This is an interesting paper from our good friend Dr. John Christy of UAH and D. H. Douglas. In it, a bold claim is made about the likelihood that the atmosphere no longer shows the characteristic of CO2 radiative forcing, and that the effect apparently peaked around 1998. Here is figure 1 from the paper:
From the paper: “The global values of ΔT in Figure 1 show for the period Jan 1979 to Jan 2008 that the anomalies reached a maximum in 1998 which has not been exceeded by later values.”
Here is how the abstract reads:
“The global atmospheric temperature anomalies of Earth reached a maximum in 1998 which has not been exceeded during the subsequent 10 years. The global anomalies are calculated from the average of climate effects occurring in the tropical and the extratropical latitude bands. El Nino/La Nina effects in the tropical band are shown to explain the 1998 maximum while variations in the background of the global anomalies largely come from climate effects in the northern extratropics. These effects do not have the signature associated with CO2 climate forcing. However, the data show a small underlying positive trend that is consistent with CO2 climate forcing with no-feedback.”
You can read the paper and the link below. which provides a new perspective on the role of CO2 as a radiative climate forcing.
Douglass, D.H., and J.R. Christy, 2008: Limits on CO2 Climate Forcing from Recent Temperature Data of Earth.
I’m sure this will raise the ire of a number of people, but at the same time, what else have we to explain the nearly flat response in global temperature in the last 10 years?
h/t Dr. Roger Pielke, Sr.
Robert Wood (17:00:49) :
Mike Ramsey has voiced a concern I have. Do you have an exposition on this?
I have not been to decipher Mike’s comment so can’t comment. Maybe you can explain to me what his concern is.
Robert Wood (16:46:07) :
Although I am pretty sure that that great hot ball of fire in the sky might have just, perhaps, a little something to do with earth’s temperature, past records and historical correlations are poor evidence.
As long as you keep it small enough, I’m comfortable with that. It’s the ‘major player’ thing that I argue against on both observational grounds and theoretical grounds.
What the models really say…
We have found that if we run enough different models, enough different ways, we can show cooling in a small percentage of the runs. Now if this is not sufficient, we can run these models as many times as it takes to get any length of cooling trend you require.
You can not win. We made the models.
Thank you, now run along children,
Really not real climate, just models…
Leif you are correct, however when the sun blinks out, we’ll see whether it was a major or a minor player. 🙂
Leif Svalgaard (18:49:45) :
Robert Wood (17:00:49) :
Mike Ramsey has voiced a concern I have. Do you have an exposition on this?
I have not been able to decipher Mike’s comment so can’t comment. Maybe you can explain to me what his concern is.
If I make a guess as to what he means, it seems to be something with UV and it heating the Earth.
UV is absorbed in the high atmosphere and does not heat the troposphere where we live. The troposphere is not heated from above, but from below.
Leif:
I believe you know a lot about our sun but maybe there is still a lot to learn.
It has been observed that other planets (melting south pole of mars) have also warmed during the same time as our’s planet has warmed. If our sun did not contribute to our warming then the sun did not contribute to the other planets’ warming, then what caused the other planets to warm?
Leif Svalgaard
Are there any particular parameters of the sun now being investigated that might indicate the sun may be entering a phase that we may never have witnessed before or that the science was not sophisticated enough to discover previously?
old construction worker (19:25:47) :
It has been observed that other planets (melting south pole of mars) have also warmed during the same time as our’s planet has warmed.
It has been observed to melt three summers in a row, but it melts back every summer, then freezes again, just like our polar ice.
Apparently, there are people that predict global warming disasters on Mars too:
http://www.colonyworlds.com/2007/03/melting-martian-ice-caps-could-flood.html
‘Save the planet’ gets a whole new meaning here.
Pluto is melting too [as it comes closer to the Sun in its orbit].
You can learn more about Mars’ climate and what drives it here http://www.skepticalscience.com/global-warming-on-mars.htm
Leif,
I was more interested in whether the asymmetric pulse mechanism makes any physical sense (e.g. you have explained repeatedly why the barycentric motion concept is nonsense – does the pulse mechanism I proposed fall into the same category?).
As for the Oort minimum and the MWP – I don’t think we have any data that can precisely time the MWP but if you look Loehle 2008 you will see that the Oort minimum corresponds with a drop in temperatures:
http://www.worldclimatereport.com/index.php/2008/02/11/a-2000-year-global-temperature-record/
I noted the same pattern when you commented about the Tornetrask series at climate audit (i.e. the temperature dropped during the minimum even if it started at a high point). See http://www.climateaudit.org/?p=3348
edcon (19:36:07) :
Are there any particular parameters of the sun now being investigated that might indicate the sun may be entering a phase that we may never have witnessed before or that the science was not sophisticated enough to discover previously?
It would be very nice if there were such things, but alas, the Sun right now is just where it was 107 years ago. Solar cycle 23 has behaved just as solar cycle 13. Now, if by ‘we’ you mean you and I, then, of course, we have never seen the Sun like that before. There are also many things that we can now observe that they couldn’t observe 100 years ago with their technology, but that does not mean that those things have just popped into existence, so as far as we know, the answer is ‘no’.
Leif,
Thanks for the data. Yes, I will handle with care!!
Raven (19:51:43) :
I was more interested in whether the asymmetric pulse mechanism makes any physical sense (e.g. you have explained repeatedly why the barycentric motion concept is nonsense – does the pulse mechanism I proposed fall into the same category?).
Maybe you are right about where it falls :-), but it hardly matters as the solar effect is so small. And small cycle are not so asymmetric. Here is a very small cycle http://www.dxlc.com/solar/cycl5.html
As for the Oort minimum and the MWP
The cosmic ray record http://www.leif.org/research/Heliospheric%20B%20from%2010Be.pdf shows that the Oort minimum is really the broad swath from 900 to 1100 [with a extra deep through 1010-1050] covering the MWP. I can live with the deep dip as a second order effect. Even at its deepest Loehle’s temperature plots still show a temperature one degree higher than the Maunder Minimum on par with the temperature now [according to the plot]. My main point is the broad picture is not determined by the Sun as it should have been had the Sun been the dominant player. The simple argument goes like this: if low solar activity caused a dip during the MWP, then what caused the MWP itself so there was something to dip from?
My real argument is not derived from reconstructions and wiggle matching but from the physics we know about the Sun, especially the evidence from helioseismology that I referred to earlier. Right now the Sun is as dim [and UV is as low] as it has ever been as and it is at every solar minimum, Grand or not.
But, please, folks, has this not gone on for long enough? Just about every thread on this blog that has anything to do with climate change and the Sun [must be approaching a dozen] ends with this very same discussion, not to talk about the 4000 posts at ClimateAudit. Go look at some of the [rather sad] other threads for more of the same.
I’ll continue to answer questions about the Sun, should there be some.
So are there then functional stop limits in the system that lend to a thermal constant? But what other factors are at play here and could noise up Christy’s analysis? Soot, GCR flux, sulfates? This is where I find everybody’s analysis to be embarrassingly audacious, the science is far from settled. Climatology is no more developed toward it’s hopeful goal of real climate prediction as cognitive psychology is in predicting human behavior (and cog psy has come a long way in the past 30 years…). And yet 30 years ago as a psych student I heard all manner of proud statements about the efficacy of behavioral and cognitive methodologies in the field. The insurance co’s bought that nonsense for a while….
Read this on CA sea ice stretch run:
” I see the question of “will increasing GHGs warm the earth” as being akin to asking “will a car slow down when it goes uphill”? Well, it depends on whether it is running under “Cruise Control” or not, doesn’t it …
The missing link in most analyses, in my opinion, is that the earth’s climate is not a passive system. It is not like a pool ball on a level table, where a shove will deterministically move it a distance proportional to the applied forcing, and in the direction of the forcing.
Instead, it is like a madly spinning pool ball on a complex surface with hills and hollows. When you push it, it pushes back. It sometimes moves less than the forcing applied, and sometimes more. At certain points, an immeasurably small difference in the direction of the shove will take it along a totally different trajectory. It does not move in straight lines.
All of which makes talk of “deterministic trends”, in my opinion, absurdly simplistic. Very little in Nature is linear, very little is “deterministic”. Climate exhibits self-organized criticality at a host of levels from ice melting to thunderstorms forming, and if there is anything which is definitely “non-deterministic”, it would be self-organized criticality.”- Willis Eschenbach
Tony wrote:
The temperature trend has generally followed the baseline logarithmic function for CO2 fairly well since the mid-19th C.
Cases in point:
The mounting improbability of dangerous feedbacks:
http://i27.tinypic.com/25fuk8w.jpg
The gradual relaxing of the CO2-driven trend:
http://i32.tinypic.com/28h3dqh.jpg
Leif Svalgaard (18:49:45) :
Robert Wood (17:00:49) :
Mike Ramsey has voiced a concern I have. Do you have an exposition on this?
I have not been to decipher Mike’s comment so can’t comment. Maybe you can explain to me what his concern is.
Leif,
Sorry for being so obtuse. I was having trouble getting the HTML right. Not all of the normal HTML escape
characters were working.
About my point, let me try again.
1. The ultraviolet and x-ray part of the solar spectrum has a wavelength < 300 nanometers and
accounts for about 8% of total solar insolation. Can we agree on this?
2. The portion of solar insolation with wavelength >= 300 nm contributes the bulk of the TSI (about 92%)
and varies by about 0.1%
3. The irradiance of the UV, x-ray portion of the spectrum varies by 8% or more and rises and falls
in lock step with the solar sunspot cycle.
4. Almost all (99.95%) of the UV, x-ray portion of the incoming solar insolation (wavelength < 300 nm)
is absorbed by the earth’s atmosphere.
5. On average, only about 70% of the remaining solar insolation (wavelength >= 300 nm) is absorbed by
the earth. The remaining 30% is reflected out into space and does not contribute to heating the earth.
6. This leaves 70% of 92% =.7 * .92 = .644 = 64.4% of the original total insolation with wavelength >= 300nm
that is actually absorbed and contributes to global heating.
7. That 8-9% of the original total solar insolation represented by UV, X-Ray (wavelength < 300nm) accounts for ~12%
of the remaining insolation that actually heats the earth.
8. 8% variation * 12% of the solar energy heating the earth = 0.96% which is a larger variation than the
0.1% variation that gets kicked around in the press.
I hope that this makes more sense.
Mike Ramsey
“The simple argument goes like this: if low solar activity caused a dip during the MWP, then what caused the MWP itself so there was something to dip from?”
Umm, the Medieval Maximum.
Mike Ramsey (21:05:57) :
7. That 8-9% of the original total solar insolation represented by UV, X-Ray (wavelength < 300nm) accounts for ~12%
of the remaining insolation that actually heats the earth.
Whatever the percentage is, it does not heat the Earth. It heats the upper stratosphere, but not the troposphere where we live.
The troposphere is heated from below by the visual and and infrared that shines through the transparent air. Again: the troposphere is heated from below, not from above, and it doesn’t matter how much the UV varies.
Glenn (21:08:49) :
Umm, the Medieval Maximum.
Umm, the cosmic ray record shows there was a Medieval minimum in solar activity, in contrast to a Medieval maximum in temperature.
The troposphere is heated from below by the visual and and infrared that shines through the transparent air.
I said that poorly. The meaning was supposed to be:
The air is transparent to visual and infrared radiation so that shines through to be finally absorbed by ground and sea [what is not reflected back out]. The heated ground heats the air just next to it by conduction, casing the heated air to rise by convection heating the troposphere from below. It doesn’t matter how much the thermosphere and stratosphere is heated by UV as there is no way of getting that heat to the ground [hot air does not sink. but rises]. Also the heat content is very small as the density of the air decreases by a factor of a thousand for each 50 km step in altitude.
[…] puede seguir el resto de la conversación, con otros intervinientes, en este enlace. […]
Clouds.
Old Man Winter (15:36:54) :
I really think you should re-read what you have written, then you might realise how preposterous it is. You’re saying the MWP happened because the Oort minimum was not as deep as the Maunder Minimum, so if your belief is true surely ANY minimum would produce cold periods.
Kudos to Leif for being so patient and hopefully the readers will finally realise that the sun is NOT a major factor in climate change during recorded history.
@Mary:
My understanding of Leif’s position is that he is saying that he does not see any acceptable mechanism to demonstrate that the sun had a major role in historic climate change.
That does not mean that such a mechanism does not exist waiting to be discovered. As a good skeptic, I think this next solar cycle is going to upset a lot of pet theories, one way or another.
Hi Mary. If you want to quote me, then please do so fairly. I countered Dr. Svalgaard’s claim that the Oort Minimum produced no drop in temperatures, as well as his claim that it was an equally significant minimum as the Maunder Minimum. According to Svensmark, among others, the Maunder Minimum was a factor of 1.5-2 times deeper. The relatively shallow Oort Minimum did nonetheless produce a shallow dip in temps and thus disproves nothing.
The Little Ice Age was not produced by internal variations, as Dr. Svalgaard has suggested at various times. It was produced by Svensmark clouds during a series of significant solar minima, most notably Maunder.
Dr. Svalgaard,
thank you for the explanation of solar physics, this is much appreciated.
However, I don’t quite understand your statements about the terrestrial atmosphere:
If the stratosphere is heated by UV (or whatever), why can’t the “heat” get to the ground? Radiation? Interface of the stratosphere with the troposphere via the tropopause?
If “solar energy” of x[W] is introduced into the stratosphere, of what relevance to its energy balance are the other parameters (like density)?