Anatomy of a Climate Model: How Robust are Climate Projections?

[Barotropic]

Note: spectral (wave) models are much easier to simulate global circulations with than finite difference (grid point) models because, simply put, lines of longitude converge at the poles while lines of latitude remain everywhere parallel. While this is indeed the "polar singularity" problem, it is nothing "new".

[mojevalka]

eh, why is the audio so choppy?

[watup2154]

Computer and Computer and Computer..... You white people are just too much relying on """Computer""" and """Scientists""""

and ignoring what you are looking with your own eyes..... its the Ice Age people........... great changes already happening to our Planet......

[bmecher]

Yawn, talking about trees and ancient history. I lose my engagement.

[Nuedad]

Lets see if she can explain the 1300-1400s AD to me? There was no industrialization and certainly not any cars.

[Nuedad]

I bet she cant tell me what the weather will do next week much less in 25 years.

[addmoreice]

@Nuedad

weather != climate.

congratulations, You have demonstrated you are to ignorant to have an opinion on the subject.

[MargusMartsepp]

I knew, that there are intelligent and smart females, but she seems to be wise.

[flowewritharoma]

basically, I will like this video.

[Mathview]

Normally, we would require error bars, propagation of errors, and the like. Non-linear statistical extrapolations are well known to be highly sensitive to uncertainties in the data set. Hardly a scientific gold standard. I have to say that, I am concerned with what I hear in this talk.

[brennanww]

@Mathview seems like you know what you are talking about with this weather gizmo, teach me

[addmoreice]

@Mathview

if we are worried about weather then sure you can't predict it any further then about a week out. This is climate. not weather.

[Mathview]

@addmoreice The speaker describes two numerical models: (1) Time dependent fluid equations for the coupled air-sea system. Equations of a continuous time variable. They provide time dependent evolution of not only short time scales (weather) but also longer timescales (climate), subject to numerical convergence. (2) Less rigorous models "climate models" invoke a "block averaging" that aims to average out short timescales and get a longer timescale picture, "the climate." Both are discussed.

[addmoreice]

@Mathview Yes, I know. What I mean is that for what we are worried about in weather this works fine to the scale OF weather. For what we are worried about in climate, this works well in the scale of climate.

One is concerned with the exact phase state at a particular time during a simulation and it's relative accuracy. The other is concerned with the over all attraction state of the system, not the individual states.

not 'will there be rain on x date' but 'is rain to be more likely overall'.

[Mathview]

@addmoreice There is an important distinction between the two approaches: 1) Atmospheric Physics Simulations and 2) Climate Modeling. Numerical Simulations actually solve the coupled fluid equations, derived rigorously from fundamental physical theory, Navier Stokes Equation, thermodynamics, equations of state, etc. These are simulations. This contrasts with climate models obtained from various approximations and assumptions, of a less mathematically rigorous nature. Models, but still useful.

[addmoreice]

@Mathview

good point. Though the second model type is strongly dependent on the first in theory at least. Both are models though (that is what a simulation is).

The models seem reasonable, there are no glaring mistakes in any of them, the data input seems reasonable, and the conclusions reached, again, seem reasonable. The only ones who really claim otherwise seem to be screaming howler with no education in science, let alone the relevant field. The few exceptions all have specific concerns

[thegoodlocust]

Garbage in, Garbage out. 

[werecow2003]

Wonderful! I wish there were more talks on youtube about climate modeling.

[zassounotsukushi]

Great talk! I wish everyone spouting nonsense about the issue could sit and pay attention to this entire talk, but that's the problem, that they were never interested in listening.

[lennyhome]

More like anatomy of a pseudoscience and a very convenient set of lies.

[StarcrossedPacific]

@lennyhome how people in the face of a talk like this can make such a comment baffles me.

[lennyhome]

@StarcrossedPacific Well, I just did and I didn't feel weird or anything. What baffles me instead is how can educated people pick some sort of fancy interpolator, use it to make a prediction and then accept that as if it was scientific truth. It's just dumb... Or the biggest scam in the history of this planet.

[addmoreice]

@lennyhome

yeah, like all of physics.

[lennyhome]

@addmoreice No, like all of "climate science".

[addmoreice]

@lennyhome

No, I mean ALL of physics is taking a model to approximate reality, using it, getting a result, realizing it's not an exact match to reality, but that it's close enough.

The fact that the computer you typed that message on works is evidence enough that this system works.

Unless you have something a bit more then 'nuh uh!' I'm not exactly convinced YOU know more then the experts in the field of climate science. which is more likely.

you being ignorant or a world conspiracy?

[lennyhome]

@addmoreice Me being a what?

[addmoreice]

@lennyhome

Is it more likely that tens of thousands of reputable scientists with degree's from multiple collages (which have competing political, social, and economic backgrounds) ALL agree on the general climate predictions with vast agreements on the cause and effects.

OR is it more likely you are ignorant of the science, the evidence, and have a political and social bias?

which is more likely?

[lennyhome]

@addmoreice Sir, it doesn't matter is something is likely or not. What really matters is if something is true or not. Me having a personal bias doesn't change the fact that "climate science" is a sad farce. Also in your reasoning you're falling for the Argument from authority fallacy. If somebody with multiple college degrees would tell you to jump off a bridge, you would do it without questioning. That's how smart you are.

[addmoreice]

@lennyhome

*sigh* basic fallacy education time.

I didn't say 'this is true because these people are smart'. THAT is the argument from authority fallacy.

I said, I find it unlikely that this is false given the current consensus of well informed individuals.

probability, not certainty, admission of the possibility of error, not certitude.

your evidence for why climate science is wrong has so far been 'nuh uh'.

that doesn't convince me. The evidence indicates it's true.

[addmoreice]

"Sir, it doesn't matter is something is likely or not. What really matters is if something is true or not."

all we can test for is what is probably true, we can never know if something actually IS true. Science is in the business of falsifying theories. not proving them. All the evidence you can EVER find will only say 'this hasn't been shown wrong, yet. i am ever more certain it's true, but i still could be wrong".

The scientific consensus indicates that climate science works.

[lennyhome]

@addmoreice Exactly as you said. The scientific consensus indicates that climate science works but facts and observations prove that it doesn't.

[addmoreice]

@lennyhome

except you haven't demonstrated that. I've inspected the evidence, I've read many of the papers. I'm not an expert by any means. but it all seems pretty solid.

[lennyhome]

@addmoreice Wasn't this one supposed to be the hottest winter ever according to "climate scientists" predictions?

[addmoreice]

@lennyhome

Do you know the difference between speculative predictions which have not been vetoed by the scientific community but then are sensationalized by an eager to scoop but scientifically illiterate news corporation, and reputable scientific predictions?

the edges of scientific knowledge is that which is reported by news rooms, the edges are by there nature, the least sure. i said the core science is solid. not the edges of our knowledge.

[lennyhome]

@addmoreice Just say: "I was wrong. I now realize I was being deceived."

[addmoreice]

@lennyhome

you where wrong, you now know you where deceived. ok.

[addmoreice]

@lennyhome

here watch, weather prediction is based on a model of fluid flow dynamics, air flow behavior etc etc etc. with enough data you can predict relatively accurately how the weather will look in 7 days. you will NOT know when and where a specific updraft will occur, or when a specific wind gust will happen. but you will know that it will be windy.

going to a smaller scale you can use the same math and the same model and data to predict air/water flow in a small volume....

[addmoreice]

@addmoreice

you may not be able to predict when a specific vortex will form, but you WILL be able to predict IF a vortex will form, and where.

scale in the other direction. That's climate prediction. certain features are lost, other features are gained. yes it's a chaotic system, yes a butterfly in one location can change the direction of a hurricane a hundred years out....but the system tends towards regions of stability. they are mapping the regions of predictability.

[addmoreice]

@addmoreice

unlike the local weather report or a laminar flow assessment we don't have just a couple measurements and then trying to predict out for 7 days, we have MILLIONS of measurements and thousands of constant corrections according to the current measurements. Ie, the model is more accurate for what they are mapping and is constantly being corrected.

Some stuff *is* hard to predict, other stuff is dead simple. "it's going to get hotter" is about as damn simple as it gets.

[lennyhome]

@addmoreice You're being delusional.

[addmoreice]

@lennyhome

excellent rebuttal. how ever could I have thought my well reasoned, well argued, and evidentially supported thinking would ever hold up against your brilliant soliloquy? Your reasoning tour de force has utterly destroyed any conceptual construct that stood between me and your point of view! Your argument of "you're being delusional" effectively destroys my thinking.

I stand and salute you sir.

[thesparitan]

@addmoreice LOL

[thesparitan]

@lennyhome Do you know the difference between climate and weather?

[lennyhome]

@thesparitan Yeah. "Climate change" (or Global warming, whatever you call it today) is a scam and weather prediction is as accurate as a tarot reading. There you go.

[thesparitan]

@lennyhome You are likely a person with few friends, socially isolated and have a low level of trust. Further more you are paranoid and you make assumptions about everything. You also find contradictory information very uncomfortable. You not doubt have noticed that I have accurately understood your personality. You want to know why, because you are conspiracy minded and these are the common traits of those kinds of people. You also very ignorant of the subject.

[lennyhome]

@thesparitan Ad hominem attacks. Meningless.

[thesparitan]

@lennyhome That is not an ad hominem attack. An ad hominem is were you try to disprove someones claim by attacking there character, I was just attacking your character. I have not tried to disprove anything you have said. So maybe you also do not understand logic ether. Its common for uneducated people like yourself to get that logical fallacy wrong. Insults are not ad hominems. If that were true then being stupid would be logically impossible. clearly its not.

[lennyhome]

@thesparitan You suck.

[thesparitan]

@lennyhome There you go, good work. How long it take you to come up with that clever retort?  What is this 2nd grade level debate LOL

[Mathview]

This is an excellent seminar style talk. Intro for a general scientific audience to numerical modelling of the atmosphere-ocean coupled fluid system. We have time-dependent CFD-style predictive modeling using quasi-2D fluid equations, namely predictive weather forecasting. The second part of the talk is a discussion of mathematically less-rigorous approximate models which finesse the time dependence using various block-averaging schemes to "average-out " the weather and get the climate.

[Bitt33]

Uhnn it's hard to see the slides...

[HarshColby]

Lame first post