Climate Change - The Scientific Debate

[IainT]

Gandahar said:

And denialists sphere also, but sides get too excited.

Please don't equate being sceptical over the extent of man's influence on climate change or if we can measure it or if measures in place will have any impact or the desired impact with a term purposely chosen to draw parallels with Holocaust denial.

Alarmist is not in the same league of descriptive terms.

[plunker]

Jinx said:

plunker said:

and then another one came along (sort of): http://www.theguardian.com/environment/climate-con...

And it's cherry picked model outputs (in 15 year segments) WUWT

Funny how the people making the most noise about short 15-year segments of temp obs suddenly declare 'cherry-picking'. Surely if you're genuinely interested in how models perform against reality over short periods, then looking at model runs that match closest the short-term natural variability created by ENSO is an obvious thing to do?

[Jinx]

plunker said:

Funny how the people making the most noise about short 15-year segments of temp obs suddenly declare 'cherry-picking'. Surely if you're genuinely interested in how models perform against reality over short periods, then looking at model runs that match closest the short-term natural variability created by ENSO is an obvious thing to do?

Erm Plunks I was complaining about using 15 year segments of multiple Model outputs and comparing these to observations and then declaring that "models" are good! That's like looking at Alan Hansen's (yes the footballer) predictions, Alan Shearer's predictions and Lineker's predictions on MOTD - picking out where the predictions match reality and declaring pundits are good a predicting football results!
They may or may not be but a paper using the above methodology does nothing to improve knowledge.

[plunker]

Jinx said:

plunker said:

Funny how the people making the most noise about short 15-year segments of temp obs suddenly declare 'cherry-picking'. Surely if you're genuinely interested in how models perform against reality over short periods, then looking at model runs that match closest the short-term natural variability created by ENSO is an obvious thing to do?

Erm Plunks I was complaining about using 15 year segments of multiple Model outputs and comparing these to observations and then declaring that "models" are good! That's like looking at Alan Hansen's (yes the footballer) predictions, Alan Shearer's predictions and Lineker's predictions on MOTD - picking out where the predictions match reality and declaring pundits are good a predicting football results!
They may or may not be but a paper using the above methodology does nothing to improve knowledge.

Your football-pundit metaphor shows you haven't understood the paper.

Let's try a horse-racing one...

A computer model is used to project how a bunch of horses will perform in the Grand National but the results are quite dependent on the ground conditions (because horses perform differently depending on the ground conditions). The models aren't able to predict what the ground conditions will be like on the day and multiple model runs produce differing ground conditions affecting the race results. This paper looks at the model runs that, by chance, had the closest match to the real world ground conditions on the day to see how well those runs predicted the race results and finds those runs matched reality well.

Jinx said:

...then declaring that "models" are good!

Bit of a vague statement - good at what? I don't think the paper tells us much about long-term climate sensitivity to increasing CO2 which is the major issue, but it does speak to the issue of whether big claims made about 'the pause' and model invalidation are justified.

[Jinx]

plunker said:

Your football-pundit metaphor shows you haven't understood the paper.

Let's try a horse-racing one...

A computer model is used to project how a bunch of horses will perform in the Grand National but the results are quite dependent on the ground conditions (because horses perform differently depending on the ground conditions). The models aren't able to predict what the ground conditions will be like on the day and multiple model runs produce differing ground conditions affecting the race results. This paper looks at the model runs that, by chance, had the closest match to the real world ground conditions on the day to see how well those runs predicted the race results and finds those runs matched reality well.

All well and good if that was what the paper showed. Unfortunately by not declaring the criteria of the 4 models which showed correlation with observations during the 15 year time periods we are none the wiser as to the parameters that led to this correlation.
The paper itself declares the futility of using even the "good" models:
"In the CMIP5 models run using historical forcing there is no way to ensure that the model has the same sequence of ENSO events as the real world. This will occur only by chance and only for limited periods"
So only by chance - so little more than a random walk.

plunker said:

Jinx said:

...then declaring that "models" are good!

Bit of a vague statement - good at what? I don't think the paper tells us much about long-term climate sensitivity to increasing CO2 which is the major issue, but it does speak to the issue of whether big claims made about 'the pause' and model invalidation are justified.

This was a slightly tongue in cheek comment against the way our friend Nuttelli described the paper in the Guardian. Given as the paper by it's own admission is little better than using a plethora of random walk models (phase shifting models to match starting conditions) the paper adds nothing to human knowledge and therefore should have been rejected.

[plunker]

Jinx said:

plunker said:

Your football-pundit metaphor shows you haven't understood the paper.

Let's try a horse-racing one...

A computer model is used to project how a bunch of horses will perform in the Grand National but the results are quite dependent on the ground conditions (because horses perform differently depending on the ground conditions). The models aren't able to predict what the ground conditions will be like on the day and multiple model runs produce differing ground conditions affecting the race results. This paper looks at the model runs that, by chance, had the closest match to the real world ground conditions on the day to see how well those runs predicted the race results and finds those runs matched reality well.

All well and good if that was what the paper showed. Unfortunately by not declaring the criteria of the 4 models which showed correlation with observations during the 15 year time periods we are none the wiser as to the parameters that led to this correlation.
The paper itself declares the futility of using even the "good" models:
"In the CMIP5 models run using historical forcing there is no way to ensure that the model has the same sequence of ENSO events as the real world. This will occur only by chance and only for limited periods"
So only by chance - so little more than a random walk.

plunker said:

Jinx said:

...then declaring that "models" are good!

Bit of a vague statement - good at what? I don't think the paper tells us much about long-term climate sensitivity to increasing CO2 which is the major issue, but it does speak to the issue of whether big claims made about 'the pause' and model invalidation are justified.

This was a slightly tongue in cheek comment against the way our friend Nuttelli described the paper in the Guardian. Given as the paper by it's own admission is little better than using a plethora of random walk models (phase shifting models to match starting conditions) the paper adds nothing to human knowledge and therefore should have been rejected.

Indeed I don't think the paper adds much to the sum of scientific knowledge (which is probably why - despite being an obvious thing to do - it hasn't been done before). It fits with what I've been saying for years about the recent temperature obs and natural variability though so I'm fine with it as a simple illustration/confirmation of what I already know.

[Silver Smudger]

Twould be less disingenuous to use a title like "Climate models accurately predicted global warming when reflecting natural ocean cycles" to show that models actually predicted something accurately before it had happened - Instead of showing how some of a range of model runs could be matched up with reality after the events they are said to be predicting

Unless this is some strange usage of the word "predict" that I wasn't previously aware of

with apol. to Douglas Adams

[wc98]

IainT said:

wc98 said:

another interesting paper http://onlinelibrary.wiley.com/doi/10.1002/2014GL0...

Since the 1980s anthropogenic aerosols have been considerably reduced in Europe and the Mediterranean area. This decrease is often considered as the likely cause of the brightening effect observed over the same period. This phenomenon is however hardly reproduced by global and regional climate models. Here we use an original approach based on reanalysis-driven coupled regional climate system modelling, to show that aerosol changes explain 81?±?16 per cent of the brightening and 23?±?5 per cent of the surface warming simulated for the period 1980–2012 over Europe. The direct aerosol effect is found to dominate in the magnitude of the simulated brightening. The comparison between regional simulations and homogenized ground-based observations reveals that observed surface solar radiation, as well as land and sea surface temperature spatio-temporal variations over the Euro-Mediterranean region are only reproduced when simulations include the realistic aerosol variations.

Would I be reading that abstract correctly to assume that the lack of warming over the recent period may well have been cooling if we hadn't reduced aerosol emissions?

looks that way to me. i would expect an uptick in the magnitude ,depicted by marcott et al 2013, of papers showing various factors currently overwhelming agw resulting in the pause/divergence of C02 temperature relationship (unless you use a nasa algorithm ) .

[wc98]

IainT said:

Certainly seemed to be a consensus () supporting paper.

if you believe the energy budget as measured at the top of the atmosphere is accurately quantified. as there is a huge difference in the defined height of the top of the atmosphere between the equator and poles,the height varies constantly and a many other factors including atmospheric mixing of gasses ,cloud formation etc etc,the notion of a known energy budget to the accuracy described by climastrology would appear to be as accurate as argo bouys capability to measure the temperature of the oceans,ie bks. all imo of course.

[plunker]

wc98 said:

all imo of course.

Your opinion last week (when you thought the paper said something else) was 'it really is all over'.

So science not settled after all - pity. Maybe next week.

[wc98]

plunker said:

Your opinion last week (when you thought the paper said something else) was 'it really is all over'.

So science not settled after all - pity. Maybe next week.

to be fair it was all over a while ago ,just the back pedalling stage to go now. now what was it the increase in atmospheric carbon dioxide was supposed to do ? http://hockeyschtick.blogspot.co.uk/2014/08/paper-...

Abstract
A trend analysis was applied to a 14-yr time series of downwelling spectral infrared radiance observations from the Atmospheric Emitted Radiance Interferometer (AERI) located at the Atmospheric Radiation Measurement Program (ARM) site in the U.S. Southern Great Plains. The highly accurate calibration of the AERI instrument, performed every 10 min, ensures that any statistically significant trend in the observed data over this time can be attributed to changes in the atmospheric properties and composition, and not to changes in the sensitivity or responsivity of the instrument. The measured infrared spectra, numbering more than 800 000, were classified as clear-sky, thin cloud, and thick cloud scenes using a neural network method. The AERI data record demonstrates that the downwelling infrared radiance is decreasing over this 14-yr period in the winter, summer, and autumn seasons but it is increasing in the spring; these trends are statistically significant and are primarily due to long-term change in the cloudiness above the site. The AERI data also show many statistically significant trends on annual, seasonal, and diurnal time scales, with different trend signatures identified in the separate scene classifications. Given the decadal time span of the dataset, effects from natural variability should be considered in drawing broader conclusions. Nevertheless, this dataset has high value owing to the ability to infer possible mechanisms for any trends from the observations themselves and to test the performance of climate models.

Edited by wc98 on Wednesday 6th August 00:57

[plunker]

wc98 said:

plunker said:

Your opinion last week (when you thought the paper said something else) was 'it really is all over'.

So science not settled after all - pity. Maybe next week.

to be fair it was all over a while ago ,just the back pedalling stage to go now. now what was it the increase in atmospheric carbon dioxide was supposed to do ? http://hockeyschtick.blogspot.co.uk/2014/08/paper-...

Abstract
A trend analysis was applied to a 14-yr time series of downwelling spectral infrared radiance observations from the Atmospheric Emitted Radiance Interferometer (AERI) located at the Atmospheric Radiation Measurement Program (ARM) site in the U.S. Southern Great Plains. The highly accurate calibration of the AERI instrument, performed every 10 min, ensures that any statistically significant trend in the observed data over this time can be attributed to changes in the atmospheric properties and composition, and not to changes in the sensitivity or responsivity of the instrument. The measured infrared spectra, numbering more than 800 000, were classified as clear-sky, thin cloud, and thick cloud scenes using a neural network method. The AERI data record demonstrates that the downwelling infrared radiance is decreasing over this 14-yr period in the winter, summer, and autumn seasons but it is increasing in the spring; these trends are statistically significant and are primarily due to long-term change in the cloudiness above the site. The AERI data also show many statistically significant trends on annual, seasonal, and diurnal time scales, with different trend signatures identified in the separate scene classifications. Given the decadal time span of the dataset, effects from natural variability should be considered in drawing broader conclusions. Nevertheless, this dataset has high value owing to the ability to infer possible mechanisms for any trends from the observations themselves and to test the performance of climate models.

Edited by wc98 on Wednesday 6th August 00:57

I see Watts has rushed to repeat the hockeyshtick article adding the word 'BOMBSHELL:' to the headline - but the paper in the article was published in 2011. Must be one of those slow-fuse jobbys.

http://wattsupwiththat.com/2014/08/05/bombshell-st...

[Silver Smudger]

plunker said:

I see Watts has rushed to repeat the hockeyshtick article adding the word 'BOMBSHELL:' to the headline - but the paper in the article was published in 2011. Must be one of those slow-fuse jobbys.

Any change to that story found in more recent publications?

Edited by Silver Smudger on Wednesday 6th August 11:58

[plunker]

I dunno, SS.

[QuantumTokoloshi]

plunker said:

I don't want to know, if it does not support global warming death catastrophic heating C02 death and destruction theory. SS.

Fixed that for you.

Edited by QuantumTokoloshi on Wednesday 6th August 17:31

[wc98]

plunker said:

I see Watts has rushed to repeat the hockeyshtick article adding the word 'BOMBSHELL:' to the headline - but the paper in the article was published in 2011. Must be one of those slow-fuse jobbys.

http://wattsupwiththat.com/2014/08/05/bombshell-st...

by that response i will assume i have interpreted the results of this paper correctly
it must just be terribly unfortunate that out of all the possible locations on the planet they happened to choose one of the few where the exact opposite of what is posited by the agw hypothesis is occurring .

Edited by wc98 on Wednesday 6th August 18:50

[plunker]

QuantumTokoloshi said:

plunker said:

I don't want to know, if it does not support global warming death catastrophic heating C02 death and destruction theory. SS.

Fixed that for you.

No I just have no clue what developments, if any, there's been on the subject of downwelling IR radiation measurements in the southern great plains of the U.S. (or anywhere else for that matter) since 2011.

It's an interesting topic in general though so feel free to chip in something yourself, brave truth-seeker.

Edited by plunker on Wednesday 6th August 19:55

[plunker]

wc98 said:

plunker said:

I see Watts has rushed to repeat the hockeyshtick article adding the word 'BOMBSHELL:' to the headline - but the paper in the article was published in 2011. Must be one of those slow-fuse jobbys.

http://wattsupwiththat.com/2014/08/05/bombshell-st...

by that response i will assume i have interpreted the results of this paper correctly

That assumption is unsafe and your originality claim is suspect

wc98 said:

...it must just be terribly unfortunate that out of all the possible locations on the planet they happened to choose one of the few where the exact opposite of what is posited by the agw hypothesis is occurring .

Perhaps that's why this one paper of measurements of a small area (relative to the globe) 'happens' to have been brought to your attention. In other words, maybe it's a cherry-pick?

[Variomatic]

plunker said:

Perhaps that's why this one paper of measurements of a small area (relative to the globe) 'happens' to have been brought to your attention. In other words, maybe it's a cherry-pick?

Or, just maybe, having got these results in one location they found that funding mysteriously wasn't available for studies that might show the same elsewhere?

Personally, I would have thought that the scientific community would be eager to see if it was an abberation given the possible implicaions, yet there don't appear to be any follow-ups.

[hairykrishna]

wc98 said:

by that response i will assume i have interpreted the results of this paper correctly
it must just be terribly unfortunate that out of all the possible locations on the planet they happened to choose one of the few where the exact opposite of what is posited by the agw hypothesis is occurring .

Edited by wc98 on Wednesday 6th August 18:50

How is "the amount of cloud cover has changed, in some seasons, over Oklahoma" the exact opposite of the AGW hypothesis?

People take measurements similar to these all over the world. I'm sure you could find data if you looked.