Why would an AGW supporter care about computer generated climate models that are most always wrong?

Trevor

2014-01-31 13:13:30 UTC

If you take an honest and objective look at climate models, not the nonsense peddled on sites such as WUWT, then you’ll see that they were fairly accurate up to the point when warming stopped.

We don’t yet know for sure why the warming stopped, but more and more evidence is pointing to the same thing, namely that the heat has been absorbed by the oceans; other factors such as a prolonged low sunspot number and the Asian Brown Cloud are also contributing.

Climate models generally do not account for oceanic oscillations because a) they are unpredictable and b) the positive and negative phases balance over time.

The various oscillations that have the predominant influence on our climates have time-scales varying from a few months to approx 30 years, thus rendering climate models of less than 30 years duration highly susceptible to errors.

One you go beyond say 50 years, and have a balance between the positive and negative phases of natural fluctuations (i.e. they average themselves out), you get a more reliable forecast.

That said, the models have to incorporate a lot of variables and some of them are more guesswork than anything else, hence the wide range of outcomes.

To say that the models are wrong is demonstrating a lack of understanding of how they work, what they do and how they’re programmed.

Many of the models that sites such as WUWT claim are wrong were generated some 10 to 30 years ago. During the early years there was a more or less neutral influence on the climates from natural variations, during this period the models accurately projected temperatures. The projections continued but then the Pacific Decadal Oscillation entered a strong negative phase and the models diverged. However, the PDO will of course switch to a positive phase and this is likely to produce a period of very rapid warming bringing actual temps back up to projected levels.

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EDIT: TO WAGE SLAVE

It’s 1st Feb today and 7°C, what will be the temp a month from today, or two months, or three months…?

You don’t know, no-one does. It could be colder, it could be the same or it could be warmer. We do know that summer is coming and therefore the overall trend will be one of warming temps, but there are too many variables to give precise predictions.

It’s the same with the climate. The overall trend is an upward one but along the way there will be cooling and static periods.

You state that the PDO is well-known, knowing something doesn’t make it predictable. Lightening is well known, so on that basis we should know when and where the next strike will be.

From what we know of the PDO, it has a periodicity of 30 to 50 years, it’s been in the negative (cooling) phase for the last 15 years (since Aug 1998). It switched from a very high PDO Index and is now at it’s lowest known value. At some time within the next few years it will revert back to it’s positive phase, this will spell disaster for those claiming that global warming has stopped, it will also bring the observed temperature values closer to the modelled predictions, which will be yet another nail in the sceptic’s coffin.

EDIT: TO JIM

As I’ve already explained, models generally do not take oscillatory factors such as the PDO into consideration. When the PDO is negative, as it has been for the last 15 years, then the models will appear to overestimate temperatures. When oscillations are taken into account, the models are remarkably accurate; see link below (credit to Ottawa Mike for the link).

http://www.nature.com/nature/journal/v501/n7467/full/nature12534.html

Anil Mc

2014-02-02 07:38:14 UTC

In Trouble with Terraforming Mars, I looked at many things that could go wrong with such a project. But setting aside those issues, Mars terraforming takes us far into the realm of magical thinking - where if you can imagine something vividly, you can make it happen.

In this imagined future, with the ability to use giant space mirrors to warm up Mars, it is also easy to solve the energy crisis on Earth - just beam all the energy we need back to Earth from space solar power stations. With the fine control we need over planetary atmospheres, it is a trivial matter to adjust levels of CO2 from 0.04% back to 0.03% and stop global warming instantly.

Who knows what else we can do? We surely have fusion power by then, and with such vast powers we can probably also construct habitats anywhere in the solar system, including the Oort cloud, and the atmosphere of Saturn. Would we still want to terraform Mars? Would we be grateful to pioneers who attempted to terraform the planet a few decades or centuries previously? Or would we shake our heads in dismay at the way they have messed up the planet and made things hard for us?

FAILURES OF FUTURE IMAGINATION

Who knows, perhaps those vivid future imaginings will become a reality some time in the future. But there again, it might not happen. There might be many things about that picture that we are unable to imagine clearly and accurately right now.

What's easy to forget is that science fiction writers don't always get things right. They imagined television long before its time, but also wrote stories with explorers using slide rules in spaceships that travel faster than light. (Full text of the book, "Islands in Space" by John Campbell). The hard science fiction writer Isaac Asimov got many things wrong including his Multivac, a vast multi-story, half a mile long supercomputer made of vacuum tubes, with only one computer in the world.

Detail of the back of a panel of ENIAC, showing vacuum tubes. This was taken from the computer lab, which has a glass window to the back of the piece of ENIAC on display at the Moore School of Engineering and Applied Science. The image was perspective-corrected and cropped by myself. Original photo courtesy of Paul W Shaffer, released under GNU license along with 3 other images in an email to me. Copyright 2005 Paul W Shaffer, University of Pennsylvania.

Back of one of the panels of ENIAC. In his early stories, Asimov imagined that by now we would have a huge supercomputer several stories high and a half a mile long built of vacuum tubes like these - or in another story - that it would be the size of Washington DC - with many interior corridor, with the one supercomputer serving the entire world, or an entire country.

All the famous hard science fiction writers have had epic fails like this, as well as, sometimes, astonishingly accurate predictions.

John

2014-01-31 08:22:17 UTC

When one looks at the links that you have given us then it becomes quite obvious as to why you cannot carry on an intelligent conversation concerning AGW.

Global climate models have performed very well. When you look for absolutes in a model then you are looking for something that does not exist. The models were never designed to show absolutes since the natural variability of the climate still has an influence on the short term trends. "Noise", as it is known cannot be fully implemented into the models. No one carry predict, with any real degree of accuracy, as to how strong or enduring the TSI or any of the oscillations will be within the framework of the models. When will these variabilities begin, when will they end and in conjunction with which other short term variables that will come into play.

Models are tools used to help show the probabilities. Never the absolutes. Absolutes do not exist in the real world when you are projecting into the future. Observations can still be made that show what is happening. You do not need models or thermometers to know that much of the world's ice is in a state of decline. This is the result of a warming and not a cooling, in case you have forgotten this.

Added***

C, actually there are supporters of the AGW. They are all lining up now to exploit the Arctic region even further as the sea ice and permafrost melt into oblivion.

Mike

2014-02-01 16:27:06 UTC

They care about models because it is the only basis for scaring people that CO2 and greenhouse gases are a serious problem. Basic physics says CO2 warms the planet by 1.2C when levels double. They use the models to increase that number.

anonymous

2014-02-02 01:38:30 UTC

It's usually denialists who talk about climate models.

If our best scientists can't model climate, how can we know that global warming isn't very bad?

Caliserve

Wrong.

http://www.woodfortrees.org/plot/hadcrut3vgl/from:1969/scale:200/plot/hadcrut3vgl/from:1969/scale:200/trend/plot/sidc-ssn/from:1969/plot/sidc-ssn/from:1969/trend/plot/esrl-co2/from:1969/offset:-350

?

2014-02-02 18:06:34 UTC

I rely on observation, the earth is warming, despite denialist claims to the contrary.

Hey Dook

2014-01-31 13:20:05 UTC

If you accept the solid historical facts of the Holocaust, does that make you a "Holocaust supporter"?

If you accept that Nagaski was destoyed by a nuclear bomb, does that make you a "nuclear war supporter"?

So why does my accepting the solid science of climate change make me a "supporter" of climate change?

I can see how it might be difficult to understand science, most of it written up in English, when reading and writing in English is difficult.

But, even if you knew nothing about the Holocaust, and didn't want to bother to try to learn, would you trust neo-Nazi kook websites over 97% of history textbooks?

Edit to Raisin: You could delete every computer climate model ever made, and the observational evidence alone would be very solid and consistent in support of the general scientific consensus which for decades has found current long-run global climate change to be real, significant, mostly human-caused, and mostly negative for centuries to come. The order of magnitude for how long fossil-fuel derived CO2 remains in the atmosphere have been well known for decades. Don't take my word for it. Read the science.

Wage Slave

2014-01-31 13:13:48 UTC

Simple. Liberals have short memories. They don't care that the dire predictions from five years ago and ten years ago and 20 years ago never happened. Global warming is a serious problem which requires massive government intervention. Only the government can save us.

Edit: and here we have Trevor, a card carrying liberal who says:

"To say that the models are wrong is demonstrating a lack of understanding of how they work"

No, models are supposed to predict the future. That is their purpose. That is their reason to exist. If they cannot incorporate something as well known as the PDO, then they are worthless.

anonymous

2014-01-31 09:45:50 UTC

You know I always hear how much I don't know. I hear how much more the scientists know than I do.

BUT, I create models. It is part of my job as a statistician. Here is what I do know.

1.) They are trying to predict out 100 years into the future. At that range, the error bars start becoming so large that any prediction is useless. This is true of models that are known and systems that are both stable and not terribly choatic.

2.) The climate is a choatic system (note point 3 is that it is a stable system). When discussing chaos, the entire idea of the "butterfly effect" was in discussion of one of the most well known chaotic systems, THE CLIMATE. When you are modeling a choatic system, your error bars become huge very quickly.

3.) The climate is relatively stable. We need to remember that life has been on this planet through meteor strikes and many very large changes. The CO2 concerntration in the past has been as high as 7000 ppm. So any models that shoot off to positive or negative infinity are clearly wrong.

4.) The climate still has many unknowns. In producing any model, the lack of information or misunderstanding of factors can kill the model.

1-4 is what I KNOW. So when I see small error bars for temp 100 years out. STRIKE 1. When I see models that have exponential temp increases. STRIKE 2 When I see models that are running hot when compared to current temps. STRIKE 3, you are OUT.

I need those 3 strikes to entirely disregard a model. BUT, that is not what the debate is. We are talking about making seriously costly decisions based upon the models. I don't need 3 strikes to say we should not use that models for those decisions. I just need 1 strike. You do not use untrustworthy models to justify billions of dollars of spending.

Now the "smarter than me" warmers may disagree, but look at how they do so. Because they do not rightly address my concerns. They point to some nebulous group as being smarter than me. They may well be. But I don't care how smart you are, these 4 factors that I have mentioned will not care about your IQ score when they cause your model to fail.

?

2014-02-01 03:40:52 UTC

Because if one confines oneself to empirical data, the CAGW case melts away. They cannot make their case without the models; but, there is no way to validate the models. The idea that they can predict climate 2 weeks into the future (let alone 50-100 years) is an unverifiable hypothesis. The empirical data do not support their conclusions. It is all a fiction. There is no scientific case for CAGW.

But, there are predictable ad hominem attacks on anyone who dares to point out the lack of scientific rigor within the CAGW movement. To those still 'afflicted with the malady of thought', such attacks are further evidence of the anti-scientific, anti-critical thinking nature of the CAGW movement.

pegminer

2014-01-31 07:59:45 UTC

"Essentially all models are wrong, but some are useful." --George Box, from his book, Empirical Model-Building and Response Surfaces

Saying that models "most always wrong" is a completely meaningless statement. If you can't quantify what you mean, you're not saying anything.

Then you ramble on in your "question" to mumble gibberish about Einstein. What a bunch of nonsense. You really should move into the Religion and Spirituality section if you're going to prattle on about your own personal brand of mysticism.

EDIT: Zippi62, you have no idea what you're talking about. Nobody runs a climate model for one day to get a forecast. If you're talking about numerical weather prediction models (related in the physics, but with different goals than climate models) then they are quite accurate out several days. Their accuracy has improved tremendously over the past 20 years. Any "forecasts" done with climate models are only forecasts in a statistical sense. Oddly, the statistician in the group seems to miss this point also. He mentions chaos, but is unaware of how ensemble prediction provides guidance to the significance of the sensitivity to the initial conditions in any particular situation.

Sagebrush

2014-02-01 05:34:01 UTC

Quote by Chris Folland of UK Meteorological Office: “The data don't matter. We're not basing our recommendations [for reductions in carbon dioxide emissions] upon the data. We're basing them upon the climate models.”

Quote by David Frame, climate modeler, Oxford University: “Rather than seeing models as describing literal truth, we ought to see them as convenient fictions which try to provide something useful.”

I'll let the greenies explain this one. They are the ones who admittedly toss data in the dumpster and thrive on fiction.

Trevor: "If you take an honest and objective look at climate models, not the nonsense peddled on sites such as WUWT, then you’ll see that they were fairly accurate up to the point when warming stopped."

"I was fairly accurate halfway through my calculation, and even though I came up with the wrong answer, I was half right and I tried so hard. So teacher you must give me an 'A'". Ha! Ha! Ha! Where do they find these losers?

C

2014-01-31 07:58:41 UTC

Actually Dook asked a simple question, he wasn't promoting models, and you have to go and write a book about Einstein. BTW what the **** does Einstein have to do with AGW

Just to smarten you up a hair, there are really no AGW supporters, there are however people who comprehend science and the reality of AGW who try to answer question to provide answers. A supporter is one who would be in favor of it and the only thing I have seen iin favor, s a link here to some moronic a**hole who thinks CO2 is just great for the planet

I don't understand why you deniers have a love affair with models anyway. Most of the rest of us know they have flaws That is why you don't see warmists here linking to models.

?

2014-01-31 16:19:30 UTC

Translation of Trevor's answer (and far more concise).

Models were right until they were wrong. Since we don't have any better excuse, we should go with the Ocean until something better comes along.

Elizabeth

2014-02-01 12:40:56 UTC

http://skepticalscience.com//pics/DvDFmodel-data.png

The models look ok to me ... which bit is a failure?

?

2014-01-31 08:25:05 UTC

quoting WUWT does not give you credibility. You have no idea how models work