the Air Vent

Because the world needs another opinion

Archive for June, 2011

Experts or little white lies?

Posted by Jeff Id on June 11, 2011

UPDATE, It appears that my post uses data published yet not recommended by Phil Jones.   Perhaps a retraction by Dr. Jones  is in order or is it as Lucia points out in her post, a case of white noise.

Douglas J. Keenan 

in comments below notes:

Here is a quote from that: “global and regional time-series should be calculated using unadjusted data”. Indeed, the authors have criticized others for attempting to use HadCRUT3v for time series. Note that Jones is one of the authors.

Here is the full quote:

Whether variance adjusted or unadjusted data should be used in an analysis depends on what is to be calculated. If it is necessary that  grid-box anomalies have a spatially and temporally consistent variance, then variance adjusted data should be used. Otherwise, better results may be obtained using unadjusted data.  In particular, global and regional time-series should be calculated using unadjusted data.

The barely significant adjusted data should NOT be used for trend analysis per Dr. Jones himself.  Will climate wonders never cease.

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Phil Jones made a few famous quotes around the time of climategate.  One of them was brought up again in a happy correction to the record as reported by the BBC on June 10th.  Lucia covered it here already.  Back a year and a half ago, Phil let slip in an unusually difficult interview for a climate scientist that there was no statistically significant warming since 1995.

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

Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

This refers to the arbitrary yet regularly used 95% threshold or 1/20 chance that the result happened by accident alone.  Now in a new article Phil reports this:

Climate warming since 1995 is now statistically significant, according to Phil Jones, the UK scientist targeted in the “ClimateGate” affair.

Yay!!  We all knew it was coming, because as the data record grows longer even in a temperature stable world, statistical thresholds are naturally crossed.  The Earth would have to cool quickly in order to prevent this threshold from being crossed.  We discussed the issue in 2009 here, just days prior to climategate.

Lucia took the annual averages and corrected she for AR1 (autocorrelation), she found that the claim by Jones was still invalid.  Well, that caught my interest so I looked more closely at the data and wrote a downloader for the monthly HADCRUT3 and HADCRUT3V data in R.  I then dug up some old algorithms and did some of my own plots.  HADCRUT3 is a simple gridded version of the temperature data where anomalies are combined by grid and averaged.  HADCRUT3V has some sort of variance adjustment as described by Jones 2001, which ‘corrects’ the variance.  I have not read or looked for the paper and so cannnot comment on its veracity.

I made the following plot using the code below.  This uses all the available data, calculates a trend and a confidence interval for that trend based on the Quenouille AR1 degrees of freedom correction.  Nothing too magical about that. The red lines are the +/- confidence interval, the black line is the slope of the data in C/Decade for each month to the most recent month.  In other words, I fit a slope for the data from every month in history starting with 1980 January to present,, 1980 February to present, March etc, all the way until 2008 because a slope for three years of global temperatures is silly.

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People

Posted by Jeff Id on June 9, 2011

There is a basic reality of our modern existence which we ignore at our collective peril.   So eloquently spoken by Dr. Christy.

H/T Brian Hall.

To imagine that our world or our existence is anything other than this, is foolish narcissism.  It is the false educations of our liberal universities which have led our naturally simple minds away from what made our lives better.  We are animals, beasts, things of nature with little more intellect than how to eat, yet through simple technologies we assign ourselves abilities of gods.  En masse, our media assigned  intellect does not sum, but rather subtracts to the average control of low-brow phraseology. This is the present danger of democratically invoked oppression.  Yet, in singularity, our selfishness is even worse, the stuff of dictatorships.

Let us be free to do individually what we can for our betterment – and we shine.

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On The AMO+PDO Dataset

Posted by Jeff Id on June 9, 2011

Guest post by Bob Tisdale

Including A Discussion Of Its Use In Wyatt el al (2011)

INTRODUCTION

Graphs that illustrate the sum of the Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) data, Figure 1, have appeared in blog posts for more than three years. The first example I can find appeared in a pdf document written by Joe D’Aleo of IceCap: US Temperatures and Climate Factors since 1895. It appeared shortly after in the January 25, 2008 post Warming Trend: PDO And Solar Correlate Better Than CO2 at Watts Up With That? and in numerous posts since then. More recently, the AMO+PDO dataset appeared in the May 22, 2011 post Arctic Cycles – AMO+PDO corresponds to Arctic station group and was referred to in the June 2, 2011 post “Earth itself is telling us there’s nothing to worry about in doubled, or even quadrupled, atmospheric CO2″, which was also posted at Jeff Id’s blog The Air Vent as Future Perfect. A description of the “AMO+PDO” dataset and a link to a spreadsheet can be found at the January 25, 2008 at 9:13 pm comment from the first post at WUWT. A variation on the AMO+PDO graph has also recently found its way into a poster for Wyatt et al (2011) paper Atlantic Multidecadal Oscillation and Northern Hemisphere’s climate variability.

Figure 1

The AMO+PDO curve has been compared to a number of surface temperature variables. Unfortunately, the AMO and PDO datasets cannot be summed.

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We’re the Echo Chamber Crowd?

Posted by Jeff Id on June 7, 2011

Ben Lawson? at Wotts up with that, the believer site attacks Pat Frank’s Air Vent post where he found some interesting details in various surface temperature datasets.

What’s really funny is he referred to this blog as the ‘echo chamber’, for WUWT!

Anthony helpfully offers a new example of his excellence, copy-and-pasted from his echo chamber partners at The Air Vent: ”Future Perfect“, which asserts this comforting “fact”:

I guess that’s because like Tamino’s closed mind blog, we always agree with each other here and play so nicely together.  Never daring to critique the host or any of the other guest authors or commenters.  After all, the ‘believers’ know that questioning authority is not how science works anyway.

Well I thought it might be nice to give Dan a little traffic, his true ‘science’ blog needs some readers.

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Carbon Reduction

Posted by Jeff Id on June 6, 2011

Guest post by Tony Brown

Two weeks ago I started a thread over at Climate Etc. entitled ‘The futility of Carbon reduction?’ (note the important question mark.)
It came about when I received some calculations on likely temperature reductions from carbon mitigation policies, from a colleague, Ed Hoskins, who in turn had run them past the Chief Scientist of the UK’s powerful Department of Energy and Climate Change.
The article explores the likely cost of an aggressive carbon reduction policy and the practicalities of achieving it, but at its heart was a desire to find out what would be the end result in terms of an actual temperature reduction. Here is the question as posed.

Question: Temperatures are expected to rise by 3 degree Centigrade because of actions we have already taken. If the world collectively closed down their carbon economies what temperature reduction could be achieved?

a)    By 2100 b)    By 2200

(source IPCC AR4 WG1 SPM report pp. 13 and 18  and 350.org (20.5)

Please describe your calculations together with caveats or provide a reference/link.

I hope readers here will go through the article to put it all into context as it includes a useful chart of emissions by major countries and the likely cost to of reducing them, according to such official documents as the Stern report.

Climate Etc attracts an eclectic mix of sceptics and ardent warmists and every shade of opinion in between. Consequently what transpired was somewhat remarkable as with over 630 responses to date only one or two people attempted any sort of answer.

This led me to briefly believe that Ed and I were geniuses for thinking up a question that no one had asked before, but reality quickly re-asserted itself that it would be irresponsibility on a grand scale if those advising our governments had failed to undertake the calculations themselves. So those calculations surely exist, but those who believe in CAGW seem reluctant to promote them.

Is it because the answer is one they don’t like? That the vast costs of mitigation and the astonishing social and technological upheavals needed to achieve them would result in a temperature mitigation so tiny as to go unnoticed?

Jeff kindly agreed that I could re-state the question in this forum in the hope that readers will supply answers-complete with their calculations- or alternatively provide a link to an existing study that directly answers the question.

Tony Brown (tonyb)

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Lightsabers and Thermodynamics – Poll Below

Posted by Jeff Id on June 4, 2011

UPDATE:  Ids poll answers –

Question 1 – Would a minus 180 C block of ice the size of the moon and in lunar orbit warm or cool the Earth.

Ids Answer – It  would warm the Earth.   No matter what you assumed the definition of lunar orbit to mean for the majority of the time, the ice chunk would find itself blocking a view of the blackness of space at 3K or minus 270C.  In place of that minus 270C radiation which continually strikes the earth, a small section of the sky has a hotter, brighter minus 180C emission.  Therefore – the Earth Warms.

Question 2 – Would it warm the Sun.

Ids Answer – It  would warm the Sun for the same reasons as above.  The tiny little pinpoint in the distance would probably add as much as a distant star, but it would add a little and that is all it takes.

Now, if you get all caught up in how much and could it be measured etc. etc. and so on, you are probably lousy at story problems. The answers are actually quite simple.  It will be interesting to learn where I am wrong in the inevitable follow up comments :D.

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Sometimes I’m too short with people.  It comes from some of the pressures of the rest of life, I really should show more patience though, after all we’re all just trying to understand.

There are a group of people on who have published articles on global warming (on the internet only) who claim to have disproven the effect that CO2 has on surface air temperatures.  There are a variety of these sorts of things but one, which is most annoying, is the claim that backradiation from a colder source (air at higher altitude) to a warmer one (the ground) somehow violates the second law of thermodynamics.  This argument is false.  Now I could spend time with the equations and demonstrate that the net heatflow is always from warmer to colder, which it is, but I think those who misunderstand this point are missing the fundamental understanding of what temperature is and how energy can also flow from cold to hot.  Therefore, we only need words today.

This first section discusses the physical mechanisms of thermodynamic conduction.

Thermodynamic laws are based on a bulk material reactions to temperature.  When two objects come in contact with one another, one hot the other cold.  Heat energy will transfer from the hot object to the cold one – this is basically the simplest conceptual form of the second law of thermodynamics.   What would you say if I claim that on a microscale, some heat goes the other way?

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More Venus Discussion

Posted by Jeff Id on June 1, 2011

On the previous thread, I made the point that the reason for Venus surface temeprature being so high was the pressure and that any gas would create a huge warming effect.   Chris Colose had made the contention that CO2 is a strong gas and it is responsible for Venus having a surface temperature that could melt lead.   This statement, while correct, was placed inappropriately in the middle of a discussion of Earth’s greenhouse effect so I took the moment to explain that it isn’t a realistic comparison and basically amounts to fear mongering.  As always, some had contention with my point,  so I will attempt to explain further below.

The surface pressure is 93 times that of Earth on Venus. Venus’s gravity is 8.87 m/s^2 whereas earths is 9.78 or about 10% greater. Venus has a surface pressure of 93 Earth atmospheres so we can calculate 93*9.78/8.87 = 102 times the mass of Earth’s gaseous atmosphere. If we divide Venus’s gas atmosphere into 102 separate layers assuming each has the same conditions as the others, each layer has an equivalent (similar) capacity for global warming to Earth’s own due to the retardation of upwelling infrared radiation. An interesting number might be an estimate of how much warming does each Earth mass layer of Venusian gas create?  This is an estimate and must be taken with care as there are many effects of the high density gas and clouds in Venusian atmosphere but it is an interesting start point.

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