New solar reconstruction paper suggests 6x greater solar forcing change than cited by the IPCC

“This implies that observational data do not allow to select and favor one of the proposed reconstructions. Therefore, until new evidence become available we are in a situation that different approaches and hypothesis yield different solar forcing values. Our result allows the climate community to evaluate the full range of present uncertainty in solar forcing.”
My! My! What an ingenious escape clause! We don’t claim our results are true because that would undermine the foundations of AGW theory. We merely did all this work to expand the band of uncertainty! We can still maintain that AGW theory is sound, but with the caveat that “the band of uncertainty” is merely expanded.
That kind of equivocation, boys and girls, is what it takes to get such a paper published these days. The fact that such a paper can see the light of day, even with said equivocation, is progress over where things stood only a couple of years ago.

Interesting. How do they justify extending the proxy for TSI into a region beyond the level which has been proposed as a stable background level on top of which the solar cycle adds modulation? I think I’m right in saying that there is no evidence yet to directly link the LIA with reduced TSI?

Claude Harvey,
I have to disagree with you. That quote was my favorite part. It means the people who put together this paper are actual scientists. Scientists who recognize the limits of their research and the possibility they can be wrong. As oppose to “scientists” who try to hide their data, or don’t want people to admit the limits of science in public as it could give those “deniers” ammunition.

Scottish Sceptic says:
May 10, 2011 at 1:12 am
Breaking news on BBC Today
0719: It has emerged that the coalition cabinet is reportedly spit over the government’s policy on climate change. Environment correspondent Roger Harrabin reports.
I think you’ll find that the dissenters want to go further.

Anthony,
Is it me or strictly using the Greenland ice core as proxy is a little ridiculous as to the proximity it is away from the rest of the planet for measuring the sun spots using a proxy?
A massive amount of atmosphere and weather conditions to be able to reach that point compared to the equatorial region.

John Finn says, May 10, 2011 at 1:40 am
the TSI trend since ~1950 is approximately zero
Indeed, but one may not forget that it costs a lot of years to warm the oceans up. Even with a constant high level of TSI, it takes about 30 years (or more) to reach a new high in seawater temperature. The fact that since about 2000 there is no increase in temperature anymore (besides ENSO variability), shows that the new equilibrium is more or less reached. The next decade will show the real impact of the sun, as we currently have a less active sun, which should translate in lower temperatures (or not)…

. . .comparable to late 20th Century
yes, if you prefer to ignore sensitivity to initial conditions or assume a straightforward, contemporaneous, purely linear climate response. Doubt it works that way.
Interesting post though. Whilst welcome, I can’t get too carried away, since reading this blog has taught me to treat proxy reconstructions with a pinch of salt.

“The main argument against solar forcing being responsible for post 1970-warming still seems valid, i.e. the TSI trend since ~1950 is approximately zero. Also (from the TSI reconstruction since 1600) would we not expect temperatures during the 18th century to be comparable to those in the late 20th century.”
It is very likely that post 1970 warming is overestimated (anthropogenic local warming).
Even if the solar forcing during the 18th century was comparable to the late 20th century, that still does not mean that the temperatures should be comparable as well. Durin the LIA we had a lot of ice buildup and when the solar forcing increased again, there was a lot of thermal inertia. A lot of heat is needed to melt the ice.
But I still think that the temperatures during ~40s were comparable to the ~80s/90s.

Should point out the item is 1 hour 20mins 30 secs.

Interesting study but although I scoured it most carefully to see if their findings could correlate with the warming over the last ten years, it actually seemed to have a negative correlation – quieter sun, more warming. So when they use the word ‘historical’ in the title of the report, they obviously do mean ‘historical’.
So as a scientifically robust counter to the IPCC argument, this is very far from doing the job.

Alistair McKechnie says:
May 10, 2011 at 3:24 am
Interesting study but although I scoured it most carefully to see if their findings could correlate with the warming over the last ten years,
What warming over the last 10 years?

Alistair McKechnie
I suggest you don’t use the word ‘robust’ on this site if you want to avoid ridicule.
However, judging by the rest of your comment that aim does not appear to be high on your list of priorities.
It never ceases to amaze me that CO2 is given every possible route and timeframe by which warming could show itself. Solar influence on the other hand . . . apparently that has to be both immediate and without any complexity attached.

John Finn,
“The main argument against solar forcing being responsible for post 1970-warming still seems valid, i.e. the TSI trend since ~1950 is approximately zero. ”
Keep in mind that solar activity was still at this unusually high plateau for the latter half of the century, and there is a mid-century cooling that is a problem for the CO2 hypothesis as well. Model diagnostics show that models disagreeing with each other on sensititivity ranging from 2C to 6C can all “match” the observed 20th century climate, because of the uncertainty in aerosols, that same uncertainty in aerosols can aid solar forcing in explaining the mid-century cooling and rapid temperature increases in the 1980s and 90s.

thingadonta,
“Yeah ,but the AGW crowd have a get out of jail free card. They say that if the climate is very sensitive with regards to the sun, it must be very sensitive for everything else as well, so the C02 greenhouse effect increases even more if the sun’s effects are larger”
On the contrary, this result works against that “get out of jail free card. We have no model independent estimates of climate sensitivity to CO2 forcing in the current climate regime, so the best model independent attempts have used estimates of the sensitivity to variation in solar and aerosol forcing. Because the estimates of solar variability were low, the required sensitivities solar forcing to explain the medieval warm period and the little ice age had to be correspondingly higher, and based on an invalid assumption of equivilence justified higher sensitivities to CO2. Sensitivity to solar was often in the 2 to 3 degrees C range. A result of higher solar variability like this report, removes one of the model independent justifications for a higher sensitivity, because it is no longer needed for solar. The geographical, vertical and chemical couplings to the climate (including the oceans of course) are quite different for solar and CO2, and the assumption of equivalence in a nonlinear dynamic system was never justified.

The sun has risen and the British policy cock crows.
=============

Peter Taylor says:
May 10, 2011 at 3:20 am
I agree.
The main residual factor to be resolved is the correct mechanism for the cloudcover changes.
Svensmark’s cosmic ray effect is certainly a possibility and well thought of by many but I find it implausible for various reasons.
I prefer the idea that more clouds globally result primarily from more air mass mixing from longer air mass boundaries when the jets shift equatorward or become more meridional.
If the solar variations can drive that (and as explained elsewhere I think they can) then we have a suitable amplification mechanism explaining the large energy budget effect from small solar changes.
The cosmic ray changes could just be a coincidental separate effect from reduced solar activity.

In the face of the tremendous energy available in Earth’s coupled oceanic/atmospheric natural oscillating variations, as it spins and tilts on its axis, I am unimpressed with the Sun’s relatively tiny changes in available energy to out perform our own Earth. IMHO, the Sun, and dare I say anthropogenic CO2, remain distant cousins in the major Earthly drivers of temperature change.

Mike Jonas says:
May 10, 2011 at 6:20 am
“They assume that the solar activity indicated by the 10Be records, and which relates to temperature changes, can be interpreted and evaluated as TSI. ie, the assumption is that the temperature changes were caused by direct solar forcing. Hence the TSI variations must have been x times greater than previously thought.”
I don’t think they have been as simplistic as that:
“Fig. 4 presents a reconstruction of the integrated
flux for several, selected spectral regions. The contrast between
different brightness components of the quiet Sun is especially
high in the UV, which results in a large historical variability of
the UV spectral irradiance. The irradiance in the Schumann-
Runge bands and Herzberg continuum increases from the
Maunder minimum to the present by about 26.6% and 10.9%
respectively, which is much larger than 0.4% for TSI and the
visible region. The variability is also relatively high around the
CN violet system whose strength is very sensitive to even small
temperature differences due to the high value of the dissociation
potential. The large UV variability reported here is especially
of importance to the climate community because it influences
climate via an indirect, non-linearly amplified forcing.”
Thus they seem to be recognising the wavelength variations as a greater contributor to climate forcing than the absolute level of TSI.
My judgement is that those variations alter the vertical temperature profile of the atmosphere to alter surface pressure distribution and cloudiness.
Thus when the sun was more active during the late 20th century the entire atmosphere did not respond in the same way to the solar forcing.
Instead the thermosphere and troposphere warmed but the stratosphere and mesosphere cooled.
Now with a quieter sun the thermosphere has cooled, the troposphere has stopped warming and the stratosphere and mesosphere appear to have stopped cooling.

Is it just my eyes or do the cyan lines end at 1970? Is this “Hide the decline – Part II”?

Alan D McIntire says:
May 10, 2011 at 6:15 am
Another reply to John Finn:
I put a pot on the stove, pour soup in the pot, turn the stove burner up to warm and leave it there- there’s no change in burner level over a period of time, yet my soup still warms. Evedently you’ve never warmed soup in a pot.
Evidently you aren’t aware that there was strong warming in the early 20th century. In other there words there was little or no lag. There was also supposedly cooling in the early 19th century after high solar activity during the 18th century – agin no lag is evident.
You need to make up your mind – is there a lag or isn’t there? If there is then the past solar/climate correlation would be less obvious.

“You need to make up your mind – is there a lag or isn’t there? If there is then the past solar/climate correlation would be less obvious.”
There seems to be little lag in the effect on albedo but it then takes a while for the effect of increased or decreased sunlight into the surface waters to become apparent over and above the interannual ENSO cycle and the multidecadal so called PDO cycle.
And there may well be longer low frequency oceanic cycles involving the thermohaline circulation.
So in effect the lag is variable as a result of other internal system features involving primarily the oceans sometimes supplementing and sometimes offsetting the solar effects.
So it is common sense that there will be variable lags due to an ever changing interplay between sun and oceans.
During the early and late 20th century the periods of high solar activity were by and large at the same time as the positive PDO so there was little or no lag in the air.
However in the mid 20th century the warming effect of the high level of solar activity from cycles 18 and 19 was partly offset and when sightly weaker cycle 20 came along the combination with a negative PDO gave a slight cooling.
Since 2000 the sun has been getting quieter and global albedo changed pretty promptly but the residual ocean heat content from the late 20th century is taking a while to dissipate. Nearly gone now though.

vukcevic, I certainly wouldn’t call 10Be “useless”, but I appreciate your caution about misinterpretation. I encourage you to acknowledge that wind drives your pet ocean currents.

Leif Svalgaard,
“John, you miss the point: there is a variable lag to match the record as the believer sees fit.”
Sometimes this impression should be attributed to complexity rather than bias, or lack of intellectual integrity. There are “lags” at several levels in the climate system. The coolest night time temperatures are often not reached until just before sunrise. The climate response to the solar cycle lags a year or over two years, per Lean, et al, and Camp and Tung. The climate commitment studies of Meehl, et al, and Wigley, et al. show that the mixing layer of the ocean achieves most of its response in the first one to three decades, but the deeper ocean was still responding after a millenia. See level rose most rapidly for centuries after the end of the ice age. There are other well documented lags in the earth system. isostatic rebound from the melting of the ice sheets is still occurring.
Can a solar maximum really be ruled out as a contributer to the warmest temperatures seen since the Medieval Warm Period, because of a plateau in activity reached as the a period of mid-century cooling occurred? Or could the climate response to the maximum have been delayed by more than just the thermal capacity of mixing layer of the ocean, something like the same uncertainty in aerosol forcing that allows models with sensitivities as disparate as 2 and 6 degrees C to “match” the recent warming and mid-century cooling. Even a solar maximum can be frustrated by aerosols. The CO2 hypothesis can’t get by without considerable help from aerosols, that is why the IPCC was so careful to group and evaluate natural and anthropogenic forcings separately. Classify aerosols with solar and CO2 starts looking small. Could that be selection bias?

John Finn,
“Look at the top RH graph in Fig 1 above. Where was the lag in ~1900? Surface temperature records show a strong warming (and pause) at the same time as the increase in solar activity. What about the Dalton Minimum? The Maunder Minimum which ended in ~1715? What about solar activity in the 18th century?”
Figure 1 does not have temparature. I think you misunderstand the nature of the lag. The land temperatures respond pretty quickly, it is the ocean state that lags. Coming out of a relatively prolonged cool period like the little ice age, the over all ocean heat content will be less than it would be after a short term excursion to the same temperature. Therefore if a variable warming forcing plateaus, the ocean will still be gradually getting warmer. This happened after the great ice sheets melted, the thermal expansion of the oceans continued for thousands of years because the oceans had been in such a deeply cold state. If a warming forcing dips but still is above the equilibrium state of the ocean and the ocean will keep on absorbing heat. The temperature dip may be deeper than it would have been with a warmer ocean, and if after the dip, the forcing reaches its previous level of forcing, the temperature may be higher due to the warmer ocean. Coming into the solar plateau at the midcentury cooling, the temperature should have continued noticably upward for a decade or so, and the mixing layer of the oceans should have continued heat uptake for a couple more decades beyond that. If the plateau in forcing continued, while the temperature effections would have been minimal, the thermal expansion of the oceans would have continued for centuries. But the climate system, of which the ocean is the major part, never reaches equilibrium because the climate is always changing. Once the mid-century cooling (which wasn’t caused by CO2 BTW), was over still high solar activity could once again resume bring the ocean up in temperature.
“I do think it’s possible that changes in solar activity cause a shift in weather patterns which give an apparent relationship, but assumptions about past climate have been heavily biased by observations in Europe and North America.”
Yes that is where most of the observations have been, but the trend in the science is to find more confirmation that these were global events.

Stephen Wilde wrote:
“The thing is that solar changes seem to alter the surface pressure distribution which has a large effect regionally but conceivably a small effect globally until much later due to the global effect of the oceanic lag times.
So the effect of solar changes on the air circulation and albedo is virtually instant and has a regional effect straight away. The global temperature change is subject to variable oceanic lag effects and only becomes apparent much later. After all, the immediate air circulation effects just send as much energy poleward as equatorward so it’s primarily just a redistribution. Hence the increase in both hot and cold periods especially in the mid latitudes. The global consequence has to await the subsequent manifestation of the increase or decrease of solar energy into the oceans.”
THERE’S NO LAG.

Paul Vaughan says:
May 11, 2011 at 7:11 am
“THERE’S NO LAG.”
The idea that there are no lags within the system seems bizarre to me when we need to consider ENSO, PDO and the Thermohaline circulation all of which alter the rate at which solar energy that has entered the oceans is then released back to the air.
One could say that that is not a true ‘lag’ being merely a product of internal system variability but it amounts to much the same thing.
Given that air circulation shifts have a rapid effect regionally but only a much later effect globally it seems to me that the surface temperature datasets are only a guide to the current energy distribution at the surface and no guide at all to the temperature of the entire system.
We need satellites for the latter.
Effectively the surface temperature datasets and the satellite datasets are measuring entirely different phenomena.
Quite a lot of rethinking should follow on from that.

Another IPCC assumption bites the dust.

vukcevic – appears we’ve had a misunderstanding. I agree with your call for cautious interpretation of 10Be – i.e. maybe it just doesn’t represent what many think — but nonetheless it might represent something else — perhaps something even more interesting… Cheers!
–
Stephen Wilde – diplomatic response – well done. I’ll elaborate soon at a preliminary level, but of course the discussion will carry on for months or years. Thanks for your interesting notes. We should be asking around to figure out what existing datasets might represent the variable loopiness you describe. If no such summaries exist, they could be devised. Fractal dimension would be one candidate; perimeter/area ratios another; etc. I have some related ideas to pursue on semi-annual LOD’… Thanks again.

New paper by physicist Denis Rancourt on some of these matters, titled: “Radiation physics constraints on global warming”
http://climateguy.blogspot.com/2011/05/radiation-physics-constraints-on-global_12.html
A few excerpts:
The abstract begins:
“I describe the basic physics of planetary radiation balance and surface temperature, in the simplest and most robust terms possible that capture the essential ingredients of planetary greenhouse warming.” […]
And the abstract ends:
[…] “Earth’s radiative balance determining its surface temperature is shown to be two orders of magnitude more sensitive to solar irradiance and to planetary albedo and emissivity than to the atmospheric greenhouse effect from CO2. All the model predictions robustly follow from the starting assumptions without any need for elaborate global circulation models. A recent critique of the dominant climate change science narrative is evaluated in the light of our model.”
Paper begins:
“Let us start by building the simplest possible model of planetary radiation balance, realistic enough to capture the essential global average features.”
“We take the planet to be a perfect sphere with a smooth and homogeneous surface and to have a thin (compared to the planet radius) and homogeneous atmosphere. The planet is uniformly irradiated by a distant sun.”
[…]
And paper ends:
[…]
The above sensitivity results corroborate these statements in my recent critique [20]:
“There are three main problems with this amplification hypothesis [positive water vapour feedback]. First, there is no empirical support or experimental verification for it. Global average atmospheric water vapour concentration is impossible to measure because water constantly changes phase (vapour, liquid, ice) and is distributed inhomogeneously (vapour, rain, snow, clouds, fog, surface condensation/sublimation/vaporisation, etc.).
Second, there are innumerable hypothetical mechanisms whereby any feedback between CO2 and water vapour could be negative rather than positive and no practical way to evaluate most of these possible mechanisms. For example, just to name one, an increase in CO2 could change the plant ecology in such a way as to reduce evaporation from plants. One could sit and invent hundreds of such plausible scenarios (all equally irrelevant with respect to global climate).
Thirdly, it is likely that there are other negative (or positive?) also negligible climate feedbacks with CO2 that do not depend on coupling with water vapour. CO2 can be a growth limiting plant nutrient such that its impact on albedo might produce greater climate leverage than any greenhouse effect gas coupling could ever achieve?
In summary, as I showed in 2007 [2]: “There is of course much more wrong with state-of-the-art global circulation models (climate models) than the assumption and implementation of CO2-H2O feedback. Although these models are among the most elaborate predictive models of complex non-linear phenomena, they are nonetheless sweeping oversimplifications of the global climate system and its mechanistic intricacies.”
Overall, therefore, there is no established reason to believe that CO2 could be a climate driver and many reasons to conclude that, although CO2 may often follow or correlate with climate indicators [2], climate drivers are related to solar irradiance and albedo and have nothing to do with CO2.”

@Joe Lalonde,vukcevic,Stephen Wilde
It seems to me that they used different 10Be data sources to go back to the Maunder minimum, and only Greenland to go back further. From the article,
“Three different datasets of the 10Be data were used: measurements at DYE 3,
Greenland, and the South Pole provided by McCracken et al.
(2004) for the reconstruction back to the Maunder minimum,
and measurements from the Greenland Ice core Project provided
by Vonmoos et al. (2006) for the reconstruction back to 7300
BC.” and “Prior to 1952 the composites are based on
10Be data (cyan based on DYE 3, and red on South Pole records,
bothwith 22-year resolution).”