Guest post by David Middleton
From the BBC…
Climate: Cherries are not the only fruit
Just about the most predictable event of the week was the tempest of opinion created by the analysis of global temperature changes published in the Proceedings of the National Academy of Sciences (PNAS) on Monday.
As we (and a number of other mainstream news outlets) reported, Robert Kaufmann and colleagues analysed the impact of growing coal use, particularly in China, and the cooling effect of the sulphate aerosol particles emitted into the atmosphere.
They concluded that with a bit of help from changes in solar output and natural climatic cycles such as the El Nino Southern Oscillation (ENSO), the growth in the volume of aerosols being pumped up power station chimneys was probably enough to block the warming effect of rising greenhouse gas emissions over the period 1998-2008.
For some commentators, such as the UK Daily Mail’s Christopher Brooker, this was further proof that the “climate scaremongers” had got it wrong…
[…]
Cherry in the pie
One thing that everyone in the climate blogosphere seems to agree on is that the best fruit in the world is the cherry, judging by the number that are picked.
And the Kaufmann paper has brought a few more down from the tree.
The Global Warming Policy Foundation (GPWF), the UK-based pressure group, said researchers “tweak an out-of-date computer model and cherry-pick the outcome to get their desired result”.
To which the opponents’ rejoinder is, and long had been: “well, choosing 1998 as the baseline is cherry-picking, to start with”.
To illustrate the point, I’ve been through a quick exercise using the approach that groups such as GPWF favour – and that Kaufmann’s research group adopted – of using annual temperatures rather than any kind of smoothed average, and looking for the temperature change over a decade.
I took the record of global temperatures maintained by Nasa’s Goddard Institute for Space Studies (GISS) which is one of the three main global datasets, and calculated the rate of change over each of the most recent 10 decades – ie, 1991-2001, 1992-2002, and so on up to 2000-2010.
I’ve summarised the results in a table on this page. What it basically shows is two things:
- the numbers vary quite a bit from year to year; and
- all but one give a temperature rise – the only one that shows a small drop being 1998-2008.
Seeing as it’s logically impossible that the world warmed between 1997 and 2007, cooled between 1998 and 2008, and warmed again from 1999 to 2009, one conclusion you might reach is that using annual temperatures is not a sensible thing to do as it gives you a set of answers that does not make sense.
… which is why most scientists use the running mean approach.
[…]
Mr. Black seems to be suggesting that Figure 3 from Kaufmann is a cherry being picked by climate realists…
While he thinks that GISTEMP is the “tree”…
Well, I say that Mr. Black is Goldilocks-picking. Mr. Black asserts that it is cherry-picking to use 1998 as a starting point and that the starting point must be 1880. What’s so special about 1880 (apart from it being the start of the instrumental record)?
First off, let’s have a look at a few “cherries.”
Here is the HadCRUT3 global temperature anomaly (GTA) for 1977-2010 plotted with the GTA for 1911-1944…
HadCRUT3 Global Temperature Anomaly 1911-1944 & 1977-2010
Here’s the HadCRUT3 Northern Hemisphere temperature anomaly for 1976-2010 plotted with a non-carbonated interval from the Medieval Warm Period (Moberg et al., 2005)…
HadCRUT3 Northern Hemisphere 1976-2010 & Moberg 863-897
In both examples, the slopes are statistically indistinguishable.
The 66-yr period from 1944-2010 is pretty well indistinguishable from the first 66 years of three different century-scale cool-warm-cool cycles from Moberg’s Medieval Warm Period reconstruction…
HadCRUT3 global 1944-2010 & Moberg NH 831-930, 961-1050, 1038-1138 (Yes, I know I should have used HadCRUT3 NH… I just don’t have a display handy).
The peak of the Modern Warming is, at most, 0.1 to 0.2°C warmer than the peaks of three comparable, non-carbonated, intervals of the Medieval Warm Period, consistent with a net climate sensitivity of ~0.5°C. However, that difference is probably not statistically meaningful.
- The error bars of all of the data sets are greater than the differences between them.
- The proxy data show the MWP to be warmer than the late 20th century.
- The proxies invariably have a lower resolution than the instrumental data; thus the amplitude of the proxy time series is attenuated relative to the instrumental record.
This means that the late 20th century warming might have been slightly warmer than the peak of the MWP. Almost all of the potential error is in the direction of magnifying the warmth of the Modern Warming relative to the MWP, so the odds are that the modern warming is very comparable to the Medieval Warm Period.
Since Mr. Black would probably say that the Medieval Warm Period is another “cherry,” let’s go back another 1,000 years, or so.
What happens if I project the polynomial trend-line a few hundred years into the future?
It starts looking like a cyclical pattern doesn’t it?
One of the “problems” with the way climate data are handled is in the obsession with applying linear trend lines to non-linear data.
A Sine wave has no secular trend…
But… What happens if my data represent only a portion of a Sine wave pattern?
The r-squared of a linear trend line of this partial Sine wave is 0.88… 88% of the data fit the trend line. This implies a very strong secular trend; yet, we know that in reality Sine waves do not have secular trends.
If we take the entire HadCRUT3 series and apply a linear trend line, we get an apparent secular trend…
The r-squared is 0.55… 55% of the data fit the secular trend. This implies that there is a real long-term warming trend.
What happens to that secular trend if we expand our time series like we did with the Sine wave?
The apparent secular trend vanishes in a puff of mathematics…
How can such a clear secular trend vanish like that? The answer is easy. Each “up hill” and each “down hill” leg of a Sine wave has a very strong secular trend. Unless you have enough data to see several cycles, you don’t know if you are looking at a long-term trend or an incomplete cycle.
Using the GISP2 ice core data from central Greenland we can see that over the last 50,000 years, there have been statistically significant warming trends…
And there have been cooling trends of varying statistical significance…
What does all of this mean?
It means that the Earth’s climate is cyclical. It means that the climate changes we’ve experienced over the last 150 years are not anomalous in any way, shape, fashion or form. And it means that the Mr. Black and the other warmists must “Goldilocks-Pick” their data. Too short of a time series yields no warming trend and too long of a time series also yields no warming trend. The time series must be “just right” in order to show an anomalous warming trend.
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+1 Very funny.
“You air-borne particle, you!” Then run.
LOL
Fair enough, but even a 60-yr time period would be an enormous improvement, particularly since there is much evidence that that pretty closely matches the period of observably cycles. You;d get both phases of the ‘wave’. As an exercise, try a super-simple model that predicts that weather and climate for the next few years will match that of the early ’50s.
This is blatant headline cherry-picking and obfuscation. The paper is about decreased carbon capacity in the ocean. The paper WAS NOT about determining exactly what the absorption limit of the ocean is.
I find it rather interesting that within an hour or so of this posting here, Richard Black posted a new article on his BBC blog, pushing the subject of this one off the front of the BBC’s Science/Environment page.
@ur momisugly David Middleton July 11, 2011 at 7:24 am
Thank you for both your article and especially for the above post.
I have read over the past about the multi-decadal and millennial oscillations and supporting evidence. In filtering through all involved in the CAWG scam I have been trying to put a summary of where the two oscillations come together. Your post as noted above was what I was looking for.
With an engineering background, it probably took me over a 1,000 hours research to get a firm grasp on what was going with the CAWG issue. I’ve probably logged over 4,000 hours now. That house of cards is in total collapse now. Due to over 30 years in building such a scam it took a while to expose its foundation. Keep up the good work as it’s a complex issue and takes a lot of reading to get a grasp of what has transpired. I would guess that many with the ability to understand are now seeing the light, so to speak. The less knowledgeable will likely continue to be more religiously afflicted as it will be difficult if not impossible for them to understand the degree of involvement in this scam. Few politicians have the technical knowledge to understand anything near the complexity of this issue. They will likely just follow the public sentiment with hopes to be re-elected, many will not be.
Again, I want to thank you as well as the many others who are the watchdogs of science and policy. With over 82,000,000 hits on his blog I don’t have to mention Anthony, but thanks anyway!
“oglidewell says:
July 11, 2011 at 10:50 am”
Out of sight, out of mind mentality. Similar to that 10 second sound bite pollies rely on and our “youth” seem to soak it up like crusty bread in a stew. Strewth if ever a “carbon tax” app is developed for “smart phones” (LMAO), these suckers will lose $’s so fast they won’t know what is happening. Oh hang on, iTunes, SATNAV and Google Maps, via ISPs, are doing that right now! LOL.
This “disappering” of stuff also happens all too frequently at the Australian SMH website, especially when posts seem to be in disagreement with the authors’ PoV.
We can only thank Al Gore for inventing the inter-webby thing. Thanks Al “50% man, 50% bear, 50% pig” Gore.
M.A.Vukcevic says:
“I have strong reservations about your above claim. I have not found any evidence of the 60 year cycle within the climate indices. ”
Dear Vukcevic,
a quasi 60-year cycle in the climate has been observed by a lot of people in a lot of climate records some of them covering centuries and millennia. In addition to the clear results from my paper where 10 records are explicitly studied, you need to look at the numerous references that I add there.
Just two papers dealing with the issue where several multisecular and millennial records are studied and found 60-year cycles lasting for millennia are:
Cyclic changes of climate and major commercial stocks of the Barents Sea
http://www.tandfonline.com/doi/abs/10.1080/17451000802512283
see for example figure 4 and table 1
and
Tracking the Atlantic Multidecadal Oscillation through the last 8,000 years
http://www.nature.com/ncomms/journal/v2/n2/full/ncomms1186.html
see for example figure 5d
(Of course, when I say that a 60-year cycle exists in the climate system, I am not saying that the climate system contains “only” a 60-year cycle. There are other cycles longer and shorter. Nor I am claiming that this 60 year cycle is “perfectly” sinusoidal: I am talking about physics of complex non-linear chaotic systems, not trigonometry.)
I think you meant to comment on a different post.
If this is really happening (see link below) Gillard does not have a chance in hell in getting this tax through.
http://www.couriermail.com.au/news/national/cast-your-vote-in-national-plebiscite-on-carbon-tax-hosted-by-news-ltd-websites/story-e6freooo-1226091387866
It seems that exposure to this tax has made people read up on the science and 60% don’t believe in it any more and now 80% are against it. I suspect the survey may be biased but if anywhere close there appears to be a massive shift going on just now in the Australian Psyche. Thanks to the insistence of the greenies and warmistas on getting this through despite massive opposition. I predict a complete collapse of the whole Carbon Tax within a week or two
@JJB MKI says:
July 11, 2011 at 9:12 am
I would second Theo Goodwin’s applause of your post. Well said.
Nicola Scafetta said:
“The climate system is clearly characterized by a 60-year cycle. We have seen statistically compatible periods of cooling during 1880-1910, 1940-1970, 2000-(2030 ?) and warming during 1850-1880, 1910-1940, 1970-2000.”
Great!
Quoted and linked from “Climate Change (“Global Warming”?) The cyclic nature of Earth’s climate “, at http://www.oarval.org/ClimateChange.htm
Thanks!
Nicely presented and all very true, everyone picks their trend to make their case, however, there is one big difference, everyday, all across the planet, scientists are conducting research to find the reasons behind climate dynamics. They are measuring a myriad of things and finding that these trends and cycles are not random walks– but have actual causes. There are real reasons behind every major climate change, from major changes like the coming and going of glacial and interglacial periods to relatively minor changes like the so-called “Little Ice Age.” All these things have causes, and for some of the warming that has occurred in the later part of the 20th and into the 21st century, when all other known factors are excluded, including solar cycles, (yes, solar cycles have long been known to affect temperatures) the only known factor that remains is the anthropogenic fingerprint of greenhouse gas increases.
Might there be some other, as yet unidentfied, cause? Absolutely! And if there is, it is only through the hard work of climate research that it will be discovered and quantified.
“Erik Styles says:
July 11, 2011 at 11:22 am”
I remind you of Thatcher (UK) and Clark (NZ) and men before them. Under Gillard, in Aus, there will be a carbon tax, and The Greens and Labor will commit political suicide along with it, but it will take a while for the Aussie public, sleeping and driving at the wheel, to wake up. Fu&% me, I hope it is soon! At least KRudd747 knew if “labor” wanted to stay in power…an ETS was not the way to go (Sorry bankers) without support from Japan, India, China, and the USA…well, Gillard has no clue, she will not fail, politically, in implementing the “proice on cahbon”. Trouble is, in Aus, we have the likes of Abbott and Turnbull, Turnbull being an ex-(w)banker…and knows what this “pollution” tax really means. Its the biggest ponzi scheme evah!
Bob Tisdale says:
…the choice of the base years for anomalies makes no difference to the trend of the data or to the year-to-year variations. Changing the base years only shifts the entire dataset up or down.
But Bob, that’s my point. The selective individual can make the anomaly data look like anything they want it to, by starting wherever the data gives them their most sensationalist narrative. And when you start adding an artificial cut-off date, as some are wont to do… well, now we really enter into the Wonderland made famous by Alice (pardon me for mixing my fictional metaphors). When hard-hitting top-notch investigative journalists like Richard Black (cough! Excuse me while I choke up a hairball!!) get hold of this stuff, he spins a yarn better than the girl trapped in the tower in Rumpelstiltskin (sorry, couldn’t resist again!). “Now kiddies, lie back and close your eyes and suspend all rational thought while Uncle Richie concocts a tale guaranteed to scare the pi** out of you.” Remember that, while you might be extremely scientifically articulate, the average reader of Black’s literary genius probably isn’t. Black knows this and, in fact, counts on it. That’s why he’s always spinning like a Republican at a Democratic convention (or visa versa, if your politics prefers). When Phil Jones said that there hadn’t been any statistically significant warming since 1998, and that news got trumpeted at the tops of our lungs, journalists like Black (who, after all, are only looking to report the TRUTH, aren’t they?) had to find a way to get the narrative back on track. “So… let’s see…if we calculate a 10-year rolling average anomaly for each of the last 10 years, and show that most of them have gone up each time…well lookie what we have here. Let those damned deniers try to get out of this one.” And the reaction of the Stepford wives reading his column is to believe, believe, believe. Have you ever tried to explain a temperature anomaly to a guy while he’s standing over the grill sucking on a brew? It’s just so much easier to believe what the nice man wrote in the newspaper. I didn’t really understand it, but after all, if it’s in the paper then it has to be true. Doesn’t it?
oglidewell says:
July 11, 2011 at 10:50 am
“I find it rather interesting that within an hour or so of this posting here, Richard Black posted a new article on his BBC blog, pushing the subject of this one off the front of the BBC’s Science/Environment page.”
Yes, and replaced with a ‘filler’ article. In the meantime, and for some time now, the comments on Black’s blog have been becoming increasingly skeptical and mocking which is why the BBC has decided to reduce them to mega-tweet size.
Enjoyed your comments there by the way. But rather than take your advice and read this post I expect Black will keep his head firmly in the AGW sand or just cover his ears and keep screaming that the debate is over. After reading that blog for several years I’ve concluded that Black is a very simple parrot.
nicola scafetta says:
July 11, 2011 at 11:13 am
“Of course, when I say that a 60-year cycle exists in the climate system, I am not saying that the climate system contains “only” a 60-year cycle. There are other cycles longer and shorter. “
They’re not all really cycles, as in deterministic sinusoidal oscillations at a particular frequency. There are such cycles, as governed by diurnal and seasonal and Milankovitch forcings. But, there are also quasi-cyclic phenomena which reflect the response of narrowband system modes to random forcing. The distinction is important because, the first argument you will get against the idea is that there is no known forcing with a ~60 year period.
But, all systems governed by partial differential equations with limited rates of energy dissipation exhibit particular modes of oscillation which can be excited by random inputs of no particular coherence. These modes are determined by the physical properties of the system and its boundary conditions. In the simplest idealization, for example, a linear spring with spring constant K attached to a perfectly rigid support at one end and a point mass M on the other will oscillate at a radial frequency sqrt(K/M), or a pendulum of length L in a constant gravity field with acceleration g will oscillate about the equilibrium at a frequency of sqrt(g/L).
A particularly notorious example of a system oscillating at its natural frequency due to random forcing, to the point of catastrophic failure, is the Tacoma Narrows Bridge.
*sniff sniff* Am I smelling maraschino cherries?
It’s really one of those ‘miracles’ of Science that the decrease in temps from aerosols emanating from power plants has almost exactly balanced out the increase in temps from increasing CO2 for a period of 20 years as BOTH sources increase/change at different rates.
One would think that, if this hypothesis were true, and if the rate of increase of aerosols is greater than the rate of increase in CO2 (which appears to be the case), and if aerosols do tend to cool, that there would have been net cooling over the 20 year period instead of a net plateau in temp increases.
In the end this comes down to the fact that reality has failed to support the models , and although in climate science that means reality is wrong . In the real world for real people the failure of temperatures to match to ‘doom serous’ pushed out by the CRU etc is real problem for Black and Co and so there is very much a need to explain the problem away . Step forward another model and speculation its ‘ aerosols’ that is keeping the temperatures rises of ‘doom’ at bay .
Bart says:
July 11, 2011 at 1:15 pm
…..
It is easy to be mislead by the quasi-cyclical appearance within some of the climate related data. Most of the ‘identified’ cycles are very little to do with celestial events, and far more to do with ocean currents and Coriolis force. Detailed map of the ocean currents
http://upload.wikimedia.org/wikipedia/commons/6/67/Ocean_currents_1943_%28borderless%293.png
shows number of gyres (circular currents). All of these take certain number of years to complete a full cycle, leaving individual imprint on the climate data (either global or a hemisphere’s), with number of sub harmonics with cross-modulation products, combination of which may leave impression of existence of a unique forcing factor.
These range from few years (Beaufort gyre 4 years, Circumpolar current 8 years, Indian ocean gyre 10 years, N. Atlantic subpolar gyre 20 years etc.) up to above 100 years for some of the Pacific gyres, and finally the great ocean conveyor belt estimated at ~1600 years.
Might I point out that a linear fit is simply a first-order polynomial fit?
And *lots* of people use linear fits without blushing.
R. Gates says:
July 11, 2011 at 12:01 pm
More pseudo-intellectual, worthless and wholly incorrect pontification/claptrap from our resident non-scientist.
Is this you ?
http://dl.glitter-graphics.net/pub/500/500731j91oravmk2.jpg
Warning!! Scientific over-achievers may find this boring, imprecise or both.
Regular folks may want to skip to the last paragraph, immediately, or when you get saturated.
Conclusions may be classified somewhere between “educated Scientific guess” and “Wild eyed speculation”.
As an introduction, Many WUWT contributors and commentors forget (or ignore) that most of us followers of that blog have less than 60 college hours in Science classes. While I have more, the grades were almost all “C’s” except for one Physics, one Chemistry, one Botany and two Geology classes. (These were “A’s”… also got an A in “Physics for Elementary Teachers” but that hardly counts) The following is aimed at making sense of entries by the scientific over-achievers here.
Sometime in the ’90’s some college students were examining spectral lines (Bright lines made by glowing chemicals, when the light from those chemicals are passed through a prism… chemicals on the sun’s surface tend to glow) from sunspots on the sun. A followup study revealed that some of these lines were getting dimmer. This lead to a serious study of those spectral lines. The study showed these lines were indeed diminishing. A forward projection of the rate of decline showed these spectral lines indicated they would be entirely gone by 2015 or so. Then came the bad news. Further study showed when these spectral lines were bright the solar activity was high. When they were dim the solar activity was low. or simply: Bright lines hot sun, dim lines cooler sun. Science based speculation extends this evidence to guesstimate that a repeat in the “Little Ice Age” is upon us.
The sun directs about 1,350 watts of visible light to the earth surface (per square yard/meter per second of time) when directly overhead. As the earth is nearly a sphere, time of day and latitude (Distance away from the tropics) diminish this number. That is slightly less energy than you get from an 1500 watt electric heater. In the northern hemisphere, the difference in solar energy between summer and winter averages about 150 watts per second or so (again depending on time and latitude). The difference between hotter and cooler sun is two or three watts per second. {{You can experiment: Take a radiant electric heater outside about noon Local time (no wind). Lay in full sun for a minute. Stand in full shade for a minute. Turn on heater and stand 3 feet from it for a minute In the shade. If the heater has a 1200 watt setting try that. Don’t forget to record results.}}
In addition, some research shows a cooler sun has a weaker magnetic field. This allows more cosmic rays from outside the solar system to strike the earth causing more clouds and cooler earth. (clouds reflect some of the sun’s energy back into space before it warms the earth.) (yes, they also reflect outgoing energy back down… less incoming, less outgoing). Also, particulate pollution (smoke, dust, volcanos) enable clouds and reflect sun energy… remember, less in, less out. Evaporation rate studies show refectance can range from 10% to 30% in some conditions.
And more: Sea surface temperatures also affect land temperatures. Warm Pacific= El Nino, cool Pacific=La Nina. (for reasons that entirely escape me, oceanographers think sea SURFACE temperatures extend down to 700 feet, or is it meters?) For reference purposes, the last 12 months, July 2010 to July 2011, have been classified as a La Nina year. Warm Sun warm Pacific El Nino. Cool sun cool Pacific La Nina.
A classic La Nina draws a line around the northern hemisphere at about the 40 degree latitude line. Above the line, cold wet/snow winters, stormy summers with heat. Below the line, hot dry summers, cold dry winters. La Ninas are also associated with low solar activity… few sun spots.
Because of the elliptical orbit of the earth around the sun, the Earth (and northern hemisphere) is closest to the sun on January 6 or so giving warmer winters north and warmer summers in the southern hemisphere. This gradually changes to colder winter north and cooler summers south. The Earth also varies its tilt on its axis having a similar result. Sometimes they happen at the same time. This requires more research… could I get a grant?
Mostly agreed upon facts: Temperatures during our time, “Recorded History” have been remarkably stable when compared to the last 600,000 years or so. The advance of continental glaciers during the last several ice ages stopped about the 40 degree latitude. (give or take). The last several warm periods, between ice ages lasted about 10,000 years. Our current warm period is about 12,000 years old. Glacial periods last about 90,000 years. Between 1645 and 1715 there were very few observable sunspots, (ie, low solar activity) This period is sometimes referred to as “The little Ice Age”
Four possibilities: 1. The weather for the next year will be like the last year. 2. The weather for the next 75 years will have a new normal, of which last year is the best example. 3. A new Ice age is about to commence and we will get to see the beginnings, with last year’s weather being greatly longed for. 4. What I have been smoking is not what I think I have been smoking.
Seriously – 0.8 C over 100 years is supposed to have caused disasters already ?
C’mon this is just silly.
The world temperatures seem flat for more than a decade and they all begin shouting nonsense.
How could it have been the hottest decade on record without the temperature increasing – even going down ??
The other thing I don’t get is the precision – we’re talking about fractions of a degree in measurements from places where the heat will burn you up to places where you need snowsuits to survive ??
I always learnt in my science studies that if you gave an answer with more precision than your least precise result you were simply wrong !
I don’t believe them – full stop!
M.A.Vukcevic says:
July 11, 2011 at 2:05 pm
“Most of the ‘identified’ cycles are very little to do with celestial events, and far more to do with ocean currents and Coriolis force.”
That was more or less my point. The various gyres are examples of modal responses of the oceanic subsystem.