Arguments
Recent Comments
Prev 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Next
Comments 2001 to 2050:
-
One Planet Only Forever at 02:19 AM on 8 June 2023What does past climate change tell us?
EddieEvans,
If the responses by Bob Loblaw and BaerbelW fail to help you satisfy the people challenging you to 'falsify the understanding that human activity, particularly the burning of fossil fuels, is causing global warming' there may be another way to obtain satisfaction.
You could advise those who demand an evidence-based test that would 'attempt to falsify the understanding that human activity is causing global warming' that such a test would be as follows:
- Rapidly reduce human activity that is 'understood to be causing increased levels of CO2 and the resulting global warming (and the resulting climate changes) based on the current understanding that is to be falsified'
- Monitor the global warming (and CO2 levels) during that rapid impact reduction. And continue to monitor for at least 30 years after total global human impacts have been dramatically reduced.
- The lower the impact level is brought down to, and the more rapid the reduction of 'understood impacts' is, the more robust the 'proof of falsification' would be ... if indeed the understanding that human activity is causing global warming is false.
An alternative 'falsification test' would be to find another earth-like planet with a humanoid population that has developed without the 'understood global warming impacts' but still experienced rapid global warming like the type that is currently occurring on this planet.
Note that the harmful consequences of failing to reduce impacts ‘because of wishes to have falsification tests done’ make the alternative of ‘finding an alternate planet’ highly unlikely to be ‘completed in time to be helpful’.
-
Charlie_Brown at 02:01 AM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
Likeitwarm @1529
It’s easy to understand how one could be confused by this myth. It takes some serious study to sort through all of the distractions that are posed by Gerlich & Tscheuschner’s paper and discussed in over 1500 posts in this thread, especially since the little understood 2nd law of thermodynamics is invoked incorrectly as one of the main distractions.As I mentioned @1528, the 1st law of thermodynamics - conservation of energy – is applied.
Input = Output + AccumulationFor the global system of the surface and atmosphere, conservation of energy is:
Solar in = Solar reflected + Radiant Energy Out from greenhouse gases + Radiant Energy Out from Earth’s surface + AccumulationWhen input = output, the energy is balanced and accumulation = zero. As EddieEvans @1530 mentions, it’s all about changes to the energy balance. The blanket analogy is an example of affecting the energy balance, although it does not describe the mechanism of radiant energy.
Increasing greenhouse gas concentrations reduce radiant energy loss to space from the cold upper atmosphere. That upsets the global energy balance. Warming occurs until the energy loss to space, including radiant energy from the surface at specific wavelengths that are transparent to greenhouse gases, increases and the energy balance is restored.The 2nd law of thermodynamics describes limitations on how energy can be used in forms of heat and work. The problem with the myth is that it is based on an incorrect description of global warming. G&T’s paper describes modern global warming theory as “radiatively equilibrated”. It claims that the atmosphere acts as a perpetual heat pump that transfers heat from the cold stratosphere to the warm surface. G&T introduce distraction with a long discussion about the technical distinction between heat and energy, and a very long misrepresentation of global warming theory. However, since the energy balance is upset by increasing greenhouse gas concentrations, it is not equilibrated. Neither is global warming perpetual. The external energy source is the sun. Additional warming will stop when greenhouse gas concentrations stop rising and the equilibrium energy balance is restored at an elevated surface temperature.
-
Likeitwarm at 01:49 AM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
Sysop 1529
Why can no body just answer my simple question? Seems that thisis getting blown way out of proportion. Sorry my question was so offensive.
Moderator Response:[BL] You were pointed to a thorough explanation of how adding an object that absorbs and re-radiates IR radiation will heat an object that is being primarily heated by the sun. Here is is again:
http://rabett.blogspot.com/2017/10/an-evergreen-of-denial-is-that-colder.html
If you are not willing to read the references that people are providing - references that clearly answer your question and clarify your misunderstandings - then you are only wasting people's time.
-
Likeitwarm at 01:43 AM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
EddieEvans 1530 & scaddenp 1531
My question was simply; can an object be made warmer by reflecting its own radiation back on it?
It has nothing to do with all the other stuff you mentioned.scaddenp 1531
I do want to know the answer.
A blanket works by preventing convection of air near and heated by conduction from my body. My body generates heat due to its life processes. In the summer I might want that convection to occur in order to cool my body.
CO2 does not stop convection of the air. So, it does not act as a blanket.EddieEvans 1530
CO2 does not hold on to that energy. It loses it within milionths of a second by conduction of heat or emission of IR, most likely conduction via collisions, to get back to equillibrium with the air around it. Water vapor on the otherhand can hold on to it for a comparatively long time, at least until it rises via convection due to being heated and condenses at a higher altitude releasing the heat. The amount of energy, possibly returned to earth, if it makes it all the way to the surface, is but a fraction of what was originally emitted from the surface, especially with CO2 being only .04% of the air. CO2 emits much better than oxygen and nitrogen, so CO2 has a cooling effect. Emissivity is necessary for things to cool. Low emissivity makes thing have to get hotter in order to emit IR. I would be inclined to say oxygen and nitrogen having much lower emissivity are the real greenhouse gasses as they would hold on to the heat longer. The other things you mention may be. But, I digress. First, I just want to hear/read the answer to my question.Thanks.
Moderator Response:[BL] I have already tried to correct you on your confusions between "reflection" and "absorption and re-emission". Clearly you are not willing to let go of your misunderstandings.
The answer to your question does indeed have very much to do with the things that people are telling you. You are refusing to listen to anything that is outside the mental box you have put yourself in. That leaves you blind to the correct answers to your questions.
Your comments about CO2 vs. water vapour only further illustrate your poor understanding.
Before you can learn an answer to your "question" there is much you need to unlearn.
-
EddieEvans at 18:52 PM on 7 June 2023What does past climate change tell us?
BAERBELw@35, Bob Loblaw@34
Thanks!
"As a matter of fact, the ‘AGW-hypothesis’ is not a hypothesis in the Popperian sense. The human impact on climate is a theory, supported by many hypotheses, each of them tested according to widely accepted scientific standards. Just as Popper and his successors in the philosophy of science would have wanted."
-
BaerbelW at 15:19 PM on 7 June 2023What does past climate change tell us?
Eddie @33
Here is an old blog post from 2014 which gives some examples of how it would be falsifiable:
-
Bob Loblaw at 12:15 PM on 7 June 2023What does past climate change tell us?
Eddie @ 33:
Given that there is no single, simple hypothesis on which "anthropogenic global warming" is based, providing a simple example that would "falsify" it is a dishonest challenge.
The prediction of rising temperature in response to increased greenhouse gases is a logical consequence of many falsifiable aspects of physics. Just a handful, off the top of my head:
- energy conservation
- radiation theory (many sub-theories)
- CO2 gas absorbs and emits IR radiation at wavelengths that occur on earth.
- geophysical fluid dynamics
- gravity
- etc.
By "computer models", I assume that you mean models such as general circulation models used to simulate global climate. Such models are really just "computer solutions to mathematical models". The mathematical equations in such models are many - and cover the many aspects of physics that are required. All of those equations are - in principle - falsifiable. All of them have strong evidence that they are reasonably correct - i.e., nothing has been observed that would falsify the theories that they describe.
-
EddieEvans at 07:58 AM on 7 June 20232nd law of thermodynamics contradicts greenhouse theory
scaddenp at 07:01 AM on 7 June 2023
2nd law of thermodynamics contradicts greenhouse theoryI've forgotten how to use this board and answer. I'm not clear on what you don't understand. The blanket analogy is a common metaphor because the Earth's heat is being trapped by greenhouse gases, not unlike Venus.
I understand that the Earth warms and cools, primarily, by the Malankovich Cycles and trapped greenhouse gases. Is someone saying otherwise, and if so, how do they explain worldwide glacier melt and sea level rise?
-
scaddenp at 07:01 AM on 7 June 20232nd law of thermodynamics contradicts greenhouse theory
"Can someone please explain that to me?" Um, I would assume that you put a blanket on your bed at night to keep warm? How do you think that works? (Your body is irradiated in infrared). Since there are explanations here (the article) and plenty of others around the internet (eg here is a very good one), then I wonder how much you want to know the answer.
-
EddieEvans at 06:06 AM on 7 June 20232nd law of thermodynamics contradicts greenhouse theory
Likeitwarm
It sounds like the energy captured by greenhouse gases changes the Earth's energy balance. Without the greenhouse gases, Earth would freeze. From the page, "he Second Law does not state that the only flow of energy is from hot to cold - but instead that the net sum of the energy flows will be from hot to cold. That qualifier term, 'net', is the important one here. The Earth alone is not a "closed system", but is part of a constant, net energy flow from the Sun, to Earth and back out to space. Greenhouse gases simply inhibit part of that net flow, by returning some of the outgoing energy back towards Earth's surface.
The myth that the greenhouse effect is contrary to the second law of thermodynamics is mostly based on a very long 2009 paper by two German scientists (not climate scientists), Gerlich and Tscheuschner (G&T). In its title, the paper claimed to take down the theory that heat being trapped by our atmosphere keeps us warm. That's a huge claim to make – akin to stating there is no gravity."
More though, it seems that melting albedo on the Arctic Sea allows solar radiation to warming the ocean, which is something else to consider. I'm not a scientist, just interested.
-
EddieEvans at 05:51 AM on 7 June 2023What does past climate change tell us?
I've been asked to "falsify" anthropogenic global warming. I propose using computer models. Are such models available?
-
Likeitwarm at 04:55 AM on 7 June 20232nd law of thermodynamics contradicts greenhouse theory
I am confused, of course. According to greenhouse effect theory, about 50% of the radiation from the earth that CO2 captures is re-radiated back to the earth or somewhere in the atmosphere and recaptured. I didn't know an object could be made hotter by reflecting its own radiation back on it. Can someone explain that to me, please? Thanks.
Moderator Response:[BL] Yes, you certainly are confused, and your pattern of posing questions without reading the material available to you is very tiresome.
First, I suggest that you read up a bit on radiative transfer, and learn about how reflection is not the same things as absorption followed be re-radiation. Mixing up reflection and re-radiation is a pretty basic error, and tells me that you have a very poor understanding of some basic physics.
For the specifics about the greenhouse effect, scaddenp's comment (second after yours) points to a good post.
As to your "an object could be made hotter" comment - does it occur to you that the earth's surface receives heat from the sun at a pretty constant rate, and you can heat it up by reducing the rate that heat is lost back up through the atmosphere? Scaddenp's question about how a blanket can help keep you warm is a good starting point.
If you really want answers, you would be far better off explaining what you do understand (or think you understand), rather than asking the kind of questions you've been asking. Unless you engage in serious discussion, expect to see moderation applied to your posts.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive, off-topic posts or intentionally misleading comments and graphics or simply make things up. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter, as no further warnings shall be given.
-
BaerbelW at 19:25 PM on 4 June 2023It's cosmic rays
Please note: the basic version of this rebuttal has been updated on June 4, 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
Thanks - the Skeptical Science Team.
-
Bob Loblaw at 00:36 AM on 3 June 2023At a glance - How reliable are climate models?
For what it is worth, RealClimate has a recent post on model evaluation:
-
Bob Loblaw at 00:25 AM on 3 June 2023At a glance - How reliable are climate models?
Gootmud @ 41:
In the long-term, the "at a glance" is not intended as a stand-alone item. It's just the opening for the full rebuttal. Something more than a headline, but still something that is supposed to introduce the full article.
It sounds like you want something more like an abstract for a paper - something that very briefly introduces the subject and very briefly gives the answer. That could be a constructive improvement - something worth considering.
Full disclosure: I have not been active in the writing of these at-a-glance updates, although I am part of the SkS "team".
Keep in mind that the rebuttals here at SkS are responses to certain common myths found in the contrarian meta-world. The specific myth for this rebuttal basically comes down to an argument that models are completely useless. The Freeman Dyson quote at the top of the main article starts with "[Models] are full of fudge factors that are fitted to the existing climate..." Similar sentiments are often expressed more or less in the form "they just make the models do whatever they want". You don't need to show that climate models are perfect to dispute that myth - just show that there are (a lot of) things that they can do well.
Evaluating models is a complex process. A full-scale global climate model produces far more output than we actually have in weather/climate observations. Far more spatial resolution in temperature, humidity, wind speed, radiation, etc - both vertically and horizontally.
And global climate models are really an assembly of many other sub-models. A radiation model. A cloud formation model. A precipitation model. A fluid dynamics model. A surface evaporation model. (My background mostly focuses on microclimate models, incorporating surface conditions and soil temperatures.)
Each of these sub-models will undergo its own evaluation, usually on a localized scale where far more detailed observations are available and can be used to confirm proper model performance. Then, when all sub-models are integrated into a global climate model, more validation is done with global observations.
Often, the global climate model will contain simplified models, due to the need to run them for thousands of points at high temporal resolution for long periods of time. The simple models can be tested against the more complex models that have been validated against more detailed observations.
As you said: "reliable for what purposes?". There is no simple answer to quantify "reliability" under any circumstances, and even complex answers require an answer to that "what purpose?" question, first.
-
Eclectic at 23:56 PM on 2 June 2023At a glance - How reliable are climate models?
Gootmud @41 & prior ,
as I mentioned @40 , you need to clarify your thinking on reliability.
Especially re the purpose of reliability. Then you will be less confused.
-
Gootmud at 23:48 PM on 2 June 2023At a glance - How reliable are climate models?
Bob @38: sorry, I'm finding that super confusing. If the at-a-glance section isn't meant to summarize the answer, I don't understand what it's for.
Or perhaps what's confusing is the answer it's summarizing? The basic answer seems likewise wide of the mark. It restates the quantitative question as more of a binary--do the models work or not?--and suggests they do as demonstrated by hindcasting. But then it shows a graph saying they're too conservative. And then it cites Hausfather's claim that 14 of 17 projections are indistinguishable (another binarization) from what actually occurred, which obviously leaves three others. I'm still left wondering...how reliable are climate models?
What would help is more discussion of how we should think about reliability, as that's the title's load-bearing characterization. Are models that are right 14 out of 17 times reliable? Reliable for what purposes?
-
Eclectic at 23:45 PM on 2 June 2023At a glance - How reliable are climate models?
Gootmud @ 33 etc ,
the OP title indicates a brief description of the subject. Nicht wahr?
If you wish an exhaustive description/analysis , then you must read further into the subject. But best if you first decide on exactly what you wish to obtain ~ do you wish for results that are adequately reliable for practical purposes [and evidently they are ] . . . or do you wish for some mathematical quantification of "reliability" (in which case you will need to produce some cutting-edge methodology for the assessment).
PSBaker @34 & elsewhere ,
There is a great deal of vagueness everywhere, to be sure ;-)
However ~ "Driving with a fuzzy view of the climatic road ahead . . . is better than driving into the future with eyes closed." [Or have I misremembered that aphorism by Sun Tzu ? ]
But for short-medium term purposes in agriculture (including coffee growing) . . . it is fuzzily unclear why you would criticize models of 30+ year resolution [i.e. "climate" ] for not being useful in the shorter term. And to quote again perhaps from Sun Tzu :-
~ "Do not be angry that an elephant is not the size of a mouse."
-
Bob Loblaw at 23:22 PM on 2 June 2023At a glance - How reliable are climate models?
Gootmud @ 36:
If my comment at #38 seems to be an overreaction, I think it is partly due to your comment #33 appearing as if it was just a general overall dismissal of the new "At a glance", rather than a constructive suggestion of ways to improve it.
If you want to try again, giving specifics as to how you think such an answer to the question could be introduced into the text that has been posted in the OP, then that would be far more helpful.
-
Bob Loblaw at 23:01 PM on 2 June 2023At a glance - How reliable are climate models?
Gootmud @ 36:
Given that this specific post - in the very first sentence in the green box - says "the added "At a glance" section in the updated basic rebuttal versions", it is safe to say that yes, I see it differently.
I know this is probably "impossible expectations", but I expected readers to actually read the post, and understand that this post is just a way of presenting the new material added to the full post. After all, the second sentence in the green box at the top says "This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask."
-
Bob Loblaw at 22:55 PM on 2 June 2023At a glance - How reliable are climate models?
PSBaker @ 34:
And your response is pretty much what I expected from you. You consider the people that put hard work into models that you admit "are good at some things", and call them "the priesthood who elect to guard the eternal flame".
The full rebuttal is pretty clear about the type of models being examined - global climate models. These are not designed to do everything, and never will be. Nobody ever has a "model of everything".
The examples you gave are very limited in scope, yet you have decided that "There’s a whole sub-industry of scientists applying them to make unrealistic projections."
You have dismissed my previous comments with the phrase "Much of your ire seems to be focussed on lack of specificity, vagueness etc." In comment #30, I gave specifics comments on what I read in the Nature Climate Change articles you referenced. You have not provided any response or rebuttal to those comments of mine.
For someone who claims "That... is what the discussion of climate models should be addressing", you seem to be very reluctant to actually engage is serious discussion of the references you supplied. Instead, you just call it "a particular snarky rage".
Given that you will be unlikely to actually engage in any discussion if I provide comments on the video you link to, I think I'll save my effort.
-
Gootmud at 22:51 PM on 2 June 2023At a glance - How reliable are climate models?
Bob @35: I was commenting on this post, not on other posts it links to. I thought the whole point of the at-a-glance series was to present entry-level answers for people without the time or the mettle for more detailed versions. I was expecting an answer, albeit a simplified one, but one that addresses the question framed. Do you see it differently?
-
Bob Loblaw at 22:33 PM on 2 June 2023At a glance - How reliable are climate models?
Gootmud @ 33 and PSBaker # 34:
I will take those comments about lack of answers and vagueness in this specific post as a clear indication that neither of you have bothered to follow the links in this post to other posts that have additional details. The full "How reliable are Climate Models?" post has a basic and an intermediate tab with increasing level of detail.
I know that information about those extra details are hidden deeply in this post. You have to read all the way to the end of the very first paragraph in the green box at the top of this post to find where it says "Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there." And the actual links to 15 related SkS posts are also hard to find, being buried at the bottom under a big red heading that says "Click for further details".
[Still searching for that html sarcasm tag]
-
PSBaker at 21:44 PM on 2 June 2023At a glance - How reliable are climate models?
Goodness @Bob Loblaw @eclectic !
Much of your ire seems to be focussed on lack of specificity, vagueness etc …Sorry, I didn’t realize there is some sort of rule about it … but if you look at the OP, it is a model of vagueness, no papers cited – frankly, it’s pretty much waffle.
In my response I did provide examples, albeit the first to hand. I could have done better, but since @eclectic stated “ . . . but uncertainties are, for the rest of us, probably not worth addressing” I felt that, together with the lack of specificity in the OP, this gave me some liberty to extemporize. I also did not want to finger specific papers since I know some of the scientists involved, who have enough problems trying to navigate their careers without feeling picked upon.
I’m not surprised by the response though, this has been my experience through the latter part of my career – that criticizing modelling evokes a particular snarky rage from the priesthood who elect to guard the eternal flame.
My central point however remains valid, the models are good at somethings, lousy at others and there’s a whole sub-industry of scientists applying them to make unrealistic projections. We who work in the field, trying to help (in my case poor farmers) find them of little use and even counterproductive.
That, in my humble opinion, is what the discussion of climate models should be addressing and what I, in my albeit halting fashion, was trying to convey.
Here’s Dr Baethgen covering some of these points better than I can, in a lecture from 2020, (start ~8 mins), esp. 18 & ~35m “So when you see these beautiful maps with reds and greens, don’t trust them, remember that behind that colour is a big uncertainty.”
https://worldcoffeeresearch.org/news/2020/watch-a-new-way-to-think-about-climate-change
Moderator Response:[BL] Link activated. As previously stated, you need to do this yourself when preparing your comment.
-
Gootmud at 21:32 PM on 2 June 2023At a glance - How reliable are climate models?
So...how reliable are climate models? The title poses a quantitative question that the article never answers.
-
Eclectic at 09:23 AM on 2 June 2023At a glance - How reliable are climate models?
Bob Loblaw @31 ~ horrible to see how the Christy sausage is made !
Bob Loblaw @30 ~ thank you for the detailed critique. But you may (or perhaps may not) wish to make a small typo correction, where at about 70% of the way down, you quote the paper saying:
~ "heathland and grassland plant taxa"
~ which you rendered as: "heartland and grassland plant taxa".
Dr Freud (and I ) can't imagine how that slip happened. But delightful !
Moderator Response:[BL] Thanks. Corrected. That's what happens when you re-type instead of copying and pasting...
-
Bob Loblaw at 06:18 AM on 2 June 2023At a glance - How reliable are climate models?
In #28, Philippe states "considering how much of John Christy's work has been done by others, who caught his mistakes..."
Maybe Gordon thinks this is a feature, not a bug. I have actually known people to use this approach. It more or less works like this:
- Collect some data, write a sloppy paper in a hurry.
- Submit it to a journal, and let the reviewers tell you what you did wrong.
- Make those changes, and re-submit (to the same journal, if they will let you. If not, proceed directly to step 4.)
- If refused again, take the new comments, re-write it, and submit to a different journal.
- Repeat steps 3 and 4 until someone finally accepts it.
- List the paper on your C.V.
At the end, you've got your publication, and someone else has done most of the work for free.
If the first draft was so bad it can't be fixed, no problem - you didn't spend much time on it anyway.
Sometimes you'll get lucky and a poorly-informed editor will send it to people that can't properly review it, and the journal will accept it in it's original crappy version.
Even better: your original crappy version can be sent to a journal where the editor is your pal, and will accept it no matter how crappy it is because they like the conclusions.
The few people actually involved in reviewing the paper in the early stages get to know that you are a crappy scientist, but most people only see the final paper and judge you on that.
John Christy's mistake has been to see steps 2-5 play out in the published literature, instead of behind-the-scenes review. The mistakes and corrections by others are all part of the public record.
...but at least John Christy gets to put several papers on his C.V. (albeit bad ones, but it's the quantity that matters, not the quality). So, you know, glass half full.
-
Bob Loblaw at 06:01 AM on 2 June 2023At a glance - How reliable are climate models?
PSBaker @ 15:
First, let's address your statement "I was not referring to..."
In your first comment (#1), you weren't referring to anything specific. You finished off with a broad, sweeping generalization about "senior scientists and journal editors". This gives the appearance that you are casting a wide net - as Eclectic said in comment #2 "unless you feel something misleading or nefarious is being concealed by their omission."
So, now that you have actually provided some specific references, let's look at them. Eclectic has already made some comment in #18, but I have a few more points to make.
For your first reference (link to full artcle):
- Eclectic commented on the vagueness of much of the discussion. I tend to agree.
- I also note that the key figure 2, on precipitation changes, makes what I would consider to be a fundamental error in the use of global climate model projections. It uses the multi-model mean as if it is the predicted path. It is not. In the figure I included in comment #8, the Model ensemble spread that gives a better indication of the possible future paths as predicted by the models.
- In section 2.1, they talk about people often use an average from several models "so that only the trend remains", so they are aware of the issue, but then they went and used that same ensemble mean to do their analysis in figure 2.
- In the first part of section 2, they actually state "Although the limitations of climate change projections are well-documented... the consequences of these limitations for practical decision-making in development practice have not been clearly laid out for the nonspecialist." [emphasis added]
- I also note that the sentence from the abstract immediately preceding the one that you quote states: "Climate model projections are able to capture many aspects of the climate system and so can be relied upon to guide mitigation plans and broad adaptation strategies..."
Thus, your first reference is not a broad condemnation of climate models - and basically sounds like a cry that it's the fault of climate scientists that non-specialists don't pay attention to the well-documented efforts of those climate scientists to explain the limitations of climate models.
Now, for your two references to Nature Climate Change:
- The Lembrechts one is a short News & Views article, and the first reference it contains is to the Maclean and Early paper (the other reference you provide). It hardly constitutes a second, independent analysis.
- In the Maclean and Early paper, the data that they use to evaluate their microclimate approach (as opposed to a macro-climate approach that global climate models work with) uses two time periods: 1977-1995, and 2003-2021.
- The changes in "heathland and grassland plant taxa" that they are looking at would not experience substantial change during that period, compared to the expected changes over the next century. The differences in range shift they get from their two modelling approaches are 14km (macro) and
- The short time periods means that much of what they are modelling in the way of microclimate changes is going to be related to weather and short-term variability, not long-term major shifts.
- A major weakness in their argument is that they basically present a case where short-term small changes in climate conditions do not lead to major range shift - but the concerns for future climate are not related to minor shifts that have already occurred. They are related to the major shifts expected in the future, and how they will be occurring much faster than species have adapted to in the past.
So, your second and third references also do not reflect on unreliability of global climate models.
P.S. The next time you want to post a comment similar to #1, please provide the references you are relying on in your first post. And as Eclectic has stated in #18, you should also be providing some sort of detail on what it in those papers that you think is relevant, and what point you want to make.
Moderator Response:[BL] Typo corrected, as per comment below...
-
Philippe Chantreau at 03:08 AM on 2 June 2023At a glance - How reliable are climate models?
"Let's just look at the headlines."
No, let's not, under any circumstance. It is possibly the best way to be misinformed and disinformed. If that is your idea of thinking critically, you have a major problem.
-
Philippe Chantreau at 03:03 AM on 2 June 2023At a glance - How reliable are climate models?
That's rather funny considering how much of John Christy's work has been done by others, who caught his mistakes...
-
Rob Honeycutt at 00:42 AM on 2 June 2023At a glance - How reliable are climate models?
FYI... Christy doesn't do any climate modeling. He manages a satellite data set.
-
Rob Honeycutt at 00:40 AM on 2 June 2023At a glance - How reliable are climate models?
John Christy's presentations are cherry picked and deliberately misleading. So, no. Not like John Christy.
-
Gordon21829 at 15:57 PM on 1 June 2023At a glance - How reliable are climate models?
Like John Christy :-)
-
Rob Honeycutt at 14:53 PM on 1 June 2023At a glance - How reliable are climate models?
What's also clear, and is extensively discussed in each of the articles you've linked to, is the "models" being discussed are a subset of the ensemble mean. They're discussing a few of the models. They aren't saying all models run hot. Some actually run cool. And different model runs can run hot or cold. And modelers will often tweek the weighted balance of models to produce better results.
Before dismissing a major body of research because it doesn't conform to what you think it should do, perhaps it would be appropriate to do more research and perhaps even talk to an actual scientist who does modeling so you can better understand how they do their work.
Just a suggestion.
-
Rob Honeycutt at 14:45 PM on 1 June 2023At a glance - How reliable are climate models?
Don't just look at the headlines, Gordon. Read the materials in full.
It's clearly no "unfortunate" precisely because the models do a very good job. You are merely confusing scientists seeking ways to improve the models with thinking that means they're all bad. You're essentially motivated to throw the baby out with the bathwater.
The rebuttal states that models are not perfect.
-
Gordon21829 at 14:38 PM on 1 June 2023At a glance - How reliable are climate models?
Rob @ 20
Lets just look at the headlines:
"Use of ‘too hot’ climate models exaggerates impacts of global warming" "Guest post: How climate scientists should handle ‘hot models’" "Climate simulations: recognize the ‘hot model’ problem"
I will restate that It's unfortunate that so much of the scientific literature relies on these models in making projections. This is especially true in light of the concerns that have been raised in the linked articles and the fact that these projections are used by policy makers to determine our future.
I fail to see in the rebuttal any mention that there is an issue with models running too hot - just that the models are not perfect. If the reverse was true and the models were running colder that the observational data would the rebuttal still be primarily about an issue of perfection ?
-
Rob Honeycutt at 12:17 PM on 1 June 2023At a glance - How reliable are climate models?
Gordon... "If there is an issue shouldn't it be addressed in this rebuttal?"
It is addressed in this rebuttal. It's clearly stated that, "Climate models are not perfect. Nothing is. But they are phenomenally useful."
That statement is appropriately inclusive of the points you're bringing up.
-
Rob Honeycutt at 11:01 AM on 1 June 2023At a glance - How reliable are climate models?
Gordon... I get the sense you didn't actually read those articles because they state that "some" of the models run hot, not that "models run too hot."
Zeke's article on Carbon Brief that you've linked is a good one to read.
Perhaps you're also not understanding the expectations of climate models. No one expects that climate models are going to give us a precise pathway for global temperature. What they are intended to do is inform us in a way that benefits our understanding of the climate system and the likely impacts of our behaviors.
I've seen many a climate modeler saying, "Models are always wrong, but observations of the future are currently unavailable."
Climate models have actually done a very good job of projecting future temperatures over the years. Here's another Zeke piece on that topic.
You started commenting using Christy's work and haven't attempted to defend it. You're pulling up other examples of modelers doing their work improving the skills of their field by openly discussing areas of concern and methods to address them. But out of that you're somehow concluding, erroneously, that, "It's unfortunate that so much of the scientific literature relies on these models in making projections."
Your statement there is bizarre because, well, how else would one make projections if not by using models? And, your conclusion that the models are poor reveals your motivated reasoning on the subject, when in truth the models are not poor. They're really incredibly good.
Can models get better? Absolutely.
Are models a waste of time and money? Clearly not since they've consistently proven to be accurate within the range of uncertainties necessary to inform us of the challeges we face with climate change.
-
Gordon21829 at 09:37 AM on 1 June 2023At a glance - How reliable are climate models?
Rob @ 16
Why do science.org carbonbrief.org and nature.com all report that there is an issue with the models running too hot ? If there is an issue shouldn't it be addressed in this rebuttal ?
-
David-acct at 08:37 AM on 1 June 2023Skeptical Science New Research for Week #21 2023
The NERC 2023 reliability assessment/risk assessment goes into much further detail regarding the risks.
the Key point is detailed on page 44 of the report which shows the expected share of nameplate capacity for wind will be approx 19% (with only ERCOT exceeding 20% at 33%). What the reliability/risk assessment report is showing is the limitation of wind during peak loads.
EIA . gov is an excellent source of real time data which details the supply of electricity generated by source. Its very worthwhile to study and understand the detail provided, and thus become educated on the topic based on real time data.
Please note that you can select any US grid and any time period to get actual real time data
As comparison - you can select the months of July or August of 2022. The MISO, SWP and Ercot grids experienced significant declines in wind production of 7-9-22 through 7-14-2022, then again later in the month, Then again 8-9-2022 through 8-14-2022 and again starting 8-22-22, each of which were for periods 5 to 6 plus days.
-
Eclectic at 07:29 AM on 1 June 2023At a glance - How reliable are climate models?
Doug Bostrom @17 ~ A good point. Very !
PSBaker @15 ~ it would be helpful if you gave more detail on the 3 papers you mention.
Your first paper (H.Nissan et al., 2019) appears very vague, and talks in a general way about farmers' need for medium term weather predictions wrt pesticide spraying scheduling and suchlike agricultural management. Also talks (slightly) about 30-50 year plannings for dam construction. Overall, the paper had such an unapt & vague manner, that I began to suspect the authors were using AI-generated [ChatGPT] . This was not helped by their mention of soil-moisture predictions in three disparate parts of Bangladesh, nor of vague reference to rainfall pattern prediction in Kenya/Somalia. PSBaker, your quoted extract from the paper provides little-to-nil relevance to global climate modeling . . . and yet you seem to be using the #15 quote to circle back to a disparagement of climate models. [ If this was not your intent, then please be very specific on the point you were wishing to make. ]
Your second paper ( J.J.Lambrechts 2023) was paywalled [for me] but a half-Extract talked of micro-climates in a manner that suggested the body of the paper was not relevant to global climate modeling. Remember, this thread is a computer climate model thread.
Your third paper (Maclean & Early, 2023) was similarly unapt . . . but the paper's body did provide some amusement :- "We model ... distributions of 244 heathland and grassland plant taxa using both macro- and microclimate data and project these distributions ... [regarding] improving protection of refugial populations within species' geographic range ..."
Refugial populations of humans ~ would be more relevant to this thread.
-
Doug Bostrom at 05:03 AM on 1 June 2023At a glance - How reliable are climate models?
Tip of the hat to Gordon for reminding us of why Skeptical Science must unfortunately exist.
-
Rob Honeycutt at 00:54 AM on 1 June 2023At a glance - How reliable are climate models?
Gordon @12... For the tropical mid-troposphere that's not an accurate statement, though, since those "observed temperatures" are known to be very hard to collect and have a very high level of uncertainty. It's as likely the obs are running cool. That's an area of the atmosphere (specifically selected by John Christy) where the modeling is probably giving us better information than oberserations.
-
PSBaker at 18:38 PM on 31 May 2023At a glance - How reliable are climate models?
@ Bob Loblaw 8: I was not referring to contrarian sources, nor the global models of which you give an example.
Read Nissan’s et al paper to see what I mean DOI: 10.1002/wcc.579 “Climate models are unable to represent future conditions at the degree of spatial, temporal, and probabilistic precision with which projections are often provided, which gives a false impression of confidence to users of climate change information.”
Or more recent critiqueshttps://www.nature.com/articles/s41558-023-01632-5
https://www.nature.com/articles/s41558-023-01650-3
Moderator Response:[BL] Full link to the first reference mentioned is this
Second and third links turned into actual links..
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.
-
Eclectic at 18:19 PM on 31 May 2023At a glance - How reliable are climate models?
Gordon ~ Dr Christy's chart of 300-200 hPa . . . .
represents the atmosphere above the summit of Mt Everest.
Even a Yeti would die at those altitudes.
Possibly Dr Christy did not inform the Congressmen of the uselessness of his chart. But he still drew up the chart for them.
-
nigelj at 17:19 PM on 31 May 2023At a glance - How reliable are climate models?
Gordon @10
The IPCC WR5 projection in your comments includes observational data from 1970 - 2012 only. Its old data possibly from an older IPCC report. The observational data is quite close to the modelling for much of that period but the years 2005 - 2012 (approx) in that graph clearly fall significantly below the modelling mid line prediction. But this is a relatively short time frame, and it represents short term natural variation that models can't fully predict in terms of timing. This is the alleged pause in surface temperatures, which amounted to a flat period in the warming trend of about 7 years and was due to the influence of natural variation ( in simple terms)
The graph posted by Bob Loblow @ 8 includes observational data from 1970 - 2022 and so its much wider and more recent data, and its obvious that the warming trend from 2012 - 2022 has swung back to near the model mid line prediction, and that the observational trend is tracking quite close to the modelling overall for the full period 1920 - 2022. The modelling is obviously not running significantly hot.
I'm surprsied you didn't notice any of this.
-
Gordon21829 at 15:19 PM on 31 May 2023At a glance - How reliable are climate models?
Ron @11 similar insofar as the models are running hotter than the observed temperatures.
-
Rob Honeycutt at 15:05 PM on 31 May 2023At a glance - How reliable are climate models?
Gordon @10... It's not a similar chart, not least of all because it's an actual global mean projection rather than mid-troposphere.
-
Gordon21829 at 14:45 PM on 31 May 2023At a glance - How reliable are climate models?
Bob @ 6
Why does the IPCC run a similar chart in AR5 ?
-
Rob Honeycutt at 14:19 PM on 31 May 2023At a glance - How reliable are climate models?
A question for Gordon: Do you understand what "300-200hPa tropical temperature anomalies" are?
