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:
-
nigelj at 08:42 AM on 11 June 2023The little-known, massive advantage that renewables hold over coal
David-acct
Nameplate ratings and related performance can be misleading:
"Rated output, also known as Nameplate Rating, is determined by the wind turbine manufacturer, based on their chosen wind speed. The rated output can be a high number or a low number, depending on the wind regime chosen for performance calculations. In its current state, there is no unified approach to wind turbine ratings, making the process capricious."
There are of course periods where output of wind turbiness drops meaning we need gas backup. This is better than using gas 100% of the time. And storage systems are developing as an alternative to gas backup. There are other solutions as well.
No system is going to be perfect, but until you propose an alternative to renewables you arent making much of a case.
I agree with M Sweets take on the situation.
-
michael sweet at 02:08 AM on 11 June 2023The little-known, massive advantage that renewables hold over coal
David-acct:
Think about it: what do you expect to happen in 50 years of BAU when all the cheap fossil fuels have been used up? Will everyone go back to living in caves or will they set up a completely renewable energy system? There is no need to ruin the entire ecosystem when we have the technology to make the switch now.
-
michael sweet at 02:01 AM on 11 June 2023The little-known, massive advantage that renewables hold over coal
David-acct,
So no analysis to respond to the scientific consensus that renewable energy can powe r the entire economy for about half ote cost of fossil fuels, including any storage needed. There are a great many scientific papers, written by specialists with actual experience and data to support their conclusions, that analyze this issue in great depth and you respond with "look at this website with no analysis".
Fwiw, NERC is a legacy organization run by utilities who have a vested interest in not changing the profitable status quo.
-
fertilityacupuncture at 23:18 PM on 10 June 2023The little-known, massive advantage that renewables hold over coal
You make an excellent point about the inefficiency of burning fossil fuels to generate electricity. Not only does burning coal have detrimental effects on the environment, human health, and emit large amounts of carbon pollution, but it is also an astonishingly inefficient process.
-
Aimeeraupp at 21:41 PM on 10 June 2023What ‘The Simpsons’ taught ’90s kids about climate change
Great article! "The Simpsons" has always been known for its clever satirical commentary on societal issues, and it's fantastic to see them tackle the topic of climate change. By using humor and wit, the show effectively raises awareness about the urgent need for action and the potential consequences of ignoring climate change. It's important to recognize that even popular culture plays a role in shaping public opinion and driving conversations about such critical issues. Kudos to "The Simpsons" for using their platform to educate and entertain while addressing the pressing reality of climate change.
-
David-acct at 20:30 PM on 10 June 2023The little-known, massive advantage that renewables hold over coal
Michael
I again urge you and others to become familiar with the EIA detail, Its a great source of the real time and historical source data.
My comments are consistent with the NERC 2023 summer risk assessment. As noted on page 44 of the report, wind will produce in the range of 19% of name plate capacity during peak periods. fwiw, the NERC is run by individuals with actual experience .
www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/NERC_SRA_2023.pdf
-
One Planet Only Forever at 13:32 PM on 9 June 2023The little-known, massive advantage that renewables hold over coal
I disagree with using ‘thermal efficiency’ to promote Renewable Energy vs. Fossil fuel use. And I also disagree with claims that ‘reliability’ of a specific type of renewable generation justifies continued fossil fuel use.
Comparisons of the relative merit of different energy generation and use (the full cycle evaluation) should be based on Sustainability and Harmfulness.
Developing sustainable improvements requires less sustainable and more harmful activity to be corrected, even if the correction is more expensive, or less efficient, or unpopular. Coal with effective CCS will have lower ‘overall, complete system, thermal efficiency’. However, based on ‘harmfulness’, that ‘lower efficiency’ is clearly better than continuing to run the coal plant without CCS. Of course, if modifying a coal plant to add CCS is not ‘cost effective’ compared to less harmful and more renewable alternatives, then the coal plant should be shut down and replaced by the less harmful and more renewable generation. However, even more expensive replacements that are less harmful than existing developments should be implemented. And ‘more expensive’ alternatives could include needing to over-build the capacity of renewable generation with associated renewable sustainable energy storage. That will probably be required for truly sustainable energy generation system development.
The obvious resulting understanding is that reducing energy consumption to what is ‘truly needed’ and reducing the harmfulness of ‘that essential (actually needed, not desired)’ energy generation and consumption is the most important action. Reduced energy use is the most efficient way to limit the harm done while the system is corrected to end harmful unsustainable developed activity.
As is mentioned in the article: “No form of energy is without environmental and social consequences, but they certainly are not all equal. Energy that’s cleaner and more efficient is a clear improvement in many ways.” Reducing energy use is a very Efficient way to be cleaner (very effectively limiting harm done)’.
But the article makes a major error by saying that energy generation is “essential for powering modern life”. That fails to clarify that a major problem with modern life is the development of popular and profitable harmful unsustainable over-consumption. The more popular or profitable an activity and related beliefs become, the harder they are to correct. The ‘successful resistance’ to reducing, and ultimately ending, fossil fuel use is only one of many developed proofs of that understanding.
Supplementary points:
- Sustainability: Only renewable energy generation has the potential to be continued and improved on for the millions of years that this amazing planet could potentially support humans living as a sustainable part of a robust diversity of other life.
- Harmfulness: The harm to the sustainability of life on this planet, not just human lives, should be the primary measure for ranking the merit of ‘potentially sustainable’ alternatives. A potentially sustainable alternative would not be sustainable if it cause accumulating harm or consumed, rather than recycled, non-renewable materials.
-
michael sweet at 08:22 AM on 9 June 2023The little-known, massive advantage that renewables hold over coal
David-acct at 1:
Many peer reviewed papers like Jacobson et al 2022 find that a completely renewable system can be built at a much lower cost than using fossil fuels that provides 100% of power 24/7/365. They use past weather data to show that enough electricity can be generated so that all uses are met. They measure every 30 seconds for several years to show that all needs can be met. They also put in the various times you cherry pick to see if all needs can be met during those periods.
You claim without any analysis that the supposed low wind periods you mention will cause a problem. I note that one was during the summer when large amounts of solar will be available. Sufficient battery storage to cover low wind periods is part of the system. Hydro can cover 1-2 week periods in seasons when there is not an excess of solar power.
-
Rob Honeycutt at 07:07 AM on 9 June 20232nd law of thermodynamics contradicts greenhouse theory
Also @1533... "CO2 does not hold on to that energy."
CO2 does, though, slow the rate at which energy is emitted to space. Essentially, what greenhouse gases do is raise the altitude at which energy is emitted to space. In turn, it is the resulting thermal incline which determines the rise in surface temperature.
-
Rob Honeycutt at 07:01 AM on 9 June 20232nd law of thermodynamics contradicts greenhouse theory
Likeitwarm @1533... You might want to take note that the earth does not shed heat to space via convection. It does so through radiation.
-
Jim Eager at 00:29 AM on 9 June 2023The little-known, massive advantage that renewables hold over coal
Another advantage that renewables have over coal are the CO2 emissions of first extracting that coal from the ground, and then moving it from the mine to the power plant, which can be considerable.
True, some strip mines use electricly powered draglines to dig out the coal, and some power plants are located adjacent to the pit, but in the United States most extraction is by diesel-electric excavators and haul trucks, and then huge quantities of coal are moved very long distances by rail, powered almost exclusively by diesel-electric locomotives.
-
John Mason at 17:38 PM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
@ Likeitwarm #1533
Your dismissal of the blanket analogy - "a blanket works by preventing convection of air near and heated by conduction from my body", demonstrates a gross misunderstanding of how the human body loses heat.
If you lie outside with no clothes on on a cold day or night, your body will lose little heat due to conduction. Air is an utterly useless conductor of heat. Instread the human body loses almnost all heat by radiation - look up "radiative cooling". Then when you've done that, contemplate how frequently on winter mornings you've noticed cars covered in frost crystals but no grass frost. Some things are better at radiative cooling than others. Conduction within the metal body of the car makes sure it cools more evenly, but the cooling mechanism with respect to the surrounding air IS radiative.Anything that blocks that radiation through the surrounding air - by any mechanism - will give you a chance of survival - hence space-blankets, carried by many outdoor folks. It's also why we wear clothes and why on a hot summer's day we wear less of them.
-
MA Rodger at 16:00 PM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
Likeitwarm @1534,
You ask "Why can no body just answer my simple question?"
Your "simple question" was posed up-thread asking (as presented @1533 "Can an object be made warmer by reflecting its own radiation back on it?") to which the simple answer is "Yes" although your question is so poorly framed and using such inexact terminology that the "simple" answer is pretty meaningless. That is why you don't "just" get an answer to your "simple question."
An object's temperature is defined and defined by the energy it emits to its surroundings. Also, emitted energy cools the object while energy absorbed warms it. If an object has its radiation somehow reflected back to itself while also still receiving energy that has been maintaining its temperature, it will "be made warmer."
The interesting phenomenon in all this is the cause of the "reflecting its own radiation back" if the physics creating that energy flux is not actually 'reflection', which it isn't in this case. Such circumstance will require the "reflecting" agent to itself be "warmer" so what causes that. There in lies the cause of the greenhouse effect.
-
David-acct at 08:48 AM on 8 June 2023The little-known, massive advantage that renewables hold over coal
From Key takeaways in the article
· Selecting one example from the graph above, coal and renewables generated approximately the same amount of electricity in February 2022 — around 250,000 billion British thermal units, or BTUs.
While it is true that renewable electric generation with coal, One important point in the article which is missing is how poorly renewables did during parts of February 2022. Starting Feb 23, 2022 through Feb 28, 2022, electric generation from wind was only producing 30%-40% of the average for the month.
Similar though much worse drought of electric generation from wind occurred across the north amercian continent from February 8, 2021 through february 19, 2021 ( 11 days) with a loss of electric generation from wind averaging 60-80% over those 11 days. The month of august 2022 had nearly 3 weeks where electric generation from wind was only 20%-40% of the regular level of electric generation. ( even lower percentage of name plate capacity)
I have linked to the EIA.gov website which provides real time electric generation by source.
You can follow the link to see how frequently electric generation from wind drops percepiticely for several days at a time.
I can not over emphasize the benefits of using source data for understanding and comprehending the variability of electic generation by source
-
scaddenp at 08:10 AM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
Leaving aside the exact mechanism of a blanket, it keeps you warm by slowing the heat loss from you body. The earth is exactly the same - it is warmed by sun more than internally because atmosphere is largely transparent to incoming radiation and opaque to outgoing radiation. You dont have to dance around complicated explanations. You can simply measure it. And Eli succinctly explains how in that link, yes , a body can be made hotter by reflecting radiation back.
I'm curious - you have repeated myths all over the place which suggests somehow you got impression the science is wrong and then went searching for confirmation. Right back when you first heard about global warming, what made you decide that the science must be incorrect?
-
Charlie_Brown at 02:23 AM on 8 June 20232nd law of thermodynamics contradicts greenhouse theory
Likeitwarm @1533
You are correct that CO2 does not hold onto the radiant energy that it absorbs. By Kirchoff’s law, absorptance = emittance. But Kirchoff’s law has a caveat – at thermal equilibrium, which involves the collisions between molecules. However, your description about the importance of water vapor is not correct. The radiant energy mechanism for water vapor is similar to CO2, but the energy emitted to space is greater because it is emitted at warmer temperatures of the troposphere. By Beer’s law, the low concentration of CO2 is sufficient to create a cold emitting layer in the tropopause. Your discussion of emissivity gets lost in descriptions of cooling, getting hotter, and oxygen and nitrogen being the real greenhouse gases. I suggest that you review the “Intermediate” rebuttal of the 2nd law myth. It has a very good description of the radiant energy mechanism of global warming. -
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.
