I really wish Gavin would put as much effort into getting the oddities with the GISTEMP dataset fixed rather than writing coffee table books and trying new models to show the sun has little impact.
This paper gets extra points for using the word “robust”. – Anthony
Solar trends and global warming (PDF here)
R. E. Benestad
Climate Division, Norwegian Meteorological Institute, Oslo, Norway
G. A. Schmidt
NASA Goddard Institute for Space Studies, New York, New York, USA
We use a suite of global climate model simulations for the 20th century to assess the contribution of solar forcing to the past trends in the global mean temperature. In particular, we examine how robust different published methodologies are at detecting and attributing solar-related climate change in the presence of intrinsic climate variability and multiple forcings.
We demonstrate that naive application of linear analytical methods such as regression gives nonrobust results. We also demonstrate that the methodologies used by Scafetta and West (2005, 2006a, 2006b, 2007, 2008) are not robust to
these same factors and that their error bars are significantly larger than reported. Our analysis shows that the most likely contribution from solar forcing a global warming is 7 ± 1% for the 20th century and is negligible for warming since 1980.
Received 17 December 2008; accepted 13 May 2009; published 21 July 2009.
Citation: Benestad, R. E., and G. A. Schmidt (2009), Solar trends and
global warming, J. Geophys. Res., 114, D14101,
doi:10.1029/2008JD011639.
hat tip to Leif Svalgaard
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So we’re looking at a stretch of .8 Kelvin from low to high points – which would come out to… 1.44 Fahrenheit.
Damn.
You know, if he redid the chart with .1 Kelvin graduations, it’d be MUCH more impressive and scarier.
Leif Svalgaard (14:16:00) :
There are, however, objective criteria that can be used. Solar activity maintains the ionosphere and cause an electric current to flow 60 miles overhead during the day. The magnetic field from this current causes the compass needle to deviate from its usual [i.e.. night time] direction. This deviation is easily measured [even in 1750 – was discovered actually in 1722]. We can thus keep track of the currents in the ionosphere and thus of solar activity without relying of people counting spots.
Thanks for the interesting links Leif, I’ve read the laymans paper, very clear.
If we have such a good handle on the ionosphere though, why were NASA caught on the hop with CINDI?
http://www.nasa.gov/topics/earth/features/outer_atmosphere.html
How do we know the ionospheric magnetics correlate to solar activity if we don’t know why it’s height changes the way it does? Wouldn’t that leave open the possibility that the ionosphere might have been different back before 1850 and so make the corrections invalid?
I realise you have to juggle the visual data and magnetic data to get a best fit. It must be fascinating forensic work. I’m just trying to get a feel for the levels of uncertainty involved in all this.
Show me the error bars. 😉
As an old steam man, I find this site with it’s mind-boggling calculations, well…mind boggling.
Then I saw something I think I understand less more than the other stuff.
That is, Which way is a Photon?
OK, What is a Photon?
Suppose one pops up, (from where?) where does it go?
I would have thought, in all directions at once.
And yet all the pictures I’ve seen of photons is (are?) as particles travelling most purposefully in a direction, any direction, yet usually through a little slit, and then, in its photonic way, causing any amount of theoretical confusion.
Why?
Joel Shore:
Who said anyone was dismissing the effect?
And most of the remainder that isn’t is water vapor.
Which means the effect gets less as the concentration increases.
Regardless of what you may have us believe, there’s still considerable uncertainty over the magnitude of the effect.
Phil:
Yes, within that tiny portion of the electromagnetic spectrum known as visible light.
CO2 absorbs a tiny portion of the IR band. It does not, by any stretch of the imagination, make the atmosphere anything like ‘opaque’ to IR. In fact, it is dwarfed by the IR absorbtion of water vapor. And, at its strongest absorption band (~16um) it’s practically at saturation.
You cannot describe the Earth-atmosphere system in terms of ideal blackbodies. It’s only at the top of the atmosphere that most (all) of the heat loss is through radiation.
Try disconnecting the radiator fan on your car, leave it idling, and see how quickly (and expensively) it overheats.
And what proportion of that is in the 16um CO2 absorbtion band? And, in turn, how much of that is re-radiated downwards towards the surface?
Peter (11:56:35) : “How else would you explain the paleoclimate record unless the sensitivity is so high that it responds to CO2 increases 800 years in the future?”
Obviously carbon dioxide shares some properties with thiotimoline.
Who would have thought that Isaac Asimov was the father of climate science? 🙂
To those debating I would say it may be getting to the point that the warmers would still believe man can cause a catastrophic warming even if the Sun was to suddenly disappear and thus would be believing that the Earth continues to get warmer because of the CO2 and there’s absolutely no light from the Sun because the star no longer exists.
That sort of thinking may be already here looking at this discussion.
“Why?”
Here is as good an explanation as you are likely to get, assuming you are serious. A layman’s introduction by one of the most brilliant men who ever lived. Watch the first video “Corpuscles of Light”, which takes you from Newton’s experiments on light through the development of the theory of Quantum Electrodynamics.
http://vega.org.uk/video/subseries/8
tallbloke (15:07:46) :
If we have such a good handle on the ionosphere though, why were NASA caught on the hop with CINDI?
Because they are talking about the thermosphere, some 10 times further up than [the part of] the ionosphere where the currents flow [~60 miles, 100 km]. The air up at CINDI there is VERY much thinner than where the currents flow. The density goes down by a factor of a thousand for every 50 km we go up, so you figure out how many billions of times thinner.
How do we know the ionospheric magnetics correlate to solar activity if we don’t know why it’s height changes the way it does? Wouldn’t that leave open the possibility that the ionosphere might have been different back before 1850 and so make the corrections invalid?
Because we have explored the ionosphere for ~80 years in great detail [including in situ observations] and we know how it works.
I realise you have to juggle the visual data and magnetic data to get a best fit. It must be fascinating forensic work. I’m just trying to get a feel for the levels of uncertainty involved in all this.
Show me the error bars. 😉
It is very difficult to put error bars on these old data. The best one can do is to use many stations and compare the spread of the data. Look at figure 16 of the Napa paper and note the spread [e.g. in the lower panel]. The layman’s error bar would simply to by eye fit a band over the blue symbols such that the width of the band contains 2/3 of the points. Similarly for the red [filled[ points. It is clear that these two bands have a separation such that it is very unlikely that it is die to chance.
There is a greater issue. Even with error bars, this could just be a fluke [such happens], But we have now 4 independent methods and data sets that show this:
1) geomagnetic variation
2) sun spot areas
3) Calcium K-line
4) measurements of the foF2 layer height [not mentioned in any of my papers, but known for a long time:
http://www.leif.org/EOS/TE053i001p00079.pdf and
http://www.leif.org/EOS/JZ057i004p00473.pdf
These papers showed:
“Analysis of data for Washington and Watheroo indicates differences in the relationship between foF2 and sunspot number for the current and preceding sunspot cycles. The sunspot number is therefore not entirely satisfactory as an index for ionospheric variations. Consequently, ionospheric data for the current cycle only should be used in preparing ionospheric radio propagation predictions whenever possible.”
Basically what they found was that the relationship between the height of the F2 layer and the sunspot number changed when Waldmeier took over in 1945. Same conclusion as I have come to.
Any one of these lines of evidence can be dismissed as a fluke or a data problem. However you can’t say that about all four of them collectively, so there is little reason to doubt the validity of this.
Jimmy Haigh (00:43:16) :
Global Climate Modeling. Getting it wrong for 20 years… and counting!
But don’t worry – we’ll get it right eventually!
Well get closer when we get a handle on the sun’s effect on climate.
Apparently Piers Corbyn, and the makers of The Farmers Almanac, have know that all along.
Gavin Who at RealWhat has it bass akwards. And I have some kind of hunch he knows that full well that he does.
John Edmondson (00:38:48) : does it include secondary effects of the solar cycle i.e. magnetic field influencing cosmic rays influencing cloud formation
I think that would be primary, not secondary.
I notice his “reconstructed” graph of the 20th century “forcings’ – NOT real, measurable temperatures! – now strangely has a “hot spot” from 1935 through 1945 of less than 1/10 of one degree C, while earlier “histories” of that same period clearly show that recorded temperatures were equal to the miraculously higher 1990-2005 temperatures.
Strange, this trend of ever-decreasing GISS NASA temperatures ever-earlier in the century.
George E. Smith (14:13:46) :
But Phil’s point is being missed; the fact that the atmospheric abundance of GHG species (other than water) is microscopic, does not negate their effects on the atmosphere.
Thanks George I knew you’d get it with your background.
Jim (14:18:22) :
Phil. (13:15:03) : “Rubbish, most of the loss from the surface is IR radiation unless you’ve found a way to bypass Planck’s law of blackbody radiation!
300K surface emits about 460W/m^2″
You are SO FOCUSED ON RADIATION!
It’s because you are so focused on getting it wrong! The poster to whom I was replying asserted that heat transfer from the surface was dominated by conduction and convection which is flat out wrong it’s mostly radiation as Planck’s Law shows.
The air convection currents that help form clouds put large amounts of heat in short order into the upper atmosphere, bypassing much of the CO2. THEN the heat radiates into space. Also, clouds prevent the radiant energy from hitting the ground (or ocean) in the first place. You guys are really hung up on CO2 and radiation – as if nothing else existed or mattered.
Because it’s the only source of heat for the planet and the only way in which heat can be lost by the planet and it’s the dominant mode of heat transfer from the planet’s surface to the atmosphere. How could anyone considering the Earth’s energy balance not pay attention to radiation?
Allan M (14:33:40) :
Phil:
Since when did CO2 have more than a limited (~15 microns) absorption,
For ever.
which is covered already by water vapour and other gases.
It isn’t
Even the IPCC couldn’t characterise CO2 as a “very strong absorber.”
They should.
Peter (15:27:26) :
Phil:
“They do more than ’shift absorption bands slightly’ they dramatically change its absorption characteristics from transparent to strong absorption”
Yes, within that tiny portion of the electromagnetic spectrum known as visible light.
“…exactly the same effect that CO2 has on air!”
CO2 absorbs a tiny portion of the IR band. It does not, by any stretch of the imagination, make the atmosphere anything like ‘opaque’ to IR. In fact, it is dwarfed by the IR absorbtion of water vapor. And, at its strongest absorption band (~16um) it’s practically at saturation.
It’s not a tiny portion of the Earth’s emission spectrum. It is opaque at certain frequencies that’s IR space telescopes based on the Earth can’t observe in that range. It is not dwarfed by the IR absorption of water vapor. Except for some line centers it’s not saturated.
“Rubbish, most of the loss from the surface is IR radiation unless you’ve found a way to bypass Planck’s law of blackbody radiation!”
You cannot describe the Earth-atmosphere system in terms of ideal blackbodies.
Certainly can in the IR band we’re talking about which is an almost perfect black body.
It’s only at the top of the atmosphere that most (all) of the heat loss is through radiation.
Not true as discussed above.
Try disconnecting the radiator fan on your car, leave it idling, and see how quickly (and expensively) it overheats.
Now that really is an irrelevant analogy.
“300K surface emits about 460W/m^2”
And what proportion of that is in the 16um CO2 absorbtion band?
~20%
And, in turn, how much of that is re-radiated downwards towards the surface?
Depends on the altitude.
Vincent (08:41:58)
I bow to your superior grasp of thermodynamics Vincent. I’m not a physicist either and know next to nothing on the subject.
I had assumed that the paper, being peer reviewed, was good science!
Gene Nemetz (17:36:40) :
Absolutely. The warmers don’t have a very high opinion of Piers Corbyn – ergo, he’s probably correct!
Peter says:
Well, the way that their paper is written makes it difficult to figure out exactly what they are saying. I agree that they tend to nitpick on terminology / pedogagy. However, in the end they seem to draw grand conclusions from it, such as that the atmospheric greenhouse effect is “fictitious”. If they just stuck to the point that people don’t always get the pedagogy correct, like this guy, Alistair Fraser, does: http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html , then I wouldn’t have any real quarrel with them. However, that is certainly not what they do…and certainly not what most people who point to this paper believe that they have done.
I’ve also thought that the best summary of their paper is that everything that is correct (such as that a real greenhouse does not primarily work by trapping IR radiation) is not original and everything that is original is not correct.
This sort of statement (besides being pedagogically incorrect as noted by Alistair Fraser) is essentially a “red herring”. What is important for the energy balance is the rate (in Watts) at which heat flows, so changing that rate changes the energy balance.
“Gavin et al will attack on the solar front because it’s where they can win. ”
I agree, you don’t need to know the answer to know what it isn’t.
Solar forcing will not explain temps any better than CO2 forcing, and if you make it solar vs CO2 then CO2 starts to look reasonable.
Most likely there is no one dominant factor over these minor short-term fluctuations.
Phil. (17:53:36) : I don’t see how Planck’s black body law prevents convection moving heat, or clouds from reflecting the Sun’s light. That isn’t logical.
Phil said: “It’s because you are so focused on getting it wrong! The poster to whom I was replying asserted that heat transfer from the surface was dominated by conduction and convection which is flat out wrong it’s mostly radiation as Planck’s Law shows.”
Phil, can you explain how Planck’s law means that molecular collisions happen less frequently in our quasi-black-body absorber than the emission of photons?
” Bill Illis (11:49:05) :
Kevin Cave 22:38:16) :
So the sun is irrelevent in the context of AGW is it? Here’s a very simple, but I believe effective, thought experiment… the sun’s been switched off.
I wonder how long it would take for the Earth to start getting intolerably cold, and whether the fraction of a percent of human-introduced carbon dioxide would make a blind bit of difference.
The temperature drops on average by 10C in the 12 hours after the Sun sets. So, on average, the Earth’s temperature drops by 0.83C each hour after the Sun is no longer beating down on the Earth each day.
By the middle of day 3, temps will have fallen by 40C and every river on the planet will be frozen right to the bottom (followed soon after by every lake and then the oceans). Land near the ocean at the equator will be moderated somewhat but everything else will already be frozen solid by day 3.
This example also provides a good explanation for the timelines of the greenhouse effect. Before the end of day 2, all of the 33 degree greenhouse effect has already been lost to space. There is no 30 year lag in the greenhouse effect – it is only a delay (or accumulation) of 36 hours in how long it takes for the Sun’s energy to escape into space. The energy random walks around the molecules in the ground and then in the atmosphere for an average of 18 hours before it escapes into space. (oceans and icesheets can also accumulate that energy so this where the lags come from but this accumulation will be much less than 10% of the total).”
—————–
Bill, excellent post, most interesting, as it also highlights a few things that I also find rather curious;
1) The way CO2 is treated by the AGW’ers to be some kind of Magic Mirror Molecule which acts as some extremely effective heat blanket around the planet.
2) Does any climate scientist take into account how much heat is supplied to the atmosphere from heat which is contained within the planet itself? I’m referring to geothermal heat from below the Earth’s crust. Now, my understanding of the current knowledge is that below the crust we have a viscous Mantle, a liquid Outer Core, and a solid Inner Core – all are very hot. The vast majority of the heat generated is fuelled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle – something like 90% of the heat generated, I think the figure is.
This heat has to go somewhere – thermodynamics dictates it can’t just be being kept back by our thin crust – and if my understanding of basic physics is correct, the heat will escape the body of the planet and out into space – obviously the atmosphere is in the way.
I’m wondering if this heat has in any way some significant additional effect on the atmosphere and if so, if that additional input has been taken into account.
Joel Shore:
“And, what makes you believe that the models use a significantly different sensitivity for a given W/m^2 of solar forcing as they do for a given W/m^2 forcing of CO2? I don’t believe that they do.”
Beliefs are meaningless, what is the science?
“I am sure that we could find substances that would kill you at far lower concentrations. However, more to the point in this particular case: When ~99% of the atmosphere consists of diatomic molecules that are essentially transparent to infrared radiation, the remaining ~1% can have a disproportionate effect on the climate. ”
The problem is you can’t even seem to do basic math, in addition to putting your beliefs before science. 330/1,000,000 = .00033 or 0.033%, not ~1%, a factor of 30 difference. If there were as much as 1% of the atmosphere made up of CO2 (about 10,000 parts per million) then I am sure we would see some actual warming. The difference between 260 and 330 ppm is so miniscule as to be worthless.
Joel Shore,
“And, what makes you believe that the models use a significantly different sensitivity for a given W/m^2 of solar forcing as they do for a given W/m^2 forcing of CO2? I don’t believe that they do.”
One of the problems with the models is that they do treat solar and CO2 radiative forcing more equivilently than they should. For instance solar penetrates 10s of meters into the oceans, while the CO2 wavelengths are essentially a skin effect, a few microns, yet CO2 forcing is coupled to the whole mixing layer. The hubris of assuming the forcings are equivilent is perhaps best demonstrated by the use of a simple formula to convert senstivities derived from solar or aerosols to a sensitivity to CO2.
Phil. (17:53:36) :
It’s because you are so focused on getting it wrong!
Ascribing motivations is a two-edged sword… Careful with that axe, Eugene.
Kevin Cave 20:37
2) Does any climate scientist take into account how much heat is supplied to the atmosphere from heat which is contained within the planet itself?
This effect is supposed to be very, very little – much less than 1.0C.
But there is another similar effect that is not taken into account and that is the gravitational compression of the atmosphere itself. The weight of the atmosphere itself causes an increased temperature effect.
This is the force that causes stars to reach temperatures high enough for fusion to start. This is the force that makes the “atmosphere” of Jupiter near its core at 10,000 kelvin even though no sunlight gets down there and there is little greenhouse gases in Jupiter’s atmosphere. This is the force that explains about half (200C) of the temperature in the atmosphere of Venus which cannot be explained on the basis of solar input and greenhouse gases.
I haven’t seen anyone calculate the effect for Earth but it would not be a non-significant amount. Technically, the solar input and the greenhouse gas effect numbers do not make any sense as the temperature impact is ten times higher per watt for solar versus the greenhouse effect. So there are other factors which are not built into the theory.
Leif Svalgaard (16:53:00) :
Basically what they found was that the relationship between the height of the F2 layer and the sunspot number changed when Waldmeier took over in 1945. Same conclusion as I have come to.
Any one of these lines of evidence can be dismissed as a fluke or a data problem. However you can’t say that about all four of them collectively, so there is little reason to doubt the validity of this.
Thanks Leif, interesting stuff. Clearly, our measurements have got a lot more accurate since the discovery of radio, and as you say, there is much more uncertainty the further back we go.
One thing from the laymans paper which struck me was when you said Wolf got it right in 1848 (high cycle). Why would a careful man like Wolf get it right in 1858 but get it wrong at other times? It looks like 1875 was correctly counted too, so why would the intervening low cycle be under counted?
Even now there are problems, PMOD is dropping off the chart, and confounding baselines beyond the issue of it’s decoupling from sunspot (sunpore!) numbers.
Maybe you didn’t spot my post at (06:14:48) or maybe you don’t want to comment at the moment while the controversy between the PMOD and ACRIM/NEPTUNE teams is unresolved. It would only take a very small error (less than 0.3% ?) in the calibration corrections for the radiometer sensor’s early degradation to change the picture regarding the sun’s alleged lack of climatic effect completely it seems to me.
When controversies like this one arise it’s because there is sufficient uncertainty in the data that the proponents of both the “It’s the sun!” and the “it can’t be the sun!” agendas can derive evidence to support quite opposite conclusions from it.
Researchers are [slowly] moving their estimates of the long-term trend closer and closer to what I have been saying for quite some time now [that there is very little, if any, long-term trend]:
ftp://ftp.pmodwrc.ch/pub/Claus/IAMAS-2009/iamas-poster_SABF.pdf
Note the red curve in the last Figure [lower right, how flat it is.