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.
Luis Dias wrote
“Tamino posted in his blog a nice decent explanation on how a CO2 forcing combined with a noise generator formula could give you more than a decade of supposed cooling. It’s just about perception. Ten years is nothing, not because it does not bode well for warmers, but because the noise of weather makes it possible for one or even two decades go slightly down in temperature, while the big picture is clearly headed upwards.”
this is interesting:
if weather noise can cancel (or “hide”) the global warming feedback over the next 2 decades, it could have easily (at lower CO2 levels) created two decades of rising temperatures without existence of any feedback or even a small negative feedback.
So Tamino has proven that the warming in 1990-2002 cannot be assumed to be a global warming signal and a 90% confidence level is completely unfounded.
This is further confirmed by the fact, that the temperature rise has also been far below the expectations and ended in 2002.
http://www.climate-skeptic.com/2008/06/gret-moments-in.html
Niels A Nielsen (11:56:51) :
It is however my impression that no consensus has been reached as to the timing and possible global character of the Medieval Warm Period. What temperature reconstruction are you referring to and why do you believe it is valid?
Oh no, not here 🙂 But if you must, here is a starting point:
http://www.climateaudit.org/?p=3348 try google too.
But it is perhaps simpler than that. Here is the argument:
1: the Sun had a Maunder Minimum in 1650-1700 [one can quibble about the endpoints]
2: most people [not all] think there was a global Little Ice Age event at that time
3: the Sun had an Oort Minimum [we see that in cosmic rays] in 1010-1050
4: if the Sun is a major driver of climate we would expect [provided that 2 was caused by 1] a similar global ‘little ice age’ then, and yet the Vikings were thriving in Greenland and the Mann reconstruction does not how a dip during the 11th century and many others show warming [the MWP] – e.g. the one I referred you to above.
The simplest explanation is that the various solar minima have but a minor, hard to detect, effect, consistent with the latest findings that the Sun seems to vary a lot less than we thought just a few years back.
Luis,
You cannot have it both ways. You tend to buy into Hansen’s arguements but when things do not go quite to plan, you back off and temper those arguements or points.
What must be done is to sift the Alarmist’s point of view from the scientist’s point of view. Once that is done, about 90% of the AGW arguement is gone. Most of Hansen’s temperature analysis is based on a faulty, imprecise temperature network that cannot be replicated without a ton of adjustments. Even after adjustments are made, his office continues to adjust past temperatures almost monthly. Without his temperature analysis, he has no arguement. The same holds true with paleo-climatology. Once one removes the Mannomatic PCAs, the Hockey Stick is gone.
Which takes us back to the last leg of the Alarmists point of view: the GCMs. Oh, that and the artic icecap.
mr svalgaard,
it seems to me that the maunder minimum is well documented as a cool period…the medieval warm period accepted as a period of high solar activity…the last half of the 20th century temperatures appear to correlate to a “modern maximum” of greater solar activity…the recent cool down in global temperatures appear to correlate to an unusual drop in sunspot activity…taken into context that the recent temperature record is better understood than say the oort or sporer minimums, i do not understand why equal weight is given to these lesser magnitude events (cannot have it both ways) as the highest magnitude max and min of sunspots (MM, MWP)…perhaps the temperature anomilies are not as well understood during the oort or sporer minimums because of decreasing accuracy with history…it seems to me that it is tenous to place lesser magnitude events (oort, sporer) on the same scale as the MM, MWP…perhaps the temperature record is not well understood during the lesser magnitude solar min, max partly due to the lack of thermometer records during these times or recognizable global temperature signatures…secondly, why is the period before the modern maximum where temperatures have been recorded to have been rising since the late 1800’s not called something like the “svalgaard minimum” similar to say the oort minimum…tks in advance, sk
With the increasing knowledge about the poor, warm biased and constantly deteriorating quality of the land based measurement network, I find it disturbing that Hadcrut3 appears to “measure” a 0.05° C/decade higher temperature than the UAH satellite.
This sums up to 0.5°C/century and thus of the size of the total temperature increase during the last century (if pre-satellite data measurements and “corrections” can be trusted).
Leif
“The latest research seems to indicate the the Sun changes a lot less than we thought just a few years ago.”
– Ive seen many graphs of solar activity and temperatures since year 1600.
I personnaly find the match between the sun and falling temperatures (maunder minimum, dalton etc.) to be convincing.
But the suns impact is only small as you indicate, these matches should be coincidence?
K.R. Frank
“It’s just about perception. Ten years is nothing, not because it does not bode well for warmers, but because the noise of weather makes it possible for one or even two decades go slightly down in temperature, while the big picture is clearly headed upwards.”
That’s stretching it a bit, and I failed to read anything from the 2007 IPCC TAR that even remotely included an analysis of “cooling weather”. The IPCC was rather emphatic that all statistical analysis showed an obvious if not drastic upward trend in global temps since the 1970s. Now, that some have said this trend ended in 1998, one is to believe that the folks who wrote the TAR were wrong? Either we were warming or we were not. Either the editors at the IPCC were wrong or they were right. Enough of the navel gazing statistical analysis.
DAV: “Changing the length of the period changes the duty cycle.
%duty = Pon/(Pon+Poff)”
You must have misunderstood me. Poff does increase, but so does Pon, so the ratio Pon/(Pon+Poff) remains constant.
Leif,
OT, but my curiosity is getting the better of me. What is that horizontal line showing in the NH on the MDI Magnetogram?
sammy k (12:48:06) :
lesser magnitude solar min, max
The Spoerer minimum was deeper than and the Oort minimum as deep as the Maunder minimum. We know this from cosmic rays.
secondly, why is the period before the modern maximum where temperatures have been recorded to have been rising since the late 1800’s not called something like the “svalgaard minimum” similar to say the oort minimum
It is actually called the “Gleissberg Minimum”. I have suggested that the next minimum [possibly just around the corner] should be called the ‘Eddy Minimum” to honor Jack Eddy who drew attention to [and named] the Maunder Minimum. Jack confesses that he chose that name because of the nice alliteration with the two Ms.
Chris H (03:44:29) :
**Why haven’t the oceans warmed? BUT THE OCEANS HAVE WARMED:**
The graph in the site you posted is up to 2003. Until I see the 5 years 2003-2008, I will not accept that. My understanding is there has been a change.
– sorry Leif, I can see someone else asked you the exact same question 🙂
DAV: “Though “duty cycle” usually is reserved for binary states.”
I know what you mean. You can use the same terminology though, just as long as you recognize that there are differences – like the power in a square wave is twice that in a sine wave of the same peak amplitude.
Frank Lansner (12:51:16) :
I personnaly find the match between the sun and falling temperatures (maunder minimum, dalton etc.) to be convincing.
If you go back in time before 1600, the match breaks down. During the Oort Minimum 1010-1050 and the Spoerer minimum [there were actually two of these, a smaller one 1510-1535] 1425-1475 temperatures were warm [e.g. http://www.climateaudit.org/wp-content/uploads/2008/07/tornet78.gif ]
So, coincidence may be a good description, although you can always blame things on poor data and conniving scientists.
Frank Lansner (13:14:25) :
– sorry Leif, I can see someone else asked you the exact same question 🙂
Then exactly the same answer would seem to suffice…
jonk (12:59:59) :
OT, but my curiosity is getting the better of me. What is that horizontal line showing in the NH on the MDI Magnetogram?
Alien spacecraft below warp-speed. Perhaps a stray cosmic ray lighting up the pixels.
I think in general there is a problem for the thought of great feedback;
The feed back is supposed to take place via a warm-iduced rise in other greenhouse gasses, mostly water.
So if there can be any special positive feedback we should see that there is more water in the air.
But we dont.
Except for low altitudes, where water content in the atmosphear has increased slightly the last 30 years, water content has mostly gone down in the atmospheare. At least we can say that there is no more water in the atmosphere.
I believe that would make positive feedback out of the question?
Also, Methane increase in the atmosphere has stopped many years ago.
How could there be a positive feedback when there are no increase in these greenhouse gasses accompanying rise in CO2?
I guess there cannot.
I have an observation and a couple of questions. As far as I can tell, Douglass and Christy don’t account for thermohaline circulation/meridional overturning circulation signals in the North Atlantic (AMO) and North Pacific (NOT the PDO). Their effects would have contributed to the warming trend from 1979.
North Atlantic SSTs
http://i27.tinypic.com/212s789.jpg
AMO
http://i25.tinypic.com/2cffxir.jpg
North Pacific SSTs
http://i25.tinypic.com/2cyg07k.jpg
North Pacific Residual
http://i28.tinypic.com/jrwjk6.jpg
If the impacts of these two signals were considered, wouldn’t that reduce the warming from the CO2 forcing? If so, by how much?
Anthony,
Here something that may be worth a posting:
Ancient ice survived hotter Earth than today
http://www.theglobeandmail.com/servlet/story/RTGAM.20080918.wpermafrost0918/BNStory/Science/home
This post in the comments section is telling:
“T Sharpe from Toronto, Canada writes: I wish they didn’t even write about this. It’s articles like this that just propagate the idea that the world’s in better shape than the ‘experts’ tell us, and it’s only going to hasten the degredation of our world.:
I mean, I don’t want a kind of 1984 news sensorship situation, but people should be generally wary about publishing material that might give people a wrong impression… a more optimistic impression… than is needed to influence change.”
An bets that thinking like that goes throw a reviewers mind when seeing skeptical papers like the Douglass & Christy one discussed in this thread?
Bruce: “4% more sunshine per decade is a lot.”
Especially when you consider that that would be roughly equivalent to decreasing the incoming albedo by 4%, which would (according to the theory) equate to an equilibrium temperature increase of roughly 4K/decade.
Now where on earth could all that heat be hiding?
Peter (12:59:09) : You must have misunderstood me. Poff does increase, but so does Pon, so the ratio Pon/(Pon+Poff) remains constant
Peter, I tried to fix what I wrote and botched that as well. Not my day 🙁
I shouldn’t have tried to normalize. “Duty cycle” isn’t really the proper term here but I understood what Raven meant.
Average power = Total Energy/ Period Length.
Total Energy is the integral of P(t)dt so the equation is a weighted average with time as the weight.
If you lengthen the solar cycle by extending the “quiet” period, such as in the current cycle, the average over the period has to go down. By power. I don’t necessarily mean visible light. Energy transference by particles should also be counted.
It’s hard to ignore the correlation between solar cycle land climate cycle. Is it simply coincidence that the deepest part of the LIA began at the start of a very quiet sun period and both cycles ended at about the same time? Amazing coincidence in my view. It shouldn’t be summarily dismissed as mere coincidence.
@Gerald Machnee (13:10:22) :
The graph in the site you posted is up to 2003. Until I see the 5 years 2003-2008, I will not accept that. My understanding is there has been a change.
You may be thiking in … The Mystery of Global Warming’s Missing Heat.
DAV (13:46:01) :
Is it simply coincidence that the deepest part of the LIA began at the start of a very quiet sun period and both cycles ended at about the same time? Amazing coincidence in my view. It shouldn’t be summarily dismissed as mere coincidence.
It is NOT being summarily dismissed. It is dismissed for several good reasons. I have given those in another thread, and will post them here again [Anthony permitting]. First, I have already mentioned the Oort Minimum during the MWP, but here are my solar reasons:
Leif Svalgaard (16:43:03) :
setting forth several lines of inquiry and evidence:
Line 1:
The Total solar Irradiance (TSI) has several sources. The first and most important is simply the temperature in the photosphere. The hotter the sun, the higher the TSI. Some spectral lines are VERY sensitive to even minute changes in temperature. Livingston et al. has very carefully measured the line depth of such temperature-sensitive lines over more than 30 years spanning three solar cycles [Sun-as-a-Star Spectrum Variations 1974-2006, W. Livingston, L. Wallace, O. R. White, M. S. Giampapa, The Astrophysical Journal, Volume 657, Issue 2, pp. 1137-1149, 2007, DOI; 10.1086/511127]. They report [and I apologize for the somewhat technical turn my argument is taking, but if you really want to know, there is no avoiding this], “that both Ca II K and C I 5380A intensities are constant, indicating that the basal quiet atmosphere is unaffected by cycle magnetism within our observational error. A lower limit to the Ca II K central intensity atmosphere is 0.040. This possibly represents conditions as they were during the Maunder Minimum [their words, remember]. Within our capability to measure it using the C I 5380A line the global (Full Disk) and basal (Center Disk) photospheric temperature is constant over the activity cycles 21, 22, and 23″. I have known Bill Livingston [and White] for over 35 years and he is a very careful and competent observer.
Line 2:
Since the 1960 we have known that the sun’s surface oscillates up and down [with typical periods of ~5 minutes]. These oscillations are waves very much like seismic waves in the Earth [from earthquakes] and just as earthquake seismic waves can be used to probe the interior of the Earth, they can be used to probe the solar interior. There are millions of such solar waves at any given time and there are different kinds (called ‘modes’) of waves. The solar p-modes are acoustic [sound waves] normal modes. You can imagine a frequency increase with an increasing magnetic field, due to the increase in magnetic pressure raising the local speed of sound near the surface where it is cooler and where the p-modes spend most of their time. Of course one can also imagine higher frequencies may result from an induced shrinking of the sound cavity and/or an isobaric warming of the cavity. Another kind is the solar f-modes that are the eigenmodes of the sun having no radial null points [i.e. asymptotically surface waves; again I apologize for the technical mumbo-jumbo]. From the solar cycle variations of p- and f-modes [and we have now enough data from the SOHO spacecraft to make such a study] we now have an internally consistent picture of the origin of these frequency changes that implies a sun that is coolest at activity maximum when it is most irradiant. Now, how can that be? How can a cooler [overall, including the cooler sunspots, for instance, as the temperature of the non-magnetic areas of the sun didn’t change {see line 1 above}] sun radiate more? It can do that, if it is bigger!. Goode and Dziembowski (Sunshine, Earthshine and Climate Change I. Origin of, and Limits on Solar Variability, by Goode, Philip R. & Dziembowski, W. A., Journal of the Korean Astronomical Society, vol. 36, S1, pp. S75-S81, 2003) used the helioseismic data to determine the shape changes in the Sun with rising activity. They calculated the so-called shape asymmetries from the seismic data and found each coefficient was essentially zero at activity minimum and rose in precise spatial correlation with rising surface activity, as measured using Ca II K data from Big Bear Solar Observatory. From this one can conclude that there is a rising ‘corrugation’ of the solar surface due to rising activity, implying a sun, whose increased irradiance is totally due to activity induced corrugation. This interpretation has been recently observationally verified by Berger et al. (Berger, T.E., van der Voort, L., Rouppe, Loefdahl, M., Contrast analysis of Solar faculae and magnetic bright points. Astrophysical Journal, vol. 661, p.1272, 2007) using the new Swedish Solar Telescope. They have directly observed these corrugations. Goode & Dziembowski conclude that the Sun cannot have been any dimmer, on the time steps of solar evolution, than it is now at activity minimum.
Line 3:
Foukal et al. (Foukal, P., North, G., Wigley, T., A stellar view on solar variations and climate. Science, vol. 306, p. 68, 2004) point out the Sun’s web-like chromospheric magnetic network (an easily visible solar structure seen through a Ca II K filter) would have looked very different a century ago, if there had been a significant change in the magnetic field of the sun supposedly increasing TSI. However, there is a century of Mt. Wilson Solar Observatory Ca II K data which reveal that the early 20th century network is indistinguishable from that of today.
Line 4:
Svalgaard & Cliver have recently (A Floor in the Solar Wind Magnetic Field, by L. Svalgaard and E. W. Cliver, The Astrophysical Journal, vol. 661, L203�L206, 2007 June 1, 2007) shown that long-term (∼130 years) reconstruction of the interplanetary magnetic field (IMF) based on geomagnetic indices indicates that the solar wind magnetic field strength [and thus that of the sun itself, from which the IMF originates] has a ‘floor’, a baseline value in annual averages that it approaches at each 11 yr solar minimum. In the ecliptic plane at 1 AU [at the Earth], the IMF floor is ∼4.0 nT, a value substantiated by direct solar wind measurements and cosmogenic nuclei data. We identify the floor with a constant (over centuries) baseline open magnetic flux at 1 AU of 4×10^14 Weber. Solar cycle variations of the IMF strength ride on top of the floor. They point out that such a floor has implications for (1) the solar wind during grand minima: we are given a glimpse of Maunder minimum conditions at every 11 yr minimum; (2) current models of the solar wind: both source surface and MHD models are based on the assumption, invalidated by Ulysses, that the largest scale fields determine the magnitude of the IMF; consequently, these models are unable to reproduce the high-latitude observations; and (3) the use of geomagnetic input data for precursor-type predictions of the coming sunspot maximum; this common practice is rendered doubtful by the observed disconnect between solar polar field strength and heliospheric field strength [the wrong prediction by the NASA panel for cycle 23 was based on this, and the prediction {of a high cycle} by one half of panel for cycle 24 is also partly based on this]. The constancy of the IMF also has implications for the interpretation of the Galactic Cosmic Ray flux.
Line 5:
But maybe it is the Ultraviolet flux that varies and affects the stratospheric ozone concentration and thereby influences the climate. I have earlier in (Calibrating the Sunspot Number using the “Magnetic Needle”, L. Svalgaard; CAWSES News, 4(1), 6.5, 2007] pointed out that the amplitude of the diurnal variation of the geomagnetic Y-component is an excellent proxy for the F10.7 radio flux and thus also for the EUV flux (more precisely, the FUV, as the Sq current flows in the E layer). There is a weak trend in the amplitude of 10% since the 1840s that can be understood as being due to an increase of ionospheric conductance resulting from the 10% decrease of the Earth’s main field. Correcting for and removing this trend then leads to the conclusion that (as for the IMF) there seems to be a ‘floor’ in rY and hence in F10.7 and hence in the FUV flux, thus the geomagnetic evidence is that there has been no secular change in the background solar minimum EUV (FUV) flux in the past 165 years.
Line 6:
Careful analysis of the amplitude of the solar diurnal variation of the East-component of the geomagnetic field [we have accurate measurements back to the 1820s] allows us the obtain an independent measure of the FUV flux (and hence the sunspot number) back to then. The result is that the Wolf number before ~1945 should be increased by 20% and before ~1895 by another 20%. The Group Sunspot number in the 1840s is 40% too low compared to the official Wolf number. When all these adjustments are made we find that solar activity for cycles 11 and 10 were as high as for cycle 22 and 23. Thus there has been no secular increase in solar activity in the last ~165 years [a bit more precise than the 150 years I quoted earlier]. Of course, there has still been small and large cycles, but we are talking about the long-term trend here [or lack thereof].
Line 7:
Direct measurements (although beset by calibration problems) of the Total Solar Irradiance (TSI) from satellites have only been available for 30 years and indicate that solar irradiance increases with solar activity. Correlating mean annual TSI and sunspot numbers allows one to estimate the part of TSI that varies with the sunspot number. If TSI only depends linearly on the sunspot number then irradiance levels during the Maunder Minimum would be similar to the levels of current solar minima. But TSI is a delicate balance between sunspot darkening and facular brightening, and although both of these increase (in opposite directions) with increasing solar activity, it is not a given that there could not be secular variations in the relative importance of these competing effects. Several earlier reconstructions of TSI, reviewed in Froehlich, C. & J. Lean (Solar Radiative Output and its Variability; Evidence and Mechanisms, Astron..& Astrophys. Rev., 12(4), 273, 2004, Doi;10.1007/s00159-004-0024-1.[6] all postulate a source of long-term irradiance variability on centennial time scales. Each group of researchers have their own preferred additional source of changes of the ‘background’ TSI, such as evidence from geomagnetic activity, open magnetic flux, ephemeral region occurrence, umbral/penumbral ratios, and the like. The existence of ‘floors’ in IMF and FUV over ~1.6 centuries argues for a lack of secular variations of these parameters on that time scale. The six other lines of evidence discussed above suggest that the lack of such secular variation undermines the circumstantial evidence for a ‘hidden’ source of irradiance variability and that there therefore also might be a floor in TSI, such that TSI during Grand Minima would simply be that observed at current solar minima. At the recent SORCE meeting in Santa Fe [2008] Judith Lean discussed the various contributions to variations of TSI:
0.003% from 5-minute oscillations, 0.2% from solar rotation, 0.1% from 11-year solar cycle, and ended with: “longer-term variations not yet detectable – do they occur?”
I concluded that “So, if there is ’solar activity’ forcing, the sensitivity of the climate system to this must be much greater than generally assumed and understood. A simpler hypothesis is that there is no clear solar effects on the timescale of decades or centuries.”
Even the paper by Douglas and Christie conclude that solar influence explains but a fraction of the recent trend.
Leif: “4: if the Sun is a major driver of climate we would expect [provided that 2 was caused by 1] a similar global ‘little ice age’ then, and yet the Vikings were thriving in Greenland and the Mann reconstruction does not how a dip during the 11th century and many others show warming [the MWP] – e.g. the one I referred you to above.”
Could it be that the temperatures during the MWP were so high that if there was a dip caused by the OM, the temperature would still have been relatively high?
Leif Svalgaard (00:23:05) :
Figure (A1) seems to be correlation plot of smoothed values. If so, the R2 values are much to high [i.e. nonsense] as adjacent data points are not independent. This would [should!] never have passed peer-review [certainly not if I were a reviewer].
Leif,
Go back to the original data from
http://www.agu.org/journals/jd/jd0805/2007JD008864/
and look at
http://www.agu.org/journals/jd/jd0805/2007JD008864/2007jd008864-f01_enh.eps
One more point about the maunder minimum and the sun.
The only part of the solar spectrum to have significant variation
in intensity is the UV, X-Ray range (i.e., wavelength= 300nm
is reflected right back into space. The detailed shape of the plot is
vaguely parabolic with the wavelength and amplitude of the peak
varying depending on the surface (e.g. cloud, ice, ocean, desert, forest).
But a 30% figure is widely accepted as an average.
This leaves 70% of 92% =.7 * .92 = .644 = 64.4% of the total
insolation with wavelength >= 300nm that is actually absorbed and
contributes to global heating.
That 8-9% represented by UV, X-Ray (wavelength < 300nm) accounts
for ~12% of the insolation heating the earth.
The remaining 91-92% varies by only 0.1%. Lean (2000) gives a
slightly higher historical variation of about 0.3% but let us stick
with the conservative 0.1% number.
Now consider that the UV, X-Ray (wavelength =300 nm, 0.1%
Shorter wavelengths are absorbed in the earth’s upper atmosphere and
see even larger variations:
120 nm, 50%
140-200 nm, 10-15%
So I conclude that ~12% of the sun’s energy heating the earth is
being pumped directly by the solar cycle.
8% * 12% = 0.96% which is still larger than the 0.1% variation that
gets kicked around.
Mike Ramsey