The general impression one gets from the popular press is that over the last few years there has been accelerated global warming from the elevated levels of atmospheric carbon dioxide. In fact global warming has stalled since 1998.
But there was warming during the early part of the 20th Century, and the rate of warming then was almost identical to the rate of warming at the end of the century.
“Without getting into details (ask questions in comments if you have them), using HadCRUTv3 the rate of change during the early part of the 20th century was almost identical to the rate of change at the end of the century. Could there be some sense in which the warming at the end of the 20th century was a repeat of the pattern seen in the earlier part of the century? Since the rate of increase in greenhouse gas emissions was much lower in the earlier part of the century, what could possibly explain why temperatures increased for so long during that period at a rate comparable to that experienced during the recent warming?
Read more here: http://wattsupwiththat.wordpress.com/2008/03/26/evidence-of-a-significant-solar-imprint-in-annual-globally-averaged-temperature-trends-part-1/
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
To think this turkey is one of the stars of the so-called skeptic movement.
http://tamino.wordpress.com/2008/03/30/how-not-to-analyze-data-part-deux/
He digs himself even deeper in part II. I simply cannot believe how credulous people are.
Skeptics….pfffft!!!
Tamino – aka Grant Foster – batting for the climate alarmist movement. Game set and match over at CA:
http://www.climateaudit.org/?p=2920
http://www.climateaudit.org/?p=2897
http://www.climateaudit.org/?p=2869
http://www.climateaudit.org/?p=2852
So Nexus,
What was the rate of warming at the beginning of the 20th century and then at the end of the 20th century?
And I would prefer if you explained, rather than provided a link.
PS I did have a quick read of the link you provided but it didn’t seem to be on topic.
Jennifer: “I did have a quick read of the link you provided but it didn’t seem to be on topic.”
It isn’t! That argument is about the possible solar cycle fingerprint in the temperature record. I am undecided about that one but have an open mind for now.
Jan,
The two posts by Anthony are about the possible solar cycle fingerprint, but my post/this post is about the rate of warming which Anthony mentions as an introduction.
Your thoughts on this?
Jennifer: April fools day ended at noon.
The need for Watts HP filter completly eludes me
Re warming rates, there is absolutly nothing there to stop a third step forming like the previous two
Gavin
1. Watts did not do the heavy statistics, as he explicitly states in his introduction of his blog,
2. The High Pass filter was explained by this rather neat link by Copeland/Watts.
The Hodrick-Prescott filter is a mathematical tool used in macroeconomics, especially in real business cycle theory. It is used to obtain a smoothed non-linear representation of a time series, one that is more sensitive to long-term than to short-term fluctuations. The adjustment of the sensitivity of the trend to short-term fluctuations is achieved by modifying a multiplier λ.
It sure does not escape me – it’s used to smooth short-term fluctuations, revealing the longer underlying fluctuations.
Since it cannot be CO2, the only plausible canditate for the temperature rise is the sun, which itself is powered by the galactic electric currents.
As Neddy Seagon might have said, “It’s all rather simple, really”.
Seagoon!
Whoops, concerning same authors…wrong link.
http://tamino.wordpress.com/2008/04/01/how-not-to-analyze-data-part-3/
Comments in the first link cover part I though.
Paul’s set a good example of “in your own words” above. Shall I follow his lead? What do you reckon, Jen? I have a sneaking feeling that he doesn’t fully understand either Tamino’s or McIntyre’s position on that particular argument. Just cheerleadin’ I’d say.
As for a similar rate of warming – sure. I believe you’ll find some nice info about that in chapter 9 of the IPCC 4AR WG1. Best have a look.
Nexus, yours was the first comment in this thread – suggesting my post was ridiculous. can you just tell me what you think about rates of warming – was it faster at the beginning or the end of the 20th century?
Jennifer: “Your thoughts on this?”
I’ve been aware for a while now that the rate of increase in the second half of the 20th century was more or less the same as the first. We can a similar result with a linear regression. To be sure it’s another instance of poor correlation with rising CO2 levels.
I’m not sure that in this instance using the Hodrick-Prescott filter is necessary but the exercise is invaluable as a proof of concept that it can be used for removing cyclic signal from data and I’ve been looking for a way to this. From that point of view it’s very interesting.
PS Nexus, I think Paul was responding to your comment with his links.
And Gavin,
regarding that possible ‘third step’ – so do you think there might be some cooling in between?
Jen, perhaps I wasn’t clear enough. Sure = yes. The rates are similar. Read chap. 9 to understand why.
Watts’ posts (pts. I and II) are ridiculous. Yours is…I dunno. Impressions you get from the general press are unquantifiable and essentially meaningless unless you provide some examples. Though to be fair, I think we can take it as a given that some parts of the press aren’t entirely accurate. I for one am shocked at some of what I read in New Idea.
Wow… I can’t believe you are buying the Watts stuff…
Jennifer, why don’t you explain it in your own words. With no links…
Tell me, does this mean you acknowledge there has been warming in the twentieth century? Because if you accept Watt’s post as true then you have to accept there was warming in the twentieth century.
It’s interesting to contrast this with his other claims.
e.g.
I thought that Watt’s whole meteorological station station analysis was to show there was no warming… Doesn’t it strike you as strange that this analysis confirms the warming of the Twentieth Century?
Jan, serious question: Why does a linear increase in temp conflict with rising CO2 levels given that we know the effect of increasing CO2 diminishes. It’s a logarithmic decay no? So as each time you double CO2, the effect is less each time.
Louis: “Since it cannot be CO2, the only plausible canditate for the temperature rise is the sun, which itself is powered by the galactic electric currents.”
As far as I was aware the sun is powered by fusion.
Will this nonsense end if March is hotter than Feb in the HadCrut3 data?
What is most interesting is that these graphs seem to show that it doesn’t matter how strong (number of sunspots) a particular cycle is. That is that the solar cycle strength, doesn’t affect the temperature. For example we know that the sunspot numbers (and presumably the TSI) were much greater for the cycle ending around 1958/59 and that the sunspot numbers have been decreasing with each maxima ever since.
Doesn’t this contradict a number of his other hypotheses? Where he matches sunspot number to temp. Or was that a different blogger?
Strange…
Although it’s not strange that you can see solar cycles in climate. No one has ever denied the sun influences climate.
Also it is obvious that the warming for the cycle ending 1997-2000 is greater than the others. Would you not expect the next solar max in 2010 or 2011 to be even higher? It looks like the trend of the trend is up…
I don’t see how he can make this statement”
In terms of the underlying rates of change, the warming of the late 20th century appears to be no more “unusual” than the warming during the 1920’s and 1930’s. ”
The warming rate (by his graph) is clearly higher, he hasn’t actually related this to a solar phenomenon other than to say the max rate occurs at solar max. Which is to say nothing at all. The rate of increase is increasing (by his graph) – the line tends to be moving higher and higher from the 0 bar.
Interesting in a strange way this little essay. Interesting the way he draws conclusions not actually in the data he presents.
Oops Solar max, apparently should be around 2012 2013
http://www.swpc.noaa.gov/SolarCycle/
But apparently we don’t need to worry about sunspot number because Mr Watt’s friend just showed us that sunspot number is unrelated to climate. So it won;t matter if the sunspot number is low.
I guess that means the Maunder Minimum wasn’t so cold?
Mr T, “I thought that Watt’s whole meteorological station station analysis was to show there was no warming”
Perhaps you need to stop mischaracterising the work of others.
Watt’s meteorological station *survey* is to audit the quality and level of compliance with standards.
” It’s a logarithmic decay no? So as each time you double CO2, the effect is less each time.”
Er no that’s not quite how it works, each time you double the effect is the same for any other doubling. What does this mean?
the effect of going from 1 – 2 ppmv is the same as going from 190 -> 380 ppmv and the same again for 280 -> 560 ppmv.
This however is not the conflict; a monotonic increase in CO2 conflicts with cooling. This has happened once last century from the 40 – 70s and all of this century. Also a linear increase in temperature vs CO2 is not the correlation we seek.
An interesting game is to look at how many times CO2 has doubled from 1 ppmv to today at ~380 and that is 8.6 times and at 3K per doubling this conflicts with the 9K warming generally attributed to the presence of CO2.
Boy this blog is really trolling bottom now, snagging a nexus6 from the detritus!
Arguments sans reasoning or facts. Just naked conclusions and begged questions wrapped in opaque, fractured prose. What a treat.
Nexus,
While I might go away and read chapter 9, chances are that the many other people who read this blog won’t.
So can you please explain to those who have got this far down this tedious thread why the rate of warming at the beginning of the 20th Century was similar to the rate of warming at the end of the 20th Century.
Honest question/request.
Mr T.
There are very few skeptics who would agree with you that there has been no warming. 😉
Most simply question the extent to which carbon dioxide has driven warming over the last 100 years. And also dispute that we experiencing a climate crisis.
Jan Pompe:
Watt’s meteorological station *survey* is to audit the quality and level of compliance with standards.
I believe this was driven by the discrepancy between the satellite/balloon records and the NH surface temp record.
The satellites and balloons now agree reasonably but the NH surface record shows larger increases in temperature which must be explained. One possibility is that there is something wrong with the measurements and a site survey is a first step to resolve this.
One other possibility is that the CO2 induced warming has its greatest effects on populated areas.
Jen,
Combination of AGW (less than now) and external forcing (solar)/internal variation (more than now, though papers differ on the relative importance of the latter two).
There’s a good figure in the report that’s worth posting – I’ll have a look after work.
Eyrie: “I believe this was driven by the discrepancy between the satellite/balloon records and the NH surface temp record.”
In the case of such discrepancy on of the first question I’d ask is how good is the data and how good are the instruments obtaining that data. Another early question is should they be the same i.e. how good is the theory.
It’s all part of getting to the truth not as Mr T, suggests “to show there was no warming”.
Jan, fair enough re CO2. So in effect a monotonic increase in CO2 won’t give a linear response. It will give a slowly decreasing response.
So how do you feel about the solar cycle analysis? Pretty rough and ready yes?
The best part is showing that cycle strength and TSI play no role in climate. This is genius that Galileo would be proud of.
Jen, glad to hear that.
I think everyone is pretty much at that point; wondering what the effect will be. Do you like this analysis though? Seems a little ummmmm simple?
Interesting how comments on this blog have slowly drifted away from the original post. Maybe people are realising that the post doesn’t actually mean anything?
A much better study:
http://publishing.royalsociety.org/media/proceedings_a/rspa20071880.pdf
Before we get too worked up we need to remember that this is raw data. To get a truer picture we need to go back and adjust for volcanic aerosols.
http://www.geocities.com/mcmgk/TempAdjust2.html?1199762345031
This puts the second rise of the same magnitude but ending in 1992 after first reaching that point in 1982. So unlike the earlier rise of 33 years at 0.14C/decade, the actual 1967-1992 rise is only 25 years and with a decadal rise of 0.225C.
But in fact, the data suggests that the aerosol adjusted late 20th century rise really only began in 1976 and only lasted 16 years and had a decadal rise of 0.35C. This does conform to an accelerated warming, possibly due to some CO2 response. But that still leaves us with the recent 16 year temperature plateau which directly contradicts the CO2 forcing hypothesis.
Note also that the mild decline and plateau from 1941 to 1976 lasted 35 years and constitutes the longest consistent trend in 160 years of data. The next longest sequences are the 32 year decline from 1878 to 1909 and the 32 year rise from 1909 to 1941. But it should be noted that this earlier data has not been adjusted for volcanic aerosols.
All up, some 98 years (61%) of the past 160 year data set have been part of a consistent mild decline while only 62 years (39%) have been part of a consistent rising trend.
And the question remains, how do these sudden, and seemingly aberrant, jumps from plateaux reconcile with CO2 greenhouse theory?
Mr T, “So in effect a monotonic increase in CO2 won’t give a linear response.”
More precisely a linear increase in CO2 does not give a linear response in temperature but the logarithm of the increase in CO2 does.
A monotonic increase is one that does not cease i.e it’s always positive and there are times when the increase in temperature is negative i.e. it cools. Ten years is enough to break the correlation because it should not happen at all if there is to be a correlation than can be called a correlation.
How the correlation is broken is that it does not fit the numbers the slopes in the two halves of the century should not be the same and aren’t if we plug in the numbers and we actually have to do this to see it an not just hand wave.
E.g. for a ~3K/2xC02 for for the 1970 – 2007 increment from 322 – 383 ppmv is 3 * log2(383/322) = .75K ( .2 /decade) and for the 1900 -1940 of 290 – 330 ppmv it’s .55K (.13/decade) neither tightly agree with the observed but the earlier one is better.
However let me add this caveat water vapour is not taken into account here at all and that will further limit the observable effect of CO2.
Thanks Jan,
I am interested in your opinion, here’s a little thought experiment.
Let’s say that most of 1998 was El Nino affect and this last 6 months has been La Nina affected. So the extremes we saw in 1998 and early this year we ‘ignore’. So let’s assume that the Global temp anomaly is basically stable at around 0.4 (based on HadCrut3). This is what people on this blog tend to believe – that’s there’s been a stable period around 0.4 since around 2000.
Let’s also assume that CO2 levels will continue to rise pretty much as they have recently.
So they’re our assumptions.
How long will it be until there is no ‘observable’ effect from CO2? What is your prediction of the resulting anomaly?
So can we expect it to get much hotter, say between now and the next solar max in 2012?
Jennifer: “regarding that possible ‘third step’ – so do you think there might be some cooling in between?”
I doubt it depending on you definition of “cooling” and a few other things.
Sorry if I can’t help you guys get over the graphs too but it comes down to how we each build reference systems and gain a personal perspective. For me there is always something beyond these short term temperature curves and that is all the ice and lea levels.
For decades I have studied various measurements without using math. However it required a lot of consideration based on developing other approaches besides the obvious. Looking for alternative references is just the first step. Sure all disciplines and practices including climate physics must have the imaginative element working in order to redefine the value of information, but this secondary evaluation of curves above doesn’t help anyone see rates of change.
Vibrations Inc: Do you grab a stethoscope and place it on the steering wheel of the bomb you are driving, then dash home with the tape recording for lambda filtering before discovering you only had a flat back tire? With this experience behind us we should at least know these once normal rhythms can throw us all over the place.
Every day I look for fresh signs of climate change. Today was a mild 22C max but wait for it, we had a total fire ban too. Mid afternoon during my second attempt at a reply I heard a rapid series of explosions nearby outside and the desk top died along with the radio. So I picked up the phone and called the Government switchboard and suggested there were some overhead wires banging together but the power was back on again.
On the next power down I jumped in the wagon and drove down to the creek expecting to see the maintenance crew pulling a branch down. Sure there was a truck there but the line down was round the corner and one phase was still on after they cleared the first bit of tree. How good was my guess work?
As our sky turned to oatmeal I heard on the radio Melbourne was close to impossible and a commentator there had never seen anything like it before. She wasn’t going home because that usually involved a trip over the West Gate Bridge. I bet the news tonight will have more stories of particularly wild weather. Let’s get used to it.
And Gavin, I bet your reporter was not born or too young to see 5 feet of water flowing down Elizabeth street in 1972. I wonder what climate event that would have been put down to? That was the era of the imminent Ice age wasn’t it?
Global mean temperature has not increased smoothly since 1900 as would be expected if it were influenced only by forcing from increasing greenhouse gas concentrations (i.e., if natural variability and other forcings did not have a role). A rise in near-surface temperatures also occurred over several decades during the first half of the 20th century, followed by a period of more than three decades when temperatures showed no pronounced trend. Since the mid-1970s, land regions have warmed at a faster rate than oceans in both hemispheres and warming over the SH was smaller than that over the NH during this period, while warming rates during the early 20th century were similar over land and ocean.
Detection and attribution as well as modelling studies indicate more uncertainty regarding the causes of early 20th century warming than the recent warming. A number of studies detect a significant natural contribution to early 20th-century warming (Tett et al., 2002; Stott et al., 2003b; Nozawa et al., 2005; Shiogama et al., 2006). Some studies find a greater role for solar forcing than other forcings before 1950 (Stott et al., 2003b), although one detection study finds a roughly equal role for solar and volcanic forcing (Shiogama et al., 2006), and others find that volcanic forcing (Hegerl et al., 2003, 2007) or a substantial contribution from natural internal variability (Tett et al., 2002; Hegerl et al., 2007) could be important. There could also be an early expression of greenhouse warming in the early 20th century (Tett et al., 2002; Hegerl et al., 2003, 2007).
* I may have in fact plagiarised this from a document I’m sure nobody here has actually bothered to read.
* Jen, why don’t you post IPCC 4AR WG1 Chapter 9 Figure 9.5. It contains some interesting modelling which we all know and love.
And for the record I think the analysis by Watts and Copeland interesting and relevant – but I’m not completely sold on their theory.
I particularly like the second graph (see above). It is ‘apparently simple’ yet compelling. Almost a work of art.
Nexus, send me the graph as a jpeg with some text and I’ll do it as a new post/new thread from you.
GAvin, you are not being logically consistent. if you envisage a ‘step’ then there must be a consequence in between.
Jennifer, what do you think Fig 2 shows?
I am really getting curious about this topic. It’s fascinating.
From my reading it seems that a Hale Cycle is actually two complete Schwabe Cycles. So effectively it is a reversal and return to normality. It doesn’t really have a “peak” but rather two peaks. I don’t understand how they label the peaks in Fig 2.
Some reading:
http://articles.adsabs.harvard.edu//full/1971PASAu…2….7P/0000007.000.html
http://articles.adsabs.harvard.edu//full/1998ASPC..140..293W/0000296.000.html
The second is especially interesting as it shows complete Hale Cycles. So you can see there is a peak in around 1979 (as listed on the diagram) but the 1990ish peak is missed… but why?
Any ideas? Why would one peak be important and not the other, and why is TSI apparently not important?
Someone want to buy this?
http://arxiv.org/abs/physics/0509248
Actually here it is… It’s FREE!
http://arxiv.org/PS_cache/physics/pdf/0509/0509248v1.pdf
So, from the conclusions:
“The climate sensitivity to the 22-year cycle, Z8, is approximately 1.5 times stronger than the climate sensitivity to the 11-year cycle, Z7, and, in average, the 22-year climate
response lags Hale solar cycles by approximately 2.2±2 years. Both effects are approximately
predicted by theoretical energy balance models. In fact, the actual climate response to
cyclical forcing is stronger at lower frequencies because the damping effect of the ocean
inertia is weaker at lower frequencies [Wigley 1988, table 1]. This frequency dependence
arises because the system is typically not in thermodynamic equilibrium. The ratio Z8/Z7 =
1.55±0.55 is consistent with that between the damping factors for 20 and 10 year periodicities
20/10 1.45 indicated by the Wigley’s model [1988, table 1]. Wigley’s model also predicts
a response-lag of 2.5-2.8 years for a 20 year periodicity.
In conclusion, we believe our estimates Z7 and Z8 of the climate sensitivity to solar
variations from 1980 to 2002 are realistic. By using the ACRIM TSI increase estimate
Isun (1), the climate sensitivity Z8 in Eq. (6) and Eq. (3), the warming caused by Isun is
Tsun ‘ 0.08±0.03. Thus, because the global surface warming during the period 1980-2002
was T1980−2002 = 0.40±0.04 K, we conclude that according to the ACRIM TSI composite
the Sun may have minimally contributed 10-30% of the 1980-2002 global surface warming.”
The fonts make it hard so there is some strange characters in there.
So there you go, it has already been studied and quantified… No Nobel for Wattsy.
And then the Scafetta and West paper was disputed by the folk at RealClimate…
http://www.realclimate.org/index.php/archives/2006/03/solar-variability-statistics-vs-physics-2nd-round/
Strange how we keep going in circles. This is why people should do literature reviews before they do ‘research’. This will prevent them re-hashing earlier work.
The discussion on RealClimate at least makes an attempt to untangle the science and analyse if the 22 year Hale Cycle is important.
Anyway, even if the Scafetta and West work is right, it still only gives us 10- 30% of the global surface warming
Mr T, “Strange how we keep going in circles”
It might appear that way but the circle paths actually change a little more knowledge a little more data is gleaned on the way. Very little of the research can be done in a laboratory so must be done as opportunity presents and observables change etc.
Regarding the future temperature you are asking me to guess. The solar physicists are predicting a late and weak cycle so I don’t expect a great deal of warming if any.
I really can’t say that we’ve seen any climate change that correlates well with CO2 levels of late, so I don’t quite understand what you mean by “How long will it be until there is no ‘observable’ effect from CO2”
Given the two graphs above I fail to see as stated above what’s going on with the extra filtering and the conclusion regarding rates of change. Let’s subtract the second curve from the first and come up with the warming curve, T1-t2 = Hockey Stick. Howzat?
Note our cyclical t2 varies between +/- point one C therefore its no big deal!
Alternatively we could focus on just the current dip provided someone can satisfactorily explain its similarity with other dips say around1910 and 1950. As both these were short lived I reckon they are almost irrelevant on my hockey stick. What ‘say I predict the 3rd step will be longer based on our observation of the last two? Ramping up takes a while though. My next guess is everybody here will be paying carbon taxes long before we all fall into the following temperature dip.
A discussion round this blog or others similar is not a good indication of either climate science or the latest in methodology. After listening to a brief conversation between a environment science student and a PS officer moving on to “climate change” issues I naturally asked my usual Q’s at the first opportunity. Do you believe in global warming, man made climate change etc and how do you know?
Since I already knew one has been busy doing land cover research around the ranges I was most curious about the other. She eventually stopped stuttering “b, b, but everybody knows don’t they?” and finally said “’I’ve SEEN the glaciers” Fair enough, I thought, that’s one up on me.
Beano: As I was living on the eastern fringe and monitoring local Melbourne weather almost every day forgive me if I can’t recall your city downpour in 1972. Besides we were not dealing with single thunderstorms yesterday. This was a widespread unusual event and I say that as a long time watcher of southern ocean weather patterns.
“An intense low passing just south of Tasmania will move away across the south Tasman Sea during the day” BoM. 3rd April.
As the day job commuter passed me on the back steps just after dawn she asked “what’s all the yellow stuff?” I waited till there was more daylight to find an appropriate answer. Yellow probably meant pink in my book. There was a fine coating of brick red dust everywhere and it was most noticeable as wet streaks on the patio tiles under the back door.
From my perspective, grpah two shows no trend overall, so any assertion that global temperature rise is accelerating is not supported by these data.
Jan, looking at the solar cycle prediction(s) by NASA it doesn’t look “late”. They have a ‘low’ prediction and a ‘high’ prediction, the low a bit lower than the last cycle and the high a fair bit higher.
The question I posed was about what is the maximum amount of warming you see eventuating from increasing CO2. Given that it can’t increase forever where do you see the limit? Given that the equations you gave earlier in the post suggest there should be a warming:
“E.g. for a ~3K/2xC02 for for the 1970 – 2007 increment from 322 – 383 ppmv is 3 * log2(383/322) = .75K ( .2 /decade) and for the 1900 -1940 of 290 – 330 ppmv it’s .55K (.13/decade) neither tightly agree with the observed but the earlier one is better.”
Gavin, that low is actually the remains of Tropical Cyclone Pancho, the remains of which passed through Perth on Monday. This storm is doing a tour of Oz!
Louis, Fig 2 is actually found by going through the link at the top of this page. The two graphs on this page comprise Figure 1.
Looks like Mr Watts has been convinced of the error of his analysis and is doing a new Fig 2
Mr T,
In answer to your question, I thought the second figure as posted at this blog (which you are now referring to probably correctly as the second graph in figure 1) showed the rate of temperature change. but i am happy to be corrected.
Mr T, “Jan, looking at the solar cycle prediction(s) by NASA it doesn’t look “late”. ”
Too late it’s already late getting started. I’ll go with Dr Leif Svalgaard’s predictions if it’s all the same. Late generally also is low.
As for the other it’s one thing to find discrepancies in existing work that shows that more work is needed and another coming up with a newer better method. finding the discrepancy is just the first step.
Jennifer, I’ll call it graph 2 now as well. I see, yes that second graph apparently shows the rate that temp changed. I guess my biggest problem was with the other graph they created (seems other people had problems with it too).
I would’ve thought the best way to analyse that grpah would be to find the integral for sections of the graph, say each section is around 11 or 12 years. Or perhaps take the integral based on the solar cycle length. Then you would see what solar cycle actually had the greatest ‘warming’. It’s a difficult graph to just eyeball and get any meaning.
It’s interesting that the graph shows no real change in character. So the region between 1850 and 1920 looks very similar in character to the rest of the graph, but if you compare that to the HadCrut graph that period showed little or no warming. Why would that be so? Why wouldn’t it change character?
Actually reading a bit about the filter, it talks about it’s ability to remove cyclical components.
So is the second graph the cyclical component that they are removing? In that case, the second graph shouldn’t be used to determine if there is warming or cooling, as it effectively shows us the ‘weather noise’ – which is probably why it looks so similar the whole way. It’s a self-similar graph that you see in any chaotic system.
Does that sound right?
That would mean the blue line is the temp with the ‘noise’ removed.
The filter:”The Hodrick-Prescott filter is a mathematical tool used in macroeconomics, especially in real business cycle theory. It is used to obtain a smoothed non-linear representation of a time series, one that is more sensitive to long-term than to short-term fluctuations. The adjustment of the sensitivity of the trend to short-term fluctuations is achieved by modifying a multiplier λ.” So the second grpah can’t be the filtered component, it’s the bit that was removed.
And if you read their article they then use that blue line to show it’s relationship with the 22 year solar cycle (which as I mentioned earlier was discussed in 2005 and has led to more heated debate).
Yes, I think the second graph just shows the ‘weather noise’.
Mr T,
Neat explaination for graph 2.
And there is no carbon dioxide influence here?
I would say that graph 2 has no CO2 influence… The smoothed Graph 1 on the other hand possibly does.
I agree graph 2 doesn’t appear to have a co2 influence.
So where is it possibly in graph 1 – in the blue line?
It would be in the blue line yes,
BUT it would be pretty hard to figure out how much.
I’d say: Blue line = Sun + Albedo + emissivity + GHGs + any ‘stored’ heat in Oceans
I may have missed some other factors out too. And that is just my guess. And I am sure someone will point out how I am wrong.
Cooling anyone? Mt Reid Tasmania: wind gusts 95 – 139 km/h yesterday
TASMANIAhttp://www.bom.gov.au/products/IDT60801/IDT60801.95952.shtml
The 169 km/h winds were reported at Maatsuyker Island just south of the state before the weather station was damaged by the cyclone strength winds at three o’clock this morning. This is the strongest wind recorded at this site in at least six years and the strongest recorded anywhere in Tasmania in four years. In 2004, 190 km/h winds were measured at Mt Wellington.
http://weather.news.com.au/breakingweather.jsp?site=newscomau
It’s the remains of Tropical Cyclone Pancho Gavin. Weird weather that’s for sure.
Mr T, “I would’ve thought the best way to analyse that grpah would be to find the integral for sections of the graph, say each section is around 11 or 12 years.”
Something lie that is actually bound to give spurious correlations on apparent 11 year or 12 year cycles. It’s called the Slutsky effect which is an observation that using moving averages can give the appearance of cycles being present even in random series. I’d be wary of such a method.
Jan
And thus I prove I am no mathmetician.
Mr T, “And thus I prove I am no mathmetician.”
My remark was not intended as a criticism just a warning. Being aware of the effect is what makes the Hodrick-Prescott method interesting because I don’t think it’s subject to that effect – more later maybe.
Jan, I didn’t think it was presented as a negative. I appreciated the tone.
It’s an interesting filter, as I had often wanted to see what weather noise would look like in one of the GISS or HadCrut graphs.
Mr T, “It’s an interesting filter, as I had often wanted to see what weather noise would look like in one of the GISS or HadCrut graphs.”
Same here and I plan to find out. When I have time and when I do I will share.
Anthony Watts comes up against some data he didn’t like.
http://wattsupwiththat.wordpress.com/2007/07/14/the-stevenson-screen-paint-test/
Haven’t heard about his Stevenson screens paint job for a while now.
SJT: “Haven’t heard about his Stevenson screens paint job for a while now.”
What is your point exactly?
Anthony Watts comes up against some data he didn’t like.
SJT must have come up against something he didn’t like we haven’t seen an answer. What was is I wonder.
“Haven’t heard about his Stevenson screens paint job for a while now.”
Wrong!!!!
http://wattsupwiththat.wordpress.com/?s=Screen+paint+test
Jen, what do you mean when you say you find the second graph compelling? There’s actually one figure with two graphs and with some text on the first graph for rates of change of different periods. The whole exposition confused me for a bit. The bottom panel is not a derivative. If we wanted to make comments about rates of change over time, plotting the derivative would be helpful. But that cyclicality panel is measuring “cyclicality”, whatever that means. And it seems like the “cyclicality” is not consistent either. (I intuit that this HURTS Watts’s point of suncycles actually.)
Or if it is a derivative (in the lower panel), it’s not called one…it’s called “cyclicality”. Also the text (inset upper panel) gives rates of change of long periods of time from the SMOOTHED graph. Is the cyclicality (derivative?) done on smoothed or raw data? For instance from 1980 to 2000, the slope is positive (smoothed). And even if derivative of raw data taken (which will be more sawtoothy), will still see by averaging, that it tends to be more positive than negative (has to be…given the endpoints).