5 ms·

> You're wrong. The predictions are very good, and your claims are based on... some wrong sources obviously. The main reference I have in mind is just http://

by graycat 10y ago

> You're wrong. The predictions are very good, and your claims are based on... some wrong sources obviously. The main reference I have in mind is just http://www.energyadvocate.com/gc1.jpg http://www.energyadvocate.com/gc1.jpg that for dozens of climate models plots the predicted values of global temperature along with the observed values. Nearly all the predicted values are wildly too high. So, if we believe the graph, then in science we essentially junk nearly all the models. As I tried to outline, the model builders were on a long walk on a short pier: Nearly all their modeling efforts, with whatever approximations, short cuts, etc. they took, failed. Then, really, to return to first principles, they had to solve the Navier-Stokes equations for the surface of the earth, the oceans and the atmosphere. Doing a good job with that would be essentially minute by minute weather prediction, and as we know we can't do that accurately for more than two weeks or so. That's what the model builders ran into -- the Navier-Stokes equations. IIRC we've had some good progress with those equations for, say, some boat hulls and some aircraft wings. The whole earth? Not a chance. > It's irrelevant that you don't know. Sure it is relevant if accept a little diplomatic circumlocution: I've tried to follow some of the global warming issue for years, and so far I have not seen the data. Without the circumlocution and diplomacy, the more literal and blunt remark is that nearly all of us are short on such data either because it has not been collected very well or the people writing the main arguments don't include it. Or, the situation is like I was a customer at a fast food restaurant, got a hamburger, opened it up, and asked "I don't know where the beef is". > No "denier" was able to make anything scientifically relevant up to now. That's the fact. Well, in the graph in the link I gave above, a few of the models, maybe only one, were fairly accurate -- they predicted nearly no increase in global temperatures. So, maybe the author of that model was a "denier" in which case at least one "denier" did something "scientifically relevant". For more on "scientifically relevant" from deniers, there is the argument that at least for the past few thousand years, we know the cause of the temperature changes, and CO2 had nothing to do with the changes. Really, basically the greenhouse effect -- from CO2, methane, water vapor, etc. -- didn't either. Instead the cause of global cooling was more clouds -- they have a net cooling effect (net, not a greenhouse effect). The clouds were from some water molecules in the atmosphere collected into water droplets from the action of cosmic rays. Of course, the cosmic rays come at essentially constant rates over time but maybe with some variation with direction. So, when there was fewer cosmic rays, there were fewer clouds and some global warming. Why fewer cosmic rays? Well, when the sun has sun spots, there is more solar wind -- think really 3D all around our solar system, not just in the plane of the orbit of the earth, and reducing the rate of cosmic rays from all directions including way out and high above the plane of the earth's orbit. So, when the sun has more sun spots, there is more solar wind, more cosmic rays blocked from hitting the earth, fewer clouds, and global warming. When the sun is quieter, there is some global cooling. IIRC, over the past few thousand years or so, and maybe longer, the data on variations in sun spots do well fitting the variations in global temperatures while data on CO2 concentrations does not. So, people with the sun spot explanation are "deniers" and may have found the real cause of global warming/cooling for the last few thousand years or so at least and, thus, been "scientifically relevant". More generally, science needs to be subject to review, and a reviewer, even a "denier", who does find actual errors is also "scientifically relevant". Along the lines of reviewing, I would note that so far it appears that over the past 800,000 years, the cases of global cooling were not preceded by lower concentrations of CO2. E.g., the Little Ice Age was not preceded by lower concentrations of CO2. Neither was the cooling from 1940 to 1970. For more, yes, sure, CO2 is a greenhouse gas. Fine. We agree on that. So, CO2 can warm the earth -- we agree. But we can also agree that lighting a match will warm the earth. So, for CO2 warming the earth, the question is how much? Hate to say: (A) Just looking at the historical record from the past few thousand years, maybe the past 800,000 years, it appears that more CO2 has no detectable warming effect. (B) For some solid science, e.g., evaluating the effect of CO2 just from first principles of mathematical physics, including the Navier-Stokes equations, we can't do the calculations and, thus, for this approach, are stuck-o. Here maybe (A) is a review and "scientifically relevant". For (B), that's also "scientifically relevant" but so obvious that it is a trivial contribution. There are a lot of research problems without good solutions -- some of the details of the big bang, dark energy, dark matter, the origin of the highest energy cosmic rays, the origin of life on earth, quantum mechanics and relativity inside a black hole, a cure for cancer, how good natural intelligence works, etc. Well, one more is prediction of the temperature of earth for the next 100 years. Sorry 'bout that. While I've solved some problems in applied math and published the results, I can't apologize for not solving all outstanding problems. Sorry I don't know how to predict the temperature of earth for the next 100 years, but maybe I should say that I can't see that anyone else knows how either. In that case, my view is that carbon taxes are not justified.

rusk 10y ago
Ah! Circumlocution. My new favourite word :) I had a look at the Navier-Stokes stuff and what I found was incredible complicated maths. I'd like it if you'd linked out to some discussions on this topic but in any case I was able to find this [0] which takes the position that many climate scientists have invoked Navier-Stokes as a theoretical basis but mathematicians in general consider the finer details of NS behaviour at this scale to be (practically) unknowable. My personal insight from an information science pov is that NS would be the wrong tool to use. It looks like an exhaustive model used at a fine-grained scale that would be simply too complex at macro level. [0] https://climateaudit.org/2005/12/22/gcms-and-the-navier-stokes-equations/ https://climateaudit.org/2005/12/22/gcms-and-the-navier-stok...
- graycat 10y ago
  When I was applying to grad school for applied math, one place I applied was the Division of Applied Math at Brown University. I had a business trip to the small jet engine shop of GE in Lynn, MA, so went down to Brown to meet some profs. Had lunch. Talked. I got one piece of advice: "Stay away from the Navier-Stokes equations." Yup, good advice. The Navier-Stokes equations are old stuff now. Basically they are just Newton's second law, the gas law, etc. -- just basic physics. If you want to calculate the flows of fluids -- liquids and/or gasses -- from first principles of the basic physics, then you are stuck with the Navier-Stokes equations. It's like calculating the trajectory of a home run baseball -- need Newton's second law, the law of gravity, and at least something first cut on air resistance (right, in fine detail, the air resistance would again be the Navier-Stokes equations but good enough for a baseball or artillery shell, there are some good enough, simple approximations). Or for calculating what fluids do, from the basic physics, that is, from what we DO know about the basic physics, we just can't avoid the Navier-Stokes equations anymore than for the baseball we can avoid Newton's second law force = mass times acceleration. Yup, this is a case were we know too much: We DO know that, for calculating from a solid basis, that is, from first principles, for the math we need, we DO have the equations and they are just the Navier-Stokes equations. Sorry 'bout that. You mentioned that you noticed that the Navier-Stokes equations are complicated math -- right! As I mentioned, maybe we can do well with the Navier-Stokes equations for some boat hull or some airplane wing. Okay. Early in my career, I got started on the Navier-Stokes equations at the US Naval Ship R&D Center at Carderock, MD -- right, with the big towing tank used for designing ship hulls. That was before the guy at Brown told me "stay away from the" equations. He was right! So, you are correct: Trying to solve the Navier-Stokes equations for all the oceans and all the atmosphere of the earth is a wild thigh slapper, absurd, out of the question. We don't have such a computer. Even if we did, we don't have even the required initial conditions -- that is, the current state of the flows in the oceans and the atmosphere. Or, we are stuck-o. We will also want to know that the Navier-Stokes equations are nicely stable, that is, that a butterfly flapping its wings in NY will not cause rain instead of sunshine in Japan (to borrow from various movies). IIRC, Richard Bellman wrote his Princeton dissertation on the stability of ordinary differential equations -- IIRC the stability of the Navier-Stokes equations is a challenging topic, e.g., appears to be part of one of the Clay Math problems along with P versus NP, etc. And the real problem is still worse: E.g., likely we would have to handle turbulence, known to be difficult. When I was at Carderock, there was a guy working on turblence; he had been for years; maybe he is still there still working on turbulence; maybe in another 100 years he will have some good progress! In principle, we are talking about handling winds blowing through trees (would need the details on all the leaves of all the trees!!!) and the resulting turbulence. Would need some good details on associated biology. Would need .... And after have all of that, as the climate started to change, we would need good details on how the biology would change, and we don't have any equations from first principles for that. So, why do we need to do the fluid flow calculations? Well, we're talking about CO2. For that, we want to know where it goes, e.g., into the water, out of the water, into/out of seashells into the upper atmosphere, close to the ground, as it warms, as in the greenhouse effect, where it goes, sucked up by the plants, reacts with rocks, etc. So, what people have done is use various assumptions, simplifications, and approximations. It's a little like in freshman physics where we assume a block slides down a plane, and the plane has no friction, or a ball rolls down a plane and we ignore the moment of inertia of the ball. So, people tried such approximations, etc. We DO know the basic physics, and a big part of that is the Navier-Stokes equations. And we have more physics on the black body radiation that is the source of the infrared radiation that is the source of the warming of the CO2 that is the warming of the greenhouse effect. We have a lot of the basic physics and chemistry. And that basic science just does not tell us that there are some nice, easy approximations that will let us predict the climate. E.g., suppose some day during the years we are predicting, it rains. It might! Then after the rains, where is the CO2? Do we have partially carbonated rain water? In principle, we will want to know where the CO2 goes. So, part of our calculation will be to predict when it rains. Hmm .... Yes, as is often the case in physics, for some purposes we can just use the law of conservation of energy, calculate energy into the earth from the sun and energy out of the earth from radiation to space and get the balance and temperature change. Okay. But the details, if we want them, of the energy in and energy out will take us back to the Navier-Stokes equations. So, maybe we can make some simplifying assumptions. Apparently then ... we come up with the models that predicted much higher temperatures by now. Then, in all of this, we have an assumption that is now looking like week old dead fish: It's all about the greenhouse effect and CO2 and not something else. What "something else"? Apparently an argument can be made that, really, at anything like currently realistic levels of CO2, CO2 and the greenhouse effect are essentially irrelevant and the main cause is just clouds from water droplets from cosmic rays blocked or not by the solar wind from sun spots. In that case, we can calculate all we want with the Navier-Stokes equations, make more bad predictions, and accumulate some big computer bills. So, for accurate predictions, we'd be into predicting the sun spot activity of the sun. Hmm .... Is that at all promising? The lecture on geology and CO2 was really interesting: It got into the orbit of the earth, the power (energy per unit time) to the earth from solar radiation, some geology, and some tricky chemistry but not sun spots! Net, so far, it's tough to predict either the weather or the climate. Sorry 'bout that! It's also tough to cure cancer, explain dark matter and dark energy, ..., etc.

by graycat 10y ago

rusk 10y ago

Ah! Circumlocution. My new favourite word :) I had a look at the Navier-Stokes stuff and what I found was incredible complicated maths. I'd like it if you'd linked out to some discussions on this topic but in any case I was able to find this [0] which takes the position that many climate scientists have invoked Navier-Stokes as a theoretical basis but mathematicians in general consider the finer details of NS behaviour at this scale to be (practically) unknowable. My personal insight from an information science pov is that NS would be the wrong tool to use. It looks like an exhaustive model used at a fine-grained scale that would be simply too complex at macro level. [0] https://climateaudit.org/2005/12/22/gcms-and-the-navier-stokes-equations/ https://climateaudit.org/2005/12/22/gcms-and-the-navier-stok...

graycat 10y ago
When I was applying to grad school for applied math, one place I applied was the Division of Applied Math at Brown University. I had a business trip to the small jet engine shop of GE in Lynn, MA, so went down to Brown to meet some profs. Had lunch. Talked. I got one piece of advice: "Stay away from the Navier-Stokes equations." Yup, good advice. The Navier-Stokes equations are old stuff now. Basically they are just Newton's second law, the gas law, etc. -- just basic physics. If you want to calculate the flows of fluids -- liquids and/or gasses -- from first principles of the basic physics, then you are stuck with the Navier-Stokes equations. It's like calculating the trajectory of a home run baseball -- need Newton's second law, the law of gravity, and at least something first cut on air resistance (right, in fine detail, the air resistance would again be the Navier-Stokes equations but good enough for a baseball or artillery shell, there are some good enough, simple approximations). Or for calculating what fluids do, from the basic physics, that is, from what we DO know about the basic physics, we just can't avoid the Navier-Stokes equations anymore than for the baseball we can avoid Newton's second law force = mass times acceleration. Yup, this is a case were we know too much: We DO know that, for calculating from a solid basis, that is, from first principles, for the math we need, we DO have the equations and they are just the Navier-Stokes equations. Sorry 'bout that. You mentioned that you noticed that the Navier-Stokes equations are complicated math -- right! As I mentioned, maybe we can do well with the Navier-Stokes equations for some boat hull or some airplane wing. Okay. Early in my career, I got started on the Navier-Stokes equations at the US Naval Ship R&D Center at Carderock, MD -- right, with the big towing tank used for designing ship hulls. That was before the guy at Brown told me "stay away from the" equations. He was right! So, you are correct: Trying to solve the Navier-Stokes equations for all the oceans and all the atmosphere of the earth is a wild thigh slapper, absurd, out of the question. We don't have such a computer. Even if we did, we don't have even the required initial conditions -- that is, the current state of the flows in the oceans and the atmosphere. Or, we are stuck-o. We will also want to know that the Navier-Stokes equations are nicely stable, that is, that a butterfly flapping its wings in NY will not cause rain instead of sunshine in Japan (to borrow from various movies). IIRC, Richard Bellman wrote his Princeton dissertation on the stability of ordinary differential equations -- IIRC the stability of the Navier-Stokes equations is a challenging topic, e.g., appears to be part of one of the Clay Math problems along with P versus NP, etc. And the real problem is still worse: E.g., likely we would have to handle turbulence, known to be difficult. When I was at Carderock, there was a guy working on turblence; he had been for years; maybe he is still there still working on turbulence; maybe in another 100 years he will have some good progress! In principle, we are talking about handling winds blowing through trees (would need the details on all the leaves of all the trees!!!) and the resulting turbulence. Would need some good details on associated biology. Would need .... And after have all of that, as the climate started to change, we would need good details on how the biology would change, and we don't have any equations from first principles for that. So, why do we need to do the fluid flow calculations? Well, we're talking about CO2. For that, we want to know where it goes, e.g., into the water, out of the water, into/out of seashells into the upper atmosphere, close to the ground, as it warms, as in the greenhouse effect, where it goes, sucked up by the plants, reacts with rocks, etc. So, what people have done is use various assumptions, simplifications, and approximations. It's a little like in freshman physics where we assume a block slides down a plane, and the plane has no friction, or a ball rolls down a plane and we ignore the moment of inertia of the ball. So, people tried such approximations, etc. We DO know the basic physics, and a big part of that is the Navier-Stokes equations. And we have more physics on the black body radiation that is the source of the infrared radiation that is the source of the warming of the CO2 that is the warming of the greenhouse effect. We have a lot of the basic physics and chemistry. And that basic science just does not tell us that there are some nice, easy approximations that will let us predict the climate. E.g., suppose some day during the years we are predicting, it rains. It might! Then after the rains, where is the CO2? Do we have partially carbonated rain water? In principle, we will want to know where the CO2 goes. So, part of our calculation will be to predict when it rains. Hmm .... Yes, as is often the case in physics, for some purposes we can just use the law of conservation of energy, calculate energy into the earth from the sun and energy out of the earth from radiation to space and get the balance and temperature change. Okay. But the details, if we want them, of the energy in and energy out will take us back to the Navier-Stokes equations. So, maybe we can make some simplifying assumptions. Apparently then ... we come up with the models that predicted much higher temperatures by now. Then, in all of this, we have an assumption that is now looking like week old dead fish: It's all about the greenhouse effect and CO2 and not something else. What "something else"? Apparently an argument can be made that, really, at anything like currently realistic levels of CO2, CO2 and the greenhouse effect are essentially irrelevant and the main cause is just clouds from water droplets from cosmic rays blocked or not by the solar wind from sun spots. In that case, we can calculate all we want with the Navier-Stokes equations, make more bad predictions, and accumulate some big computer bills. So, for accurate predictions, we'd be into predicting the sun spot activity of the sun. Hmm .... Is that at all promising? The lecture on geology and CO2 was really interesting: It got into the orbit of the earth, the power (energy per unit time) to the earth from solar radiation, some geology, and some tricky chemistry but not sun spots! Net, so far, it's tough to predict either the weather or the climate. Sorry 'bout that! It's also tough to cure cancer, explain dark matter and dark energy, ..., etc.