Note: This is my analysis of a new paper by Joe D’Aleo, I’ve tried to simplify and explain certain terms where possible so that it can reach the broadest audience of readers. You can read the entire paper here.
Joe D’Aleo, an AMS Certified Consulting Meteorologist, one of the founders of The Weather Channel and who operates the website ICECAP took it upon himself to do an analysis of the newly released USHCN2 surface temperature data set and compare it against measured trends of CO2, Pacific Decadal Oscillation, and Solar Irradiance. to see which one matched better.
It’s a simple experiment; compare the trends by running an R2 correlation on the different data sets. The result is a coefficient of determination that tells you how well the trend curves match. When the correlation is 1.0, you have a perfect match between two curves. The lower the number, the lower the trend correlation.
|
Understanding R2 correlation |
|
| R2 Coefficient | Match between data trends |
| 1.0 | Perfect |
| .90 | Good |
| .50 | Fair |
| .25 | Poor |
| 0 or negative | no match at all |
If CO2 is the main driver of climate change this last century, it stands to reason that the trend of surface temperatures would follow the trend of CO2, and thus the R2 correlation between the two trends would be high. Since NCDC has recently released the new USHCN2 data set for surface temperatures, which promises improved detection and removal of false trends introduced by change points in the data, such as station moves, it seemed like an opportune time to test the correlation.
At the same time, R2 correlation tests were run on other possible drivers of climate; Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and Total Solar Irradiance (TSI).
First lets look at the surface temperature record. Here we see the familiar plot of temperature over the last century as it has been plotted by NASA GISS:
The temperature trend is unmistakeably upwards, and the change over the last century is about +0.8°C.
Now lets look at the familiar carbon dioxide graph, known as the Keeling Curve, which plots atmospheric CO2 concentration measure at the Mauna Loa Observatory:
A comparison of the 11year running mean of the USHCN version 2 annual mean temperatures with the running mean of CO2 from CDIAC. An r-squared of 0.44 was found.
The results were striking to say the least. An R2 correlation of only 0.44 was determined, placing it between fair and poor in the fit between the two data sets.
Now lets look at other potential drivers of climate, TSI and PDO.
Scafetta and West (2007) have suggested that the total solar irradiance (TSI) is a good proxy for the total solar effect which may be responsible for at least 50% of the warming since 1900. To test it, again the same R2 correlation was run on the two data sets.
In this case, the correlation of TSI to the surface temperature record is better than with CO2, producing an R2 correlation of 0.57 which is between fair and good.
Finally. Joe ran the R2 correlation test on PDO, the Pacfic Decadal Oscillation. He writes:
We know both the Pacific and Atlantic undergo multidecadal cycles the order of 50 to 70 years. In the Pacific this cycle is called the Pacific Decadal Oscillation. A warm Pacific (positive PDO Index) as we found from 1922 to 1947 and again 1977 to 1997 has been found to be accompanied by more El Ninos, while a cool Pacific more La Ninas (in both cases a frequency difference of close to a factor of 2). Since El Ninos have been shown to lead to global warming and La Ninas global cooling, this should have an affect on annual mean temperature trends in North America.
This PDO and TSI to surface temperature connection has also been pointed out in previous post I made here, for former California State Climatologist, Jim Goodridge. PDO affects the USA more than the Atlantic cycle (AMO) because we have prevailing westerly wind flow.
Here is how Joe did the data correlation:
Since the warm modes of the PDO and AMO both favor warming and their cold modes cooling, I though the sum of the two may provide a useful index of ocean induced warming for the hemisphere (and US). I standardized the two data bases and summed them and correlated with the USHCN data, again using a 11 point smoothing as with the CO2 and TSI.
This was the jackpot correlation with the highest value of r-squared (0.83!!!).
An R2 correlation of 0.83 would be considered “good”. This indicates that PDO and our surface temperature is more closely tied together than Co2 to surface temperature by almost a factor of 2.
But he didn’t stop there. He also looked at the last decade where it has been commonly opined that the Top 11 Warmest Years On Record Have All Been In Last 13 Years to see how well the correlation was in the last decade:
Since temperatures have stabilized in the last decade, we looked at the correlation of the CO2 with HCSN data. Greenhouse theory and models predict an accelerated warming with the increasing carbon dioxide.
Instead, a negative correlation between USHCN and CO2 was found in the last decade with an R or Pearson Coefficient of -0.14, yielding an r-squared of 0.02.
According to CO2 theory, we should see long term rise of mean temperatures, and while there may be yearly patterns of weather that diminish the effect of the short term, one would expect to see some sort of correlation over a decade. But it appears that with an R2 correlation of only 0.02, there isn’t any match over the past ten years.
As another test, this analysis was also done on Britain’s Hadley Climate Research Unit (CRU) data and MSU’s (John Christy) satellite temperature data:
To ensure that was not just an artifact of the United States data, we did a similar correlation of the CO2 with the CRU global and MSU lower tropospheric monthlies over the same period. We found a similar non existent correlation of just 0.02 for CRU and 0.01 for the MSU over troposphere.
So with R2 correlations of .01 and .02 what this shows is that the rising CO2 trend does not match the satellite data either.
Here are the different test correlations in a summary table:
And his conclusion:
Clearly the US annual temperatures over the last century have correlated far better with cycles in the sun and oceans than carbon dioxide. The correlation with carbon dioxide seems to have vanished or even reversed in the last decade.
Given the recent cooling of the Pacific and Atlantic and rapid decline in solar activity, we might anticipate given these correlations, temperatures to accelerate downwards shortly.
While this isn’t a “smoking gun” it is as close as anything I’ve seen. Time will give us the qualified answer as we have expectations of a lower Solar Cycle 24 and changes in the Pacific now happening.
References:
US Temperatures and Climate Factors since 1895 , Joeseph D’Aleo, 2008
Persistence in California Weather Patterns, Jim Goodridge, 2007
Phenomenological reconstructions of the solar signature in the Northern Hemisphere surface temperature records since 1600 Scafetta and West, 2007
The USHCN Version 2 Serial Monthly Dataset, National Climatic Data Center, 2007
A correlation may be a cause. Or it may be a result. Or may be neither. Perhaps both elements are slaved to a third cause. Or there is some sort of mutual dependency or positive reinforcement.
We see this in history all the time, as well as in science.
HOWEVER, a good correlation sure as heck is a starting point.
And a–lack–of correlation speaks somewhat louder, does it not?
And I am not speaking of simply removing the adjustments and using raw data (though that should be eyeballed as well). I very strongly suspect that raw data has been compromised by site violation.
I am talking about ADDING an adjustment.
The “Watts Adjustment” .
Factor in the “Watts Adjustment”!
“Would it be possible to put in various realistic estimates for the amount of global warming caused by the increase of CO2 which the science really does tell us should happen – and then see how other possible factors might be involved.”
That, too.
timetochooseagain
Thanks.
It depends a lot on what “counts”. Trop only? Or does the lower strat get admitted to the club? In the former case, we get modest warming. In the latter, it’s PDF (pretty darn flat). We have some upper trop warming, but not the “bubble” consistent with CO2 theory. But then there are all these dang adjustments. Hard to say . . .
But the surface stations are something even a layman can get one’s teeth into. And they ain’t been adjusted for.
Evan, RE The “Watts Adjustment”.
The surfacestations.org project is still in flux, thus the possibility remains that the result may or may not be a significant adjustment to the surface temperature record. Or it could be large or miniscule. The point is I can’t tell you which it will be until I and the volunteers get a majority of stations surveyed, and then run an analysis to find out.
So I think it is way too early to start naming things after me, but thank you just the same.
As I said before, I really need some help in the midwest. Kansas, Nebraska, Oklahoma, Arkansas, Dakotas all need volunteers.
So why wasn’t a multiple linear regression made between the 3 factors and temperature instead of the rather “high school” statistical analysis of adding up the variables?
Johathan. Degrees of freedom?
seeblog, you can use http://babelfish.altavista.com/ to translate the text from English to German and visa versa.
Wow!
The proximate hydrological drivers of internal variability correlate with the measure of internal variability. (For US temps[?] over centennial scales and global temps over the last decade.)
I’m so impressed. Not!
luminous beauty, I’m not sure I understand your lack of impressed-ness (a word?). Do you mean to say that you think, “Well Duh-uh!” because I think it certainly isn’t obvious to some people who seem to think that temperatures as a function of time can be reproduced only via functions into which anthropogenic variables are input. Or do you mean to suggest that the result is well known and unimportant? Not following here…
Evan, everything is important, of course. Interesting, on the other hand, is a different matter. Trends in the mid-troposphere don’t interest people who live in the lower troposphere. Unless they happen to be scientists or “dangerously curious” laymen. 😉
wayne, its got nothing to do with degrees of freedom. This unfortunately, is beyond doubt, the worst thing about climate science. The lack of good understanding of statistics. Almost all people in the climate science area are not statisticians yet continually decide to analyse data themselves in their own “high school” maths methods, believing that their analysis is perfectly fine.
JL: Sad to do so, but I must agree. I am not properly educated in stats (although I am a wargame designer and thus have a crude, limited, but hands-on experience).
Stats are vital in my own field (history), though, and increasingly so. I may have to buckle down and crack the texts I should have back a-when. Especially since I spend lots of time fiddling with demographics. (Besides, is getting frustrating–and old– having to begging to my pals for a basic polynomial formula.)
As I’m sure you know, St. Mac of hockeystick-sundering fame is a statistician, and he’s told the tale of how Mann (IIRC) boasted proudly about not being one–as he was about to defend his soon-to-be busted stats!
Andrew:
We’ll need to get Our Friend the Lower Strat a homepage, then eh? The beastly trop seems to be stealing all his thunder. And he’sbeen getting the cold shoulder.
But I do find the data series that timetochooseagain posted to be most interesting. I am assuming It’s trop sans lower strat. The worldwide measure seems to indicate maybe a mere 0.4C bump since 1979, or less than half of the measurted increase. If it’s lower trop only, that makes it more interesting, still, but that would be too much to hope for! (It’s also in text, in nice neat rows, all ready to be pasted into Excel and graphed.)
Thx again, ttca
You can run through my blog post here (see point j) to see how the solar argument falls apart rather quickly.
http://chriscolose.wordpress.com/2007/12/18/the-scientific-basis-for-anthropogenic-climate-change/
If someone wants to quantify a radiative forcing, rather than look at lines going up and down (and not even being honest enough to compare with global temperatures, but U.S. temperatures), then we can discuss. I can make lines to, make the Y axis scale how I want, not to bother to discuss how temperature is not expected to go up proportional to CO2 concentration (but to the logarithm), not consider mid-century aerosols, earlier century solar variability, not include thermal intertia in the climate system, and run a nice R^2 value…or I can just tell you that the radiative forcing from delta TSI relative to 1750 is around a quarter that of CO2 when you run the calculations. If someone wants to find an academic journal which supports 1-2 W/m^2 RF from solar since pre-industrial time, then we can discuss. Stop confusing people with lines…
chris
MODERATORS REPLY: “…then we can discuss…..” Chris this is not a blog where people dictate terms to others for discussion, if you want to discuss something, please do so, if not don’t, but please don’t expect others to perform on your terms.
Chris, if you are going to focus only on CO2 and complain about other variables, then it is only fair to point out that the “Greenhouse” effect is a two way street. Just as a Greenhouse gets hotter inside than the ambient outside during the day, it conversely gets colder inside than the ambient outside during the night for exactly the same reason – radiation. The true effect of a Greenhouse is both raditation and a lack of convective heat transfer due to an enclosed space. In a true Greenhouse we expect to higher than ambient temps during the day and lower than ambient temps at night. Is this reflected by the observed data????
DScott- What is predicted is warmer nights, and this is what has been observed. The Earth is not quite the same as a “true” greenhouse.
As for Luminous Beauty’s comment, I think what they mean is that you’ve just noticed what everyone else knew ages ago, that there are certain things which cause the year to year variation, whilst the CO2 and other forcings keep on pushing the temp up.
You can’t claim greenhouse effect if the observations don’t support the theory. CO2 doesn’t change it’s physical properties at night time. If they are hanging their hat on the radiative qualities of CO2 to influence the temperature then it must be consistent otherwise the theory is in conflict with the observations. So that’s strike two on CO2 theory in conflict with the observations. 1. Negative GAT temperature trend since 1998 despite increasing CO2 levels and 2. Warmer not cooler nights as required by the theory. Quite frankly, CO2 as a driver flies in the face of the known chemical and physical properties of the atmosphere. The claim 380 ppm CO2 can greatly influence temperature is ludicris.
Water Vapor is the major physical variable in the atmosphere, changing from latitude, height and seasonally. The temperature response is dramatically different with different levels of water vapor content in the air. Anyone who knows (meteorologists and engineers) the psychrometric chart sees through the fallacy of claiming temperature as the true indicator of whether the earth is warming or not. http://www.truetex.com/psychrometric_chart.htm Temperature is only a partial measure of the heat content of the air. Enthalpy is the only true means to determine heat/energy content. Anyone who claims 80F in Tampa, Fl is the same as 80F in LA is a total idiot, the difference is in the water vapor content.
Anthony, I’m curious, is there a data base from NOAA with the humidity recorded with these temperature readings? Has someone done their homework to run a Enthalpy series of a site? You might find the series fairly flat if you compare annually over several years.
REPLY: There are a small handfull of sites that had strip hyrgrothermometers, but thats down to a small handfull now. As far as I know, humidity is not recorded with NCDC climate records. The ASOS stations are another matter, they have both temp and humdity/dewpoint but the HO83 thermometer makes some of the 80’s/90’s records biased. So it is hard to say if we have an accurate record there either.
“Anyone who claims 80F in Tampa, Fl is the same as 80F in LA is a total idiot, the difference is in the water vapor content. ”
It’s not the heat–it’s the humidity. #B^1
And, I suppose, air density in response to pressure. (In regardss to altitude and atmospheric layers.)
So it comes down to joules, in the end?
Guess I’d include myself in the ‘highschool’ category here in many respects, because I’m working on developing proxies for retrieving paleo-wind information. As there seem to be some problems getting Milankovitch and CO2 to work well together in modeling SST and continental temperature data, I’d like to propose another temperature driver with which they might participate more usefully. This may be ‘old hat’.
Since the 70s I’ve been puzzled by the evidence for large meridional temperature gradient being associated both with 1. last late glacial maximum modeled ice extent and 2. global warming associated with interglacial rise in CO2. What is known about condtions associated with intervals of lower meridional heat transport in early Holocene and even perhaps during full glacial?
In other words, should we be looking more at the kinetic structure as a candidate for the big driver?
Yes, it comes down to energy since if people are going to make a big deal out of radiative forcing, then the tranference of energy is the be all and end all of the issue. Radiating to what and where? Law of Conservation of Energy states: Energy can not be created or destroyed only transferred. Any discussing that ignores the transfer of energy of either sensible and latent heat is going to come to the wrong conclusion. Dry air rises in temperature faster than wet air, the psychrometric chart shows the physical proof of this. If you need help reading the chart I can explain how to read it and give examples.
Evan, in any event I think Steve has this CO2 problem licked, read the thread comments 96 and 195. http://www.climateaudit.org/?p=2645#comment-205001
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dscott, you are fairly well confused
A RF does not suggest a “destruction of energy” but a change in down minus up irradiance at the tropopause, and reduction of the OLR as the effective radiating level moves up to higher levels, lower pressures in the atmosphere where it is sufficiently cold. The ability to alter the radiative balance (And hence temperature) is not a controversy. See http://chriscolose.wordpress.com/2007/12/25/basic-radiative-modelsearths-climate-system-analysis-pt-2/
Secondly, the ‘greenhouse’ analogy is a rather poor one, so this won’t go too far. In fact the diurnal temperature change is expected to decrease with more greenhouse gases, but this also depends on many things like aerosols, water-vapor feedbacks, surface evaporative effects, cloud cover, aviation, land use changes and urban heat islands, etc
Your points in McIntrye’s blog are nothing but false, and you have obviously not done temperature data runs or seen the data yourself, but bought absurd ideas like ‘it stopped in 1998’ which have no scientific basis. I strongly suggest you turn to other references like the NAS or IPCC if you have a dispassionate consideration of the issues
C
Wayne Hamilton, this reference may be informative
Pierrehumbert RT 2002: The Hydrologic Cycle in Deep Time Climate Problems. Nature 419,191-198
And a recent one which is interesting
Hogg, A. M. (2008), Glacial cycles and carbon dioxide: A conceptual model, Geophys. Res. Lett., 35, L01701, doi:10.1029/2007GL032071
[i]Your points in McIntrye’s blog are nothing but false, and you have obviously not done temperature data runs or seen the data yourself, but bought absurd ideas like ‘it stopped in 1998′ which have no scientific basis. I strongly suggest you turn to other references like the NAS or IPCC if you have a dispassionate consideration of the issues[/i]
Are you claiming 1998 was not the hottest year in the last 100 years??????
If 1998 was the hottest year, then logic tell us that any subsequent year must be colder. It’s now been ten years since 1998, the temperature trend is negative, in order to be positive, i.e. warming, some year past 1998 must be warmer. You can play all the rhetorical games you want, the cold hard facts are plain to see.
As to the McIntyre Thread, I see you don’t like the implications of Hansen C. Sorry Chris, but it was Hansen himself who made the prediction, as Steve pointed out, CFCs according to Hansen’s math, not CO2 would explain the leveling off after 1998. The reason why Hansen A way over shot the prediction was he projected a scenerio where the increase in CFCs would push up temperature if the Montreal Protocol wasn’t enacted. So unless you are willing to say Hansen had it completely wrong when he ran the scenerios, you are faced with two very distasteful options, 1. Hansen knew what he was talking about back in the 80s thus CFCs were your boogeyman or 2. Hansen didn’t know squat to the point that any prediction or advocacy by him is totally ill informed.
actually 2005 and 2007 could be said to have beaten out 1998 (from GISS), but that is hardly the point, nor is it relevant. It is not true that any one year needs to be warmer to see a continued trend, that CFC’s are/were causing the warming, or that Hansen’s projections (like scenario B) were outside the reasonable errors; his paper is publicly available at http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf . In fact even if you had a perfect model, you wouldn’t be able to say it was better, given the economic spread and temperature consistency within what actually happened in the real world.
Really, rather than spending time on McIntrye’s blog, or talking to me, an introductory textbook on the subject would be a good start, or at least spending a bit less time on wingnut sites. Just about everything you keep saying is wrong, and I really haven’t time the time for claims which don’t show up in the peer-reviewed literature, or are quite obviously false as anyone who knows how to look at data will support (ex. a trend is not Year 1 – Year 2).
Evan, I am timetochooseagain. 😉