Temperature averages of continuously reporting stations from the GISS dataset
Guest post by Michael Palmer, University of Waterloo, Canada
Abstract
The GISS dataset includes more than 600 stations within the U.S. that have been
in operation continuously throughout the 20th century. This brief report looks at
the average temperatures reported by those stations. The unadjusted data of both
rural and non-rural stations show a virtually flat trend across the century.
The Goddard Institute for Space Studies provides a surface temperature data set that
covers the entire globe, but for long periods of time contains mostly U.S. stations. For
each station, monthly temperature averages are tabulated, in both raw and adjusted
versions.
One problem with the calculation of long term averages from such data is the occurrence of discontinuities; most station records contain one or more gaps of one or more months. Such gaps could be due to anything from the clerk in charge being a quarter drunkard to instrument failure and replacement or relocation. At least in some examples, such discontinuities have given rise to “adjustments” that introduced spurious trends into the time series where none existed before.
1 Method: Calculation of yearly average temperatures
In this report, I used a very simple procedure to calculate yearly averages from raw
GISS monthly averages that deals with gaps without making any assumptions or adjustments.
Suppose we have 4 stations, A, B, C and D. Each station covers 4 time points, without
gaps:
In this case, we can obviously calculate the average temperatures as:
A more roundabout, but equivalent scheme for the calculation of T1 would be:
With a complete time series, this scheme offers no advantage over the first one. However, it can be applied quite naturally in the case of missing data points. Suppose now we have an incomplete data series, such as:
…where a dash denotes a missing data point. In this case, we can estimate the average temperatures as follows:
The upshot of this is that missing monthly Δtemperature values are simply dropped and replaced by the average (Δtemperature) from the other stations.
One advantage that may not be immediately obvious is that this scheme also removes
systematic errors due to change of instrument or instrument siting that may have occurred concomitantly with a data gap.
Suppose, for example, that data point B1 went missing because the instrument in station B broke down and was replaced, and that the calibration of the new instrument was offset by 1 degree relative to the old one. Since B2 is never compared to B0, this offset will not affect the calculation of the average temperature. Of course, spurious jumps not associated with gaps in the time series will not be eliminated.
In all following graphs, the temperature anomaly was calculated from unadjusted
GISS monthly averages according to the scheme just described. The code is written in
Python and is available upon request.
2 Temperature trends for all stations in GISS
The temperature trends for rural and non-rural US stations in GISS are shown in Figure
1.
This figure resembles other renderings of the same raw dataset. The most notable
feature in this graph is not in the temperature but in the station count. Both to the
left of 1900 and to the right of 2000 there is a steep drop in the number of available
stations. While this seems quite understandable before 1900, the even steeper drop
after 2000 seems peculiar.
If we simply lop off these two time periods, we obtain the trends shown in Figure
2.
The upward slope of the average temperature is reduced; this reduction is more
pronounced with non-rural stations, and the remaining difference between rural and
non-rural stations is negligible.
3 Continuously reporting stations
There are several examples of long-running temperature records that fail to show any
substantial long-term warming signal; examples are the Central England Temperature record and the one from Hohenpeissenberg, Bavaria. It therefore seemed of interest to look for long-running US stations in the GISS dataset. Here, I selected for stations that had continuously reported at least one monthly average value (but usually many more) for each year between 1900 and 2000. This criterion yielded 335 rural stations and 278 non-rural ones.
The temperature trends of these stations are shown in Figure 3.
While the sequence and the amplitudes of upward and downward peaks are closely similar to those seen in Figure 2, the trends for both rural and non-rural stations are virtually zero. Therefore, the average temperature anomaly reported by long-running stations in the GISS dataset does not show any evidence of long-term warming.
Figure 3 also shows the average monthly data point coverage, which is above 90%
for all but the first few years. The less than 10% of all raw data points that are missing
are unlikely to have a major impact on the calculated temperature trend.
4 Discussion
The number of US stations in the GISS dataset is high and reasonably stable during the 20th century. In the 21st century, the number of stations has dropped precipitously. In particular, rural stations have almost entirely been weeded out, to the point that the GISS dataset no longer seems to offer a valid basis for comparison of the present to the past. If we confine the calculation of average temperatures to the 20th century, there remains an upward trend of approximately 0.35 degrees.
Interestingly, this trend is virtually the same with rural and non-rural stations.
The slight upward temperature trend observed in the average temperature of all
stations disappears entirely if the input data is restricted to long-running stations only, that is those stations that have reported monthly averages for at least one month in every year from 1900 to 2000. This discrepancy remains to be explained.
While the long-running stations represent a minority of all stations, they would
seem most likely to have been looked after with consistent quality. The fact that their
average temperature trend runs lower than the overall average and shows no net warming in the 20th century should therefore not be dismissed out of hand.
Disclaimer
I am not a climate scientist and claim no expertise relevant to this subject other than
basic arithmetics. In case I have overlooked equivalent previous work, this is due to my ignorance of the field, is not deliberate and will be amended upon request.
Garrett Curley (@ga2re2t) says:
October 24, 2011 at 3:13 am
“I just don’t get it with this site. On some posts (e.g. a recent one by Willis Eschenbach), there’s the argument that skeptics have never doubted that the world is warming. And then this article comes along to doubt that warming. Which is it?…..”
_______________________________________________________
It depends on the context. The temperature is cyclical so if you pick the right time period it is warming, another time period it is flat and a third it is cooling. This is why BEST looked at 1956 to the end of the century. This is why Hansen redid his graphs and Jones refused to honor Freedom of Information requests and when cornered “lost” the data. This is why Mann is fighting tooth and nail against FOI requests and skeptics greeted the Climategate e-mails with glee.
SCIENCE is all about validity, repeatability and consistency . See http://www.experiment-resources.com/definition-of-reliability.html
This is how the selection of context game can be played:
1970 to 1999 – slightly warming
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_current.gif
http://wattsupwiththat.files.wordpress.com/2011/01/gw-us-1999-2011-hansen.gif
21st century – pretty much flat
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_current.gif
last 6000-8000 years – cooling
http://www.biocab.org/holocene.html
last 0.03 million years – sharply warming
http://img836.imageshack.us/img836/9484/lasticeageglant.png
To HenryP
I was logged in to this site for posting comments using my Twitter account, so I thought I was okay. When logged in though the Twitter authorization there is no option to add an e-mail address. They should remove the Twitter/Facebook buttons at the bottom of the “Reply” section.
I do understand how the greenhouse effect works, but you’ve still got it wrong. Nothing in the greenhouse effect prevents max temps from rising. The average temp rises, bringing with it both the min and max temps, though not necessarily in sync locally because of local climate patterns. It’s got to do with temperature equilibrium in the upper atmosphere, but we’re not gonna go in to all that here.
Steve C says:
October 24, 2011 at 3:21 am
There’s another graph I’d like to see…
__________________________________________
You might want to look at Frank’s work over at Joanne Nova’s. He slices and dices the data in a much different way than we normally see.
http://joannenova.com.au/2011/10/messages-from-the-global-raw-rural-data-warnings-gotchas-and-tree-ring-divergence-explained/#comment-625436
Rhys Jaggar says:
October 24, 2011 at 4:45 am
I think the debate is beginning to move toward the position where we can see that the result obtained in terms of temperature trends depends on the source data. SURPRISE, SURPRISE!
It may in fact be the case that about 50 independent analyses be done to show what happens depending on what data you use. This one is just for the USA. Whch is a large continental land mass bounded by the world’s two largest oceans to the East and West, a warm sea to the South and a major land mass to the north, with a smaller land mass in the SW.
You might find different results in you studied Russia: a large continental land mass surrounded by ice/ocean to the north and a continental land mass to the south……
_____________________________________________
The Russians already did the study and cried FOUL!
the Russians confirm that UK climate scientists manipulated data to exaggerate global warming…. http://blogs.telegraph.co.uk/news/jamesdelingpole/100020126/climategate-goes-serial-now-the-russians-confirm-that-uk-climate-scientists-manipulated-data-to-exaggerate-global-warming/
CHINA (includes info back 100 years)
Seems to echo Frank Lancer’s findings “….annual mean temperature rises occurred in most of the stations along the South and East. China Sea….”
Seasonal and regional temperature changes in China over the 50 year period 1951–2000 http://www.springerlink.com/content/r178t075r24625u6/
Barry to me: …Also, the links I posted discussed their methods for determining rural/urban stations. It’s not as if they didn’t make the effort – they all outline their methods! – so I’m not sure why you quote yourself saying that they are making “unstated assumptions.” Are you sure you actually read them?
Yes, I read enough to see that all are taking the stations’ categorizations of urban and rural as trustworthy, without dealing with the rogue strong UHI effect in some “rural” stations that my UHI page makes very clear. Also you are still avoiding the import of the longstanding stations’ statistically significant message.
All of which I’ve already said. Cut to the essentials and don’t get distracted.
It’s a pity you’ve all done so much work on inadequate premises. There are real problems that deserve our time, and we need real science again.
Bigdinny says:
October 24, 2011 at 4:48 am
I have been lurking here and several other sites for over a year now, trying to make sense of all this from both sides of the fence. In answer to this simple question, Is the earth’s temperature rising? depending upon whom you ask you get the differing responses YES!, NO!, DEPENDS! IT WAS BUT NO LONGER IS! I think I have learned a great deal. Of one thing I am now fairly certain. Nobody knows.
______________________________________
I Think he’s Got it!
You might like to read AJ Strata’s info. He looks at the error bars on the data. Something that is always left out by the main stream media and Al Gore as they flash alarming charts with temperature in 0.001 degree increments.
http://strata-sphere.com/blog/index.php/archives/11420
Smokey says “The large majority of engineers and scientists reject – in writing – the false belief that CO2 is a problem.”
That’s an incredible viewpoint to hold, given how unsupported it is by the evidence. The petition says signers must have a BS, MS or PhD in science, engineering, or related disciplines. Millions of Americans fit that definition, 30,000 is hardly a majority. Only 39 of the signers are climatologists.
This is compared to multiple polls that find scientists, especially those in related fields, overwhelmingly accept the basics of ACC. Analyses have been done on the published literature, which also overwhelmingly supports ACC. On top of that, essentially every major scientific organization in related fields accepts the consensus. Again, the wiki article gives a good summary.
http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change#cite_note-AQAonAAPG-1
You’re seriously going to claim that every major scientific organization is saying there is a consensus when “the large majority” of their members disagree? Again, when has this EVER happened in modern science? The conspiracy you’re claiming exists would have to be ginormous.
P.S. I like the “wrong” clip 🙂
Garret says
http://wattsupwiththat.com/2011/10/24/unadjusted-data-of-long-period-stations-in-giss-show-a-virtually-flat-century-scale-trend/#comment-777494
Garret, what you give me a red herring, claiming that the problem lies in some upper sphere allowing maxima to rise faster than minima, “as a result of the greenhouse effect”.
So now we are back to the beginning.
http://wattsupwiththat.com/2011/10/24/unadjusted-data-of-long-period-stations-in-giss-show-a-virtually-flat-century-scale-trend/#comment-777306
Brian says:
“30,000 is hardly a majority”
It’s a huge majority when you total up all the signatures on both sides of the debate. And since you’re presuming to know how the rank-and-file of all those organizations would vote if asked, “Do human CO2 emissions have a major or a minor effect on global temperatures,” then you’re putting yourself out as a mind reader. Because they’ve never been asked. The only honest way to ask them is with a secret ballot, to get an honest answer free of the threat of retribution. When has that ever happened? Name one organization that lets its members speak for themselves.
Prof Richard Lindzen shows how the spokespersons of those organizations have been targeted and co-opted, and he shows why the dues paying rank-and-file members are not asked those questions.
It’s no different than if I presumed to speak for you, without allowing you input. The CAGW scam exists only because of the dishonesty and censorship of its proponents.
• • •
Lucy,
barry can’t answer you right now, he’s too busy licking his way to the center of the earth.☺
Gail Combs says
http://blogs.telegraph.co.uk/news/jamesdelingpole/100020126/climategate-goes-serial-now-the-russians-confirm-that-uk-climate-scientists-manipulated-data-to-exaggerate-global-warming/
Just to let you know, I also encountered something strange with the UK data from Gibraltar.
http://letterdash.com/HenryP/what-hanky-panky-is-going-on-in-the-uk
Smokey says And since you’re presuming to know how the rank-and-file of all those organizations would vote if asked, “Do human CO2 emissions have a major or a minor effect on global temperatures,”
Again, numerous polls have demonstrated what their position is.
“Name one organization that lets its members speak for themselves.”
Which one doesn’t? The organizations are made up of the people in the organization. Often you are elected by members of the organization. Anti-science conspiracy theorists seems to think scientists belong to some kind of secret society. They don’t, it’s an open community. The sources you reference don’t support your argument.
Scientists don’t reach consensus through online petition. They publish a body of research which speaks for itself. Surveys of the research are performed. Scientific organizations develop positions based on this body of research. That’s how it works, and you don’t seem to have a problem with it except when the conclusion they reach conflicts with your pre-conceived notions. Again, you’re claiming a massive conspiracy. When has this ever happened?
You don’t seem to be persuaded by facts. If everyone who has a degree in something even remotely science/engineering related signed a petition, and it ended up with a million signatures, would that convince you? What would it take? Anthony stated what it would take to convince him, and then quickly recanted when it happened. How about you?
Brian says:
October 25, 2011 at 12:30 pm
Which one doesn’t? The organizations are made up of the people in the organization.
Read the following closely and you will see just how many scientists it takes to make a consensus. The actual # of people is surprisingly low. http://www.pnas.org/content/107/27/12107.full This is the study that they hold as 97%.
As for the groups; ask them for the survey they sent to the members for their stance on CAGW. I took the time to ask two groups. Seems they didn’t poll their members but took a vote of the board for a determination. A Noble prize winner removed himself from one of these groups for just this reason. American Scientific Association I think, Again there was an article posted here on WUWT following just this. If I have the name of the association wrong someone please correct me.
You are close to seeing the light. Dig just a bit deeper. The real truth will set your mind free. A simple test for your huge body of work:
Why is the current temperature falling for the last 10 years while CO2 has continued to rise?
Why are sea levels falling for the last year while CO2 has continued to rise?
Why has the Arctic summer ice melt stabilized while CO2 has continued to rise?
Why as the Antarctic gained ice while the level of CO2 has continued to rise?
The above are all tenets for AGW predicted by the “models”. CO2 has continued to rise and yet none of these predictions for AGW have been able to be demonstrated.
Before stating any other group think BS in response please answer the above questions. If you can’t it might be time to review your belief system.
Trust but verify… I did.
In Re; Jeff D says:
October 25, 2011 at 1:04 pm
. . . . If I have the name of the association wrong someone please correct me.;
Anthony Watts; Sept. 14;
” Dr. Ivar Giaever resigned as a Fellow from the American Physical Society (APS) on September 13, 2011 in disgust over the group’s promotion of man-made global warming fears.”
SBVOR, I have replied to you about your AMO theory thrice at your website, not wishing to go off-topic or have the subject changed on me here, but the posts aren’t showing up after making it through the posting bit. I’ll repost here, and maybe you can drag the last one out of the spam filter?
From your article:
“If one looked for a single factor explanation for the rise and fall of the CAGW religious cult (and the Global Cooling cult which preceded it), the AMO (Atlantic Multidecadal Oscillation) would be a very good candidate.
Click here (1) and here (2) for published science supporting this view.
(1) The first reference attributes multi-decadal variability to the Pacific Decadal Oscillation, NOT the AMO. It does not in any way corroborate your assertion.
(2) The second reference links AMO to the Asian Monsoon cycle, NOT global temperatures.
Furthermore, the chart you say is ‘created’ by David Evans actually comes from Syun-Ichi Akasofu, whose paper you reference in (1), and which includes that chart. David Evans, if you follow your own links to him, actually credits Akasofu with the chart, and links to a longer paper of Akasofu’s,
http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdf
which, again, displays that chart, and attributes mutlti-decadal temperature variability to the Pacific Decadal Oscillation, NOT the Atlantic Multidecadal Oscillation.
You have messed up your references here. They do not support your thesis.
If you wish to take up the matter, let’s do it at your web site.
Brian, neither peer review of consensus is a refuge for the CAGW position. The Oregon petition was signed by scientist who took the time to look at the evidence and found it lacking. You wish to include hundreds of studies by enviromental scientist who take a “what if” percautionary assumption about the climate science and feeedbacks, and from there predict disasters which have not been realized. The Wegman report showed huge problems within peer review and the relatively small circle of climate scientist predicting disaster. Suppression of evidence against CAGW can be found here…http://epw.senate.gov/public/index.cfm?
My sources on AGW are worldwide, (not outside of mainstream science) and from far more PHD scientists then represented by the IPCC, which in the end (those who write the summaries at least) is a political body with many of the valid fallacies constructed by the critics of religion, equally present in this UN organization. I could quote from among peer reviewed literature, papers by Lindzen, Pielke, Christy, Spencer, Eschenbach, Scafetta, Myhre, Akasofu, Douglass, McIntyre and many others, all of whom have robustly challenged the dogma of a few cloistered warmists. These are not “big oil shills” as some try to claim, nor are they nutters. They are all eminent climate scientists who are showing that observations do not support the hypothesis that CO2 is significantly warming the planet, a hypothesis that is predicated on the false premise that historical climate has remained fixed for millennia, which is in contradiction of overwhelming evidence that temperatures were warmer than today a thousand years ago. I could point to 100 more papers that show that the medieval warm period was real, global, and warmer than today – a mountain of evidence against the warmists broken hockey stick. Additionally these scientist are unafraid to reveal their methodology and data, unlike many deacons high in the AGW hierarchy. The fact that climate alarmists reject the Scientific Method means that they are political advocates first, and mendacious scientists second.
FuseAction=Minority.Blogs&ContentRecord_id=865DBE39-802A-23AD-4949-EE9098538277
BTW the term “climate scientist” is a misnomer as most climate scientist have degrees in another field. There is far more then the Oregon petition…
http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=2674e64f-802a-23ad-490b-bd9faf4dcdb7
http://www.appinsys.com/GlobalWarming/RS_Arctic.htm
http://friendsofscience.org/assets/documents/Veizer-Shaviv,%20Celestial%20Drive.pdf
http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmstorfDebate.pdf
http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmReplyReply.pdf
http://www.greenworldtrust.org.uk/Science/Social/Testimony.htm
@Jeff D regarding your list of ?s
The data shows that temps and sea levels are rising, and ice is melting. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html
It’s a stochastic system, you don’t expect every single year to be warmer than the last. 1998 was unusually warm while 2000-2008 was cool (relative to predictions). I’ll admit that if 2010-2020 scientists will have to re-evaluate the presumed rate of warming, but I doubt you’ll commit to believing in AGW if temperatures are higher in 2010-2020.
@David You’re really going to link me to James “the ozone layer is fine” Inhofe? Ad Hominem attacks aside, at some point a person loses credibility.
I’m still waiting for an example for when a supposed minority of scientists have risen to the top of every scientific organization and declared their minority opinion to be the consensus. OTOH I have plenty of examples for groups denying scientific consensus (evolution, smoking/cancer, ozone layer etc.)
Also still waiting for a way your position could be shown to be incorrect. For ACC proponents that’s easy. Temperatures could stop rising. As [SNIP: Policy Violation. -REP] has shown us, even “skeptical” scientists admit the earth is warming.
If you’re willing to admit that the earth is warming, and humans are causing it, we can have a more productive discussion about the likelihood that it will be bad, and what to do about it. But I doubt you’ll admit there’s any chance you’re wrong.
Lucy @ur momisugly here
You read ‘enough’…? You skimmed. Ok.
Rubbish. Zeke Hausfather applies 3 different methods to determine rural/urban, precisely because he knows that it is difficult to establish rural and urban stations. Joseph at Residual Analysis also uses 3 different methods. There is no assumption that their methods are perfect, otherwise they wouldn’t try to distinguish urban and rural in different ways. They are well aware of how problematic it is. Consider the opening remarks from Zeke:
No assumptions there.
I’m not. I lack the skill to determine if Michael Palmer’s methodology (post-selection) is sound, and wouldn’t try to speak to that. I did notice Glenn Tamblyn’s comments (who does have the skill), which articulated strong reservations about Michael’s number crunching. Michael has not given a substantive reply to that. Is there a reason why I should unskeptically accept Michael’s results?
Nor am I avoiding the import of long-standing records, as I linked for you in the last post a global estimate based on rural stations with a 90 year unbroken record. When I read your replies addressed to me, it’s as if you’re describing someone else’s posts.
I have done none of this work, and am unable to do so. I merely read about it, try to understand it (being honest about my limitations) and share the information.
I read your page on UHI, and, apart from the McKitrick/Michaels paper, note that many of the supporting links provide much in the way of criticism, commentary and anecdotal evidence, and little in the way of ‘science’ (ie statistical analysis of a large number of stations), or even original work. Most of the links do not even bother to test any method for rural/urban stations – which is a criticism you have repeatedly put out here,including in reply to me. For example, you link to the ‘6th grader’ post at WUWT, which I well remember. But the choice for rural is that determined by GISS – the father son team go to GISS and click on rural sites. By your own standard, this analysis assumes “the stations’ categorizations of urban and rural as trustworthy, without dealing with the rogue strong UHI effect in some “rural” stations.” Same goes for the John Daly site, which doesn’t really lay out any classification method, other than “few large cities”, and so could easily be a cherry-pick of any stations showing cooling (and of course there will be a subset of those even in a warming world). The page on New Zealand isn’t even about UHI.
Spencer’s work is interesting, but he expects to see a spurious warming signal at airports. These locations suffer no uncertainty as to their classification, and they show a cooler trend than the trend for all stations or non-airport. That is a remarkable result.
It seems to me that you uncritically accept whatever comports with the notion of fatally problematic official temperature records, and reject with no real discussion anything that corroborates them.
My sources try three independent methods to establish rural/urban and the work is original. I am not saying that this means UHI is properly accounted for. The satellite record (which you ignored from my last post) also corroborates the land-surface instrumental records. Interestingly, Fall et al (Anthony Watts’ peer-reviewed paper) corroborates the US average temperature record, after weeding out stations compromised by station bias.Do you doubt that this endeavour has tried to winnow out sites affected by UHI?
I would not say with absolute conviction that the UHI issue is squared away (I am not qualified to judge) but I would note that the bulk of formal and semi-popular literature that carefully examines the issue tends to discover that the effect is minimal WRT the instrumental records.
I find your web page unconvincing, as it is a hotch potch of links on a general theme, only a couple of which (M&M and Spencer) satisfy the strictures you have laid out here, and one of which isn’t even about UHI.
You said that you “needed to quantify” certain claims, but I could nowhere find original work of yours processing any data, just links to other work. Could you provide a link? I will do my best to follow, and tip my hat to you for rolling up your sleeves and doing your own number-crunching.
If you wouldn’t mind, I’d appreciate a response to the arguments I made re the satellite record and the import of Fall et al onaverage US temps. I will read M&M again, as well as the Spencer, and look for competent analysis of these, if any such exists.
@Jeff D regarding your list of ?s
The data shows that temps and sea levels are rising, and ice is melting. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html
Ok, maybe I was wrong about hope. You keep siting the biggest group of idiots on the planet and wont take the time to ” Verify ” for yourself. Take a visit to NOAA’s site and look up the charts for sea level rise for the last year and come back and admit you don’t have a clue and need our help. After that visit the sea ice page and see that current melt is in trend with the last 10 years as well. You still have not address 3 and 4.
Have a good day, hope you have learned something.
barry (October 25, 2011 at 2:06 pm)
Blogger.com automatically decided your comment aimed at my post titled “How the AMO Killed the CAGW cult” belonged in the spam bin. I agree. It will stay there. Here’s why:
1) You falsely allege:
“The first reference attributes multi-decadal variability to the Pacific Decadal Oscillation, NOT the AMO. It does not in any way corroborate your assertion.”
The study in question notes a “multidecadal oscillation” in global surface temperatures without seeking to explain the cause. So, no — it does not directly attribute the AMO. But, it also does NOT attribute this MULTIdecadal oscillation to the Pacific DECADAL oscillation. The “support” which I referred to rests in the fact that the dates and durations of the multidecadal temperature oscillations Akasofu describes line up very, VERY well with the AMO — far more so than the PDO.
A) Quoting the cited study:
“It is not the purpose of this section to discuss the multi-decadal changes in detail. The sole purpose is to explain why the warming has halted after 2000…
the multi-decadal oscillation peaked in 1940 [I contend the AMO peaked in 1933], and the temperature actually decreased from the level of the linear increase from 1940 to 1975 [I contend the AMO bottomed out in 1976] and then increased after 1975 to 2000 [I contend the AMO peaked again in 1998]. Thus, it may be speculated that the situation in 2000 is similar to that in 1940 [ditto for the AMO], so that it is predicted that the temperature change will be flat or in a slightly declining trend during the next 30 years or so”
So, although the study does not directly attribute this multidecadal oscillation in global temperatures to the AMO, the dates and the durations of the oscillations all line up very closely with the AMO. Therein rests the “support” I referred to.
B) The study does NOT attribute “multi-decadal variability to the Pacific Decadal Oscillation”. Do you really think a MULTIdecadal oscillation could be attributed to a DECADAL oscillation? To the contrary, the study says:
“It is interesting to note a striking resemblance of changes between PDO and the multi-decadal oscillation”
2) You falsely allege:
“The second reference links AMO to the Asian Monsoon cycle, NOT global temperatures.”
Quoting the cited study:
“Based on the coherency in decadal variability between the ice core data and the observed snow cover over the Tibetan Plateau during recent decades, we used three available ice core data to characterize the snow cover variability of the last 200 years. The analysis suggests that the snow cover exhibits significant decadal variability with major shifts around 1840s, 1880s, 1920s, and 1960s. Its variations are found to be closely correlated with the Atlantic Multidecadal Oscillation: Cool/warm phases coincide with large/small snow cover.”
Which part of “Cool/warm phases” does not register with you as temperature?
3) Congratulations – You got me for getting a single attribution wrong (Akasofu vs, Evans). You can pat yourself on your back while I correct that.
barry (October 25, 2011 at 2:06 pm),
To address the nits you picked, I changed the wording in my post from “supporting this view” to “consistent with this view” (which, as you could have deduced from the very next sentence, was what I intended to convey in the first place).
SBVOR – both Akasofu’s papers which include that chart specifically discuss PDO in reference to multidecadal temperature oscillations. In neither of these papers is the AMO mentioned. In both, the PDO is discussed as being the cause of multi-decadal variability (PDO is a multidecadal oscillation – do you not know that?). Akasofu is not attributing the variability to the AMO, but to the PDO. It’s that simple. The paper does not corroborate your theory – for that you would need to reference published papers on AMO and global temps, surely.
The other paper on snow cover is limited to the Tibetan Plateau. Lest we be in any doubt that the paper is about local conditions and not global, here is the title;
Decadal variability in snow cover over the Tibetan Plateau during the last two centuries
You completely misconstrue the paper, which is surprising, seeing as the abstract you just quoted clearly identifies the region of interest. This paper is about local conditions, not global. The region covered is 0.2% of the globe. Warm and cool phases of the AMO are associated with snowfall (humidity) and the monsoonal cycle, not with temperature (at least in the abstract – couldn’t find a full version online). To connect the AMO to global temperatures with this abstract is a giant leap too far.
Please admit my post at your site where we may discuss further. My comments are on-topic there and they are not incorrect. (anyone here can check if they want – the snow cover abstract is short and straightforward)
[FROM THE MODERATOR: This dispute is cluttering up the thread. If you can’t resolve it at SBVOR’s blog, at least take it to Unthreaded. -REP]
barry,
I still contend that the AMO is the most relevant ocean cycle over the last century. But, I had never examined the PDO closely enough to see that — within its decadal cycles — there are periods wherein the bias is strongly towards multidecadal scale warm phases and multidecadal scale cool phases.
Comparing a PDO chart to an AMO chart, I now see that the two cycles do display considerable synchronicity during the last century. For me, this only serves to reaffirm what Dr. Lindzen said:
“The motions of the massive oceans where heat is moved between deep layers and the surface provides variability on time scales from years to centuries. Recent work (Tsonis et al, 2007), suggests that this variability is enough to account for all climate change since the 19th Century.”
[REPLY: Apology noted. Now, please, take this dispute elsewhere. Thank you. -REP]
I get the feeling that Brian is pretty new to this subject. The number of skeptical scientists is far greater than the clique of grant hogs trying to sell CAGW to an increasingly skeptical public:
http://wattsupwiththat.com/2011/09/14/nobel-laureate-resigns-from-american-physical-society-to-protest-the-organizations-stance-on-global-warming
http://wattsupwiththat.com/2010/07/25/seven-eminent-physicists-that-are-skeptical-of-agw
http://www.middlebury.net/op-ed/un-signatories.html
http://wattsupwiththat.com/2009/11/02/160-physicists-send-letter-to-senate-regarding-aps-climate-position
You can add those names to the OISM Petition, plus 650 additional names found here.
And as David shows above, there are even more scientists skeptical of CAGW. I’m not arguing that “consensus” in science has any importance. But it is constantly being brought up by the alarmist crowd, and I am showing that they’re even wrong about that.
Finally, we have sea ice records going back only to 1979. I cited a paper here recently showing that the Arctic was entirely ice free some 6,000 – 7,000 years ago, when CO2 levels were well under 300 ppmv. An ice-free Arctic is a routine, natural occurrence that has zero to do with CO2; otherwise the Antarctic would show similar action. And regarding isostatic sea level rise [rise due to thermal expansion], it’s going away. And explain this without sounding like you’re inventing a new version of Trenberth’s “hidden heat in the pipeline”.
The fact is that every claim of the climate alarmists evaporates under scrutiny. At least CAGW skeptics have a hypothesis that has withstood all attempts at falsification: produce empirical, testable evidence per the scientific method showing that the rise in CO2, or the [natural] 0.7°C warming has been globally harmful. The null hypothesis is that CO2 is harmless and beneficial. Falsify that, if you think you can.
Glenn Tamblyn says:
…
“A fundamental problem I see with this method is that the delta’s propergate forward. So any error that will unavoidable occur if a station is missing from sample n then gets carried forward into the calculation for samples n+1, n+2 etc.”
That was the very purpose of it. If there is a gap, we get to choose – do we trust the record will carry on faithfully where it left off, or should we treat it as a separate series? My method does the latter. However, I will give you that it would have been useful to compare the two methods and see whether they give a major difference – I guess at least with the long running series they won’t, because only few points are missing.
“In addition there is the problem of propogating inaccuracies in the performance of the calculation. Computers do not calculate to infinite precision and since most of this is about calculating differences between larger values to produce much smaller differences then continually summing these differences the finite accuracy of each stage of arithmatic will propgate forward in the result. It would take some serious analysis to work out whether the net effect of this over time will all cancel out or be cumulative.”
It will be cumulative, of course, though not strictly additive. However:
– Python floats have 53 bits of precision
– the whole data series has on the order of 10,000 stations, times 100 years times 10 months per year = 10^7 delta values = 2^23, therefore
– 53-23=30 bits, or 9 decimal places of precision are still available when adding the last delta to the accumulated sum.
So this point is moot, and it is something an aspiring data cruncher should have been able to work out himself before inserting FUD into a public post.
Brian says…”@David You’re really going to link me to James “the ozone layer is fine” Inhofe? Ad Hominem attacks aside, at some point a person loses credibility.”
Brian, below this you talk of “productive communication, and yet you ignore what I presented and say this? I did not link you to a person, I linked you to a report where over 700 dissenting scientists (updates previous 650 report) from around the globe challenged man-made global warming claims made by the United Nations Intergovernmental Panel on Climate Change (IPCC) and former Vice President Al Gore. This new 2009 255-page U.S. Senate Minority Report — updated from 2007’s groundbreaking report of over 400 scientists who voiced skepticism about the so-called global warming “consensus” — features the skeptical voices of over 700 prominent international scientists, including many current and former UN IPCC scientists, who have now turned against the UN IPCC. This updated report includes an additional 300 (and growing) scientists and climate researchers since the initial release in December 2007. The over 700 dissenting scientists are more than 13 times the number of UN scientists (52) who authored the media-hyped IPCC 2007 Summary for Policymakers. The fact that your response was an adhom. atttack against one poltician is a demonstration of one not capable of any introspective thought.
Brian continues…
“I’m still waiting for an example for when a supposed minority of scientists have risen to the top of every scientific organization and declared their minority opinion to be the consensus. OTOH I have plenty of examples for groups denying scientific consensus (evolution, smoking/cancer, ozone layer etc.)”
Again Brian you show yourself not serious. The oregon petition is in itself a scientific organizatiom, as was the group which formed the senate minority report you never read. Many of the recent changes in leadership within some socities are changes to political creatures, not scientist. Yes, the CAGW claim is unique, because it is post normal, IE. poltics (the opportunity to tax the very air we breath) have entered the science and destroyed it, so when those political creatures rise to the top of a former scientific organization, you get mass defects of brilliant PHD scientist, the testimony of some I linked to earlier. CO2 science is a “scientific organization, linking hundreds of peer reviewed studies against the alarmist position. The grass roots rise against CAGW is unique massive and multi leveled, and not comparable to the claims in the smoking/cancer arena for instance. If you automatically discount thousands of international and US scientist, and hundreds of peer revied papers, and ignor the deeply flawed hockeystick and other palo studies, ignore climategate letters, ignore the numerous IPCC emabaresements to science, ignore the Wegman report, then you may have your consensous, and be welcome to it, but it says more about you then it does the science.
Brian continues…”Also still waiting for a way your position could be shown to be incorrect. For ACC proponents that’s easy. Temperatures could stop rising. As [SNIP: Policy Violation. -REP] has shown us, even “skeptical” scientists admit the earth is warming.”
Brian, temperatures have stopped rising for well over ten years, so for how long must this cont before you question? My postion is that the C in CAGW is absent, and as so many false claims attributing anything and everything to CAGW exist, but those claims fail to manifest in the real world, then when temperature rise exceeds the natural historic variation and limits, and SL rise accelerates beyond those same historic limits, and storms and droughts increase in ferocity and frequency beyond historic norms, then I will relook at the C in CAGW. Until then, seeing that we do not know the climate senstivity, and adoption to climate change is far more logical, and that developing cheep abundant energy is the fasted way to clean the enviroment and reduce population, I will ignore the political advocates that wish to rule the world.
Brian continues, “If you’re willing to admit that the earth is warming, and humans are causing it, we can have a more productive discussion about the likelihood that it will be bad, and what to do about it. But I doubt you’ll admit there’s any chance you’re wrong.”
Of course there is, but for now the earth itself is laying waste to the CAGW claims, and I never denied that the increase in CO2 can increase the residence time of energy within the atmosphere.