone else.
In comments 49 and 50, I show data from real world measurements comparing three equivalent temperature sensors, and how you need to properly divide Root Mean Square Error into the Mean Bias Error and standard deviation of differences between pairs to properly evaluate the uncertainty. And how accounting for the Mean Bias Error across sensors (by using anomalies) shows that all three sensors agree on how different the current temperature is from the monthly mean.
Nowhere in Pat Frank's paper does he discuss Mean Bias Error or any other specific form of systematic error. Every single one of his equations ignores the systematic error he claims is a key point.
-
ICU at 07:49 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
OK so systematic errors. What specific systematic errors are being claimed for temperature measurements and their magnitude(s)?
-
ICU at 07:19 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Bob,
As I see it, Frank's basic argument is that measurement errors are not random. I think it is better to address the major arguments of a position then to get bogged down in the minutia of an argument.
I would argue that, if in fact, measurement errors are not random, then observational sciences are royally fucked! Meaning, show me explicit examples where the measurement errors are not random and how far those deviate from an assumption of randomness. Actual measurements, not just some made up just so math concoctions.
-
Bob Loblaw at 06:16 AM on 2 September 2023Climate Confusion
Markp @ 27:
Bluntly, when you dismiss information you don't like with statements such as this one:
I've spoken to established research scientists who laugh off the climate modelers who so cheerfully say "temperatures will just stop rising" if net zero is achieved. These are people I trust. They've had long careers doing real science, not short ones playing with computers.
...then it is hard to take you seriously.
If you want me to actually believe that such "established research scientists" exist, then you will have to point to a credible source of the statements they make and their arguments against the "established research scientists" that have studied and modelled carbon cycles for many years.
And I'll see your "working in climate science for a couple of years now" and raise you "studying and working in climate science for 45 years now". Only five of those years were spent dealing with forest carbon cycles and their relationships with climate, though. And I've only been "playing with computers" for 45 years, too.
-
Eclectic at 06:03 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
ICU @52 , methinks you are asking Bob L to act like Sisyphus.
Sisyphus had a large stone to move to the top of the mountain ~ but Dr Frank's ideas are a much smaller stone (though obviously much denser! ) . . . and the small dense Frankenstein [sorry, the pun was irresistible] is determined to keep rolling itself back down into the gutter [in this case, the gutter press, aka NoTricksZone ] at every opportunity.
As Gavin Cawley says: Frank's methodology is "argument-by-attrition".
Wise psychiatrists know that sometimes you just have to walk away.
On the other hand, Bob may simply enjoy a bit of jousting, for the fun & mental exercise.
-
Bob Loblaw at 05:45 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Hi, ICU/Everett.
I am aware of the PubPeer discussion of this recent Pat Frank paper. I have started participating on that discussion as Camponotus mus - a pseudonym assigned by PubPeer. I saw that link to NoTricksZone, and have a short response waiting in moderation at PubPeer. (As a new, anonymous user at PubPeer, I understand that my comments will always go through moderation, at least for a while.)
I have only looked quickly through that NoTricksZone post, and it seems that Pat Frank is mostly just asserting he is right and the whole world is wrong. Part of my PubPeer response is:
I see that you are arguing that averaging is not the same as weighting. That is quite an amazing claim, as the average of two numbers is algebraically equivalent to weighting each number by 1/2. You do understand that (A+B)/2 is identical to A/2 + B/2, and that this can be re-written as (1/2)*A + (1/2)*B? If you think this is not correct, then I would add basic algebra to the topics that you do not understand.
He also seems to claim that uncertainty can't use the rules of statistics, such as the covariance term I mention in the OP. This is certainly a most bizarre idea, as the GUM makes extensive use of statistical models in demonstrating concepts of uncertainty.
Overall, Pat Frank's response at NoTricksZone looks like he is in hagfish mode, as described in DiagramMonkey's blog post. I do not think it would be productive to try to refute it here unless Pat Frank comes here and makes his arguments here. A read-this-blog/read-that-blog cycle will not be at all productive.
Of course, if Pat Frank does come here, he would be expected to follow the Comments Policy, just like anyone else.
-
ICU at 05:12 AM on 2 September 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Hello Bob,
Everett F Sargent or Francis F Sargent of ATTP infamy here. I just noticed a Crank reply in the most recent PubPeer article from Frank the Crank ...
https://notrickszone.com/2023/08/24/dr-patrick-franks-refutation-of-a-sks-critique-attempt-loblaws-24-mistakes-exposed/
Now I know that this Crank is wrong although I am not now able to go through the necessary math. Your thoughts on this more recent rebuttal to your post here would be most greatly appreciated. Thanks in advance for your thoughts and/or equations. Also think an abstract of sorts would be most useful covering this crank's misunderstandings from the 2019 and 2023 (this article) papers.
Moderator Response:[BL] Since this is your first post here, please note that our Comments Policy does ask that you keep the tone civil. The parts that I have flagged are getting a bit too close to the line.
-
Rob Honeycutt at 03:36 AM on 2 September 2023Climate Confusion
Markp... "We've had the IPCC for 35 years and not much to show for it..."
Again here, you're seemingly making the claim that nothing has happened when the opposite is true. A great deal has been accomplished. A great deal more must be accomplished. You can certainly make the claim that the changes aren't happening fast enough, but you can't rationally claim nothing has happened.
-
Rob Honeycutt at 03:33 AM on 2 September 2023Climate Confusion
Markp... It sounds to me like you're seeing this as a problem that is solved through an individual's choices in lifestyle, and I think that's misdirecting where the problem is solved.
Most climate solutions are a supply side issue. The supply of energy, the supply of low carbon emitting building materials, etc. Individuals readily embrace low carbon solutions when they are available in the marketplace. But when low carbon alternatives aren't available individuals generally have no choice but to use carbon emitting products and services.
Laying any blame at the feet of individual choice is essentially letting the fossil fuels industry off the hook for their responsibilities to humanity and a sustainable environment.
-
Markp at 03:04 AM on 2 September 2023Climate Confusion
I am not a scientist, but I've been working in climate science for a couple of years now.
I wouldn't say I dismiss models, I'm just careful with them. Perhaps "garbage in, garbage out" is more common an expression to describe models in the financial world than in the natural sciences, but even so, when it comes to climate modelers I'm merely echoing sentiments from those like James Hansen, who clearly value models but prefer using real data, real-world, whenever possible. I've spoken to established research scientists who laugh off the climate modelers who so cheerfully say "temperatures will just stop rising" if net zero is achieved. These are people I trust. They've had long careers doing real science, not short ones playing with computers.
And Rob, believe me, I do live a low-carbon life myself but I know very few others know or care about the need for that. The problem is, the accepted wisdom for many years now has been to not alarm people with GW talk, and churn out messages with hope and optimism, so what has happened is that people pretty much think "the experts" are taking care of things and there's nothing to really worry about. The person on the street has no clue how bad things are or how soon things will get very bad. No wonder they don't change their lifestyles further than maybe switching to a new sexy Tesla and eating vegan once a week.
I'm also involved in the renewable energy business and that's definitely been an excellent development but again, people are being misled into thinking that's all we need to do, but it's not going to happen. Have a look at Simon Michaux's work.
We've had the IPCC for 35 years and not much to show for it, and anyone who doesn't believe that is either simply ignorant or is fooling themselves. The IPCC plays politics with science. We need to take their estimates and double or triple them to achieve results close to reality.
All I can say regarding decarbonizing is that the money and the power is dead set against it because they're only concerned about today's profits, but as more and more of the world burns up, as food insecurity gets worse and water scarcity as well, their hands will be forced. The question is: will there be enough time then? Will the "laser focus" that might (might) be squeezed out of people when their backs are against the wall be too late? What is required, at the very least since people aren't acting like adults, are laws limiting waste in all industries, in all areas of government, and in our private lives, but is that coming? Are laws restricting unnecessary consumption coming? Laws banning the worst of the world's luxury goods would put a big dent in the fattest carbon emitters and send a message to all those people idolizing such frivolous living but is that coming? We could put tight curbs on new car sales and enforce drastic changes to allowable car specifications (reduction of size/weight/horsepower). We need governments to enforce "work at home" for all industries and jobs where that's feasible. We need public service messages telling people to stop trying to "live large," we need celebrities to publically downsize their lifestyles, television shows to stop glamorizing the selfish life... the list is very long. So much needs to be done and could be done, but is it? Scientists gluing themselves to bridges is what we need, it's just about the only sensible thing to do this late in the game to make people wake up, but instead of getting the message people scorn them and governments lock them up. We cannot blame these protesting scientists. They've been asked to do something they were never trained to do, and for which no infrastructure exists, and to make matters worse, they're being pushed into solving this emergency by adopting a profit-making model that flies in the face of the spirit of science.
The way I see it, we've got about one decade of "somewhat normal" life left before the food insecurity hits the privileged classes hard, and at that point, the societal collapse that has already begin is going to be much more life-threatening than heat. Net zero goals for 2050 may no longer matter when everything begins to fall apart.
As for the mirror concept, all the details are being researched but we're not talking about traditional glass mirrors but rather "specular reflectors" such as what you get combining PET with aluminum for a cheap, thin, durable, flexible mirror-like tool. These are already in use for local heat adaptation, but going from adaptation to global heat mitigation is just a matter of scaling up, and there are plenty of resources for it, unlike so much of the other ideas floating around. Plastics with no metal at all are also being developed that could be used. The whole concept is a simple evolution of white paint, which is not feasible for many reasons including the fact that it gets moldy and needs regular attention and re-surfacing.
-
Rob Honeycutt at 00:20 AM on 2 September 2023Climate Confusion
Markp @23...
"The fact is, when we talk about hypothetically achieving no more human emissions, we're talking about a time in the future that is not tomorrow or next year or next decade, but at the very least, several decades, at least going by the extremely lazy response by humanity thus far. Correct?"
I'd say this is a faulty assumption. It is most certainly a Herculean task that is required, made even more difficult by the need to pull ever more humans out of poverty. But when you look at the changes that are occurring, particularly in how quickly renewables are now getting deployed, I think there's a decent chance we'll get to net zero around 2050 and full zero in the decades following that.
It must be disheartening for all the scientists and engineers who have been working on renewable energy for decades, and for them to have now created methods that generate electricity that beat the cost of FF's, only to constantly hear people make statements like "the extremely lazy response by humanity thus far."
But perhaps they're too busy to take notice or even care what others say.
It's worth noting, we are definitely going to see huge global challenges in the coming decades as the planet likely warms another degree celcius. So, perhaps it's important to put yourself in the mind of someone living in 2050 with far worse climate impacts each and every year. I think all of humanity is going to be laser focused on getting the last vestigages of carbon emissions eliminated.
-
Eclectic at 23:21 PM on 1 September 2023Climate Confusion
Markp @23 , to respond is simple. Name the person you are addressing, and preferably add in the # post number, for greater precision. Occasionally that # goes "wrong" if the Moderator has altered some post numbers ~ but usually posts go onto the thread in the chronological order they were received.
Again, I am not sure why you are bothered by "models and scenarios". As you say, the social/political/technological response to CO2-derived global warming is rather tardier than ideal, in slowing and eventually halting the current rapid warming. Yes, decades.
Simply apply common sense, and remember the first step needed is the reducing of human-caused CO2 emissions. Eventually, the CO2 level stops rising (and if you are curious, you can observe how much more warming occurs after that . . . so no actual need for "models"). Then you can observe the speed of subsequent CO2 level fall . . . and take further high-tech action if that seems warranted, in order to accelerate the CO2 decline. If not going the high-tech route immediately to begin with!
Probably best to ensure the CO2 does not drop below about 350ppm (since eventually the natural Milankovitch-cycle cooling will start to show). That "natural cooling" has been estimated to become problematic in roughly 15,000 years . . . so not an urgent problem! Plus humans will then have the option of warming the planet by burning small amounts of coal (assuming we have been wise enough to keep a goodly amount of coal available for such future need . . . although by that stage presumably we will have the option of heating limestone per fusion-powered electricity).
Markp, your idea of mirrors (ground-based, not space-based) seems reasonable in theory . . . but what about the practicalities? Please go ahead and "show your workings" for areas needed / desirable locations / dollar cost per sq. meter / CO2-cost of building & installing mirrors / and so on.
Remember the old axiom : Politics is the art of the possible.
Stop worrying yourself about models ~ leave the models to the scientists. Your personal responsibility (to yourself and others) means taking practical action with what you can do now .
-
Bob Loblaw at 22:31 PM on 1 September 2023Climate Confusion
Markp @ 23:
Ah, I see. You simply dismiss models. It must be really difficult for you to do any science with no models of any sort. Since science is based pretty much entirely on models (descriptive, statistical, mathematical, etc.), dismissing models is pretty much saying you dismiss science writ large.
...but then, the people doing the science (with models) and presenting results, you dismiss as making "assertions".
I'm glad you "asserted" this viewpoint.
-
Markp at 21:50 PM on 1 September 2023Climate Confusion
Not sure how to respond to comments to my comment... There is no "reply" etc., featured in those comments, so I'll just say to Eclectic that I'm sorry you find my last paragraph unclear, and to Bob Loblaw and Rob Honeycutt: I'm clear on the difference between different types of "zero" CO2 scenarios, whether they imply constant concentrations or not. And Zeke's "explainer" is nice but is only a case in point: too many people simply assert that under a complete end to human emissions scenario, whereby natural uptake through oceans and trees continue drawing down CO2, heating will stop. Almost immediately. And they seem to base that belief purely on what has been modelled. And as everyone should know about models: garbage in, garbage out. The models don't reflect reality, though they try. Their inputs aren't complete, but merely partial. For example, ZECMIP is only CO2. The fact is, when we talk about hypothetically achieving no more human emissions, we're talking about a time in the future that is not tomorrow or next year or next decade, but at the very least, several decades, at least going by the extremely lazy response by humanity thus far. Correct? So by that time in the distant future, as emissions have continued, and tipping points have tipped, many things will have likely changed that our current thinking (or modeling) does not account for. So it is a bit silly to claim that temperatures will just stop IF/WHEN/? we ever manage to end human emissions, or "net" end them through the net zero concept. We place far too much reliance on models here, or rather I should say, those who are cheerleaders for net zero do.
So to Eclectic, I'm not proposing an alternative to reducing emissions. We need to reduce emissions. But that won't be enough. We also need to try the best form of SRM we can manage, which in my view is land-based mirrors, because the tech is here now, it's low tech, non-toxic, completely scalable, does not block sunlight from reaching our flora and fauna, and has an immediate effect on warming, unlike all the downstream GHG management methods.
-
BaerbelW at 15:09 PM on 31 August 2023At a glance - How do we know more CO2 is causing warming?
walschuler @3 - Sorry, we didn't yet have time to take a close(r) look. We'll be in touch directly once we can pick it up again.
-
walschuler at 06:52 AM on 31 August 2023At a glance - How do we know more CO2 is causing warming?
I am wondering if the information I supplied separately, including the pages from de Saussure's work, has been posted somewhere...
-
Eclectic at 00:24 AM on 31 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
[ This will be post #51 , and thus a new page in this thread. ]
Whew ~ I have just finished reading the PubPeer thread of 271 posts.
Which features the Star (Pat Frank) engaging with Paul Pukite, Ken Rice, Joshua Halpern, and Gavin Cawley, in 2019.
Towards the end, Cawley says to Frank : "you are impervious to criticism" and "I have no interest in argument-by-attrition".
And Pukite says (to Frank) "Perhaps worse than being wrong, your paper is just not that interesting and may explain why it was rejected so many times."
Earlier, Rice says (to Frank) : "... you've done a simplistic calculation using a simple model and produced a a result that doesn't represent anything at all."
And that seems to be the heart of it ~ Frank has fired an arrow which has missed the target completely . . . and he spends years wrangling uninsightfully with almost everyone, and insists over & over that they "do not understand physical science". Frank contra mundum.
I won't tax the reader by going into details. The statistics of it all ~ are much less interesting than the personality traits of Dr Frank. Perhaps the most appropriate statistic would be found in the Diagnostic and Statistical Manual [ DSM, Fifth Edition ].
-
Bob Loblaw at 05:07 AM on 30 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
...and, to put data where my mouth is....
I claimed that using anomalies (expressing each temperature as a difference from its monthly mean) would largely correct for systematic error in the temperature measurements. Here, repeated from comment 49, is the graph of error statistics using the original data, as-measured.
...and if we calculate monthly means for each individual sensor, subtract that monthly mean from each individual temperature in the month, and then do the statistics comparing each pair of sensors (1-2, 1-3, and 2-3), here is the equivalent graph (same scale).
Lo and behold, the MBE has been reduced essentially to zero - all within the range -0.008 to +0.008C. Less than one one-hundredth of a degree. With MBE essentially zero, the RMSE and standard deviation are essentially the same. The RMSE is almost always <0.05C - considerably better than the stated accuracy of the temperature sensors, and considerably smaller than if we leave the MBE in.
The precision of the sensors (small standard deviation) can detect changes that are smaller than the accuracy (Mean Bias Error).
Which is one of the reasons why global temperature trends are analyzed using temperature anomalies.
-
Rob Honeycutt at 23:46 PM on 29 August 2023Ice age predicted in the 70s
Michael... The other one that has confused me a couple of times is when a post becomes the first on a new page. Even though you hit submit, and it starts a new page, the page numbers don't update. You have to reload the page to see the new page number. I think that often leads to our "contrarian" friends here to jump to the conclusion they're being stifled in some way.
-
Bob Loblaw at 22:53 PM on 29 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
I will not try to say "one last point" - perhaps "one additional point".
The figure below is based on one year's worth of one-minute temperature data taken in an operational Stevenson Screen, with three temperature sensors (same make/model).
The graph shows the three error statistics mentioned in the OP: Root Mean Square Error (RMSE), Mean Bias Error (MBE), and the standard deviation (Std). These error statistics compare each pair of sensors: 1 to 2, 1 to 3, and 2 to 3.
The three sensors generally compare within +/-0.1C - well within manufacturer's specifications. Sensors 2 and 3 show an almost constant offset between 0.03C and 0.05C (MBE). Sensor 1 has a more seasonal component, so comparing it to sensors 2 or 3 shows a MBE that varies roughly from +0.1C in winter (colder temperatures) to -0.1C in summer (warmer temperatures).
The RMSE error is not substantially larger than MBE, and the standard deviation of the differences is less than 0.05C in all cases.
This confirms that each individual sensor exhibits mostly systematic error, not random error.
We can also approach this my looking at how the RMSE statistic changes when we average the data over longer periods of time. The following figure shows the RMSE for these three sensor pairings, for two averaging periods. The original 1-minute average in the raw data, and an hourly average (sixty 1-minute readings).
We see that the increased averaging has had almost no effect on the RMSE. This is exactly what we expect when the differences between two sensors have little random variation. If the two sensors disagree by 0.1C at the start of the hour, they will probably disagree by very close to 0.1C throughout the hour.
As mentioned by bdgwx in comment 47, when you collect a large number of sensors across a network (or the globe), then these differences that are systematic on a 1:1 comparison become mostly random globally.
-
Eclectic at 22:49 PM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
Davz @4 : you are wrong. That paper does not support your claim of showing "far fewer not more fires over a long period of time". Please read through the paper, and with particular attention to the last paragraph.
The paper is from 2016 and includes mention of "recent" study decades of up to 2012 and up to 2015 ( eight years ago ). The paper was very vague about "areas burned versus fire intensity" [unquote].
The authors also said: "We do not question that the fire season length and area burned has increased in some regions over past decades" [unquote]. Again, no quantification. And you, Davz, have the advantage of knowing something of the past eight years of global fire activity ~ unlike the authors.
They also mentioned (in an unquantified manner) the other factors of "increased fire prevention, detection and fire-fighting efficiency, abandonment of slash-and-burn cultivation in some areas and permanent agricultural practice in others" .
And the authors commenced with: "Charcoal records in sediments and isotope-ratio in ice cores suggest that global biomass burning during the past century has been lower than at any time in the past 2000 years." Davz , this is very vague unquantified stuff ~ indeed, the paper is little more than a discussion essay.
The title is grand, though. "Global trends in wildfire and its impacts: perceptions versus realities in a changing world". But the paper itself is so vague as to be almost useless.
It is certainly not qualifying as "Counter-Propaganda" ~ if that was what you were intending?
Moderator Response:[DB] Link added to the OP to the new rapid attribution paper in question, Barnes et al 2023.
-
michael sweet at 22:44 PM on 29 August 2023Ice age predicted in the 70s
Don Williamson at 142:
The software at SkS automatically logs users out after a period of time. If you spend too long typing out a comment (for example while you are finding relevant links), you get logged out. You cannot tell that you have been logged out. When you hit submit your comment vanishes. Vanished posts cannot be recovered.
At SkS all comments are posted immediately without moderation. If your comment does not appear immediately then you posted after you were logged out.
Long time users copy their posts before submitting or type their posts in word and then copy them into SkS. It is frustrating to have a post with a lot of time consuming links vanish.
-
Bob Loblaw at 22:18 PM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
Davz @ 4:
That specific paper was discussed recently on the "How human-caused global warming worsens wildfire", thread, starting with this comment.
Short version: the paper has serious weaknesses when using it to make the claim you are making. Reducing fires in savanna and grassland in Africa does not help people living in areas where increases in forest areas burned are affecting livelihoods.
In spite of "fewer fires" in Canada this year, the area burning - and the damage and cost to the Canadian economy and people's lives - has far exceeded historical records.
Which would you rather have? Five grease fires in a year while cooking dinner that were easily put out, or one house fire that burns your entire house down? After all, five is worse than one, isn't it? (According to your logic).
You only see this as "propaganda" because you don't like the message.
-
Davz at 21:18 PM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
To put this "science " into perspective I would urge you to read this paper on wildfires. It will show far fewer not more fires over a long period of time. Yet more sensational headlines that can only be seen as propaganda
https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0345
Moderator Response:[BL] Link activated.
The web software here does not automatically create links. You can do this when posting a comment by selecting the "insert" tab, selecting the text you want to use for the link, and clicking on the icon that looks like a chain link. Add the URL in the dialog box. -
Richard13699 at 20:36 PM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
And a typo on my line 2, too!!
-
Richard13699 at 20:35 PM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
Worrying.
Thank YUoui for the info.
There is a typo on line 5. 15M Ha is 37.05M acres.
-
Bob Loblaw at 07:01 AM on 29 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Yes, bdgwx, that is a good point. The "many stations makes for randomness" is very similar to the "selling many sensors makes the errors random when individual sensors have systematic errors".
The use of anomalies does a lot to eliminate fixed errors, and for any individual sensor, the "fixed" error will probably be slightly dependent on the temperature (i.e., not the same at -20C as it is at +25C). You can see this in the MANOBS chart (figure 10) in the OP. As temperatures vary seasonally, using the monthly average over 10-30 years to get a monthly anomaly for each individual month somewhat accounts for any temperature dependence in those errors.
...and then looking spatially for consistency tells us more.
One way to look to see if the data are random is to average over longer and longer time periods and see if the RMSE values scale by 1/sqrt(N). If they do, then you are primarily looking at random data. If they scale "somewhat", then there is some systematic error. If they do not change at all, then all error is in the bias (MBE).
...which is highly unlikely, as you state.
In terms of air temperature measurement, you also have the question of radiation shielding (Stevenson Screen or other methods), ventilation, and such. If these factors change, then systematic error will change - which is why researchers doing this properly love to know details on station changes.
Again, it all comes down to knowing when you are dealing with systematic error or random error, and handling the data (and propagation of uncertainty) properly.
-
bdgwx at 06:17 AM on 29 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Another interesting aspect of the hypothetical ±0.2 C uncertainty is that while it may primary represent a systematic component for an individual instrument (say -0.13 C bias for instrument A) when you switch the context to the aggregation of many instruments that systematic component now presents itself as a random component because instruments B, C, etc. would each have different biases.
The GUM actually has a note about this concept in section E3.6.
Benefit c) is highly advantageous because such categorization is frequently a source of confusion; an uncertainty component is not either “random” or “systematic”. Its nature is conditioned by the use made of the corresponding quantity, or more formally, by the context in which the quantity appears in the mathematical model that describes the measurement. Thus, when its corresponding quantity is used in a different context, a “random” component may become a “systematic” component, and vice versa.
This is why when we aggregate temperature measurements spatially we get a lot of cancellation of those individual biases resulting in an uncertainty of the average that at least somewhat scales with 1/sqrt(N). Obviously there will be still be some correlation so you won't get the full 1/sqrt(N) scaling effect, but you will get a significant part of it. This is in direct conflict with Pat Frank's claim that there is no reduction in the uncertainty of an average of temperatures at all. The only way you would not get any reduction in uncertainty is if each and every instrument had the exact same bias. Obviously that is infintesemially unlikely especially given the 10,000+ stations that most traditional datasets assimilate.
-
Bob Loblaw at 06:05 AM on 29 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
At the risk of becoming TLDR, I am going to follow up on something I said in comment #5:
On page 18, in the last paragraph, [Pat Frank] makes the claim that "...the ship bucket and engine-intake measurement errors displayed non-normal distributions, inconsistent with random error."
Here is a (pseudo) random sequence of 1000 values, generated in a spreadsheet, using a mean of 0.5 and a standard deviation of 0.15. (Due to random variation, the mean of this sample is 0.508, with a standard deviation of 0.147.)
If you calculate the serial correlation (point 1 vs 2, point 2 vs 3, etc.) you get r = -0.018.
Here is the histogram of the data. Looks pretty "normal" to me.
Here is another sequence of values, fitting the same distribution (and with the same mean and standard deviation) as above:
How do I know the distribution, mean , and standard deviation are the same? I just took the sequence from the first figure and sorted the values. The fact that this sequence is a normally-distributed collection of values has nothing to do with whether the sequence is random or not. In this second case, the serial correlation coefficient is 0.99989. The sequence is obviously not random.
Still not convinced? Let's take another sequence of values, generated as a uniform pseudo-random sequence ranging from 0 to 1, in the same spreadsheet:
In this case, the mean is 0.4987, and the standard deviation is 0.292, but the distribution is clearly not normal. The serial correlation R value is -0.015. Here is the histogram. Not perfectly uniform, but this is a random sequence, so we don't expect every sequence to be perfect. It certainly is not normally-distributed.
Once again, if we sort that sequence, we will get exactly the same histogram for the distribution, and exactly the same mean and standard deviation. Here is the sorted sequence, with r = 0.999994:
You can't tell if things are random by looking at the distribution of values.
Don't listen to Pat Frank.
-
Bob Loblaw at 00:58 AM on 29 August 2023Eastern Canada wildfires: Climate change doubled likelihood of ‘extreme fire weather’
In this post, the link to Fire Weather Index (in the Fire Weather section) points to a European site.
Details on the Canadian Forest Fire Weather Index System can be seen on this Natural Resources Canada web page. The system combines weather, fuel moisture, and fire behaviour indices into a rating of the danger of fires developing.
-
Bob Loblaw at 00:12 AM on 29 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Getting back to the temperature question, what happens when a manufacturer states that the accuracy of a sensor they are selling is +/-0.2C? Does this mean that when you buy one, and try to measure a known temperature (an ice-water bath at 0C is a good fixed point), that your readings will vary by +/-0.2C from the correct value? No, it most likely will not.
In all likelihood, the manufacturer's specification of +/-0.2C applies to a large collection of those temperature sensors. The first one might read 0.1C too high. The second might read 0.13C too low. And the third one might read 0.01C too high. And the fourth one might have no error, etc.
If you bought sensor #2, it will have a fixed error of -0.13C. It will not show random errors in the range +/-0.2C - it has a Mean Bias Error (as described in the OP). When you take a long sequence of readings, they will all be 0.13C too low.
- You may not know that your sensor has an error of -0.13C, so your uncertainty in the absolute temperature falls in the +/-0.2C range, but once you bought the sensor, your selection from that +/-0.2C range is complete and fixed at the (unknown) value of -0.13C.
- You do not propagate this fixed -0.13C error through multiple measurements by using the +/-0.2C uncertainty in the large batch of sensors. That +/-0.2C uncertainty would only vary over time if you kept buying a new sensor for each reading, so that you are taking another (different) sample out of the +/-0.2C distribution. The randomness within the +/-0.2C range falls under the "which sensor did they ship?" question, not the "did I take another reading?" question.
- When you want to examine the trend in temperature, that fixed error becomes part of the regression constant, not the slope.
- ...and if you use temperature anomalies (subtracting the mean value), then the fixed error subtracts out.
Proper estimation of propagation of uncertainty requires recognizing the proper type of error, the proper source, and properly identifying when sampling results in a new value extracted from the distribution of errors.
-
Bob Loblaw at 23:50 PM on 28 August 2023A Frank Discussion About the Propagation of Measurement Uncertainty
Eclectic # 43: you can write books on propagation of uncertainty - oh, wait. People have. The GUM is excellent. Links in previous comments.
When I taught climatology at university, part of my exams included doing calculations of various sorts. I did not want students wasting time trying to memorize equations, though - so the exam included all the equations at the start (whether they were needed in the exam or not). No explanation of what the terms were, and no indication what each equation was for - that is what the students needed to learn. Once they reached the calculations questions, they knew they could find the correct equation form on the exam, but they needed to know enough to pick the right one.
Pat Frank is able to look up equations and regurgitate them, but he appears to have little understanding of what they mean and how to use them. [In the sqrt(N) case in this most recent paper, he seems to have choked on his own vomit, though.]
