DSP analysis of global temperature by Agilent chap

The climatologists do have the advantage of knowing something about the pr ocesses generating the data presented.

Atmospheric CO2 levels stuck at about 280ppm from the end of the last ice a ge to the start of the Industrial Revolution, but they've risen exponential ly since then, to the current 400ppm. The halfway point - 340ppm - happened around 1980.

This means that half the anthropogenic green-house warming we've seen is co ncentrated in the last thirty years. It's visible in the curves presented by Anthony Watt, but it's equally clear that the warming we've seen is of t he same order as the noise imposed on the global temperature signal by the Atlantic Multidecadal Oscillation (AMO).

The DSP analysis pulls out a 57 year period. The AMO doesn't seem to be a s table oscillation, but its characteristic period - in so far as it can be s aid to have one - is something of the order of 70 years, which is close eno ugh to 57 years for an analysis of 160 years of data, particularly when the the last thirty years is bent up by rapid anthropogenic global warming

Watt talks about a 170 year component, but that's just over-fitting the dat a - he's trying to fit a sine-wave to a hockey-stick. Extrapolating on the basis that a hockey stick is actually part of a sine wave isn't all that cl ever.

A serious data analyst wouldn't make that kind of mistake - the DSP analysi s is clearly tongue in cheek - but Anthony Watt isn't into data analysis, b ut rather into giving his audience the kind of story that they will be happ y to hear.

--
Bill Sloman, Sydney

Thanks for your masterly analysis. It's nice to see you haven't lost any of your religious fervour for CO2 induced warming despite a 17 year pause in warming.

You mean like it's an opportunity to inject prejudice and obfuscation?

Even if Watt's analysis may have problems, in that it seems to expose some periodic signals that are suspiciously close to the length of the sample and its harmonics, the analysis should in principle be objective, impartial, transparent and public.

The official climatologists' story is none of that. Their arguments and data are tainted by money and politics. Even Watt's raw input data can't be trusted because of where it came from!

Jeroen Belleman

processes generating the data presented.

e age to the start of the Industrial Revolution, but they've risen exponent ially since then, to the current 400ppm. The halfway point - 340ppm - happe ned around 1980.

concentrated in the last thirty years. It's visible in the curves present ed by Anthony Watt, but it's equally clear that the warming we've seen is o f the same order as the noise imposed on the global temperature signal by t he Atlantic Multidecadal Oscillation (AMO).

a stable oscillation, but its characteristic period - in so far as it can b e said to have one - is something of the order of 70 years, which is close enough to 57 years for an analysis of 160 years of data, particularly when the the last thirty years is bent up by rapid anthropogenic global warming

data - he's trying to fit a sine-wave to a hockey-stick. Extrapolating on t he basis that a hockey stick is actually part of a sine wave isn't all that clever.

ysis is clearly tongue in cheek - but Anthony Watt isn't into data analysis , but rather into giving his audience the kind of story that they will be h appy to hear.

I spent too long curve-fitting data to set up working curves to have many i llusions left about the process. For the serious stuff I found out how to p ut confidences limits on the multiple parameters I was sucking out of the d ata, and if I tried to extract more parameters than the data would support, the confidence limits got remarkably large - as one parameter went up, ano ther parameter could go down to keep the fitting curve more or less on the data.

Educational.

"Religious fervour"? Since you don't process rational arguments, they might look just like dogmatic assertions to you. Don't worry. God still loves yo u even if you can't make sense of his creation.

The 17-year "pause" in the warming looks rather like the other bobbles the Atlantic Multidecadal Oscillation imposes on the record.

Anthony Watt has very kindly given you 160 years of bobbly data to look at.

Admittedly, the bobbles included prolonged negative-going bits in the bits before 1900, while they now are now only "pauses" in a largely upward progr ession - so you've got to be a seriously a head-in-the-sand denialist like Anthony Watt to see them as some kind of negation of an underlying upward t rend.

He'd get less support from the Heartland Foundation if his perceptions were a little better schooled. What's your excuse? Nobody is going to pay you f or ventilating your ill-founded delusions, so you've got to be compensating for an insecure childhood or something equally unfortunate.

--
Bill Sloman, Sydney

So when Ben Santer said it needs 17 years to see global warming and there hasn't been any for 17 years?

/quote

The LLNL-led research shows that climate models can and do simulate short, 10- to 12-year "hiatus periods" with minimal warming, even when the models are run with historical increases in greenhouse gases and sulfate aerosol particles. They find that tropospheric temperature records must be at least 17 years long to discriminate between internal climate noise and the signal of human-caused changes in the chemical composition of the atmosphere.

/end quote

The RSS temperature record shows no warming for 16 years 8 months.

So far no sign of a "signal for human-caused changes".

Believing in CO2 warming when there is no warming is pretty weird.

Projecting future climate by regression analysis, over a short timebase, is nonsense. Doing it by computer simulation, as most climatologists do, is just more-compute-intensive nonsense.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators

did you notice his graph 13?

2005 and beyond are cooling according to him - but the global averages were amongst the recorded highest. Great model he came up with - stuffed and proved wrong before he even posted.

"Record highest"? Baloney. Hot? Yes. Flat slope? Yes. Cooling coming. Yes. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

That was a political and not an engineering comment.

Because recent temperatures are high doesn't stop there being a downward trend since 2005:

Clear downward trend on HADCRUT3 which is the dataset he analysed.

The guys that keep the temperature records say highest. I have to believe them - but congrats for living in an area with a nice climate

:

he processes generating the data presented.

ice age to the start of the Industrial Revolution, but they've risen expon entially since then, to the current 400ppm. The halfway point - 340ppm - ha ppened around 1980.

is concentrated in the last thirty years. It's visible in the curves pres ented by Anthony Watt, but it's equally clear that the warming we've seen i s of the same order as the noise imposed on the global temperature signal b y the Atlantic Multidecadal Oscillation (AMO).

be a stable oscillation, but its characteristic period - in so far as it ca n be said to have one - is something of the order of 70 years, which is clo se enough to 57 years for an analysis of 160 years of data, particularly wh en the the last thirty years is bent up by rapid anthropogenic global warmi ng

he data - he's trying to fit a sine-wave to a hockey-stick. Extrapolating o n the basis that a hockey stick is actually part of a sine wave isn't all t hat clever.

nalysis is clearly tongue in cheek - but Anthony Watt isn't into data analy sis, but rather into giving his audience the kind of story that they will b e happy to hear.

y illusions left about the process. For the serious stuff I found out how t o put confidences limits on the multiple parameters I was sucking out of th e data, and if I tried to extract more parameters than the data would suppo rt, the confidence limits got remarkably large - as one parameter went up, another parameter could go down to keep the fitting curve more or less on t he data.

ght look just like dogmatic assertions to you. Don't worry. God still loves you even if you can't make sense of his creation.

he Atlantic Multidecadal Oscillation imposes on the record.

at.

ts before 1900, while they now are now only "pauses" in a largely upward pr ogression - so you've got to be a seriously a head-in-the-sand denialist li ke Anthony Watt to see them as some kind of negation of an underlying upwar d trend.

ere a little better schooled. What's your excuse? Nobody is going to pay yo u for ventilating your ill-founded delusions, so you've got to be compensat ing for an insecure childhood or something equally unfortunate.

"At least 17 years". Back in 2003, the significance of the Atlantic Multide cadal Oscillation hadn't been fully grasped - that press release talks about the El Nino/La Nina oscillation, which is the same kind of thing, but cycles a lot more rapidly.

s-july-data/

Don't worry. The greenhouse effect is still working, even if the ocean curr ents are injecting enough noise into the signal you choose to look at to ma ke it hard to see in the short term.

Concentrating your attention on just the last 17 years is equally weird.

Not believing in the greenhouse effect is a good deal weirder. One of the i ntellectual triumphs of our age is that we have worked out why and how the earth started alternating between ice ages and interglacials 2.6 million ye ars ago.

Milutin Milankovitch explained the timing of the alternation of ice ages an d interglacials back in the 1920's, but the changes in the heat being absor bed by the earth then known about weren't big enough to explain the changes in the earth's temperature. The fact that the large ice sheets covering th e large parts of the northern lands masses during an ice age reflected a lo t more solar radiation than ice-free forest and tundra went quite a way to explaining the difference, but it wasn't until we had ice core data that sh owed the atmospheric CO2 levels dropped from about 280ppm during an inter-g lacial to about 180ppm during an ice age that we could balance the thermal budget.

It turns out that as the climate - and the oceans - start to warm up at the end of an ice age, the carbon dioxide dissolved in the oceans starts comin g out of solution. This doesn't happen overnight and in fact there's a roug hly 800 year lag between the start of the warming and the rise in atmospher ic carbon dioxide concentrations, but once it gets under way temperatures r ise pretty steadily up to the inter-glacial norm.

The difference between ice ages and inter-glacials is definitely discernabl e, and carbon dioxide levels do seem to have had an influence. The story is still being fleshed out -see Shakun, Jeremy D., et al. (2012). "Global War ming Preceded by Increasing Carbon Dioxide Concentrations During the Last D eglaciation." Nature 484: 49-54 [doi:10.1038/nature10915] - but claiming th at CO2 isn't a greenhouse gas isn't a viable hypothesis.

--
Bill Sloman, Sydney

The prejudice is a more complete grasp of physics than Anthony Watt can cla im - or Raveninghorde either. I'm a bit surprised to see you characterising the dragging in of physical reality as "obfuscation". It may work that way for the ignorant who don't understand physics, but it clarifies matters co nsiderably for those who do.

Embeddeded in the analysis is the assumption that the processes that you ar e looking at are cyclic, which means that any extrapolation has to be a rev ersion to the mean.

We know enough about greenhouse warming to know that the baseline is shifti ng, and the strictly sine-wave only analysis can't capture that. Harmonical ly related sine waves form a great set of mutually orthogonal fitting funct ions, but it doesn't follow that the process that you are looking at are we ll-described by sine waves.

Which rather neglects that the denialist counter-propaganda is entirely dri ven by money and commercial interest. People who make money out of extracti ng fossil carbon and selling for fuel have a strong interest in devaluing t he scientific case for anthropogenic global warming - in exactly the same w ay that the tobacco companies had an interest in devaluing the scientific e vidence that smoking was bad for your health. It's a trifle comic to find t hat some of the people who were active for the tobacco companies are now ge tting money from Exxon-Mobil.

That's what Exxon-Mobil wants you to believe, and they seem to have spent e nough money on sewing doubt to have have mislead people who ought to know b etter.

--
Bill Sloman, Sydney

It used engineering data to make a political point.

But if you use a little more of the data set, it becomes an upward trend. If you go back to 1850, it becomes a totally unambiguous upward trend.

It's all nitpicking if you take the record back for a million years or so - as we now can - and can see the alternation between ices ages (CO2 levels of about 180ppm) and interglacials (CO2 levels around 280ppm).

The current scinetific understanding of what has been going on over the past 2.6 million years (which Raveninghorde has yet to get his head around) provides a useful perspective on today's temperature excursions.

--
Bill Sloman, Sydney

is

just

John Larkin sees climatologists doing computer simulations in the same way that he uses LTSpice, running the simulation for just long enough to produc e the behaviour he wants to see then stopping the simulation before the cir cuit can move off in a direction he doesn't fancy.

Climatologists run lots of different simulations, using a wide range of dif ferent models. Nobody thinks that any one model predicts physical reality, but by comparing lots of simulations they do get some kind of feel for what 's going on and can deliver a rough idea of the way the climate is going to evolve.

Crude and imprecise as their predictions are, they are a lot more reliable than John Larkin's wishful thinking, and provide a persuasive case for us t o trade off a bit of economic growth in favour of getting more of our energ y from renewable sources.

--
Bill Sloman, Sydney

So the science was settled but the alarmists hadn't grasped the significance of the AMO.

I corrected a factual error by David. Don't see thatt as an attack on your religion.

ote:

t the processes generating the data presented.

ast ice age to the start of the Industrial Revolution, but they've risen ex ponentially since then, to the current 400ppm. The halfway point - 340ppm - happened around 1980.

een is concentrated in the last thirty years. It's visible in the curves p resented by Anthony Watt, but it's equally clear that the warming we've see n is of the same order as the noise imposed on the global temperature signa l by the Atlantic Multidecadal Oscillation (AMO).

to be a stable oscillation, but its characteristic period - in so far as it can be said to have one - is something of the order of 70 years, which is close enough to 57 years for an analysis of 160 years of data, particularly when the the last thirty years is bent up by rapid anthropogenic global wa rming

g the data - he's trying to fit a sine-wave to a hockey-stick. Extrapolatin g on the basis that a hockey stick is actually part of a sine wave isn't al l that clever.

P analysis is clearly tongue in cheek - but Anthony Watt isn't into data an alysis, but rather into giving his audience the kind of story that they wil l be happy to hear.

many illusions left about the process. For the serious stuff I found out ho w to put confidences limits on the multiple parameters I was sucking out of the data, and if I tried to extract more parameters than the data would su pport, the confidence limits got remarkably large - as one parameter went u p, another parameter could go down to keep the fitting curve more or less o n the data.

might look just like dogmatic assertions to you. Don't worry. God still lo ves you even if you can't make sense of his creation.

s the Atlantic Multidecadal Oscillation imposes on the record.

ok at.

bits before 1900, while they now are now only "pauses" in a largely upward progression - so you've got to be a seriously a head-in-the-sand denialist like Anthony Watt to see them as some kind of negation of an underlying up ward trend.

s were a little better schooled. What's your excuse? Nobody is going to pay you for ventilating your ill-founded delusions, so you've got to be compen sating for an insecure childhood or something equally unfortunate.

idecadal

he El Nino/La Nina oscillation, which is the same kind of thing, but cycles a lot more rapidly.

The El Nino/La Nina and AMO change global temperature by changing the way h eat gets from the equator to the poles. It doesn't affect the amount of hea t being absorbed and re-radiated by the planet, but it does have a short te rm effect on the temperatures measured at the surface of the planet. At the time this tended to be described as "noise on the temperature record".

The fundamentals of the greenhouse warming have been widely accepted since the 1990's, so the science really is settled, but the short term fluctuatio ns do require a more detailed understanding than we've got right now - but the Argo Buoy program is starting to deliver.

The program was proposed back in 1999, in part to fill in this gap in our k nowledge, the 3000 buoy fleet was fully deployed in 2007, and the data coll ected is now being fed into climate models.

--
Bill Sloman, Sydney

s

l/from:2005/trend

. If you go back to 1850, it becomes a totally unambiguous upward trend.

so - as we now can - and can see the alternation between ices ages (CO2 lev els of about 180ppm) and interglacials (CO2 levels around 280ppm).

past 2.6 million years (which Raveninghorde has yet to get his head around) provides a useful perspective on today's temperature excursions.

You didn't correct a factual error. You indulged your usual enthusiasm for picking the time interval over which to estimate the "trend" in order to be able to present the result you thought that David should have seen.

This is a fairly serious error in technique. The planet wasn't created in 2

005, and if you want to work out what's going to happen to it over the next century or so, you need to understand what been happening over the past fe w million years, rather than concentrating on the last eight or 17 years.

There's loads of evidence available on the subject - ice cores, layered lak e and ocean sediments and so forth. Take a look at it sometime. It won't be a revelation - science lets you make up your own mind about the message - but even you might find it educational.

--
Bill Sloman, Sydney

Bill you need new glasses.

David said:

/quote

did you notice his graph 13?

2005 and beyond are cooling according to him - but the global averages were amongst the recorded highest. Great model he came up with - stuffed and proved wrong before he even posted.

/end quote

I pointed out thst David was factually wrong as HADCRUT3 temperatures have been falling since 2005. Graph 13 was not invalidated.