New paper finds climate models have greatly exaggerated warming & finds no statistica

[daveman]

New paper finds climate models have greatly exaggerated warming & finds no statistically-significant warming for past 20 years

A paper published today in Nature Climate Change finds climate models have greatly exaggerated global warming over the past 20 years, noting the observed warming is "less than half" of the modeled warming. The authors falsify the models at a confidence level of 90%, and also find that there has been no statistically significant global warming for the past 20 years. According to the authors, "The evidence, therefore, indicates that the current generation of climate models ...do not reproduce the observed global warming over the past 20 years, or the slowdown in global warming over the past fifteen years." The paper follows another recent paper falsifying climate models at a confidence level of greater than 98% for the past 15 years.

Dr. Judith Curry comments on this paper:

In terms of reasons for model underestimation, the apparent ‘preferred’ explanation of ‘the ocean ate it’ does not get any play here, other than in context of a brief consideration of natural internal variability. Their conclusion This difference might be explained by some combination of errors in external forcing, model response and internal [natural] climate variability is right on the money IMO, although I don’t think their analysis of why the models might be wrong was particularly illuminating. If you would like further illumination on why the climate models might be wrong, I refer you to my uncertainty monster paper.​

 

[Old Rocks]

No stastically significant warming, but this is rather significant, from your bullshit site;

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png

http://www.climate4you.com/images/AllCompared GlobalMonthlyTempSince1979.gif

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.global.png

http://www.swpc.noaa.gov/SolarCycle/Ap.gif

 

[Abraham3]

I'm wondering, Dave, that since the models all performed very well up to 1998 - made very accurate backcasts and predictions which were spot on - how you avoid the conclusion that something CHANGED at that point in time?

You're accusing 37 different model creators of crafting complex climate models that will work like a charm till a certain point in time at which point they will ALL, simultaneously go wonkers. Does that make sense?

I think its fairly obvious that we have had some change in what the paper would call "internal [natural] climate variability" that was not anticipated and therefore not included in the modeling functions. Jumping up and throwing out all prior climate modeling work is hardly the optimum approach to gaining a better understanding of climate function and our likely future.

 

[Abraham3]

Dr. Judith Curry comments on this paper:

I don’t think their analysis of why the models might be wrong was particularly illuminating. If you would like further illumination on why the climate models might be wrong, I refer you to my uncertainty monster paper.​

Modest, ain't she.

 

[mamooth]

The new paper is behind a paywall, so I can't comment on it fully. If Dave wants to send me $32, I'll check it all out for him. Without that, instead of looking at yet another one of Judith Curry's cherrypicking acts, I'll simply look at the actual abstract.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12534.html
---
Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
---

So the paper says what we've been saying, that the strong La Nina events of the past decade have suppressed the warming of air temperatures, but that the warming will come roaring back when it flips to El Nino. It's good to see Dave finally moving to the rational side and accepting that.

 

[daveman]

I'm wondering, Dave, that since the models all performed very well up to 1998 - made very accurate backcasts and predictions which were spot on -

Prove it.

 

[daveman]

Dr. Judith Curry comments on this paper:

I don’t think their analysis of why the models might be wrong was particularly illuminating. If you would like further illumination on why the climate models might be wrong, I refer you to my uncertainty monster paper.​

Modest, ain't she.

Stating fact isn't immodesty.

 

[daveman]

The new paper is behind a paywall, so I can't comment on it fully. If Dave wants to send me $32, I'll check it all out for him. Without that, instead of looking at yet another one of Judith Curry's cherrypicking acts, I'll simply look at the actual abstract.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12534.html
---
Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
---

So the paper says what we've been saying, that the strong La Nina events of the past decade have suppressed the warming of air temperatures, but that the warming will come roaring back when it flips to El Nino. It's good to see Dave finally moving to the rational side and accepting that.

So, you knew about La Nina's effects...but the models didn't predict it.

Remind me again -- why do you think the models are accurate?

 

[Abraham3]

I'm wondering, Dave, that since the models all performed very well up to 1998 - made very accurate backcasts and predictions which were spot on -

Prove it.

The plots you yourself have posted show a very good correlation between model predictions and actual observations up until 1998. You know what I'm saying is true. All the models missed the beginning of the warming hiatus in 1998. Occam tells us it is a great deal more likely that something in the way the world's climate works changed, than than that EVERYONE'S previously satisfactory climate models all went south in precisely the same way.

 

[Abraham3]

Dr. Judith Curry comments on this paper:

I don’t think their analysis of why the models might be wrong was particularly illuminating. If you would like further illumination on why the climate models might be wrong, I refer you to my uncertainty monster paper.​

Modest, ain't she.

Stating fact isn't immodesty.

When my children were younger we were at one of their friends house and their son went to their mom with a question from their homework. She said she didn't know and turned to me with "Maybe Mr XXXXX knows - what IS the difference between a fact and an opinion?" I was stunned that she didn't know. And here I am stunned again.

 

[mamooth]

So, you knew about La Nina's effects...but the models didn't predict it.

Of course not. Everyone in the field knows that the general climate models don't predict La Nina/El Nino events. They weren't designed to.

Even the very different models designed just for ENSO predictions are still pretty iffy. It's a work in progress. Doesn't change the fact that the general climate models are very good.

 

[daveman]

I'm wondering, Dave, that since the models all performed very well up to 1998 - made very accurate backcasts and predictions which were spot on -

Prove it.

The plots you yourself have posted show a very good correlation between model predictions and actual observations up until 1998. You know what I'm saying is true. All the models missed the beginning of the warming hiatus in 1998. Occam tells us it is a great deal more likely that something in the way the world's climate works changed, than than that EVERYONE'S previously satisfactory climate models all went south in precisely the same way.

That's not proof. That's you yapping. I suspect you can't tell the difference.

It would explain a lot.

 

[daveman]

Modest, ain't she.

Stating fact isn't immodesty.

When my children were younger we were at one of their friends house and their son went to their mom with a question from their homework. She said she didn't know and turned to me with "Maybe Mr XXXXX knows - what IS the difference between a fact and an opinion?" I was stunned that she didn't know. And here I am stunned again.

You shouldn't be. AGW cultists have been stating their opinions as fact for years.

 

[daveman]

So, you knew about La Nina's effects...but the models didn't predict it.

Of course not. Everyone in the field knows that the general climate models don't predict La Nina/El Nino events. They weren't designed to.

Even the very different models designed just for ENSO predictions are still pretty iffy. It's a work in progress. Doesn't change the fact that the general climate models are very good.

No, they're not. Read the OP.

 

[Abraham3]

You shouldn't be. AGW cultists have been stating their opinions as fact for years.

Was I being too subtle there?

Ms Curry was expressing an opinion. Even if it were true - which is exceedingly dubious, it was still an opinion.

 

[CrusaderFrank]

"Hide the decline"

"Mann's Nature Trick"

"BBC - Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?

Phil Jones: An initial point to make is that in the responses to these questions I've assumed that when you talk about the global temperature record, you mean the record that combines the estimates from land regions with those from the marine regions of the world. CRU produces the land component, with the Met Office Hadley Centre producing the marine component.
Temperature data for the period 1860-1880 are more uncertain, because of sparser coverage, than for later periods in the 20th Century. The 1860-1880 period is also only 21 years in length. As for the two periods 1910-40 and 1975-1998 the warming rates are not statistically significantly different (see numbers below).
I have also included the trend over the period 1975 to 2009, which has a very similar trend to the period 1975-1998.
So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other.

Here are the trends and significances for each period:
Period Length Trend
(Degrees C per decade) Significance
1860-1880 21 0.163 Yes
1910-1940 31 0.15 Yes
1975-1998 24 0.166 Yes
1975-2009 35 0.161 Yes

BBC - Do you agree that from 1995 to the present there has been no statistically-significant global warming

Phil Jones: Yes..."

 

[CrusaderFrank]

No stastically significant warming, but this is rather significant, from your bullshit site;

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png

http://www.climate4you.com/images/AllCompared GlobalMonthlyTempSince1979.gif

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.global.png

http://www.swpc.noaa.gov/SolarCycle/Ap.gif

You sound angry.

Why should science make you so angry?

 

[FA_Q2]

I'm wondering, Dave, that since the models all performed very well up to 1998 - made very accurate backcasts and predictions which were spot on -

Prove it.

The plots you yourself have posted show a very good correlation between model predictions and actual observations up until 1998. You know what I'm saying is true. All the models missed the beginning of the warming hiatus in 1998. Occam tells us it is a great deal more likely that something in the way the world's climate works changed, than than that EVERYONE'S previously satisfactory climate models all went south in precisely the same way.

Do you not see how that throws MAJOR problems into the mix when you are predicting catastrophe if we do not make major changes globally in our economic and energy production?

If the models did not predict a rather large change like this and go off the rails, why are we to assume that the rest of the predictions are going to be accurate or even valid enough to make policy with. It does not really even matter why at that point, if you can’t make accurate predictions then something is incorrect and needs to be addressed before we start making policy in order to see what the actual dangers might (or might not) be.

 

[CrusaderFrank]

Prove it.

The plots you yourself have posted show a very good correlation between model predictions and actual observations up until 1998. You know what I'm saying is true. All the models missed the beginning of the warming hiatus in 1998. Occam tells us it is a great deal more likely that something in the way the world's climate works changed, than than that EVERYONE'S previously satisfactory climate models all went south in precisely the same way.

Do you not see how that throws MAJOR problems into the mix when you are predicting catastrophe if we do not make major changes globally in our economic and energy production?

If the models did not predict a rather large change like this and go off the rails, why are we to assume that the rest of the predictions are going to be accurate or even valid enough to make policy with. It does not really even matter why at that point, if you can’t make accurate predictions then something is incorrect and needs to be addressed before we start making policy in order to see what the actual dangers might (or might not) be.

The ocean ate the warming. The models are shocked that the Earth appears to be a living creature and compensated for the warming by ingesting the warming.

Nevertheless they remain confident that they have accurately depicted reality by eliminating all variables save for a 200PPM increase in CO2

 

[flacaltenn]

The new paper is behind a paywall, so I can't comment on it fully. If Dave wants to send me $32, I'll check it all out for him. Without that, instead of looking at yet another one of Judith Curry's cherrypicking acts, I'll simply look at the actual abstract.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12534.html
---
Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
---

So the paper says what we've been saying, that the strong La Nina events of the past decade have suppressed the warming of air temperatures, but that the warming will come roaring back when it flips to El Nino. It's good to see Dave finally moving to the rational side and accepting that.

Important point is --- you can mathematically determine WHEN the climate models have failed. The authors have done the math and made that call..

They FAIL -- because they don't model climate. They model the effects of CO2 and MAN's ACTIVITIES on climate. And as such -- they have OVEREMPHASIZED that aspect and NEGLECTED or UNDERESTIMATED other important climate drivers.. ((Or combos of climate drivers)).

That has been my position all along.. Think I'll pay the $32 bucks to recieve my validation.