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Merc14

Climate models used by GWers suck

101 posts in this topic

"Care to answer that question about what happens if you move the start date to 1996 and what it says about data noise?"

I answered here:

http://www.unexplained-mysteries.com/forum/index.php?showtopic=245531&st=45#entry4720921

"Stonewalling reasonable points kills a discussion of facts."

you did not make a point, you asked a question. a question is not a point.

you claimed to be the expert, you should be providing answers not questions.

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Posted (edited)

That is not an answer to that specific question and I specifically told you that it was not addressing the issue. It was an avoidance.

Let me repeat - what happens to your important short term trend if you just extend it by two years earlier ?

It is a very specific question which has a fairly straightforward answer. I did not ask you to extend it 10,000 years backwards - just two.

Nice try.

The fact that you are unwilling to answer such a simple direct question tells me everything i need to know about your real understanding of the robustness of your assertion and your character.

Br Cornelius

Edited by Br Cornelius

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Posted (edited)

Even top climate contrarian at the Cato Institute, Patrick J Michaels , understands that the current pause is a statistical artifact of little significance. he states in his article "The Current short term climate trend is not your friend";

The bottom line is that short-term trends are not your friends when talking about long-term climate change.

http://www.cato.org/...d-is-not-friend

Its far to easy to end up looking a fool if you stake your reputation on dodgy stats.

Br Cornelius

Edited by Br Cornelius

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Doug, I am sorry but this is seriously underestimating the forces you are dealing with. We are nothing compared to the power of this planet and our resident star and we most definitely do not have the power, at this time, to stop another ice age. The fact you believe this speaks volumes but I respect your studies and efforts and with the above statement I rest my case.

We cut 97% of the trees on two continents in 200 years and we've cut major parts of two more. We raised the CO2 content of our atmosphere by 40% in a hundred years. We have killed large areas of the ocean floor and exterminated several dozen species in less than 50. And you don' think we're a force to be reckoned with?

And I think you seriously underestimate the effect we are having on the planet. For us, stopping an ice age is no sweat - it's starting one that's proving to be difficult.

You are resting your case without presenting any evidence. What makes you think we can't stop an ice age? Put up something to support your contention.

I have to admit that I don't understand you. You sound off, present nothing to support your ideas and then disappear? That's not a discsussion; it's a rant. Even Little Fish at least tries to put up something. But you don't even try - don't bother you with facts because your mind is made up?

At any rate, I have one of those studies to work on.

Doug

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Posted (edited)

"what happens to your important short term trend if you just extend it by two years earlier ?"

it doesn't matter whether the trend goes up or down or stays the same if we add 2 years of data, because we are only looking for a zero trend over the time interval specified by the climate modelers.

you want to add more data, then you would be extending the time interval they specified and therefore moving the goalposts.

you are not disagreeing with me, you are disagreeing with the climate modelers.

what the modelers stated was a response to an observation that there had been no statistical significant warming for 10 years, they came back with the response that 10-year zero trends were common due to internal climate noise, and intervals of 15 years of zero trend were required to create a discrepancy between observations and their models. we passed that point a while ago now.

the modelers are quiet about it, but what you are doing is contradicting the modelers by saying, "ah we need to wait 30 years"...and so it goes on and on until you get the result you desire.

climate modelers said in 2008:

"Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model's internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate."

what this means is that either one has to take the position that the models are exaggerating their predictions, or the modelers are wrong about their stated zero trend interval concerning their own models.

Edited by Little Fish
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"Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model's internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate."

The standard is 95% confidence. That's an exact figure. Confidence intervals are calculated; they're not a guess, but a precise number. Since 1998, inclusive, there has been too much variability in the temps to allow this standard to be met. If you go back to 1982, you can meet it, but then the line has a non-zero slope and is irrelevant to your contention.

To demonstrate that the models are flat-out wrong (and don't just have a low accuracy rate) you are going to have to wait several more years and hope that the temps don't vary very much.

Personally, I'd go after that accuracy rate: that can be demonstarted to be low.

Doug

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Posted (edited)

Little Fish, I can choose any number of 15 year periods within the last 20 years which disprove your statement. I wont because the data will not support such a claim.

Its really very simple the trend you speak of is not statistically significant and therefore doesn't exist in the way you say it does. Doug has pointed out to you the reason why you cannot make a statement about the trend, but you are unwilling to accept the word of a trained environmental statistician.

Again the fact that you will not countenance any other period than the specific one you have chosen, and you are not prepared to test it for significance means you are indulging in an exercise of cherry picking and are been dishonest with the data.

You have demonstrated nothing because you have not used a meaningful test of the data. Your conclusion is false because you cannot show a meaningful zero trend. Simply repeating it is not gaining any understanding of the data itself and why it cannot support such a statement.

I will ask you again. I have chosen the GISS dataset because it is the only one which has total global coverage and is therefore considered to be the most accurate.

Using the GISS dataset, and applying a simple linear regression the trend in the data over the 15 year period 1998-2012 is weakly positive in temperature trend TRUE/FALSE.

Using the GISS dataset, and applying a simple linear regression the trend in the data over the 15 year period 1996-2010 is strongly positive in temperature trendTRUE/FALSE.

Which trend is more statistically significant 1998-2012/1996-2010/Neither.

What is so special about the start date of 1998 for your 15 year period, why is a 15 year period starting from 1996 unacceptable to you ? Why is a strong positive trend starting in 1996 over 15 years less meaningful than your chosen 15 years which shows almost no trend ??

I am not interested in your statement about the modellers test here, I am interested in your specific answers to these questions from you, ignoring their relationship to the models.

Do me the curtsy I extended to you and answer my six simple questions. Note I have framed these three questions in such a way that I can show that 15 years is not a significant period for this set of data, and there was no trick of adding an arbitrary set of two more years to your preferred period. We are comparing like with like and trying to understand why you think one 15 year period is more important than another starting at almost the same time.

I know already that you will not be able to bring yourself to answer my simple request because deep down you know you are wrong. You can only avoid the truth for so long before the cracks in your world view start to appear.

How often it is that the angry man rages denial of what his inner self is telling him.

Frank Herbert

Br Cornelius

Edited by Br Cornelius

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"What is so special about the start date of 1998 for your 15 year period, why is a 15 year period starting from 1996 unacceptable to you ? Why is a strong positive trend starting in 1996 over 15 years less meaningful than your chosen 15 years which shows almost no trend ??"

corneilus, we are looking for ANY 15 year interval with zero trend.

if the test is to find a black swan and I find a black swan, any amount of white swans you find doesn't negate the discovery of the black swan.

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Posted (edited)

You cannot make that statement about a black swan event if the trends is not statistically valid, and the concept doesn't apply to simple time series with known high internal variability and short term randomness. You have looked at noise and found a pattern which doesn't exist, thats like finding patterns in the stars or clouds - they are a projection of your mind. Cherry picking any sequence of years can be made to prove anything you like - but it is fraud and not science. It only becomes science when you have applied appropriate analysis and shown that it meets the 95% confidence interval for the test you have chosen - you have never done that to your chosen 15 years and you refuse to do so because you already know the result disproves your thesis.

To put what you are attempting to do by defining the current period as exceptional into context;

escalator.gif

Let me summarize my position, based on your logic, which is by your logic as valid as the position you have proposed;

"The upward temperature trend in the 15 years of GISS data between 1996-2000 confirms beyond reasonable doubt that the climate models are valid."

This is not a true statement - just as yours is not a true statement.

I knew you couldn't answer some simple questions :w00t: Do you really imagine that you are fooling anyone with your little "trick", I don't imagine you are even fooling yourself.

I rest my case.

Br Cornelius

Edited by Br Cornelius

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Posted (edited)

"Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model's internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate."

which means there has to be statistically significant warming over all and every 15 year intervals (all swans have to be white).

if you find a 15 year period without statistically significant warming then this "absence of warming" creates a discrepancy between observations and model.

it isn't difficult to grasp.

http://www.woodfortrees.org/graph/hadcrut3vgl/from:1973/plot/hadcrut3vgl/from:1998/trend

Edited by Little Fish

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"Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model's internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate."

which means there has to be statistically significant warming over all and every 15 year intervals (all swans have to be white).

if you find a 15 year period without statistically significant warming then this "absence of warming" creates a discrepancy between observations and model.

it isn't difficult to grasp.

You have that backwards. You have to be able to say with 95% confidence that there was no warming during this period. If you cannot do that, then you cannot disprove warming. It is not enough just to say that the other guy can't prove his point when you can't prove yours, either.

Doug

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Posted (edited)

You have that backwards. You have to be able to say with 95% confidence that there was no warming during this period. If you cannot do that, then you cannot disprove warming. It is not enough just to say that the other guy can't prove his point when you can't prove yours, either.

Doug

Indeed.

Logic is wasted.

Cherry pick your question.

Cherry pick your dataset.

Cherry pick your interval.

Cherry pick your start date.

Cherry pick your analysis.

Its all cherries with LF.

Br Cornelius

Edited by Br Cornelius

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Posted (edited)

see the green line here:

http://www.woodfortrees.org/graph/hadcrut3vgl/from:1973/plot/hadcrut3vgl/from:1998/trend

that's the warming trend over a 15 year interval using the index used by the ipcc, and it's negative.

you might believe that snow is black or that that data shows a positive trend, but I believe what my eyes tell me.

split hairs to find a distinction all you like, it makes no difference.

near zero and even negative trends are common over 10 year intervals in the models, but not 15 year intervals - ask the modelers.

Edited by Little Fish

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see the green line here:

http://www.woodfortr...from:1998/trend

that's the warming trend over a 15 year interval using the index used by the ipcc, and it's negative.

you might believe that snow is black or that that data shows a positive trend, but I believe what my eyes tell me.

near zero and even negative trends are common over 10 year intervals in the models, but not 15 year intervals - ask the modelers.

Little Fish - the data is telling you its is to noisy to draw a meaningful trend over your chosen interval. You are using stats to perform your analysis, and yet you are not using stats because you refuse to test your conclusion.

You are abusing stats to your agenda.

Br Cornelius

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You have that backwards

you have it backwards

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you have it backwards

You are a statistician now :w00t:

You could have fooled me.

Br Cornelius

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Little Fish - the data is telling you its is to noisy to draw a meaningful trend over your chosen interval. You are using stats to perform your analysis, and yet you are not using stats because you refuse to test your conclusion.

You are abusing stats to your agenda.

Br Cornelius

i did not set out the test - the modelers did. take it up with them.

all i see you doing is obfuscating.

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Posted (edited)

i did not set out the test - the modelers did. take it up with them.

all i see you doing is obfuscating.

Let me repeat this - you have not established the test has been demonstrated due to the signal to noise ratio. You have not understood the test.

Even simple linear trends must be tested for significance. When did you perform that test ??? Show me how you tested the significance of your analysis.

I have demonstrated in non-statistical ways why the signal to noise level is to high in a 15 year sequence using this data - but you refused to answer the direct questions which provided ample proof of that fact. Data analysis is not about picking the data which confirms your thesis, and it is not about exceptions disproving the generality - its about looking at the data in the most comprehensive and robust way in order to understand its deep underlying pattern. You are concentrating on outliers to the exception of the greater dataset and therefore you conclusion is not meaningful.

Br Cornelius

Edited by Br Cornelius

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you are on record stating that ANY 15 year period will not have significance, therefore under your understanding the test cannot EVER be carried out successfully.

it is you that has misunderstood the test.

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you have it backwards

Who's the one with the biometry degree?

Doug

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who's the one who defended the marcott paper, when even the author has backed away from his uptick.

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Posted (edited)

you are on record stating that ANY 15 year period will not have significance, therefore under your understanding the test cannot EVER be carried out successfully.

it is you that has misunderstood the test.

If you analyze at least 30years of data (preferably all of the data you have) you can look at the significance of any 15 year segment within that data. You have failed that test by only looking at the data over 15 years. The test can be applied over a hundred and fifty different 15 year sequences given the dataset you have access to.

The analyzes you use to treat the data should have as its primary objective to minimize the influence of extreme outliers - the analysis you have chosen does exactly the opposite in that it emphasizes the extreme outliers.

You can perform your test over your chosen 15 year period, but only if you analyze at least the 15years before it as well. Even then you must apply a significance test to establish if the trend is robust enough, and if there are to many outliers you may still fail to demonstrate the significance of your thesis.

If you fail to apply this rigour to your analysis you can end up with the esculator where all segments show a downward trend within the overall dataset which shows an upward trend.

No modeller could be held to a trend which has not been shown to be statistically significant and robust.

Br Cornelius

Edited by Br Cornelius

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Posted (edited)

who's the one who defended the marcott paper, when even the author has backed away from his uptick.

Me. And I haven't seen Marcott publishing a retraction anywhere, so if you know of one, please post the link.

After looking over that sediment core data, I note there are some in there that do show an increase during the 20th century. There are also some that do not even get to the 20th century. And a couple that squeeze 200,000 years into ten (or fewer) observations. There are some problems with the data, no doubt about it. A lot of what those proxies can show is going to depend on the time span between observations. You're probably safe using a century scale; in which case, you can forget about the twentieth century. To show that, you will need finer resolution - like decadal. And there are some cores in there that have decadal resolution.

What do I conclude from that? Marcott's twentieth century reconstruction isn't what any of us would like it to be, but it's still reliable as far as recording warmer sea temperatures go. Would you like to do the analysis? I think it would be fun, but it would also take a lot of time. Maybe this summer?

So, let's see that link.

Doug

Edited by Doug1o29

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What I like is everybody on here is cherry picking. Those who say ygbv

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