Long debate ended over cause, demise of ice ages – solar and earth wobble – CO2 not main driver

From an Oregon State University Media Release (h/t to Leif Svalgaard)

Long debate ended over cause, demise of ice ages – may also help predict future

The above image shows how much the Earth’s orbit can vary in shape.

This process in a slow one, taking roughly 100,000 to cycle.

(Credit: Texas A&M University note: illustration is not to scale)

CORVALLIS, Ore. – A team of researchers says it has largely put to rest a long debate on the underlying mechanism that has caused periodic ice ages on Earth for the past 2.5 million years – they are ultimately linked to slight shifts in solar radiation caused by predictable changes in Earth’s rotation and axis.

In a publication to be released Friday in the journal Science, researchers from Oregon State University and other institutions conclude that the known wobbles in Earth’s rotation caused global ice levels to reach their peak about 26,000 years ago, stabilize for 7,000 years and then begin melting 19,000 years ago, eventually bringing to an end the last ice age.

The melting was first caused by more solar radiation, not changes in carbon dioxide levels or ocean temperatures, as some scientists have suggested in recent years.

“Solar radiation was the trigger that started the ice melting, that’s now pretty certain,” said Peter Clark, a professor of geosciences at OSU. “There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”

The findings are important, the scientists said, because they will give researchers a more precise understanding of how ice sheets melt in response to radiative forcing mechanisms. And even though the changes that occurred 19,000 years ago were due to increased solar radiation, that amount of heating can be translated into what is expected from current increases in greenhouse gas levels, and help scientists more accurately project how Earth’s existing ice sheets will react in the future.

“We now know with much more certainty how ancient ice sheets responded to solar radiation, and that will be very useful in better understanding what the future holds,” Clark said. “It’s good to get this pinned down.”

The researchers used an analysis of 6,000 dates and locations of ice sheets to define, with a high level of accuracy, when they started to melt. In doing this, they confirmed a theory that was first developed more than 50 years ago that pointed to small but definable changes in Earth’s rotation as the trigger for ice ages.

“We can calculate changes in the Earth’s axis and rotation that go back 50 million years,” Clark said. “These are caused primarily by the gravitational influences of the larger planets, such as Jupiter and Saturn, which pull and tug on the Earth in slightly different ways over periods of thousands of years.”

That, in turn, can change the Earth’s axis – the way it tilts towards the sun – about two degrees over long periods of time, which changes the way sunlight strikes the planet. And those small shifts in solar radiation were all it took to cause multiple ice ages during about the past 2.5 million years on Earth, which reach their extremes every 100,000 years or so.

Sometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age – unless some other forces stop or slow it. But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.

“One of the biggest concerns right now is how the Greenland and Antarctic ice sheets will respond to global warming and contribute to sea level rise,” Clark said. “This study will help us better understand that process, and improve the validity of our models.”

The research was done in collaboration with scientists from the Geological Survey of Canada, University of Wisconsin, Stockholm University, Harvard University, the U.S. Geological Survey and University of Ulster. It was supported by the National Science Foundation and other agencies.

UPDATE: Science now has the paper online, which is behind a paywall. The abstract is open though and can be read below:

Science 7 August 2009:

Vol. 325. no. 5941, pp. 710 – 714

DOI: 10.1126/science.1172873

Research Articles

The Last Glacial Maximum

Peter U. Clark,1,* Arthur S. Dyke,2 Jeremy D. Shakun,1 Anders E. Carlson,3 Jorie Clark,1 Barbara Wohlfarth,4 Jerry X. Mitrovica,5 Steven W. Hostetler,6 A. Marshall McCabe7

We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ~14.5 ka.

1 Department of Geosciences, Oregon State University, Corvallis, OR 97331, USA.

2 Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada.

3 Department of Geology and Geophysics, University of Wisconsin, Madison, WI 53706, USA.

4 Department of Geology and Geochemistry, Stockholm University, SE-10691, Stockholm, Sweden.

5 Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA.

6 U.S. Geological Survey, Department of Geosciences, Oregon State University, Corvallis, OR 97331, USA.

7 School of Environmental Science, University of Ulster, Coleraine, County Londonderry, BT52 1SA, UK.

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hunter
August 6, 2009 6:15 pm

Can we seek a rational energy and enviro policy yet?
No, didn’t think so.

d
August 6, 2009 6:27 pm

If it is certain that the earths orbit causes ice ages, then it must stand to reason that the opposite is true that is when the orbit is near or around its least elipical path warming will occur. ie who cares what the co2 levels are!

Fish Man
August 6, 2009 6:34 pm

So how do the changes in total solar radiation incident on earth as a result of these orbital shifts compare to the change in solar radiation caused by the observed waxing and waning of sunspot cycles (which I believe I’ve read here to be about 0.1% difference from sunspot cycle trough to crest)?
The commentary on the blogs suggests that the sunspot cycle effect (0.1% variation in solar radiation) is not large enough to cause major climate fluctuations without a secondary effect – such as the hypothesized increase in cosmic rays interacting with the atmosphere to increase cloudiness and cause cooling. So is the Milankovitch cycle effect (____%variation in solar radiation) much larger? Is that why it can cause ice ages? Does the size of that effect suggest that it is or is not enough to overcome the CO2 forcing thought to be central to AGW?

Cathy
August 6, 2009 6:34 pm

Well knock me over with a graviton.
C02. Our new best friend.

Joe Black
August 6, 2009 6:37 pm

I’m glad that the Science is finally settled.

Chris F
August 6, 2009 6:38 pm

Cooling is of much more concern than any possible warming.

David P
August 6, 2009 6:42 pm

“…and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
This is an odd statement, if I’m reading it correctly. What “greenhouse has emissions” from 200 yrs ago can he possibly be alluding to? Isn’t the consensus that there could be no AGW effect from GHGs until after WWII?

tobyglyn
August 6, 2009 6:42 pm

“due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
They still have the blinkers on. [sigh]

August 6, 2009 6:44 pm

That’s precisely what I said in my article on Continents Flooded… (red to purple angry face).

Jimmy Haigh
August 6, 2009 6:47 pm

“…these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
So Clark is saying that, in spite of what has happened over geological time, what has happened over the last 200 years is our fault?

mkurbo
August 6, 2009 6:49 pm

The natural cycle deniers are dead in the back seat…
Leave the gun, take the cannoli !

MattN
August 6, 2009 6:54 pm

“There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”
“They” will take that as complete and total victory….

Tim Groves
August 6, 2009 6:55 pm

So Milankovitch was right after all and all those years of labourious manual calculation were not in vain!
“Long debate ednded” seems pretty final. Somehow I doubt that we’ve seen the last word yet. But I would like to hear more about the details of this latest research in language a layman can understand.

Charles Garner
August 6, 2009 6:56 pm

Interesting that it wasn’t CO2 then, but it is now, and over the last 200 years, at that. Wasn’t it a bit chilly til about 1850 or so?

TJA
August 6, 2009 7:01 pm

Cathy is right, another interpretation of what Clark is saying is that absent increased CO2, Canada would be uninhabitable right now. The LIA might have just become a BIA.
The IPCC is claiming that the current interglacial will last 50k more years, even without the CO2 increase. I wonder if this is the “consensus” of scientists who have studied Milankovich cylcles?

Jeremy
August 6, 2009 7:08 pm

When I studied atmospheric physics in graduate school, thirty years ago, this theory about ice ages and planetary cycles was generally well accepted (based purely on OBSERVED MEASURED DATA rather than computer models). Despite the knowledge that CO2 was a “greenhouse gas”, CO2 greenhouse effect was generally regarded as an amusing neat idea that was only suited to high school physics because it was such an oversimplified way to describe such a complex system as the atmosphere – i.e. nobody back then was silly enough to believe computer models more than OBSERVED DATA.
How the world of science has changed – now we COMPLETELY Ignore observations!

Robert
August 6, 2009 7:15 pm

For those of us with gray hair, is this not what we learned in earth science class in high school in the 70s?

August 6, 2009 7:17 pm

Fish Man (18:34:37) :
So how do the changes in total solar radiation incident on earth as a result of these orbital shifts compare to the change in solar radiation caused by the observed waxing and waning of sunspot cycles
It is unfortunate that the article uses the word ‘radiation’ in a way that makes it ambiguous as to what it means. It means here the radiation we receive at the Earth [at the ‘top of the atmosphere’] which is not the same as what the Sun puts out [even measured at the same average distance from the Sun as the Earth has]. The Sun’s output varies only by about 1 W/m2 over the cycle, but because of the changing distance through the year [we are closest in January], what we receive varies by 90 W/m2 [almost a hundred times more].
Of course, the article ends with the mandatory statement that man is responsible for the recent [rapid] change.

August 6, 2009 7:19 pm

The orbital cycles do not change the total amount of radiation hitting the earth just the time and locations of peak radiation. The peak effects are around 4 percent for a given location so much stronger than sunspots but localized. 4 percent was for the northern hemisphere summer minimum 115,000 years ago versus the 1950 value at a latitude of 60° N

theBuckWheat
August 6, 2009 7:19 pm

Their conclusion is more along the lines of “yes, but”. Yes, if the several previously repeated pattern holds true we are about at the end of the warm part of the cycle, and yes that means we could start really getting cold, so cold that humanity would face a crisis that will perturb the world unlike any previous one, yes but, yes but global warming may have delayed it, although we really can’t say how much.

Mick
August 6, 2009 7:21 pm

Please correct me, but are we obsessed to look temperature benchmark to suit us, humans? Hockey-stick is dramatic because it referenced to an arbitrary number to magnify the effect.
The 0.1% TSI variation is bugger all to explain 0.5C referenced @20deg.C
But if we reference to 300K the delta TSI 0.1% and the orbit variation can explain that.
Perhaps Leif can explain what is wrong with that?

RoyFOMR
August 6, 2009 7:21 pm

OT but just had to share this. Just been watching BBC 24 – Hardtalk with Roger Harrabin interviewing the outgoing director of GreenPeace about Climate Change. I’d temporarily misplaced the remote control otherwise I’d have switched the TV off – so glad that I didn’t!
To my suprised delight the BBC interviewer took an entirely different approach from that which I’d expected and laid into “Mr Green” with aggressive gusto!
First he attacked the anti-democratic and over-alarmist stance taken by Greenpeace – he was particularl virulent with the Catastrophic Alarmism used by their propogandist wings!
He then made the claim that Greenpeace was itself tainted with the badge of “Denialism” just as much as the sceptics were. He poo-poohed the idea trumpeted in June by GP that the Greenland Ice Sheets would be gone by 2030 or so – this is unscientific and ridiculous he said- the GP director who by now seemed shell-shocked conceded that he thought it unlikely but was not responsible for all the press releases of his organisation.
Mr Harrabin finally brought up the subject of Nuclear Power and forced the confession from, by now, visibly sweating interviewee that – Nuclear was and in spite of 20 plus years of reassessment still not on the agenda of acceptability.
Roger Harrabin – Don’t agree with you all the time mate- but this was the BBC that I once respected. A glimpse of the future. God, I hope so!

BernardP
August 6, 2009 7:30 pm

You have to read until the last 3 paragreaphs. There, despite his own findings, Mr. Peter Clark kneels in front of the God of Manmade Global Warming.

agesilaus
August 6, 2009 7:32 pm

The surprise is that Science is publishing it, they seem to have been in the same warmist group as Nature.

Jimmy Haigh
August 6, 2009 7:36 pm

RoyFOMR (19:21:28) :
Are you sure it was Harrabin doing the interviewing? I’ve just watched Steven Sacur interviewing the outgoing Green peace guy on Hardtalk… He did give him a hard time though – I agree – is the BBC at last changing it’s tune? Like you – I hope so. The BBC used to make me proud to be British…

Jimmy Haigh
August 6, 2009 7:38 pm

Jimmy Haigh (18:47:46) :
“But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
I’ve worked it out now – it’s the money shot.
What he is saying is: “Can I have some more funding please?”

timetochooseagain
August 6, 2009 7:41 pm

So they are now informing us that Milankovitch was always right, after all? Did anyone ever actually doubt that? Well, I hardly think that they have rendered the “debate over”-it still is difficult to understand how exactly those orbital changes influence climate-in particular why changes in solar insolation in the North Hemisphere summer would be connected to climate all the way down in Antarctica. Of course we may some day understand these variations and how the work more precisely, but I doubt these guys have it figured.

August 6, 2009 7:44 pm

Nasif Nahle (18:44:07) :
That’s precisely what I said in my article on Continents Flooded… (red to purple angry face).

Well, not exactly; I didn’t say this…
…and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.
…because it’s not true. However, they had to twist their conclusions for their paper was “peer reviewed” and published.

Gary Pearse
August 6, 2009 7:45 pm

“due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
This appears to have been a clipping fallen out of another paper. I’ve noticed the odd fact recently with the tide turning on AGW that papers presenting new evidence for alternative mechanisms to CO2 causing significant climate change have a token, respectful, non sequitur or half-step back or genuflection to the Holy Synod of Gaia. Perhaps this is what one must do these days in academia to get published, to get by the peerage on the subject of Climate Change. Look for these awkward implants or scholarly tumors in future timorous papers that go against AGW alchemy. Maybe we can make a collection for the Smithsonian or some such keeper of artifacts.

Gary
August 6, 2009 7:47 pm

Science pretty much settled this 30+ years ago with http://osec.rutgers.edu/ebme/HistoryEarthSystems/HistEarthSystems_Fall2008/Week12a/Hays_et_al_Science_1976.pdf
Perhaps the detour along the scenic route is almost back to the main road.

Geoff Sherrington
August 6, 2009 7:48 pm

Fundamental geometry and physics equations relate a temperature change to distance from the sun. That is obvious. It is not so obvious how to calculate the irregular orbit of the earth around the sun.
Here’s a small competition. How far into the future can we calculate earth’s solar orbit with adequate accuracy to chart future “global temperature changes” of +/- one tenth of a deg C accuracy? I’ll start the ball rolling with a guesstimate of 500 years.
Now hindcast that.

Peter Jones
August 6, 2009 7:52 pm

Even though,
” Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age . . .”
They still say that,
“One of the biggest concerns right now is how the Greenland and Antarctic ice sheets will respond to global warming and contribute to sea level rise . . . ”
You can certainly tell where their funding is coming from. The headline should be, if you believe that GHG has contributed primarily to the warming observed: MAN-MADE GLOBAL WARMING WILL DELAY START OF NEXT ICE AGE!!!
It is clear, the equilibrium condition for our world in the last several million years is iceage conditions. We won’t truly know what will tip us into a new ice age until it happens. However, once we do see another ice age start, I bet we can create a computer model that will predict it in hindsight.

August 6, 2009 7:54 pm

Mick (19:21:24) :
The 0.1% TSI variation is bugger all to explain 0.5C referenced @20deg.C
The 0.1% TSI explains only about 0.05-0.1C.
The 50 times larger Milankovich effect explains 2.5-5 degrees, which applied in the right regions [Land, Northern Hemisphere] is enough to explain the glaciations.

August 6, 2009 7:56 pm

Geoff Sherrington (19:48:29) :
It is not so obvious how to calculate the irregular orbit of the earth around the sun.
That is actually even more obvious. I think the consensus is that we can do this accurately [enough for this purpose] for some millions of years.

August 6, 2009 7:58 pm

This article completely disregards Occam’s Razor: “Never increase, beyond what is necessary, the number of entities required to explain anything.”
~William of Ockham, 1285-1349
Gratuitously throwing in an unnecessary entity — carbon dioxide — is simple rent-seeking behavior by these researchers, who will no doubt attempt to leverage their paper into a financial grant. [Mentioning CO2 certainly got them published in Science, didn’t it?]
In place of CO2 they could have just as well have mentioned undersea volcanic eruptions, or varying albedo. All three are equally rank speculation.
Had they not added an unnecessary entity — the cause du jour [the ee-e-vil minor trace gas CO2] — their paper would have come to exactly the same conclusions, and it would have the added benefit of credibility.
[Cathy (18:34:39),
You might have been knocked over by Mr Higgs’ boson. But so far, they haven’t apprehended the culprit.]

Mike Abbott
August 6, 2009 8:02 pm

I see nothing in this research that contradicts AGW theory. The researchers propose a mechanism for the cause of 100,000-year ice age cycles. AGW theory predicts catastrophe within 100 years. If the alarmists are right, the Greenland and Antarctic ice sheets will have melted and flooded much of the world before the next ice age gets out of the starting gate. There is much evidence against AGW theory, but none is provided by this new research.

John Costello
August 6, 2009 8:02 pm

Back in the bad old days of the Soviet evil Empire scientists in most disciplines had to bend the knee to Marxism. It was often qutie amusing. They would spend the first few paragraphs declaring their allegiance to Karl and Vlad (and the Great Teacher of Humanity Joseph Stalin) and then go on to describe their research in paleontology, math, archaeology, etc., which had absoluteoy nothing to do with Marxism. Some fields suffered more than most: archaeologists had to create a new “culture” in 4th century Ukraine to replace the Ostrogothic state, and Russian SF was denied Einstinian time dilation because Lenin didn’t like it. Something similar seems to be happening here, in as much as Science or Nature will not publish “deniers” and yoiu can’t get NSF funding (and thus tenure) if you are on the outs with the Goracle.

page48
August 6, 2009 8:16 pm

Am I crazy? I thought I learned this years ago.

Lance
August 6, 2009 8:18 pm

Say it isn’t so, a wobble, a shift? But we were told it was CO2 by the Goracle and other high priests….
sarc off…
it shows that actually many factors influence climate, and why we get hung up on co2 blows me away…

Craigo
August 6, 2009 8:25 pm

“and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
Loosely translated from climatespeak this means the equivalent of “Dad – I am working hard at university – please send more money”
But seriously, this sounds like a throw away line from a media release that may come back to haunt him or may have been an attempt to avoid antagonising the believers and/or holders of the purse strings.

Elizabeth
August 6, 2009 8:29 pm

Careful, alarmists wanting to cool the planet are going to be looking for a way to jolt the earth’s wobble back…

Mark
August 6, 2009 8:35 pm

I’ve got a problem with this statement:
“the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
CO2 levels 200 years ago were about 280 ppm which is around the levels they’ve been since at least 1000 AD.
And “ordinarily might’ gives a lot of wiggle room.

Jim Powell
August 6, 2009 8:41 pm

Richard Muller outlines several problems in the first chapter of his book “Ice Ages and Astronomical Causes. http://muller.lbl.gov/pages/IceAgeBook/IceAgeTheories.html
Has this paper addressed these problems sufficiently? He also places the date of the end of the last ice age at 10-14,000 years ago. I have a problem with placing the date at 10,000. The GISP2 Ice Core records show 14,548 and 10,276 at approximately the same temperature. Younger Dryas period was most likely caused by a comet impact. The duration of this interglacial period is closer to 14,000 BP than 10,000 BP. Was 10,000 adopted to make global warming a more imamate danger?

Evan Jones
Editor
August 6, 2009 8:42 pm

Some say the world will end in Eccentricity
Some say in Obliquity
But many of my generation
Tend to favor Inclination
So we are left to wonder when
Until our earth returns through dust
And will again
As so it must

RoyFOMR
August 6, 2009 8:43 pm

Jimmy Haigh (19:36:39) :
You may be right Jimmy, I was only going by what I saw on the animated blurb prior to the program coming on. The name Roger Harrabin was repeated many times but as I was scrabbling for the remote I could well have been mistaken as to the messenger!
But not the message- that was the old BBC – the one we both grew up with AND loved!
Whoever he was, I respect him.

anna v
August 6, 2009 8:44 pm

But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.
Well, mr. Clark, as others already observed recorded warming that might be attributed to CO2 took place only in the last part of those 200 years. In addition, CO2 influence is so puny, it cannot even push against the PDO, as the measured global temperatures are decreasing the past ten years.
I wonder what trust can one have on the rest of your scientific conclusions, when you are so wrong on the obvious recent conclusions from recent measurements.
Zero?
To all: we have to be hard on these people that add those warming mantras to get their grants. They should be made aware they are prostituting themselves and their science.

Patrick K
August 6, 2009 8:44 pm

None of this information is really new. However, I have to complain about the graphic and the caption attached to it. Both of the ellipses shown are extremely exaggerated and neither is anywhere close to the actual ellipticallity of the Earth’s actual orbit which ranges from an almost perfect circle to only slightly elliptical. Even at it’s most extreme elliptical orbit, the earth’s orbit is very close to a perfect circle (A perfect circle is e=1, the Earth’s most extreme orbit is e=0.97). In fact it is so close that a human cannot usually distinguish it from a circle.
In the HS Earth Science classes I teach, I am constantly having to counter these poor graphics that are in every astronomy/ES textbook or website. They just reinforce the common misconceptions that people have about astronomy. Please either fix the graphic or at least reword the caption to something along the lines of: “The Earth’s orbit can vary in ellipticallity in a cycle of approximately 100,000 years. (The ellipses shown above are both highly exaggerated.)” TAMU should be ashamed for having that graphic up at all.

par5
August 6, 2009 8:49 pm

What about the precession of the equinox’s? I was taught back in the ’70s about ice ages and the THREE things that caused them…1) Orbit 2) Tilt 3) Precession

Chris V.
August 6, 2009 8:50 pm

page48 (20:16:26) :
Am I crazy? I thought I learned this years ago.

You’re not, and you did.
Milankovitch cycles plus positive feedbacks (albedo, CO2, and some others) have been the prevailing theory on the causes of ice ages (at least those during the pleistocene) for some time now:
http://ipcc-wg1.ucar.edu/wg1/FAQ/wg1_faq-6.1.html
It looks like this latest research has provided additional evidence for that.

Christian Bultmann
August 6, 2009 8:53 pm

OK assuming there argument is correct and when the planet gets warmer the CO2 content increases and that in turn makes it warmer yet and that releases more CO2 witch increases the temperatures even more.
But where than is the mechanism witch made it all stop and prevented the planet from exceeding temperatures that don’t support live anymore as it did billions of years?
Could it be water vapor that limits this runaway effect perhaps?

Mike Abbott
August 6, 2009 8:54 pm

This is (at least) the second time the “ice age mystery” has been solved in recent years. In 2005, Ohio State scientists made headlines when they published a paper claiming ice ages were caused by the CO2 greenhouse gas effect. See STUDY BOLSTERS GREENHOUSE EFFECT THEORY, SOLVES ICE AGE MYSTERY at:
http://researchnews.osu.edu/archive/earlyice.htm

MikeE
August 6, 2009 8:54 pm

Well, this still posses an interesting conundrum. So co2 has never been higher in (take yer pick, but ill go for ) 400thousand years. But the previous four interglacial s peaked warmer than this one has…. And we didnt hit that magical tipping point that prevented re glaciation… Were the wobbles from this interglacial less pronounced than previous interglacial s? Or have we had an ocean circulation change that has moderated the shifts more? (im thinking berring strait)
And if re glaciation is caused by this effect also, are we that confident that GHG’s trump albedo changes… i know there are instances when the earth has gone into ice ages with higher co2 levels, which would suggest, maybe not? (am aware of resolution problems with far distant record)
Oh so many questions. 🙂

layne Blanchard
August 6, 2009 8:56 pm

I’m sure I’ve read elsewhere that evidence of glaciations, and interglacials suggest they begin and end suddenly, and NOT over thousands of years.
I still like the idea that our climate experiences a variety of cyclical effects of independent period, driven by the various heavenly bodies in our solar system or perhaps beyond it.
Sometimes their amplitudes converge, sometimes diverge. Rogue wave effect.

August 6, 2009 8:59 pm

I first learned about the Milankovitch cycles (about 1972 or so) in the context of hydrology. The topic under discussion was the stationarity of long term precipitation time series and how that impacted the stationarity of long term flood series.
The take home message was that estimating the x thousand year flood or the Probable Maximum Precipitation at a location were impossible given the Milankovitch cycles making the above mentioned time series non-stationary. Although the Milankovitch cycles could be predicted, their impacts on precipitation and runoff were well beyond our scientific understanding in hydrology. I suspect this is still true in hydrology and climate science.

Chris V.
August 6, 2009 9:01 pm

Mike Abbott (20:54:31) :
This is (at least) the second time the “ice age mystery” has been solved in recent years. In 2005, Ohio State scientists made headlines when they published a paper claiming ice ages were caused by the CO2 greenhouse gas effect.

You need to read your link again! That’s not what it says.

Alan Wilkinson
August 6, 2009 9:05 pm

I am a little puzzled. If this has conclusively settled the matter, where are the calculations that decisively predict the planet’s future temperatures?
Or is this simply a rough correlation of cycles with ice ages?

OSU Engineer
August 6, 2009 9:05 pm

This is so ironic considering OSU is stressing green energy everything. In my field, all we ever talk about is how to generate renewable sources of power. Even the city of Corvallis is rated as one of the “Greenest” of cities under 100,000. The city does everything green here. If you throw a rock into traffic 6 out of 10 times you will hit a Prius. Even the mayor has an electric “mayor-mobile”. I just cannot believe that my university actually produced research that didn’t tell us how horrible CO2 is.

Marcus
August 6, 2009 9:06 pm

If you actually read the literature written by so-called “alarmists” you’ll see this is nothing shocking. I’d recommend “The Long Thaw” by David Archer as a good readable book with some nice graphs of correlations between northern hemisphere insolation reaching a trigger value and glacial growth. Archer’s book points out that the next potential trigger point would have been in about 3000 years, but that insolation wasn’t predicted to drop quite enough to trigger a new ice age… probably. On the other hand, with long-lived CO2 in the atmosphere, not only will we sail right past the 3000 year trigger, but probably the next potential trigger at 50,000 years.
I find it amusing that all of you like this paper so much, when the guy who wrote it is probably a proponent of CO2 control because he understands the climate Much Better Than You (TM).

Jim Powell
August 6, 2009 9:18 pm

Roy Spencer discussed problems with Milankovitch theory June 17th. http://www.drroyspencer.com/2009/06/ice-ages-or-20th-century-warming-it-all-comes-down-to-causation/

Jimmy Haigh
August 6, 2009 9:20 pm

Leif Svalgaard (19:54:27) :
“The 0.1% TSI explains only about 0.05-0.1C.”
I reckon the black lines on my mercury thermometer are at least 0.1C thick.

Pamela Gray
August 6, 2009 9:22 pm

I can’t believe that last statement was included in the submission without lots and lots of whiskey. This is my cow college you be talkin about. The only college that remained above and beyond the hippy generation of Oregon. The only college any respectable (cough cough) 16 year old from Wallowa County could go to back in 73. My University. I lost a LOT of stuff at that college (and gained a bit too). But back then we were firmly steeped in cow &^%$ and completely believed the cheerleader yell. Something about saving a beaver but I forget the exact words. We coulda cared less about nitrogen seeping into rivers along the Willamette Valley. And the cookbook I still have from the Home Ec department makes you gain weight just by readin it. But I guess as time goes by, you will pay the pied piper for a bit o’ grant money to study Earth’s temperature.

Jeff L
August 6, 2009 9:22 pm

This article reads as if this is some new theory – hardly. See links:
http://en.wikipedia.org/wiki/Milankovitch_cycles
http://en.wikipedia.org/wiki/Milutin_Milanković
He 1st proposed analogous ideas nearly 100 years ago!

Bill Illis
August 6, 2009 9:23 pm

Anyone have a link to the paper and the data.
It seems reasonable to me that as long as Milankovitch cycles result in the snow not melting completely in the summer on Ellesmere Island, Baffin Island and the Torngat mountain range in northern Labrado (still snow on the ground in the Torngats even at this time of the year), that the ice-albedo feedback would put us into an ice age.
The problem is the estimates for the albedo changes are not enough to drop the average temperature by the -5.0C change of the ice ages. Earlier estimates from the late-1960s, the 1970s and early 1980s showed it could happen, but once climate models came on the scene, there was not enough ice-albedo feedback to meet the temp changes: hence the need for CO2 changes as well – not surprising since the early and modern climate models are based on greenhouse gas sensitivities that can only point in this direction.
Hopefully, someone (or this paper) has some albedo estimates that I can use for a project I’m working on.

Jimmy Haigh
August 6, 2009 9:24 pm

RoyFOMR (20:43:13) :
Jimmy Haigh (19:36:39) :
“But not the message- that was the old BBC – the one we both grew up with AND loved!
Whoever he was, I respect him.”
Hear hear Sir!
OT: I still listen to the Beeb’s Test Match Special though on the interweb thingy. Out here in Thailand we don’t get a good picture on the channel which shows the cricket on the telly. ‘T Headingley test starts today. Me Dad were a Yorkshireman – Huddersfield. And a big Boycott fan – like me. He calls a spade a spade.

Mike Abbott
August 6, 2009 9:26 pm

Chris V. (21:01:50) :
Mike Abbott (20:54:31) :
This is (at least) the second time the “ice age mystery” has been solved in recent years. In 2005, Ohio State scientists made headlines when they published a paper claiming ice ages were caused by the CO2 greenhouse gas effect.
You need to read your link again! That’s not what it says.
I guess you’re right. They merely say:
“Our results are consistent with the notion that CO2 concentrations drive climate.”
“Our results are consistent with the notion that CO2 concentrations drive climate.”

Pete W
August 6, 2009 9:26 pm

As Mike Abbott said above, I see nothing in this research that contradicts AGW theory. I think the significance of their study may be a better understanding of how earths ice reacts to forcings. Perhaps it will help climatologists gain a better understanding of why the ice is currently melting faster than they had predicted it would.
However maybe they were already on the right track. This NSIDC site discusses the correlation of cloud cover with rate-of-melt; “In 2007, unusually sunny skies throughout the summer melt season were one of the factors that helped lead to the record low ice extent.”
http://nsidc.org/arcticseaicenews/
Pete

Mike Abbott
August 6, 2009 9:27 pm

Ooops.. didn’t mean to repeat myself.

anna v
August 6, 2009 9:34 pm

Marcus (21:06:24) :
On the other hand, with long-lived CO2 in the atmosphere, not only will we sail right past the 3000 year trigger, but probably the next potential trigger at 50,000 years.
Your long lived CO2 cannot even push over a PDO shift from hot to cold. ( it was riding a hot PDO when the catastrophic heating was proposed)
What chance does it have against orbital changes in input energy? Zero.

August 6, 2009 9:34 pm

Marcus (21:06:24):
I find it amusing that all of you like this paper so much, when the guy who wrote it is probably a proponent of CO2 control because he understands the climate Much Better Than You (TM).
I don’t think so:
http://www.biocab.org/Climate_Geologic_Timescale.html
My article was published on July 11th, 2009, while theirs will be published tomorrow. I win.
Anyway, I agree with you; they are trying to convince their readers that the solar activity was the culprit of all changes in the geological past, but not now because the climate change nowadays obeys to the emissions of carbon dioxide from human activities.
For your article to see the light in Science Magazine, you must to include something which blames to human beings of any change in nature, whether it is biological, geological or climatic.

philincalifornia
August 6, 2009 9:36 pm

evanmjones (20:42:35) :
Some say the world will end in Eccentricity
Some say in Obliquity
But many of my generation
Tend to favor Inclination
So we are left to wonder when
Until our earth returns through dust
And will again
As so it must
_______________________
Brilliant. I’m so glad that “greenhouse gas forcing from death trains with positive feedback and boiling oceans” does not scan well.
I shall try hard not to “steal” that “quote of the week” from you this time.

kuhnkat
August 6, 2009 9:40 pm

Marcus,
” On the other hand, with long-lived CO2 in the atmosphere,…”
Sorry, you are wrong again. No such animal as long-lived CO2.

Mike Abbott
August 6, 2009 9:44 pm

Pete W (21:26:38) :
However maybe they were already on the right track. This NSIDC site discusses the correlation of cloud cover with rate-of-melt; “In 2007, unusually sunny skies throughout the summer melt season were one of the factors that helped lead to the record low ice extent.”

Interesting. That may be the first time they have acknowledged the importance of cloud cover. The other factor they increasingly cite is atmospheric circulation patterns, the effect of which have been dramatically demonstrated in animations posted on WUWT.

John F. Hultquist
August 6, 2009 9:46 pm

I’ll just read the paper before passing judgment. These issues are complicated. Meanwhile, . . .
Over the next few days, while you are engaged with folks about town, ask a dozen of them “What causes summer and winter?”
Many believe it is because Earth is nearer the Sun in Summer. The truth is difficult to explain without a globe. Think about this when you next enter your child’s classroom.
If there is fundamental misunderstanding about “the seasons” how much more troublesome are the issues in this paper? CO2 is so much easier.

Steve
August 6, 2009 10:00 pm

Seems like the right time to float this comment. Not too long ago, I read an article where the authors noted that as the Sun rotates around the galactic center (pulling the planets along), it “meanders” in both X and Y (Z being the direction of rotation). I did not note the extremes of this “meandering” but it would cause the distance between Sun and Earth to increase and decrease slightly over time. Just wondering if anyone ever calculated the effect of this activity.

Evan Jones
Editor
August 6, 2009 10:05 pm

I shall try hard not to “steal” that “quote of the week” from you this time.
#B^1

Freezedried
August 6, 2009 10:06 pm

Marcus,
“On the other hand, with long-lived CO2 in the atmosphere,”
At odds with this
http://pubs.acs.org/doi/full/10.1021/ef800581r

August 6, 2009 10:08 pm

John F. Hultquist (21:46:13) :
I’ll just read the paper before passing judgment. These issues are complicated. Meanwhile…
Here the article is:
http://www.sciencemag.org/cgi/content/full/325/5941/710

Jimmy Haigh
August 6, 2009 10:08 pm

Fire and Iceby Robert Frost
evanmjones (20:42:35) :
I like it! I Googled the first line and found the poem by Robert Frost called ‘Fire and Ice’.
Some say the world will end in fire,
Some say in ice.
From what I’ve tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.
Perhaps “Frost” will have the last word…

August 6, 2009 10:17 pm

From the article at http://www.sciencemag.org/cgi/content/full/325/5941/710:
“The responses of the Northern and Southern Hemispheres differed significantly, which reveals how the evolution of specific ice sheets affected sea level and provides insight into how insolation controlled the deglaciation.”

D. King
August 6, 2009 10:32 pm

Wow, now maybe they’ll discover the pressure on Venus,
at the surface, is 90 atmospheres.

August 6, 2009 10:36 pm

Nasif Nahle (21:34:56) :
they are trying to convince their readers that the solar activity was the culprit of all changes in the geological past,
Solar insolation changes and Milankovich mechanisms are NOT solar activity.
John F. Hultquist (21:46:13) :
Many believe it is because Earth is nearer the Sun in Summer.
It is, if you live in Australia…

August 6, 2009 10:47 pm

Leif Svalgaard (22:36:44) :
Nasif Nahle (21:34:56) :
they are trying to convince their readers that the solar activity was the culprit of all changes in the geological past,
Solar insolation changes and Milankovich mechanisms are NOT solar activity.
John F. Hultquist (21:46:13) :
Many believe it is because Earth is nearer the Sun in Summer.
It is, if you live in Australia…

I stand corrected.

August 6, 2009 10:57 pm

agesilaus (19:32:47) :
The surprise is that Science is publishing it, they seem to have been in the same warmist group as Nature.

Without the obligatory nod to AGW, you can bet Science wouldn’t have touched it with a ten meter bunsen burner.

August 6, 2009 10:57 pm

To Invent Armageddon
When software supposes the world ends in flame,
And Hansen and Gore paint brushstrokes of blame,
And other false prophets scream, “GREEN” in their name,
I wonder a bit, just a tiny amount, 
How many people know what it’s about,
And how many good folk can see past the shame
While driving around in their carbon-mobiles, 
immersed in the guilt of spinning their wheels,
Intent on respecting the earth just the same,
They play the victim while playing the game! 
Warming and cooling are twins of the world,
But one twin is cruel and one twin is good.
You’d know the cruel one if you saw his work,
When fog freezes flesh and wolves howl in the murk,
When glaciers come calling and icy winds blow,
And summer is absent and death stalks the snow.
And millions and millions are slain by the cold,
Crops failed and we died while rats swarmed, we are told,
When the Vikings were booted from Greenland’s embrace,
And the so-called “little ice-age” tried it’s best to erase
All that we made that the warm winds delivered,
As the darkness descended, we froze and we shivered,
Awaiting the warming that came far too late,
A third of humanity slaughtered by fate,
Four hundred years of freezing and drought,
And pestilence, plague – that “twin” goes all out!
The globe still recovers and glaciers still melt,
And though a chill in the air can almost be felt,
There’s nothing more normal than warming that’s global,
Despite Chicken Littles droning on about weather
And whether or not science daring to question
Their dogma is legal, and should even be mentioned,
Their hockey-stick lies tilt mad at the skies,
To invent armageddon, true science DIES…
© Dave Stephens 2009

rbateman
August 6, 2009 11:03 pm

Yes, this is what we learned in high school in the late 60’s.
There is something left from the last 20,000 yrs to explain, however, and that is the Younger Dryas period. Halfway out of the melting of the Laurentide Ice Sheet and you get a 1,000 yr reversal. For 19,000 of those years, the Pacific Northwest was always either a forest or a woodland. During the Younger Dryas it was supposedly a desert. Go figure. In the 1840’s the Columbia River Basin had a 10 year drought.
Why would the climate in N. America do a reversal if the only factor was orbital shape?
This is still not totally solved, but the orbit surely gives a longer and bigger picture.

August 6, 2009 11:06 pm

I have to make two corrections to my previous post Nasif Nahle (21:34:56):
1. “They are trying to convince their readers that the solar radiation striking on the Earth’s surface was the culprit of all changes in the geological past…”
2. Clark et al did not mention that the CO2 was the culprit, but that the northern latitude insolation was the main trigger of the initial deglaciation of the northern ice sheets and glaciers, which finally headed to increases of atmospheric CO2.
Nonetheless, the authors of the paper point to CO2 and oceans as feedbacks which amplified the deglaciation event. From my knowledge, it is true for oceans, not for carbon dioxide.

Patrik
August 6, 2009 11:22 pm

People here seem to miss the most important argument that this acknowledgement of natural factors gives us.
The warmists always repeat the mantra “The extra heat from GHG:s will still make the earth warmer than it would be, disregarding natural factors.”
BUT: This study acknowledges what we all already knew; that the natural process is; increased heat comes first, increased GHG:s comes second.
So, if all the basics in GHG theory is correct, and this study also is correct it will also mean that:
Any decrease in heat will also lead to a decrease in GHG:s.
A process which in turn will amplify any climatic cooling process that starts.
I write GHG:s here, because it’s 100% logical to assume that for instance H2O gas will decrease.
So it matters very little if we have 1-200 extra ppm:s of anthropogenic CO2 if such a cooling process starts, since H2O and “natural” CO2 will drastically decrease and over time things will even out.
And the most important thing is that this is of course the case regardless of what natural climate factors we are talking about:
The amplified cooling effect must be true if the amplified warming effect is true.

Paul Vaughan
August 6, 2009 11:34 pm

Elizabeth (20:29:31) “Careful, alarmists wanting to cool the planet are going to be looking for a way to jolt the earth’s wobble back…”
Very Interesting. If they move that far, there will be splintering for sure – and maybe even a split right down the middle.

Mark (20:35:24) “I’ve got a problem with this statement:
“the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.””

Recognize the funding hook. Venality is just as sickening in academia as it is elsewhere.

Paul Vaughan
August 6, 2009 11:59 pm

anna v (20:44:15) “To all: we have to be hard on these people that add those warming mantras to get their grants. They should be made aware they are prostituting themselves and their science.”
Researchers will change funding hooks with the wind. The needles should be directed strategically into the weaknesses of the funding agencies, which Anna has correctly identified.

Dave
August 7, 2009 12:00 am

I recall that there was some research that showed that ice sheets melted very quickly at the end of the last ice age.
If my memory is correct, this would be at odd with these latest findings.
Does anyone know if there is evidence of sudden melting? If so, then this would cast doubt on this paper, as it expects changes to be slow.
And werent wooly mammoths frozen suddenly as well? Didnt they live in temperate lands, as shown by the grass in their stomachs? And then were frozen solid in some cases, almost overnight?
I would like to know if this fact I remember is actually true, anyone out there able to confirm or deny it?

Terry
August 7, 2009 12:14 am

Well knock me over with a hv. It wil be very interesting how this is factored into some of the current theories on CO2 vs solar vs GCM’s etc.

RW
August 7, 2009 12:18 am

David P:
“This is an odd statement, if I’m reading it correctly. What “greenhouse has emissions” from 200 yrs ago can he possibly be alluding to? Isn’t the consensus that there could be no AGW effect from GHGs until after WWII?”
Where would you have got a notion like that from? CO2 concentrations started rising when the Industrial Revolution started, and if you know your history you’ll know that was actually a little bit before the Second World War.
Jeremy:
“When I studied atmospheric physics in graduate school, thirty years ago… CO2 greenhouse effect was generally regarded as an amusing neat idea that was only suited to high school physics because it was such an oversimplified way to describe such a complex system as the atmosphere”
Wow, you must have been to a really bad university. Your statement does not correspond to a view ever held by any serious scientists. How can the greenhouse effect be “oversimplified”? That doesn’t even make sense.

Paul Vaughan
August 7, 2009 12:21 am

Re: Steve (22:00:20)
See entry labeled “16 June. Australia” (posted by the authors of the study you mention) here:
http://nzclimatescience.net/index.php?option=com_content&task=view&id=80&Itemid=1
…That’s part of the story (…no further comment)…

F Rasmin
August 7, 2009 12:28 am

Please, please! I have not read any of the comments yet but I do hope that no ‘well meaning person’ has provided the full article for us to read without paying the required coin. Ethics please people!

STAFFAN LINDSTROEM
August 7, 2009 12:41 am

…OT but since it has surfaced on this thread, the BBC HARD TALK Stephen
Sackur interview, a little spanky…with outgoing Greenpeace boss{S Sackur’s word} Gert Leipold…
Can be seen for overseas and non-UK citizens in low quality RM MONO 35KBPS
making a small window you get a fairly good image too…At 13 min Sackur
manage to show GP simplified view of Arctic ice…A MUST BE SEEN…

stephen.richards
August 7, 2009 12:47 am

I’m afraid that one statement
and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years,
totally negates the value of the rest of the paper. If they are that sloppy in thier work then it has no value whatsoever.

GK
August 7, 2009 12:57 am

So this DEFINITIVELY proves that CO2 played no part in previous climate cycles.
There are 2 stunning conclusions from this :
1) The increase in CO2 that follows about 800 years after each interglacial starts has no (or very little) impact on earth`s climate.
2) It those massive increases in CO2 had no impact in earth`s climate back then, then CO2 can not possibily have an inpact now.
This finding proves there is no man made AGW.

NS
August 7, 2009 1:05 am

Robert (19:15:52) :
For those of us with gray hair, is this not what we learned in earth science class in high school in the 70s?
Yes it is odd – I think the diagram is out of one of my old text books….
Are we going backwards…..?

Stargazer
August 7, 2009 1:15 am

“Sometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age ”
They are right By looking at the past we should be getting an ice age about now.
Thing is… that you get about 90,000 years of glacial,10,000 years of interglacial (over very many cycles), We are now at the end of the typical interglacial length, in fact we are ‘overdue’….problem is you would look at a graph of these cycles and ‘know’ what will happen next because of the regularity of the cycles….
However the Earth is not currently in ‘position’ in a Milankovitch cycle to bring about an ice age anytime soon, Therefore I personally don’t think that Milankovitch cycles are the complete answer. unless there is something ‘special’ about the time we now live in and the next Ice age really is 50.000 years away, I will continue to believe the graph, and ponder about what the heck we will do/can do when it happens ‘soon’.

Allan M R MacRae
August 7, 2009 1:18 am

“Sometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age – unless some other forces stop or slow it. But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
Let us assume for the moment that the above paragraph is true.
So humanmade CO2 emissions are delaying the next Ice Age by several thousand years.
Can we now expect Gore LLC to advocate for ever-increasing CO2 emissions to keep delaying the Ice Age? What will Cap and Trade look like under this scenario?
Listen Big Oil, you will now have to meet or exceed your 1990 greenhouse gas emissions or pay hefty fines. And somehow, we will have to insert a further negative spin to make it all your fault.
I find it strange that so many people exhibit a Pavlovian hatred for energy companies. Since ~88% of global primary energy is generated from fossil fuels (the remainder is nuclear and hydro, with a trace of renewables), these “evil” energy companies keep our families from freezing and starving to death.

August 7, 2009 1:28 am

Whoops. Delete the first one for bad spelling, please.
To the tune of Davy Crockett
Born in Austria-Hungary,
Schooled at the U of Technology
Thought about orbital eccentricity
Cause he thought insolation was the Ice Age key
Milutin, Milutin Milankovitch
King of the science frontier
Interned during the First World War
Had the time to take on the chore
Of calculating wobbles and tilts by the score
And made himself a legend forever more
Milutin, Milutin Milankovitch
King of the science frontier
Ninety years later at OSU
The geoscientists there had nothing to do
So they copied his work through and through
And presented it all as something new
Milutin, Milutin Milankovitch
King of the science frontier

August 7, 2009 1:32 am

due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.
Somebody point this d*mb*ss to Loehle reconstruction – http://www.co2science.org/articles/V11/N5/Loehle2007small.gif

Alan the Brit
August 7, 2009 1:41 am

“these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
When will you scientific chaps stop all this double-speak, you have either nailed it or you haven’t. One cannot “nail” something more or less! How many times has a scientific discovery seemed so close to being made suddenly to be dashed against the rocks of reality, or a better theory?
This was taxpayer funded research one assumes, ergo they have to say this! How much did it cost the taxpayers of Oregon/USA to tell you something anybody over 40 with grey hairs should have already known? We did this in geograhy & history at senior school, it was assumed it was written in stone (more or less)!!!!!!
RoyFOMR/Jimmy Haigh:-)
It couldn’t have been Roger Harrabin, he has to many chubby grubby fingers in too many green pies! The leftist-greenie BBC won’t allow this to get out on to the mainstream tv, BBC 1 & 2, I’ll wager!

Laurence Kirk
August 7, 2009 1:49 am

It always did make more sense for a phenomenon as obviously cyclical as the recent ice ages to be brought about by something else as obviously cyclical as the realtive motions of the sun and planets. Milankovitch recognised this intuitively. The erratic movements of the continents, the wavering of the ocean currents and the occassional outgassings of magma, sediments and regolith never really seemed to fit.

Stefan
August 7, 2009 1:49 am

Question, am I seeing this graph right? I mean it looks like when the planet has warmed up it then stays warm for a very short period and then goes cold again. But the most recent warmth has been a sort of plateau. Doesn’t it look like we’re lucky to enjoy a long warm period? Isn’t the concern that we’ll go cold anytime now?
http://www.geo.arizona.edu/BGDL/images/Vostok_CO2_airt.gif

Dave vs Hal
August 7, 2009 1:52 am

Leif said earlier that insolation varies by 90 W/m2 with a max in January. I note in Dr Spencer’s graph of atmospheric temps, the global max temperature peaks in July. Would this be because summer albedo is greater in the Antarctic than the arctic?

August 7, 2009 1:55 am

That well known Serb ‘cyclo-maniac’ Milutin Milankovic worked it out some 60 years ago.

mark fuggle
August 7, 2009 1:57 am

GARY 19:47:19 The paper you cite does actually mention the (unknown ?) anthropogenic effects of burning fossil fuels- page 12 of the pdf-. I was surprised , the paper is 33 years old.

Rhys Jaggar
August 7, 2009 2:02 am

As I read it the article says this:
1. Exit from the last ice age was triggered by solar forcing.
2. We slip in the little kicker that the seeohtwo which was released due to warming caused an amplification (did this require the increased solar forcing to produce the amplification?)
3. Because we belched out lots of seeohtwo recently, we no longer need solar forcing to cause climate change.
I’m not an expert, so the two questions I would ask are:
i. Are detailed studies on the relationship between amplification by seeohtwo and solar radiation complete and what do they say?
ii. Can seeohtwo amplify responses if solar output drops?
The paper to me reads like the solar deniers now seeking to integrate solar influences into their theories whilst maintaining the moral high ground re seeohtwo.
It happens in politics all the time. Steal the opposition’s policies and repackage them as your own.
But I guess if the pure solar folks looked at seeohtwo and the seeohtwo folks looked at the sun, maybe we would reach truth sometime soon?
Ah well. They need new grants, I guess………

Disputin
August 7, 2009 2:06 am

Nobody seems to have mentioned the shape of the temperature curve. For the last several glaciations it has been a sawtooth, temperatures rising rapidly (followed about 1000 years later by CO2) for about 20,000 years before cooling stepwise more slowly. So don’t panic, the full rigours of a new glaciation won’t be felt for at least 50,000 years.

August 7, 2009 2:17 am

Patrick K (20:44:40) :
None of this information is really new. However, I have to complain about the graphic and the caption attached to it. Both of the ellipses shown are extremely exaggerated and neither is anywhere close to the actual ellipticallity of the Earth’s actual orbit which ranges from an almost perfect circle to only slightly elliptical. Even at it’s most extreme elliptical orbit, the earth’s orbit is very close to a perfect circle (A perfect circle is e=1, the Earth’s most extreme orbit is e=0.97). In fact it is so close that a human cannot usually distinguish it from a circle.

It is a simplified figure. Among other things, the relative sizes of the Sun & earth vs. orbit sizes are not to scale. And I don’t think the image plane is to be understood as the plane of the ecliptic, because you see the Earth’s rotation axis indicated as if viewed from some oblique angle.
We are looking towards the Sun from some point above the plane of the ecliptic, but we are not straight above the Sun. So even if the Earth orbit had been a perfect circle [it isn’t], this figure would still show ellipses for both orbits drawn.
One “extremely exaggerated” thing about the drawing is the large difference in shape of the two orbits ellipses. But I think that is just to make the point that the orbit is in fact changing its shape and orientation. Drawing the orbits to actual scale would be meaningless as they would overlap on the drawing.

ColinV
August 7, 2009 2:20 am

Note: The extract from the article above only mention changes to the Earth’s axis of rotation causing Ic ages, nothing about orbital eccentricty, so the graphic is misleading the discussion, unless the Science article (which I cannot access) does refer to this as a cause of Ice ages.

John R. Walker
August 7, 2009 2:39 am

So – why am I so sure I have known this for about 50 years?

Spence_UK
August 7, 2009 2:41 am

I hope whoever wrote “debate ended” had their tongue firmly in their cheek.
The Milankovitch “forcings” are embedded in a noisy continuum of greater magnitude than the forcings themselves. The “forcings” are therefore inseparable from background noise. People who have their mindset firmly stuck in 17th century determinism insist there must be a simple cause / effect relationship when one may simply not exist.
I would encourage people to consider Carl Wunsch’s work on this (ref 1 below) but also take a quick look at the third example in section 2 of Demetris Koutsoyiannis’ work (ref 2 below). The former article shows that the Milankovitch cycles fit equally well with a stochastic model as a deterministic one, the latter notes that even with a leasts squares fit removal of the harmonic associated with the 100ky Milankovitch forcing, the energy even in that spectral band is essentially unchanged.
Scientifically speaking, the case for a “forced” Milankovitch cycle as opposed to a continuum of unforced natural variability has not been convincingly evidenced. Likewise the 20th century climate change also fits well with unforced natural variability (see ref. 2).
That is not to say the deterministic view is clearly wrong. But to argue there are no valid alternative hypotheses is also wrong. And I would argue that the stochastic model is a single model that fits all of the data; the deterministic modelling community seem to need a new explanation for every new data set we come across.
Ref 1. “Quantitative estimate of the Milankovitch-forcedcontribution to
observedQuaternary climate change”, Carl Wunsch, Quaternary Science Reviews Vol 23 2004 link
Ref 2. “A toy model of climatic variability with scaling behaviour”, Demetris Koutsoyiannis, Journal of Hydrology Vol 322 2006, link to preprint

August 7, 2009 2:42 am

From the title of this post:
Long debate ended over cause, demise of ice ages – solar and earth wobble – CO2 not involved
From the paper under discussion
Solar radiation was the trigger that started the ice melting, that’s now pretty certain,” said Peter Clark, a professor of geosciences at OSU. “There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”
To be honest this is no different to a post I read on RealClimate about 3 or 4 years ago. The exact same argument was made, i.e. that an initial warming due to a change in insolation was amplified by an increase in carbon dioxide.

timbrom
August 7, 2009 2:44 am

Pete W
Perhaps it will help climatologists gain a better understanding of why the ice is currently melting faster than they had predicted it would.

What ice? Total sea ice coverage appears to be pretty much steady. Sea level rise is currently miniscule to zero. Ice is accumulating in Greenland and Antartica.

Alexej Buergin
August 7, 2009 2:45 am

“Jimmy Haigh: OT: I still listen to the Beeb’s Test Match Special though on the interweb thingy. Out here in Thailand we don’t get a good picture on the channel which shows the cricket on the telly. ‘T Headingley test starts today. Me Dad were a Yorkshireman – Huddersfield. And a big Boycott fan – like me. He calls a spade a spade.”
But when old Geoff beat up his girlfriend, I switched my allegiance (me luv ?) to the late Hansie Cronje; the way he could step on a ball reminds me of the antics of the AGW crowd.

Lindsay H
August 7, 2009 2:49 am

The post is interesting and gives some evidence which gives the milancovitch theory more credibility.
But it dosn’t explain the multiplicity of glacial advances and retreats over the last 20k years, expecially the 10 to 12 advances and retreats recorded since the Younger Dryas. As outline by Rothlisberger 1986 : Jahre Gletschergeschichte der Erde, and others.
Glacier activity : BP 350-100, 850-600, 1150-1050, 1500-1300, 2700-2100, 3700-3000, 4900-4500, 5300 -5100, 5870-5700, 6400-6050, 7500-7300, 8600- 8200 etc. There is good evidence that these events occured worldwide.
A theory which will give us usefull explanations for these glaciation events would advance our knowledge and further undermine the position taken by the IPCC

MarcusK
August 7, 2009 2:51 am

Hi,
what I don’t get about this theory: If it’s just ‘local’ orbital mechanics (Saturn, Jupiter, etc) why does the earth stay completely out of the ice age cycles for dozens of millions of years? What causes the deeper phases of “ice age cycles” and “no ice ages cycles”? If causation is purely ‘local’, why do the planets in the solar system stop causing Milankowitch cycles for very long periods?
My feeling is that any theory of ice ages is fragile at best, without giving a possible explanation of these very long-lasting phases.
I personally like the Svensmark / Shaviv theory, that these cycles are caused by our position in the galaxy, which sometimes puts us much nearer to clusters of short-lived, hot, heavy blue stars, whose novas causes lot’s of cosmic rays, that will greatly increase cloud formation on earth and thereby cool it. Of course, this is still something of a long shot, but at least it gives a coherent explanation for 4 billion years of history and not just 2.5 millions.
Regards,
Marcus

August 7, 2009 2:51 am

Don’t you love it!
In a paper that largely destroys the CO2 argument, they still had to mention AGW in order to “get their funding” / “get the paper published” (delete as applicable).
.

Hoi Polloi
August 7, 2009 3:02 am

Interesting. ALready 2-3 years ago on Climate Audit I mentioned the Earth tilting to be a factor in the Earth temperatures, but Steve McIntyre immediately chopped off that discussion with the remark “NO Earth tilting discussion on Climate Audit”! hmmm
REPLY: He probably didn’t want it to descend into Barycentrism arguments. – Anthony

Flanagan
August 7, 2009 3:12 am

[snip – unnecessarily accusatory Flanagan – if you want to talk about honesty, use your name and university affiliation – otherwise refrain]
“Our geochronology […] clearly demonstrates that only northern insolation led the termination and was thus the primary mechanism for triggering the onset of Northern Hemisphere deglaciation. ”
is a very important first conclusion, but is followed by
“Although the lead-lag relationships established here […] point to northern latitude insolation as the primary trigger of initial deglaciation of most Northern Hemisphere ice sheets and glaciers, subsequent increases in atmospheric CO2 and tropical Pacific SSTs (Fig. 5, C and D) demonstrate the importance of carbon cycle and ocean feedbacks in amplifying the deglacial response and causing global warming.”
So the conclusion is: changes in insolation IGNITED the deglaciation of the Northern hemisphere and CO2 and ocean feedbacks INDUCED A GLOBAL WARMING. This is actually proving CO2 can induce a warming at the global scale. Of course, a these time it was not anthropogenic :0)

Pierre Gosselin
August 7, 2009 3:41 am

This paper only confirms what the ice cores have shown time and again.

UK Sceptic
August 7, 2009 4:09 am

“…due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years…”
I was really enjoying a first class piece of science then they go and ruin the experience with a crass pile of BS warmistry (warmist sophistry). Maybe someone should introduce the authors to the temperature nuances of the Roman Warming Period and the Medieval Warming Period…

tallbloke
August 7, 2009 4:13 am

Leif Svalgaard (19:54:27) :
Mick (19:21:24) :
The 0.1% TSI variation is bugger all to explain 0.5C referenced @20deg.C
The 0.1% TSI explains only about 0.05-0.1C.

Depends whose figures you believe, but I’m glad to see Leif has moved on a bit from his previous 0.05C.
Three factors to consider when trying to see how much difference the change from solar max to solar min has on temperature.
1) El nino tends to occur at solar min, and is the manifestation of solar input to the oceans at solar max. This masks some of the true solar input to the climate system by ‘flattening’ the temperature curve.
2) Leif is using PMOD data, which uses a model to calculate TSI, based on the splicing together of records from several satellites used to measure irradiance over the last 30 years. PMOD and the IPCC prefer the use of ERBS data to calibrate the change during the ‘ACRIM gap’. The ACRIM team maintain this is not as good as the data from the other satellite, NEPTUNE which was working when the gap occurred and that consequently, TSI shows a little trend when it should show a rising trend at the end of the C20th.
3) Additionally, the Acrim data shows that cycle 21 had a difference of nearer 2W/m^2 between solar max and min than the 1W/m^2 Leif cites.
All this adds up to a spread of uncertainty about the effect of Solar max-solar min on temperatures.
Leif says 0.05 to 0.1C
I say it could be more like 0.35-0.4C depending how you account for heat storage in the oceans and heat energy release in el nino.
If correct, this means the temp change over the C20th can mostly be explained by the sun, as the lower, longer cycles with longer minima of the early part of the C20th averaged out means a lot less TSI recieved at earth.
It will be interesting to study this new paper and see if any of their figures are applicable to my model which estimates ocean heat accumulation from the sun.

Vincent
August 7, 2009 4:24 am

I must be missing something here, but what exactly is new about this? It has long been the view of AGW advocates that the ice ages were terminated by orbital variations and then the increasing CO2 further amplifies the warming. In one paragraph the authors write:
“But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
So their conclusion is, well, alarmist.

August 7, 2009 4:26 am

So… people with SUVs are making the planet wobble?

tallbloke
August 7, 2009 4:37 am

So, the ice ages are explained by changes in earth’s orbit caused by the outer gas giant planets, the ‘earth wobble’, but what about the ‘sun wobble’ also caused by the outer planets mentioned in the thread title. ?
Is Anthony finally taking a bit more of an interest in the ‘barycentric nonsense'(tm) that Geoff Sharp, myself, and Dr Nicola Scafetta keep going on about? 🙂
And,
Does the paper also explain the shift from 45,000 year cyclicity in ice ages to 100,000 years? I’m trying to get a copy to find out.

Flanagan
August 7, 2009 4:49 am

I can see I’m not the only one who’s having a problem with the title. At this stage, what it says is simply a lie. CO2 did not trigger the deglacations, but IS involved in it, it is actually the main conclusion of the paper. Maybe “CO2 not the primary cause” would fit better.
REPLY: I agree, I was working off the press release. In the paper (which wasn’t immediately available) the presentation is now clear that CO2 has a secondary role but is not the primary driver, so I’ve made a small change to the title. – A

Mike Bryant
August 7, 2009 5:23 am

Keep your eyes open for the next great AGW study that will explain the progression of the seasons…

C Colenaty
August 7, 2009 5:23 am

Will someone please put me out of my misery in regard to the Milankovitvh Theory (MT)? Here are my problems. The MT seems to account for the present ~100 K year glaciation periods, but then also for the previous (before 900 K years ago, 45 K year glaciation cycles, and then before that 25 K year cycles. And before that there was a period of about I understand that there was a period of about 13 or 14 million years when there was no glaciation. Maybe this period might be explained by tectonic movement. But then why was there a prior glaciation? And what happens to the MT for those very long periods of time when glaiation is absent? There are hopefully some compresive answers to these questions, but, as in the recent article that is the subject of this series of comments, the MT is discussed as though it could be applied to conditions on the earth is a fairly simple and straightforward manner, and that certainly does not seem to be the case to me.

Suzanne Morstad
August 7, 2009 5:28 am

Its interesting that they used Isotopes generated by cosmic rays to determine the degree of solar radiation (e.g. C14 and Be10) The real effect of the Milankovich cycles may well be the direct effect of the shape of the orbit on sunspot activity as described by Rhodes Fairbridge and Theodore Landscheidt rather than changes in insolation from the changes in orbit as postulated by Milankovich.

Bill Marsh
August 7, 2009 5:39 am

agesilaus (19:32:47) :
The surprise is that Science is publishing it, they seem to have been in the same warmist group as Nature.
______________________
I’d be willing to bet a small sum that, without the obligatory kowtow to AGW, the paper would not have been published and that the author made the statement for that purpose.

August 7, 2009 5:43 am

Dave (00:00:37) “…And werent wooly mammoths frozen suddenly as well? “
Here is one conjecture, Dave: “Preserved frozen remains of woolly mammoths have been found in the northern parts of Siberia. This is a rare occurrence, essentially requiring the animal to have been buried rapidly in liquid or semi-solids such as silt, mud and icy water which then froze.
“This may have occurred in a number of ways. Mammoths may have been trapped in bogs or quicksands and either died of starvation or exposure, or drowning if they sank under the surface.”

CheshireRed
August 7, 2009 5:47 am

The BBC iPlayer edition of HARDtalk that was mentioned in this thread is available below.
http://www.bbc.co.uk/iplayer/episode/b00m01bl/HARDtalk_Dr_Gerd_Leipold_Executive_Director_of_Greenpeace_international/
It’s the outgoing Greenpeace Director Gerd Leipold being interviewd by Stephen Sackur, who gives a reasonable account of himself regarding Greenpeace’s over-optimistic appreciation of renewable energy versus their refusal to engage nuclear.

August 7, 2009 5:53 am

Allan M R MacRae (01:18:02): “I find it strange that so many people exhibit a Pavlovian hatred for energy companies. “
Ditto, Allan… in fact more than strange. I will read with great interest anything I can find on that. Mebbe, as I have ventured before, if we gave them all a government issue of stock they would begin to purr? How deep is conviction?

John
August 7, 2009 5:58 am

Dave vs Hal (01:52:13) :
“Leif said earlier that insolation varies by 90 W/m2 with a max in January. I note in Dr Spencer’s graph of atmospheric temps, the global max temperature peaks in July. Would this be because summer albedo is greater in the Antarctic than the arctic?”
Nope it’s due to the northern hemisphere have much more land mass than the southern hemisphere. Land heats up far more quickly that the oceans. The total heat content of the oceans shows no such variations.

Robinson
August 7, 2009 6:04 am

This is an odd statement, if I’m reading it correctly. What “greenhouse has emissions” from 200 yrs ago can he possibly be alluding to? Isn’t the consensus that there could be no AGW effect from GHGs until after WWII?

You have to understand that sentences like this are an appeal for further funding from politicians, not statements of Scientific fact.
I was listening to a podcast from Sceptic Magazine the other day and they were interviewing a Geologist (actually a Palaeontologist). He started his remarks by saying how little funding there is in Palaeontology compared to many other (more politically interesting) endeavours. Of course, he spent most of his time tying advances in Palaeontology with what will happen in future due to Man Made Global Warming. I was a little surprised, given I was listening to Sceptic Magazine, that his bold assertions went unchallenged by the presenters.
Anyway, yes, as a Scientist it’s useful to add the above to your paper. It helps to pay the mortgage.

radar
August 7, 2009 6:10 am

Given the links provided in the comment thread, the IPCC’s own literature, and the comments themselves, IMO, think the title of this post goes to far (too much flag waving).
It really just confirms Milankovitch cycles, with CO2 being a negative feedback going into the ice ages and a postive feedback coming out. Where’s the “debate” that was solved?
That title is no better than the worst of alarmist media reports. Ought to be fixed lest we look like Joe Romm.

REPLY:
I agree. I was working off the press release, which was made available before the paper, the CO2 role is secondary, and I’ve made an adjustment to reflect that – Anthony

August 7, 2009 6:13 am

tallbloke (04:13:43) :
Three factors to consider when trying to see how much difference the change from solar max to solar min has on temperature.
The sunspot number at solar max varies greatly [say a factor of three or more], therefore the TSI variation from min to max will also vary greatly, hence there will be a similar spread in dT. There is no “THE change”, as the change itself varies.
I think you have misunderstood my statement. In discussing the variation of temp with TSI, it is convenient to state that 0.1% dTSI results in 0.025% dT which is 0.07K. From cycle to cycle, dTSI will vary and hence dT. For the large cycles in the past dT would be more like 0.1K, and for the small cycles to come, more like 0.05K. The oceans with their large heat capacity will tend to dampen any changes, rather than magnify them.

cba
August 7, 2009 6:16 am

“Dave vs Hal (01:52:13) :
Leif said earlier that insolation varies by 90 W/m2 with a max in January. I note in Dr Spencer’s graph of atmospheric temps, the global max temperature peaks in July. Would this be because summer albedo is greater in the Antarctic than the arctic?

The peak to peak current variation in top of the atmosphere solar power is 90 w/m^2 out of 1363 w/m^2 with the maximum in jan and with the temperature peaks in july. On an annual basis there is a somewhat higher power – like about 30w/m^2 during jan which averages out to about 8 W/m^2 above the annual average. Yet, it’s warmer in july, when the power average is about 8 W/m^2 lower than the annual average.
Why the discrepancy? It’s because in jan. the Sun is in the southern hemisphere which is substantially ocean because most of the land mass is in the northern hemisphere. It would seem this ocean/land difference is responsible for more than overcoming quite a few W/m^2 difference in incoming power. THat difference is even more interesting considering that the surface albedo of ocean is about 1/3 to 1/5th that of land surface . What is happening is the ocean water is involved in a water vapor cycle creating clouds that reduce the albedo – something that can’t happen easily when there is little to no additional water available. The notion that ocean heatsink abilities are better than that of land surface may also play a part but it seems to be problematic for multiple reasons.

idlex
August 7, 2009 6:20 am

Leif Svalgaard (19:56:41) :
Geoff Sherrington (19:48:29) : “It is not so obvious how to calculate the irregular orbit of the earth around the sun.”
That is actually even more obvious. I think the consensus is that we can do this accurately [enough for this purpose] for some millions of years.

Really? I suppose that if the solar system was entirely determinate, and we had perfect knowledge, this would in principle be possible, using our most powerful computers (rather than my notebook PC) to model its behaviour.
But is it determinate?
How accurately, for example, do we know where the planets are, and what their masses and velocities are? Isn’t the accuracy of our forecasts or hindcasts dependent on the accuracy with which we know the initial conditions? And surely we need to know all these things with very great accuracy if we are going to make million year predictions? To what degree of accuracy do we know the mass of the Sun? To the nearest 10^6 kg? Or the nearest 10^12 kg? Or what? And isn’t it true that the mass of the Sun isn’t a constant, but is always changing as Coronal Mass Ejections hurl matter out into space, and comets and other bodies fall into it.
There are large numbers of other unknown bodies – such as comets – in orbit around the sun. These will be exerting a very small gravitational influence on planetary motion. This might have a very small effect over a single year, but over a million years it might accumulate into a very considerable effect.
Equally, the solar system might periodically pass through clouds of dust, the effect of which (I am guessing) would be to slow the planets slightly, and so change their orbits. If nothing else, there’s all those unpredictable mass ejections from the sun that are striking the planets.
And then we might ask how many large dark bodies there are floating around in the universe, one of which might pass through our solar system, and screw up the orbits completely.
In short, given what we know, we may be able to predict the motion of the planets for a million years (hey, why not 500 million years?). But the effects of what we don’t know about could entirely outweigh the effects that we do know about. How much do we think we know? 99%? 99.99%? 99.9999%?
Or, putting it another way, if we’re sure we can predict the next million years (or the previous million years) isn’t that just the same as saying that we pretty much know everything?
I think Geoff Sherrington has a point. Forecasting or hindcasting the motion of planets in the solar system may well be essentially as problematic as trying to forecast the behaviour of the Earth’s climate. There’s a’consensus’ about that too, after all.

a reader
August 7, 2009 6:22 am

Dave
Roger’s link is very good! If you would like to read an account of the finding of a wooly mammoth early in the 1900’s, google Fridtjof Nansen’s book “Through Siberia, the Land of the Future” and read beginning on page 119. He includes his ideas on how the preservation occurred.

Basil
Editor
August 7, 2009 6:31 am

Pamela Gray (21:22:00) :
I can’t believe that last statement was included in the submission without lots and lots of whiskey. This is my cow college you be talkin about. The only college that remained above and beyond the hippy generation of Oregon. The only college any respectable (cough cough) 16 year old from Wallowa County could go to back in 73

Small world, Pamela. I was also at OSU then. In ’73 I was an undergraduate, in the Economics department, finishing up my B.S. I stayed for two more years, for an M.S. in Agricultural and Resource Economics.

Neven
August 7, 2009 6:31 am

“TallDave wrote: “So… people with SUVs are making the planet wobble?”
That would be an even bigger ego boost, wouldn’t it? 😀
I agree with John Finn. In the title it says that CO2 is not involved. Yes, it isn’t involved in triggering the demise of an Ice Age, but as is stated later on amplifies the process. But I thought it is said CO2 cannot possibly amplify anything? What would happen without this amplification? And what happens when you reach CO2 levels that normally would amplify this process? Interesting questions, eh?
This is one of those articles, like the one about the PETM event, that really makes me wonder what it’s doing on WUWT. The comments make for entertaining reading, though. The power of subjective interpretation never ceases to amaze me.

Steve Keohane
August 7, 2009 6:33 am

I am with all of you who learned this 40-50 years ago. As far as CO2 goes, ie. being a magnifying, enhancing, exacerbating or whatever effect, let it go. The ice records from Greenland show a 15°C increase* in less than a decade. So much for some inexorable-thousands of years creeping up of temperatures. There is obviously a lot more than TSI, GHGs, and whatever else we think we know going on under our sun.
*Richard Alley, Alley et al, 1993

SteveBrooklineMA
August 7, 2009 6:33 am

Are they serious with that figure showing how much the orbital eccentricity can change? It’s quite dramatic, isn’t it? Does anyone know what the extremes of the eccentricity are?
REPLY: It seems that other universities besides TAMU also exaggerate the eccentricity in diagrams, see:
http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm
– Anthony

bill
August 7, 2009 6:40 am

Pierre Gosselin (03:41:10) :
This paper only confirms what the ice cores have shown time and again.

Using ice core data to see which came first (Temp rise/Co2 rise) is next to useless.
This plot shows the last ice age end. Co2 and temp rise as one. The dust is interesting however.
http://img11.imageshack.us/img11/6826/iceage040kkq1.jpg
note reverse timescale, and temperature plots from NH and SH sources.
zoomed in a bit:
http://img15.imageshack.us/img15/562/iceageco2ch450018500my5.jpg
or
http://img12.imageshack.us/img12/9952/iceage100200kbq5.jpg
http://img18.imageshack.us/img18/4103/iceageco2ch4360450lh8.jpg
etc
Most exits from ice ages CO2 and temp rise simultaneously. Entry to Ice ages CO2 lags fall in temperature. CH4 and temperature falls are nearly simultaneous

Flanagan
August 7, 2009 6:46 am

Thanks Anthony for the correction!

radar
August 7, 2009 6:54 am

Yikes, sorry for comparing you to J. Romm but I hadn’t had any coffee yet. My sincere apologies.
REPLY: Heh, no worries.

Richard Sharpe
August 7, 2009 6:57 am

radar said:

It really just confirms Milankovitch cycles, with CO2 being a negative feedback going into the ice ages and a

positive feedback

coming out. Where’s the “debate” that was solved? (Spelling corrected. I hope I haven’t distorted your meaning.)

I must have misunderstood feedback for all those years.

August 7, 2009 6:58 am

tallbloke (04:37:37) :
Is Anthony finally taking a bit more of an interest in the ‘barycentric nonsense’(tm) that Geoff Sharp, myself, and Dr Nicola Scafetta keep going on about? 🙂
Not very likely tallbloke, but lets hope it doesn’t take another 60 years before the light bulb comes on.

Don S.
August 7, 2009 6:58 am

@Rhys Jaggar: Bingo. You win the kewpie doll. The piece is a straw man.

August 7, 2009 7:01 am

idlex (06:20:40) :
“I think the consensus is that we can do this accurately [enough for this purpose] for some millions of years.”
Really?

Yes, [enough for this purpose]

JohnV
August 7, 2009 7:06 am

Anthony Watts:
While I applaud you changing the title, it came a little too late. Hundreds to thousands of people read your original title and came away with the wrong info.
It was clear from the start that your title was very wrong — even the press release that you supposedly based the title on says:
“There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”
That’s been the standard model for at least a decade. Papers from the mid-1990s put the CO2 effect at about 40% (with 60% from the Milankovich cycle).
You should take the high road and place a comment at the top of the article that you changed the title, instead of quietly making the change with a quick note down here in the comments.

Jean Meeus
August 7, 2009 7:37 am

SteveBrooklineMA (06:33:53) :
< Does anyone know what the extremes of the eccentricity are?
The extreme values of the eccentricity of the orbit of the Earth are zero and approximately 0.06. Presently it is 0.017, and slowly decreasing.
< It seems that other universities besides TAMU also exaggerate the
< eccentricity in diagrams, …
I think that the diagram is just an oblique view of the (nearly circular) orbit of the Earth.

Nogw
August 7, 2009 7:38 am

It seems that it is almost impossible for anybody in US academic circles to openly deny CO2 global warming:
“There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”
Obviously these words are a dilomatic compromise.
That is why Anthony’ s WUWT saga is most valuable.

August 7, 2009 7:39 am

“John R. Walker (02:39:11) : said
” So – why am I so sure I have known this for about 50 years?”
I must confess that I thought this was all well known and established fact that I learnt at school about 45 (gulp) years ago
tonyb

August 7, 2009 7:42 am

Did some one say rational energy policy?
I do a riff on a recent Economist article:
Great Britain is running out of electricity

August 7, 2009 7:43 am

stephen.richards (00:47:02) :
I’m afraid that one statement
and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years,
totally negates the value of the rest of the paper. If they are that sloppy in thier work then it has no value whatsoever.

Clark’s is a case of double face, hence the confusion. They do not mention anthropogenic emissions of CO2 in their article; however, Clark made declarations to the Media attributing the recent warming to human beings, not to natural causes.

The title of this blog was OK because it referred to Clark’s declarations to the Media of his University. He is writing one thing on his article in Science and saying another thing to the Media.

Ken S
August 7, 2009 7:44 am

Has anyone seen the papers by Australian engineer Dr. Peter Harris
He authored a paper entitled “Probability of Sudden Global Cooling.”
and “An Urgent Signal For The Coming Iceage”
Link at Iceagenow
http://www.iceagenow.com/Probability_94%25_for_imminent_global_cooling%20.htm
His papers have a nice graph that he uses to show what he thinks is the relationship of Preccssion, Obliquity, Eccentricity, Solar Forcing to each of the
Stages of recent Glaciation.
Any comments?

Mr. Alex
August 7, 2009 7:48 am

The Debate never ends

Nogw
August 7, 2009 7:49 am

Does some of you know why September (The Seventh month), October (The Eigth month), November (The Ninth month) and December (The Tenth moth), were called like that?
Did it mean an orbit of less excentricity as to make a year of ten months of 36 days?
[REPLY – My understanding is that July and August (for J & A Caesar) were later inserted into the 10-month calendar. At least that’s what I was told. ~ Evan]

Mike Bryant
August 7, 2009 7:58 am

I can’t believe some are complaining about the scale of the illustration… If put to scale the sun and earth would have to be less than a pixel… and still wouldn’t fit on the screen… There is a reason it’s called an illustration…
Mike

Ken S
August 7, 2009 7:58 am

“TallDave (04:26:49) :
So… people with SUVs are making the planet wobble?”
Only if they are driving around with tires that are out of balance.

J. Bob
August 7, 2009 7:58 am

Bill – 06:40:49 – Would you put on a reference where you got the graphs, thanks.

August 7, 2009 8:02 am

Oddly enough, one of the first posts ever on RealClimate was on this exact issue: http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/
Jeff Severinghaus remarked that:
“The contribution of CO2 to the glacial-interglacial coolings and warmings amounts to about one-third of the full amplitude, about one-half if you include methane and nitrous oxide.
So one should not claim that greenhouse gases are the major cause of the ice ages. No credible scientist has argued that position (even though Al Gore implied as much in his movie). The fundamental driver has long been thought, and continues to be thought, to be the distribution of sunshine over the Earth’s surface as it is modified by orbital variations …
The greenhouse gases are best regarded as a biogeochemical feedback, initiated by the orbital variations, but then feeding back to amplify the warming once it is already underway.”
Its nice to see more confirmation of Milankovitch forcings as the catalyst for ice ages, but as far as I can tell this study has no real bearing on our understanding of the relationship between the climate and greenhouse gases during glacial periods (which always had CO2 and other GHGs as a feedback rather than a forcing). I also wrote an article on this a few years back: http://www.yaleclimatemediaforum.org/2007/10/common-climate-misconceptions-co2-as-a-feedback-and-forcing-in-the-climate-system/

Ken
August 7, 2009 8:12 am

There’s a related theory that somewhat refutes, or augments, the Milankovitch Theory/Cycles addressed in the above:
http://muller.lbl.gov/pages/glacialmain.htm
http://muller.lbl.gov/pages/news%20reports/ScienceNews.htm
To my sparsely limited understanding, the theory proposed at the above two links seems pretty compelling…but my endorsement means next to nothing…but I’m sure you’ll find it very interesting nonetheless!

August 7, 2009 8:16 am

SteveBrooklineMA (06:33:53) :
Are they serious with that figure showing how much the orbital eccentricity can change? It’s quite dramatic, isn’t it? Does anyone know what the extremes of the eccentricity are?
REPLY: It seems that other universities besides TAMU also exaggerate the eccentricity in diagrams, see:
http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm
– Anthony

Why show the eccentricity at all since the authors talk about obliquity (axial tilt?
“That, in turn, can change the Earth’s axis – the way it tilts towards the sun – about two degrees over long periods of time, which changes the way sunlight strikes the planet. And those small shifts in solar radiation were all it took to cause multiple ice ages during about the past 2.5 million years on Earth, which reach their extremes every 100,000 years or so.”

Nogw
August 7, 2009 8:16 am

Then the calendar was corrected during the late roman empire, after the roman empire climate optimum , supposedly caused by a less eccentric orbit, ended. That could be possible.

Nogw
August 7, 2009 8:21 am

Ken S (07:58:45) : Only if they are driving around with tires that are out of balance
That remember us of that preposterous idea of some nasa scientists of changing the orbit of the earth, by conveniently colliding an asteroid on it.
Your idea is better: To build a gigantic counterweight, which, I suppose had to be pyramidal in shape….

Surfer
August 7, 2009 8:26 am

Alan Wilkinson (21:05:42) :
“I am a little puzzled. If this has conclusively settled the matter, where are the calculations that decisively predict the planet’s future temperatures?
Or is this simply a rough correlation of cycles with ice ages? ”
Future temperatures ? Hardly, but ice ages – maybe, see links: in http://www.ncdc.noaa.gov/paleo/milankovitch.html
is interesting calculation – (Hollan 2000) http://amper.ped.muni.cz/gw/articles/html.format/orb_forc.html

Dave vs Hal
August 7, 2009 8:29 am

cba (06:16:14)
“THat difference is even more interesting considering that the surface albedo of ocean is about 1/3 to 1/5th that of land surface . What is happening is the ocean water is involved in a water vapor cycle creating clouds that reduce the albedo – something that can’t happen easily when there is little to no additional water available”
If what you say is true, it demonstrates the negative feedback qualities of the oceans.

August 7, 2009 8:30 am

I wonder how they explained the Younger Dryas period?

Jimmy Haigh
August 7, 2009 8:31 am

TallDave (04:26:49) :
“So… people with SUVs are making the planet wobble?”
I worked in a very green oil industry service company for a while. Just about everyone there drove to work and a lot of them had SUVs. I was one of the very few sceptics there and about the only one who always got the bus to and from work. (Mind you I was usually hung over in the mornings…)

Alan the Brit
August 7, 2009 8:47 am

CheshireRed:-)
Well done that man, roast the litte so ‘n so. He really looked terribly uncomfortable as if he was desparate for a underwear adjustment period! I just loved that repsonse to the Greenpeace claim that the Greenland ice sheet would be gone by 2020/30 or whatever, “I didn’t check that press release I can’t do all of them”. He’s a CEO for crying out loud, he employs people to employ people to do that for him, just shows what calibre of employee they really do have at Redwar! Just like good old Von-Daniken? of UFO/Aliens fame claiming thay he never took most of the photos in his books but relied on others, when challenged on the scale of them in a “good old” BBC doc years ago. Well done Stephen Sackur! He won’t last.

Pragmatic
August 7, 2009 8:50 am

Jeremy (19:08:36) :
How the world of science has changed – now we COMPLETELY Ignore observations!
Yes. Which leads one to suspect virtually the entire creation you call the “world of science.” Only the use of mind altering drugs would explain the collective dyspepsia that has kidnapped good scientific minds and locked them behind a wall of political hysteria.
Unless the computer models are a spectacular failure. And their supremely arrogant creators are unwilling to acknowledge it.

andy stoffers
August 7, 2009 9:00 am

Interesting paper, which CONFIRMS the overwhelming importance of CO2. Take the last lines:
“subsequent increases in atmospheric CO2 and tropical Pacific SSTs (Fig. 5, C and D) demonstrate the importance of carbon cycle and ocean feedbacks in amplifying the deglacial response and causing global warming. Whether these changes in CO2 and SSTs were induced by deglaciation of Northern Hemisphere ice sheets (12) or high southern latitude insolation (40, 41), however, remains an open question.”
That’s right– this paper note the carbon cycle (CO2) has a huge role in amplifying global warming.
Did any of you read the paper?

August 7, 2009 9:02 am

edcon,
The most common explanation for the cause of the Younger Dryas is the shutdown of the North Atlantic thermohaline circulation in response to a sudden influx of fresh water from Lake Agassiz (a massive freshwater lake covering a chunk of North America that spilled into the Atlantic as temperatures warmed). See http://www.ldeo.columbia.edu/res/div/ocp/gs/pubs/broecker_science.pdf for more on this.
The paper here doesn’t really address these sort of abrupt paleo changes, but rather deals with conventional glacial cycles.

Pamela Gray
August 7, 2009 9:06 am

I still don’t think that greenhouse gasses are the main feedback, and certainly not the driver. The melting of the ice seems to have the ability to affect oceanic oscillations. This oscillation disturbance from the ice age to the warmer period more than likely set up oscillations that continued the warming trend, regardless of greenhouse variation. That greenhouse gasses became more abundant seems less of a driver than the disturbed oceanic oscillations and their ability to create weather pattern variations across the land. As the oscillating oceans warmed the land, CO2 became more abundant, but was not the major source of more warming. It was the oceans that done it.

Common Sense
August 7, 2009 9:06 am

The Sun melts ice – who would have thought!

Nogw
August 7, 2009 9:13 am

A guess: Are oscillations always harmonic or regular?, what if sudden changes?

Nogw
August 7, 2009 9:18 am

References to months names (above) are from (if I remember well) from Inmanuel Velikovki’s “Worlds in collision”

LarryD
August 7, 2009 9:19 am

From the Wikipedia article on Milankovitch cycles:

The shape of the Earth’s orbit varies from being nearly circular (low eccentricity of 0.005) to being mildly elliptical (high eccentricity of 0.058) and has a mean eccentricity of 0.028 (or 0.017 which is current value, if we take geometric mean, because phenomena in a gravitational field of Lobachevskian pseudosphere as used by Einstein behave logarithmically). The major component of these variations occurs on a period of 413,000 years (eccentricity variation of ±0.012). A number of other terms vary between 95,000 and 136,000 years, and loosely combine into a 100,000-year cycle (variation of −0.03 to +0.02). The present eccentricity is 0.017.
…Currently the difference between closest approach to the Sun (perihelion) and furthest distance (aphelion) is only 3.4% (5.1 million km). This difference is equivalent to about a 6.8% change in incoming solar radiation. Perihelion presently occurs around January 3, while aphelion is around July 4. When the orbit is at its most elliptical, the amount of solar radiation at perihelion is about 23% greater than at aphelion.

August 7, 2009 9:24 am

This is an extremely interesting topic for me. But I am utterly unimpressed by the abstract. The evidence is essentially based on one number, between 14,000 and 15,000 years (ago, a timing of some change), and doesn’t seem to say anything about the true problems with the Milankovitch-like theories which is the apparent absence of the 100,000-year timescale in the theory and their excessive presence in the data – even though the latter are heavily discussed in the press releases.
So in some sense, I remain an agnostic on the question whether the ice age curves are predominantly described by orbital and/or radiation changes of the Earth vs the Sun. They can be due to some new internal solar dynamics, random fluctuations in surrounding galactic cosmic rays, or internal chaotic “weather” on the Earth, too.

Nogw
August 7, 2009 9:25 am

evanmjones (20:42:35) : lacking end of your poem:
“….return to the right”

rickM
August 7, 2009 9:27 am

Causality and politics? How can the researchers, or the peson being interviewed go from orbital oscillations (which have been known for quite some time) and it’s effects on global weather patterns to short term theorized CO2 induced warming ? To make the leap from a 50 million year time scale to 200 years is simply remarkable.
Mixing hypothesises is not just irresponsible but irrational.

Stephen
August 7, 2009 9:29 am

I keep reading about the recent rapid temp increase! What increase? When I look at the station temps for the well placed stations, most show a decrease since 1934… the few that show an increase can be justified by changing ocean currents, or conditions! The only increase I see is from human manipulation of the data, and or heat island effect! Ice, (like glaciers etc.), will have a rapid melt at the end of its’ life, but that is the result of a natural process, even with a steady temp… set an ice cube out in a warm room and watch it melt slowly and then suddenly vanish at the end. When conditions are warm enough for humans to live comfortably on earth, the ice is going to melt, as it has been doing for the last 19,000 years!
Stephen

SOYLENT GREEN
August 7, 2009 9:30 am

OSU, huh?
The report (I blogged about earlier this week) that said Americans should quit having children to save the planet from AGW came out of OSU.
They are obviously awash in Kool Aid.

Highlander
August 7, 2009 9:39 am

Interesting article.
.
That is it ~was~ interesting until the same old line of BS was shoveled in ‘liberally’ about so-called ‘greenhouse gases’ and the like, effectively killing every trace of the authors credibility.
.
Since it’s ALREADY been shown —numerous times— that CO2 is NOT a contributor to warming, and indeed when the Vostok core samples are factored in, CO2 lags and NOT leads whatever degree of warming had already started.
.
Allow me to rephrase my first remark: Interesting —yet deceitful— article. A connivance wrapped in a deceit, and proffered as the truth.

Nogw
August 7, 2009 9:43 am

Pragmatic (08:50:57) Which remind us the words of our co-blogger Nasif Nahle:
“Scientia Redivivus” (Tr. Reconstruction of Science)
.
Insinuating we must revisit science from the beginning, going back to Pitagoras, Democritus, Johannes Kepler, etc., before changes intoduced by “cultural”, fanatics’, creed’s, or political revolutions.
Books, knowledge it is out there, waiting for open minded and free individuals.

Indiana Bones
August 7, 2009 9:56 am

First, I’ve not read the article as it is still behind a paywall. But from the abstract:
“Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. ”
Am I the only one that sees this language a study in waffling compromise? Hey, let’s tell everyone they’re right and that way no one has to be wrong! Wrong. IMO, the clan that has been force feeding AGW theory and disseminating it like a bad cold across the earth – is wrong. Nothing quoted from this paper so far provides evidence of the empirical correlation between temperature and atmospheric CO2. Geologists tell us CO2 changes follow temperature. The paper appears to tell us temperature changes because of earth’s orbital variability (high school physics.)
Can anyone who has read the paper, confirm the authors’ demonstration of atmospheric CO2 forcing temp change? And if so, what percentage of that change?

August 7, 2009 9:56 am

andy stoffers (09:00:43) :
“Interesting paper, which CONFIRMS the overwhelming importance of CO2. Take the last lines:
“subsequent increases in atmospheric…”
You lost the word “subsequent” and you’ve added “overwhelming”. Read the whole paper.

August 7, 2009 9:57 am

Nogw (09:43:26) :
“Pragmatic (08:50:57) Which remind us the words of our co-blogger Nasif Nahle:
“Scientia Redivivus” (Tr. Reconstruction of Science).
Insinuating we must revisit science from the beginning, going back to Pitagoras, Democritus, Johannes Kepler, etc., before changes intoduced by “cultural”, fanatics’, creed’s, or political revolutions.
Books, knowledge it is out there, waiting for open minded and free individuals.”
Indeed! Tealc said.

Nogw
August 7, 2009 10:01 am

Highlander (09:39:27) : Interesting —yet deceitful—
Agree!, but, this time, instead of “pouring the empty into the void” they are “pouring the void into the empty”.
Better let us re-read Velikovsky’s “Worlds in Collision”, a beautiful book of the pre-global warming era.

David Y
August 7, 2009 10:06 am

I can accept increased insolation and elevated GHG levels as a catalyst for ENDING an ice age. However, decreased insolation, while perhaps resulting in a cooler planet, doesn’t on its own explain (in my mind) glacial genesis and sustained growth (of the extent in the last significant ice age).
We have glaciers in mountains where precipitation is the result of rising moist air dropping its moisture as it cools and air pressure drops. These glaciers can quickly grow or shrink, based on precipitation feeding them and other conditions. What really drove the continued accumulation of snow/ice in northern Canada? Do we have the zone of glacial genesis pinpointed? Shouldn’t a cooler world be drier? What was the condition of the Arctic Ocean during the last ice age–completely buried or possibly open with warm currents, feeding moisture to the glaciers?
The science of confirming changes in orbit may be settled, but I remain skeptical about our understanding of ice ages. There are too many other potential factors out there (the Earth has local climates within regional climates within a global climate; Earth is a planet in the ‘climate’ of the solar system, which is in the ‘climate’ of our galaxy, and so on).

radar
August 7, 2009 10:12 am

re: Richard Thorpe:
Thanks for the correction. CO2 would be a Positive feedback both into and out of the ice ages, [increasing the perturbation both ways].

August 7, 2009 10:16 am

rickM (09:27:06) :
Causality and politics? How can the researchers, or the peson being interviewed go from orbital oscillations (which have been known for quite some time) and it’s effects on global weather patterns to short term theorized CO2 induced warming ? To make the leap from a 50 million year time scale to 200 years is simply remarkable.
Mixing hypothesises is not just irresponsible but irrational.

Had you actually bothered to read the paper (or even just the abstract) we would have been spared this irrelevant post!
The paper considered growth of the ice sheets in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Given that, it’s hardly surprising that the author when interviewed discusses two of the three forcings they studied!

Kevin Kilty
August 7, 2009 10:19 am

Patrick K (20:44:40) :
None of this information is really new. However, I have to complain about the graphic and the caption attached to it. Both of the ellipses shown are extremely exaggerated and neither is anywhere close to the actual ellipticallity of the Earth’s actual orbit which ranges from an almost perfect circle to only slightly elliptical. Even at it’s most extreme elliptical orbit, the earth’s orbit is very close to a perfect circle (A perfect circle is e=1, the Earth’s most extreme orbit is e=0.97). In fact it is so close that a human cannot usually distinguish it from a circle.

Not only this, but the sun is also plotted at the center of the ellipes rather than at a focus. But the idea is what is important. I have another issue. Lief and other various posters are tossing around Delta insolation figures that are not clar to me. I can see that 0.1% TSI must be just a tad over 1w/m2, and I know that the annual variation is about 90 w/m2, but the only figure supplied for the variation in the orbital cycles is “50 times as much” which must mean about 50w/m2. This is the total, peak to peak, variation including all orbital parameters, and obliquity?

Nogw
August 7, 2009 10:23 am

radar (10:12:15) :
re: Richard Thorpe:
Thanks for the correction. CO2 would be a Positive feedback both into and out of the ice ages, [increasing the perturbation both ways].

I think it depends of the CO2 source, if from some grass species, it will undoubtedly provoke some peculiar perturbations, as to believe in global warming.

August 7, 2009 10:29 am

Indiana Bones (09:56:07) :
the article as it is still behind a paywall.
The ‘Supporting Online Material’ that tells what they really did can be accessed [deficiency in Science’s paywall system] and is here

August 7, 2009 10:37 am

Scientifically speaking, the case for a “forced” Milankovitch cycle as opposed to a continuum of unforced natural variability has not been convincingly evidenced.
In a chaotic system it is possible that cycles will synchronize with small external forcings.

Pamela Gray
August 7, 2009 10:41 am

A key to increased ice is lack of Summer melt in-between the Winter moisture and cold needed to build them some more. And the key to increased melting of ice is more and more Summer melt, by whatever means. My hunch is that Summer winds pick up to move the floating ice to parallels that promote melt and Summertime warm rainy days melt glaciers, more than they are restored during each Winter season. I just don’t see greenhouse gas variations being majorly involved. These weather-related long-term trends are ocean sourced that I believe occur with better results when the Earth is tilted to or away from the Sun in these extreme orbital wobbles.

Jean Meeus
August 7, 2009 10:42 am

Nogw (07:49:13) :
< Does some of you know why September (The Seventh month), October
< (The Eigth month), November (The Ninth month) and December (The
< Tenth moth), were called like that?
Those names were devised during the Roman empire. At that time, March was the first month of the year. Consequently, the seventh month was September. Those names were retained when later it was decided to start the calendar year with January.

Jim
August 7, 2009 10:42 am

**************************
GK (00:57:33) :
So this DEFINITIVELY proves that CO2 played no part in previous climate cycles.
There are 2 stunning conclusions from this :
1) The increase in CO2 that follows about 800 years after each interglacial starts has no (or very little) impact on earth`s climate.
2) It those massive increases in CO2 had no impact in earth`s climate back then, then CO2 can not possibily have an inpact now.
This finding proves there is no man made AGW.
*****************************
This is such a sweet moment and the authors of this paper either don’t get it or had to bow to the Team to get published. This result completes the process of making a complete fool of the Highest Idiot, Al Gore. He is a total clown and should be thrown in Jail for the harm to society he has done and the flim-flam he has promoted. Here is Al’s own infamous chart. You can see clearly that the temperature goes up first, THEN CO2 goes up. CO2 is the tail, not the dog.
http://tucsoncitizen.com/wryheat/2009/06/24/al-gores-favorite-graph/

George E. Smith
August 7, 2009 11:00 am

Is it just possible that once in our lives; when somebody says; ‘this is how much the earth’s orbit can change.’ or words to that effect; that they actually make a real drawing that shows ‘how much the earth’s orbit can change’. Is that too much to expect ?
The drawing above shows two egg shaped orbits that are more pointy on the right (the Little Endians), and less pointy on the left (the Big Endians), and the sun is displaced upwards from the major axis, instead of being at one of the foci of the near elliptical orbits; both of which have vastly excessive eccentricities.
Oh I see it is an Aggie joke from the chicken farm; well that might explain it.
Reminds me of a high school Physics (Optics) exam, where a classmate, with fifteen seconds left to tackle one more 15 minute question on eye defects drew some eggs like that and added lenses to show how short sightednesss etc worked; took him five seconds to scribble the eyes, and a couple of rays. Well better than missing an entire question.
The teacher; on marking his paper wrote in equally scribly red ink; “Anyone with eyes like this would be blind anyway !”
This is suppoed to be the Premier Science Blog; I’ll not blame you though Anthony; nor Chasmod.
George

George E. Smith
August 7, 2009 11:15 am

“”” Smokey (19:58:33) :
This article completely disregards Occam’s Razor: “Never increase, beyond what is necessary, the number of entities required to explain anything.”
~William of Ockham, 1285-1349 “””
And I believe it was Albert Einstein who said; “Science theories should be as simple as possible ; but no simpler !”
George

crosspatch
August 7, 2009 11:19 am

“And the key to increased melting of ice is more and more Summer melt, by whatever means.”
And that is what I believe not enough people concentrate on. They look only at temperature when considering melt and do not consider changes in precipitation patterns. An area that might have had a dry summer season could see a change in jet stream patterns that brings in more summer rain. A torrential rain can melt a very large amount of ice, particularly if followed by a few sunny days.
Also, as the ice melts, its surface will become “dirtier” as accumulated dust builds up on the surface. This would reduce the overall albedo and increase heating from sunlight even more.
There is evidence that the jet stream over North America brought Pacific storms in at a much more Southerly location than it currently does. This has been hypothesized to be the source of such lakes as Bonneville (current Great Salt Lake, UT) and Lahontan (current Pyramid Lake, NV) in the Great Basin region. As this jet stream migrated farther North, it would have brought rains to the upper Midwest and would be expected to greatly impact any ice sheets under these storms.

Gerry
August 7, 2009 11:33 am

“…due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
So, serious greenhouse gas emissions occurred 200 years ago? That’s 41 years earler than even “We must return to the Garden of Eden” James Hansen claims anthropogenic greenhouse gas emissions were starting to be a problem. U.S. climate “research” is a trainwreck.

Jay
August 7, 2009 11:51 am

Huh.
Dumb question from the the less well-schooled on this topic:
What happens when the cooling portion of the Milankovitch cycle combines with an extended solar minimum like the one we seem to be seeing now? Does it amplify the cooling even more?

August 7, 2009 11:57 am

Jay (11:51:20) :
What happens when the cooling portion of the Milankovitch cycle combines with an extended solar minimum like the one we seem to be seeing now? Does it amplify the cooling even more?
The Milankovich variations are 50 times larger than solar cycle effects, so the latter are drowned in the noise.

keith
August 7, 2009 12:00 pm

Only one thing left to do now, cut off all funding to Oregon State University, send out an army of reporters to dig through the trash of Peter Clark, Arthur Dyke, and Jeremy D. Shakun and use all material to attack personally. Heck make a youtube video, picket there places of work and home, link them to the oil companies, compare them to the third reich, etc, etc etc

ET
August 7, 2009 12:02 pm

Does anybody have a link to the actual paper itself (rather than the summary)? Would love to read it…
Ed

TomLama
August 7, 2009 12:04 pm

So? They re-observed Milankovitch’s 100,000 year natural cycle?
There is a 11,500 year cycle between ice ages. We are nearing the end of an interglacial warm period. We are only a few short summers away from an ice age in geological terms. If the sun spots do not ramp up I think we are in for a mini ice age anyway.

WilliMc
August 7, 2009 12:10 pm

How does the theory correlate with other ice ages? During the Pliocene 33 ice ages occurred—every 47,000 years. Then during the present age–the Pleistocene–we have had 16 ice ages which are 100,000 years duration, when seal levels fluctuated 120 meters. How does the time-change affect the above theory?
See William McClenney’s article for the above data:
http://icecap.us/images/uploads/McClenneyPart_I.pdf

WilliMc
August 7, 2009 12:12 pm

By the way, for those who are interested, McClenney divided his article into five parts. To access those simply change the number after Part_ .

August 7, 2009 12:20 pm

Oh great funded research from tree cutter Oregon State, and Oilers Texas A&M.
http://fiestamovement.com/agents/view/58

crosspatch
August 7, 2009 12:23 pm

Jay,
Considering that over the past couple of million years we are 90% of the time in glaciation and 10% of the time in warm interglacial, we would expect to see glaciation continuing over the entire spectrum of solar activity profiles. So glacial periods would continue even during extremely active solar cycles.
But having said that … there certainly is some “trigger” that very rapidly causes a state change from glaciation to interglacial and back. This change is apparently not gradual at all and happens very quickly … over the span of a human lifetime. Also, climate tends to be very unstable during glacial periods with extreme changes in climate happening very quickly. Areas can change from forest or grassland to tundra and back again in only a couple of human generations.
This “trigger” could be any number of things … a major volcanic eruption at just the right moment … a change in jet stream location … who knows? We will be finding out “soon”.

Nogw
August 7, 2009 12:28 pm

Dave:
And werent wooly mammoths frozen suddenly as well? Didnt they live in temperate lands, as shown by the grass in their stomachs? And then were frozen solid in some cases, almost overnight?
Chances are that if this happens again….grass will be found in “their” stomachs. 🙂

Barry
August 7, 2009 12:30 pm

Considering what has been happening at the NSIDC this makes a whole lot of sense to me.
The melt in the spring has been accelerating over the past couple of years. But the freeze has also been accelerating in the fall. I was wondering what was going on. If the earth’s orbit is slipping into a greater elliptical path this makes complete sense. As it gets closer to the sun the rate accelerates but then when it slips farther away the opposite could be expected.
Does anybody else see this trend?

Pragmatic
August 7, 2009 12:47 pm

Nogw (09:43:26) :
Interesting you should note Democritus whose atomist theory was developed alongside his euthymia view of cheerfulness. It requires a certain philosophical cheer not to be discouraged by warmist’s need to discard the foundations of science.
Agreed it takes an open mind to read the books that contain that foundation. But with the vituperous attacks on those critical of AGW “consensus” – it’s hard to find encouragement to do so(this site an exception.) Pythagorus, and Keppler would suffocate on the paucity of intellectual curiosity today. Democritus would likely collapse in a fit of laughter.

Kevin Kilty
August 7, 2009 1:00 pm

Some time ago Danish researchers, looking at Greenland ice cores, noted that we come out of “ice ages” very abruptly–perhaps in a decade air temperature goes from that typical of the ice age to that typical of interstadial. I never recall any data showing a correspondingly rapid descent into the ice age.
Now a sufficiently large positive feedback can take a slow orbital forcing input and produce a large rate of change in the output. What/where is this feedback? It cannot be CO2, which as someone else on this thread pointed out is positive in both directions. This feedback must be asymmetric.

August 7, 2009 1:01 pm

George E. Smith (11:00:41) :
The drawing above shows two egg shaped orbits that are more pointy on the right (the Little Endians), and less pointy on the left (the Big Endians), and the sun is displaced upwards from the major axis, instead of being at one of the foci of the near elliptical orbits; both of which have vastly excessive eccentricities.

I don’t understand those who have so much trouble accepting with this simple sketch. It isn’t perfect, but too bad either. Just consider the oblique viewpoint.
If you want a slightly more realistic view, I have a simulator with a similar diagram at http://arnholm.org/astro/software/ssg/ (Sun/planet sizes not to scale in web page diagram, but it is an option on the software).
Actually, the eccentricity of the earth’s orbit is so modest that it is not immediately obvious in such a diagram where the long and the short axes are oriented, especially if you select an arbitrary viewpoint relatively close to the ecliptic.

August 7, 2009 1:08 pm

When talking about ellipses, precessions and other variations we need to bear in mind that there are many bronze age (and later) artefacts designed to let the sun into a specific point at a specific hour on a specific day. The one I saw yesterday still fulfils this function exactly so presumably post ice age ellipses and variations have been minimal for the last ten thousand years and have no impact on climate during this time.
Tonyb

bill
August 7, 2009 1:09 pm

J. Bob (07:58:57) :
Bill – 06:40:49 – Would you put on a reference where you got the graphs, thanks

The plots are mine
The data is from various sources:
but mainly
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/

Vincent
August 7, 2009 1:17 pm

The basic story is, we have been living in an ice age for the last 2 million years -the pleistocene – and this had been punctuated for brief periods of so called interglacials. Yet there is no Milankovitch cycle that endures for 2 million years so the pleistocene must have been caused by something else.
The real question is how come we emerge into interglacials for periods of 10 or 11 thousand years? This period is closest to the period of precession. So maybe it is the precession that takes us out, when the NH summer is closest to the sun. Now we are at the exact opposite and are maybe ready to go back in the fridge. Just a thought.

John S.
August 7, 2009 1:25 pm

Now if they could only explain–from first principles–how the power of insolation can be amplified by CO2, they’d really have something.
Have a good weekend everybody, that’s not going to happen today.

Kevin Kilty
August 7, 2009 1:48 pm

crosspatch (12:23:46) :
But having said that … there certainly is some “trigger” that very rapidly causes a state change from glaciation to interglacial and back. This change is apparently not gradual at all and happens very quickly … over the span of a human lifetime. Also, climate tends to be very unstable during glacial periods with extreme changes in climate happening very quickly. Areas can change from forest or grassland to tundra and back again in only a couple of human generations.

This bears on the posting I just made. I have no information regarding rapidity of falling into an ice age. Is it as rapid as the climb out appears to be? The paths in and out could involve different geographical areas, but still one needs a large feedback (my term) or trigger (your term) to accomplish this. And CO2 has a long delay–perhaps H2O works better. Coming as it did at the tail end of the LIA, even Tambora was not a large enough perturbation to do the job. It did produce a year without summer. But one of the narratives about initiating an ice age, that it occurs with a summer carry-over of snow cover in northern Quebec, is not actually right. Otherwise 1815 should have done the job, right?

August 7, 2009 1:48 pm

Earth is not isolated in the cold, 3D, unbounded and infinite space:
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1978ApJ…223..589V&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES

Archonix
August 7, 2009 1:49 pm

Anthony, July and August were originally named Quintilis and Sextilis as the 5th and 6th months of the roman calendar. They did use a 10 month calendar at one time but that was a long, long time before Julius Ceasar, who had July named after himself after he was assassinated.
Which is one way to get your name immortalised, but not one I’d pick if I was given the choice…

eric
August 7, 2009 1:58 pm

The significance of this paper as other’s have mentioned is way overhyped.
The idea that the malinkovich cycles have triggered ice ages has been generally accepted for years.
However the axial tilt change is only a trigger. It causes the summer ice and snow cover to decrease, reducing the earths albedo. This is a positive feedback, causes further melting and an increase in atmospheric CO2 and methaen. The greenhouse effect causes a feedback cycle which further warms the earth and deglaciation proceeds. When the axial tilt change is reversed, the feedbacks amplify a temperature decrease, and glaciation proceeds completing the cycle.
This is explained in the following article:
http://pubs.giss.nasa.gov/docs/2003/2003_Hansen.pdf
“Can we Defuse the Global Warming Time Bomb?”
“…The natural millennial climate changes are associated with slow variations of the Earth’s
orbit induced by gravitational torque by other planets, mainly Jupiter and Saturn (because they
are so heavy) and Venus (because it comes so close). These torques cause the Earth’s spin axis,
now tilted 23 degrees from perpendicular to the plane of the Earth’s orbit, to wobble more than
one degree (about 40,000 year periodicity), the season at which the Earth is closest to the sun to
move slowly through the year (about 20,000 year periodicity), and the Earth’s orbit to vary from
near circular to elliptical with as much as 7 percent elongation (no regular periodicity, but large
changes on 100,000 year and longer time scales).
These perturbations hardly affect the annual mean solar energy striking the Earth, but
they alter the geographical and seasonal distribution of insolation as much as 10-20 percent. The
insolation changes, over long periods, affect the building and melting of ice sheets. Today, for
example, the Earth is nearest the sun in January and farthest away in July. This orbital
configuration increases winter atmospheric moisture and snowfall and slows summer melting in
the Northern Hemisphere, thus, other things being equal, favoring buildup of glaciers. Insolation
and climate changes also affect uptake and release of CO2 and CH4 by plants, soil and the ocean,
as shown by changes of atmospheric CO2 and CH4 that are nearly synchronous with the climate
changes (Figure 2)….”

Boris
August 7, 2009 2:05 pm

In other news, water wet.
Seriously, this is in the IPCC report guys.

Martin Mason
August 7, 2009 2:06 pm

@Mike Abott
Surely this report totally debunks AGW no matter how you spin it and it is what will always debunk AGW. We’ve had severe temperature swings without man made CO2 which would suggest that AGW has had nothing significant to do with the swings?

WestHoustonGeo
August 7, 2009 2:08 pm

Note the safe harbor statement:
“…and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.”
Which was neither suppported nor referenced. Nor true.

a jones
August 7, 2009 2:11 pm

Bah Goom, clever fellow that J Caeser fellow to get July named after him only after he had been murdered.
Still probably no problem to a lad used to throwing legions across rivers.
And no there is nothing new in this paper that you could not have read in papers written a hundred years ago.
Whih is why when was young the idea was so discredited, the cyles of the proposed mechanism don’t fit with the observation.
Talk about reinventing the wheel.
Kindest Regards.

Pamela Gray
August 7, 2009 2:18 pm

Eric, what then causes the temp to correlate so highly, both in overall trend and ups and downs, historically as well as currently, with oceanic oscillations? Is there no place for oceanic circulation patterns (which have changed over the millions of years) and oscillations (which have also changed over the millions of years) in your model? How can that be when we see direct and obvious cause and affect, complete with data and well-known mechanisms? Just how and when do you jump from Earth bound natural variation ending as the driver to CO2 acting as the driver?

David Y
August 7, 2009 2:23 pm

Two other quick questions/thoughts from someone way under-“edumacated” in this area:
1. Looking at Prof. Steven Dutch’s diagram (3rd down on the page http://www.uwgb.edu/dutchs/EarthSC202Notes/GLACgeog.HTM ) showing the retreat of the continental ice masses over North America, would it be logical to assume that this ‘retreat’ moved in the direction of the ‘birthing’ of those same glaciers? That ‘point of origin’ appears to be on Baffin Island, on the west side of the mountains. Other than general cooling of the planet, is there any other meteorological (jet stream variation/fixation, persistent storm zone, other), oceanic (current change) or geologic (volcanic or uplift?) mechanism that could have caused massive acceleration and persistence of the accumulation of snow on the west slope of Baffin Island? Or, could there have been a global accelerant (like a sudden doubling of global or hemispheric water vapor due to increased luminosity (driving evaporation) or an oceanic asteroid hit? (I know, reaching on that one–maybe the next Bruce Willis movie plot there)
2. (Per Nasif’s reference) What effect would the solar system’s passing through in interstellar cloud (for extended periods) have on GCR’s (thinking of the cloud ‘shielding’ the earth from the solar wind) and hence cloud formation? Any? Am I smoking dope here?
Thanks all–and have a great weekend!

August 7, 2009 2:34 pm

To qualify carbon dioxide as a secondary amplifier of the Earth’s atmosphere warming, answer the following questions:
What’s the absorptivity-emissivity of carbon dioxide at its current partial pressure in the atmosphere?
What’s the total emittancy of carbon dioxide at its current partial pressure in the atmosphere?
What’s the real value for climate sensitivity to carbon dioxide?
What’s the heat capacity of carbon dioxide at its current density in the atmosphere?
What’s the specific heat capacity of carbon dioxide at its current density in the atmosphere?
What’s the thermal diffusivity of carbon dioxide at its current density in the atmosphere?
What’s the specific volume of carbon dioxide in the atmosphere at the present time?
What’s the real effect of carbon dioxide in the atmosphere?
After answering the previous questions tell me if the carbon dioxide is capable of warming up or cooling down the Earth.
The carbon dioxide more than being an amplifier of warming effects (which definitively it is not) it’s a distributor of heat and a drainer of heat into the outer space. A very different subject is water in anyone of its three phases. I have no doubt; Arrhenius inflicted a great damage to climate science with his assumptions.
If you accept the “secondary” role of carbon dioxide in warming, you’ll be accepting one more fallacious doctrine from AGW side and you’ll be approaching more and more to the fourth religion.
As a matter of sane thinking, why the carbon dioxide, during warmhouses does not heat up the Earth stopping the trend to the next icehouse? Evidently, the carbon dioxide is not the powerful “greenhouse” gas proclaimed by AGWers.
Thanks for reading…
Nasif Nahle

Evan Jones
Editor
August 7, 2009 2:39 pm

Just how and when do you jump from Earth bound natural variation ending as the driver to CO2 acting as the driver?
I can see CO2 content as having a small underlying effect, depending on overall conditions. I could see CO2 driving up surface or tropospheric temps by that much over a century. But I doubt it is a primary driver and I doubt the positive feedback assertions.
For the IPCC to be correct in its mailine predictions, temps would have to increase 5 times the NOAA-adjusted rate (and it’d have to be faster, after a decade or so of cooling). That seems to be well off the mark.

August 7, 2009 3:09 pm

I saw a graph once showing ice ages correlated with volcanic activity.
Volcanic activity follows the sun

August 7, 2009 3:13 pm

Like I say, hope for warming.

August 7, 2009 3:14 pm

I haven’t read through all the comments, but I’m not buying this.
Unless the change in rotation is sudden, we don’t have a sudden triggering of, or out of, ice ages.
If it’s true, then we only have two sets of orbital parameters: one set which favors an ice age, and lasts a long time, and another set which favors interglacials and lasts a short time. A slow orbital change over 100,000 years doesn’t solve this problem.

Tom in Florida
August 7, 2009 3:18 pm

The curent climate of the Earth is approx 90,000 years of glaciation and approx 10,000 years of interglacial warmth. The rest is just weather.

August 7, 2009 3:37 pm

MarcusK (02:51:25) : If it’s just ‘local’ orbital mechanics (Saturn, Jupiter, etc) why does the earth stay completely out of the ice age cycles for dozens of millions of years? What causes the deeper phases of “ice age cycles” and “no ice ages cycles”?
C Colenaty (05:23:29) : Maybe this period might be explained by tectonic movement. But then why was there a prior glaciation? And what happens to the MT for those very long periods of time when glaciation is absent?

The most popular theory is that the presence of a continental landmass one or both of the Poles prevents oceanic circulation between polar and equatorial regions and causes ice to build up on the polar land mass(es). The tectonic drift of Antarctica brought it over the S. Pole 2.5 million years ago, triggering the current Ice Ages. Pangaea was the landmass over the South Pole during the Permian or Karoo Ice Age from 360–260 Mya. There are other theories, but that one seems most plausible to me.
On another issue, my understanding is that descent into glaciations is gradual, while the rise into interglacial periods is rapid (relatively). That implies some positive feedback tipping point is reached as Milankovitch insolation approaches maximum, but that such a tipping point is not present during the long neoglaciation descents.
BTW, we passed the maximum insolation point about 10,000 years ago and are in the gradual descent phase now. If CO2 can forestall neoglaciation (a big if), then it would be a GOOD THING, since warmer is better. So light up your cigars and gun the engines on your clunkers — you might be doing the entire planet a favor.

Gary Hladik
August 7, 2009 3:40 pm

If I’m reading the abstract correctly, the main accomplishment of this paper is “to constrain the timing of the Last Glacial Maximum (LGM)” more precisely than before by using a large number of proxy measurements over the period in question, i.e. 10,000 to 50,000 years ago. As a result, these more precisely dated glacial events can now be better correlated (or de-correlated) with other geological events of the same period. Is that about right?
If so, then this would seem to be an example of the “improved measurement” type of paper so necessary to science, where the devil really is in the details. Though important to our scentific understanding, such fine tuning papers aren’t terribly sexy, which would explain the unjustified attempt at hype in the press release. While not terribly relevant to the CAGW question of our times, it’s certainly worth covering on a science blog like WUWT.
BTW, according to Wikipedia the Earth’s orbital eccentricity didn’t change a whole lot in the 40,000 years covered, so the orbital illustration at the top of the article seems a bit misleading. Maybe a better choice would have been one showing changes in axial tilt and precession.
Thanks for covering this, Anthony. I’ve always thought ice ages are really cool! (Sorry, couldn’t resist.)

crosspatch
August 7, 2009 3:59 pm

“But the freeze has also been accelerating in the fall. I was wondering what was going on. ”
Changes in Earth’s orbit would not be fast enough to exhibit visible changes in a person’s lifetime. The changes are very slow. If it takes 100K years for a cycle, then it takes 1000 years for 1% of the cycle and a person’s lifetime (for the sake of round numbers) would be 10% of that so over the course of the life of a 100 year old person we see .1% of the total progression taking place.
There is some sort of a “tipping point” that takes place and flips the state.
Now that assumes the changes ARE gradual. Maybe they aren’t. Maybe alignment of things causes a sudden change in the shape of the orbit.

Jeremy
August 7, 2009 4:31 pm

find it strange that so many people exhibit a Pavlovian hatred for energy companies. Since ~88% of global primary energy is generated from fossil fuels (the remainder is nuclear and hydro, with a trace of renewables), these “evil” energy companies keep our families from freezing and starving to death.
Yes this is absolutely true. Think what fossil fuel energy has done for living standards and food production. Look around around your home or office or open the refridgerator – Imagine a world without plastic…
The sad fact is that “Greens” are completely delusional. Without all this energy and the ability of a few to produce so much stuff for the many, we all would have little time or energy to devote to being Green. We would all be either dead or living in abject poverty, diseased and totally exhausted from 14 hour days breaking our backs trying to scratch out a meagre existance.
Being “Green” is a luxury that only food and energy surplusses have recently allowed. It is jet aircraft and large diesel powered supply boats that allow some of us to study coral reefs around carribbean islands and worry about sea level rise. The very computers we all use are made from plastics and they are the very tools that help some of us write our Green research papers. Furthermore, the commercialization of these computers were actually pioneered by the massive funding of Oil Companies for seismic analysis long long before these computers found any application in business…without the funding these computers for climate modelling might not even exist.

Evan Jones
Editor
August 7, 2009 4:36 pm

I haven’t read through all the comments, but I’m not buying this.
Unless the change in rotation is sudden, we don’t have a sudden triggering of, or out of, ice ages.

There could be positive feedback that forces things more quickly than the orbital changes in and of themselves.

August 7, 2009 4:43 pm

Peter Jones (19:52:20) :
Even though,
” Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age . . .”
They still say that,
“One of the biggest concerns right now is how the Greenland and Antarctic ice sheets will respond to global warming and contribute to sea level rise . . . ”
You can certainly tell where their funding is coming from.

Probably from the nuclear industry concerned about siting their power stations near the sea?

August 7, 2009 4:52 pm

GK (00:57:33) :
So this DEFINITIVELY proves that CO2 played no part in previous climate cycles.
There are 2 stunning conclusions from this :
1) The increase in CO2 that follows about 800 years after each interglacial starts has no (or very little) impact on earth`s climate.
2) It those massive increases in CO2 had no impact in earth`s climate back then, then CO2 can not possibily have an inpact now.
This finding proves there is no man made AGW.

No it proves that you haven’t read the paper, like most of those who’ve commented so far.

Dan Murphy
August 7, 2009 4:55 pm

OT, but there was a nice mention yesterday in the Washington Examiner of Anthony, and the Surface Stations project. Unfortunately, although they mentioned Anthony by name, they did not mention surfacestations.org web site. I mentioned the web site in the comment section however. Here is the link: http://www.washingtonexaminer.com/opinion/blogs/beltway-confidential/Weather-stations-give-flawed-temperature-data-meteorologist-claims–52563192.html

cba
August 7, 2009 5:08 pm

“”Dave vs Hal (08:29:53) :
cba (06:16:14)
“THat difference is even more interesting considering that the surface albedo of ocean is about 1/3 to 1/5th that of land surface . What is happening is the ocean water is involved in a water vapor cycle creating clouds that reduce the albedo – something that can’t happen easily when there is little to no additional water available”
If what you say is true, it demonstrates the negative feedback qualities of the oceans.
“”
I think most of my comments above are correct or should be acceptible. Some may be just be hypotheses. It should demonstrate the oceans & water vapor cycle provide the negative feedback or even a temperature setpoint and control system. It also should demonstrate the importance of the Earth’s surface configuration and heat dissipation system. After all, this 8 W/m^2 +/- average annual variation which results in a Temperature curve that is maximum during NH summer where the insolation is at a minimum and a maximum during SH summer where the insolation is at a minimum means that the surface configuration related factors over ride this average difference in insolation with room to spare.
This also adds in the precession of the equinoxes – where the dates for the aphelion and perihelion (furtherest and closest approach to the Sun) shift relative to the tilt direction of the Earth (seasons). When they have shifted by 6 months, then the perihelion will occur in June/July and the aphelion will occur around January so that summer in the NH should be even hotter and winter should be colder (all else being unchanged) – with the exception that if somehow there is persistant snow cover started that reduces albedo then all bets are off on how warm things can get with that extra albedo if it exists. Otherwise, it would seem that perhaps we’d be in more of a hothouse condition as there might be less cloud cover formation and hence lower albdeo. Consequently, I’m not even sure if one could simply predict what portion of these cycles would actually permit the formation of glaciation or would actually cause the opposite or if simply some internal random variation – like ENSO – might be enough to randomly kick us into the other mode (glaciation / nonglaciation).
Nasif –
by some altitude, a doubling in co2 will increase clear sky absorption by around 3 1/2 W/m^2. This will also cause an increase in absoption and in emission for any parcel of air at a give temperature. Due to the geometry (cold space outward, warm surface inward) the power is basically absorbed only coming outward but this parcel must radiate inward at the same rate it radiates outward. Increasing the emissivity demands that more power will be radiated if the T remains unchanged – which means that the T will have to drop a bit unless there is more power coming from above as well. Of course, 62% or so of the atmosphere has cloud cover that is already doing substantial blocking as well.
Considering the whole system has a rough rise of 33 K for all GHGs and that it has around 150 W/m^2 of ‘blocking’, one can simply take 33/150 to see the actual average ‘sensitivity’. This is just under 0.25 Kelvins per W/m^2. One can also determine that a straight radiative solution to an increase in absorption results in the need for the surface to rise in T by around 0.3 K to pass an additional 1W/m^2 all the way out. That suggests that the Earth system has net negative feedback going on. It also suggests that a CO2 doubling results in about 0.75 Kelvins after all feedbacks have been accounted for in the real world.
That brings us back to the feedback/setpoint mechanism of cloud/atmospheric albedo increasing with increased water vapor – which is the realm where Lindzen’s IRIS effect ideas come from. It also provides us with a rather random sort of a mechanism that can be influenced by cosmic rays, the solar magnetic field, and solar cycle phenomenon affecting Earth’s atmosphere in a far greater fashion than a mere 0.1% solar cycle TSI variation would suggest. It also opens us up to more volcanic influence and potentially pollution factors.
My own suspicion places this current sensitivity to around half of the simple average or between 0.1 and 0.2 Kelvins per W/m^2.

bugs
August 7, 2009 5:09 pm

Back in the bad old days of the Soviet evil Empire scientists in most disciplines had to bend the knee to Marxism. It was often qutie amusing. They would spend the first few paragraphs declaring their allegiance to Karl and Vlad (and the Great Teacher of Humanity Joseph Stalin) and then go on to describe their research in paleontology, math, archaeology, etc., which had absoluteoy nothing to do with Marxism. Some fields suffered more than most: archaeologists had to create a new “culture” in 4th century Ukraine to replace the Ostrogothic state, and Russian SF was denied Einstinian time dilation because Lenin didn’t like it. Something similar seems to be happening here, in as much as Science or Nature will not publish “deniers” and yoiu can’t get NSF funding (and thus tenure) if you are on the outs with the Goracle.

You have no evidence that the authors put the reference to AGW in because of political pressure. None at all. If you have, I would love to see it.
If you want my opinion as to why they put it in, it’s because they knew their science would be misrepresented by websites like this. And that’s exactly what happened. Climate scientists have known for years about the Milankovich cycles, and studied them. That was how they knew to use the Milankovich cycles as an explanation for the end of the last glaciation. They didn’t just discover them.

eric
August 7, 2009 5:20 pm

Pamela Gray (14:18:08) :
Pamela Gray Wrote:
“Eric, what then causes the temp to correlate so highly, both in overall trend and ups and downs, historically as well as currently, with oceanic oscillations? Is there no place for oceanic circulation patterns (which have changed over the millions of years) and oscillations (which have also changed over the millions of years) in your model? How can that be when we see direct and obvious cause and affect, complete with data and well-known mechanisms? Just how and when do you jump from Earth bound natural variation ending as the driver to CO2 acting as the driver?”
These ocean oscillations, especially El Nino, affect the sea surface temperature over a wide area of ocean. The sea surface temperature by definition is part of global temperature, and will affect the air temperature over land as well. There is nothing mysterious about that. The coupled ocean atmosphere models show El Nino like phenomena but do not exactly predict the occurence of El Nino’s. The recent data shows El Nino are correlated with the oscillations in global temperature, but are not related to the overall long term 30 year trend.
http://skepticalscience.com/Global-warming-and-the-El-Nino-Southern-Oscillation.html
Currently dry conditions in asia resulting from El Nino has lead to buring of huge tracts of forest land releasing large amounts of CO2.
http://www.eleconomista.es/telecomunicaciones-tecnologia/noticias/1385944/07/09/Emerging-El-Nino-set-to-drive-up-carbon-emissions.html
In addition there is more naturally occuring emissions of CO2 from the warmer ocean water resulting from El Ninos.
While the ocean absorbs around half of human CO2 emissions, empirical observations reveal the oceans are losing their ability to absorb CO2.
http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm
“Quéré 2007 found that the Southern Ocean has reached its saturation point, diminishing its ability to absorb more CO2.
Schuster 2007 found that CO2 absorption by the North Atlantic has dropped even more dramatically, halving over the past decade.
Park 2008 found a sudden, considerable reduction in the recent uptake of CO2 in the East/Japan Sea.
If this trend continues, it potentially leads to a positive feedback where the oceans take up less CO2 leading to CO2 rising faster in the atmosphere leading to increased global warming.”
We can even see the correlation between emissions of CO2 from portions of the ocean, and El Nino conditions, where the surface temperature of the oceans is warmed.

George E. Smith
August 7, 2009 5:25 pm

“”” cba (17:08:00) :
“”Dave vs Hal (08:29:53) :
cba (06:16:14)
“THat difference is even more interesting considering that the surface albedo of ocean is about 1/3 to 1/5th that of land surface . What is happening is the ocean water is involved in a water vapor cycle creating clouds that reduce the albedo – something that can’t happen easily when there is little to no additional water available” “””
I wouldn’t be hollering about the “surface albedo” of the oceans. Given that the Fresnel reflection for water at normal incidence is about 2% for a refractive index of 1.33, and that reflection coefficient remains reasonably constant out to the Brewster angle which is about 53 degrees incidence angle, the net surface reflection is perhaps 3% for the complete hemisphere sans clouds; which would give the greatest albedo effect from the oceans; that makes the deep oceans a reasonably black body absorber with an emissivity of about 0.97 for the solar spectrum range of wavelengths (albedo applies only to solar spectrum reflections).
So Nyet for the oceans being a significant albedo contributor.
And since I just got back from a week of fishing in the Sea of Cortez, which can be as deep as 10,000 feet, I can assure you that that deep water looks visually black when you look down into it, and if you put on your polarized glasses to eliminate surface reflections then it is quite black. Yes of course when whipped up by winds; you do get higher reflections from the white water.
George

rbateman
August 7, 2009 5:27 pm

The finding proves that nothing stops the ice age from coming on or retreating. It offers nothing concrete as to how CO2 (AGW) is going to accelerate or prevent an ice age. As for the paper being behind a paywall, that is against the spirit of the Freedom of Information Act.
So, unless you are on the govt. payola grant, or can afford to throw money around, you get the leftovers (abstract). Science is for sale. I will definately take this up with my Congressman, whose party is not pleased with the lack of transparency.
4 years ago when I dug into studies of galaxies, it was rare to see papers for sale. Now it’s turned into a big business. Even older studies paid for by taxpayers are behind this paywall.

George E. Smith
August 7, 2009 5:30 pm

And on a further note; the albedo component due to clouds exceeds that of any earth surface terrain. so nyet on clouds reducing earth’s albedo by covering up ocean.
The polar regions ice cover is not much of an albedo component, even though it is most often cited. There’s a reason all that ice and snow is there at the poles; there’s very little solar radiation there to Albedize, in the first place.
George

eric
August 7, 2009 5:44 pm

Nasif Nahle wrote:
“The carbon dioxide more than being an amplifier of warming effects (which definitively it is not) it’s a distributor of heat and a drainer of heat into the outer space. A very different subject is water in anyone of its three phases. I have no doubt; Arrhenius inflicted a great damage to climate science with his assumptions.”
It is pretty clear that you don’t understand the influence of GHG’s on the climate of the globe. Without the GHG’s 100% of the upward radiation from the earth’s surface would escape to outer space. The GHG’s send about half of the radiation they absorb back toward the surface of the earth. That mechanism has been understood by physicists for 150 years since Tyndall pointed this out. This is not an assumpton. It is proven physics and is the basis for the atmospheric greenhouse effect. It has been refined by computer calculations which include the lapse rate of the atmosphere to make more accurate calculations of the greenhouse effect than Arrhenius was able to make in 1896.

George E. Smith
August 7, 2009 5:48 pm

By the way, I haven’t read the paper yet; so I haven’t commented on it. I get the dead tree issue of SCIENCE to keep in perpetuity; so I haven’t seen that issue yet.
But if the headline is meaningful and not hype; then maybe I will get more information out of it than the many times I read that “it is just Milankovitch cycles.”
All well and good by what exactly are the variable ranges of “Milankovitch cycles” ? I’m too long in the tooth to wade through all that orbital mechanics myself; and just how much do we know about the possible occasional encounter with other truly massive galactic objects that may have come through non-destructively but created one time perturbations of the whole solar sytem orbits.
Maybe astronomers are smart enough to actually untangle such events from the geologic records; they seem bloody clever at getting answers that would seem to be unavailable given the remoteness of their laboratory knobs.
George

peter_ga
August 7, 2009 5:49 pm

I actually thought that solar forcing causing the ice age periodicity was accepted science. What else could cause the accuracy of the periodicity? Earthly oceanic or chemical cycles would make them all over the place.
The periodicity of the ice ages starts 3 million years ago. The only possible cause is continental drift. The forcing, being orbital, was there before. This implies the Earths climate is now in a state where it is highly sensitive to solar variation. This sensitivity, being oceanic, takes hundreds of years to manifest.
So the question is, why is the Earths climate not equally sensitive to CO2 forcing? It probably is, but only over centuries. Therefore, although CO2 emissions are a problem, there are centuries of time to find a solution.

rbateman
August 7, 2009 5:55 pm

George E. Smith (17:30:18) :
So, in this solarly minimumed environment, are clouds or moisture more effective at albedo?
Would they cause the sun to appear dimmer due to wavelength strength changes?

Evan Jones
Editor
August 7, 2009 6:21 pm

I would assume that clouds cause albedo and vapor causes greenhouse effect. Same as in any environment.

Bob Ramar
August 7, 2009 6:21 pm

Well, well, so Dr. Milankovitch has been shown to be correct after all!
“CO2 forcing”… Carbon Dioxide levels are a following trend, not a leading trend. One thing that really gets me pissed in all the debate about human caused global warming is that carbon dioxide is the least of our worries. It can be and is removed from the atmosphere by biological processes and sequestered in rock in the form of calcium carbonate. There is a real threat however and that is methane. Methane is the fourth most potent greenhouse gas in the atmosphere (after water vapor, argon, krypton, then methane). And a lot of methane is locked up on the seafloor in the form of methane hydrates. However, methane makes a lovely fuel … .

August 7, 2009 7:08 pm

eric (17:44:20),
Why is it that alarmists always leave out Arrhenius’ 1906 correction to his 1896 paper? Maybe because it pulls the teeth from his earlier paper?
Arrhenius’ 1906 climate sensitivity number was still too high. But those pushing the CO2=AGW conjecture can’t accept a lower number, because it would mean that CO2’s effect is insignificant and can be completely disregarded for all practical purposes.
But that’s exactly what the planet is telling us: CO2 has much less of an effect than warmists want to believe. In fact, it has no measurable effect at all.
Carbon dioxide, in the minor trace amounts both current and projected, is entirely beneficial. Why is that so hard to accept? It’s what the real world is telling us.

Bill Illis
August 7, 2009 7:13 pm

It is not difficult to imagine the Sun melting the glaciers.
Anyone ever been in Chicago in July? In Yellowknife in July? How is a glacier going to survive when the snow has melted by March 1st in Chicago and by April 25th in Yellowknife.
If the Sun is 2 degrees lower on the horizon and the Earth is 1 million kms farther away, I can see some glacier melting in the summer in Yellowknife but by late August, the snow is falling again.
Chicago? Well the glacier front is going to be melting from March till late September even when the Sun is 2 degrees lower on the horizon and 1 million kms farther away. The glacier front is not going to make it much farther south. Summer temps at the glacial front in Chicago still get to +15C and the ice and snow has completed melted well before the end of the summer – Chicago is glacial termination point, even at the weakest point of the Milankovitch cycle.
But in Yellowknife, the glacial front is going to be pushed past you south because it is only melting for a few months of the year and snowing for the rest. The 2 km high glaciers north of you are going to push right past you (gravity alone) when the Sun is only melting those glaciers for 1 month of the year and it is snowing for the other 11 months.
The CO2 changes produce a degree or so of warming, enough to melt the ice in Yellowknife on July 1st instead instead of July 15th. By that time the glaciers in Chicago are long gone because the Sun is now at its present angle in the sky and it is 1 million kms closer in the summer, the ice and snow has been melting since February. It is all gone in Chicago about March 15th so the little 1.0C of CO2 warming has had Zero impact on the glacial retreat.
Yellowknife just needs to wait the 1,000 years for the glacial front to melt back completely. Another 1,000 years and the glaciers are only left in the Arctic.
Take Yellowknife and move it 200 kms north (the relative difference in solar energy provided by Milankovitch cycles). The snow and ice will still melt completely in the summer and there will be no glaciers. But put a 2 km high glacier in the Arctic archipeligo in the same conditions and its coming south to Yellowknife.
It is not CO2 but snow accumulation versus snow melt at the height of the summer in the Arctic archipelgo.

August 7, 2009 7:34 pm

eric (17:44:20) :
Nasif Nahle wrote:
“The carbon dioxide more than being an amplifier of warming effects (which definitively it is not) it’s a distributor of heat and a drainer of heat into the outer space. A very different subject is water in anyone of its three phases. I have no doubt; Arrhenius inflicted a great damage to climate science with his assumptions.”
It is pretty clear that you don’t understand the influence of GHG’s on the climate of the globe. Without the GHG’s 100% of the upward radiation from the earth’s surface would escape to outer space. The GHG’s send about half of the radiation they absorb back toward the surface of the earth. That mechanism has been understood by physicists for 150 years since Tyndall pointed this out. This is not an assumpton. It is proven physics and is the basis for the atmospheric greenhouse effect. It has been refined by computer calculations which include the lapse rate of the atmosphere to make more accurate calculations of the greenhouse effect than Arrhenius was able to make in 1896.

It is pretty clear that I don’t believe [snip]. Answer each one of the questions from my post at Nasif Nahle (14:34:53), and then we’ll talk.
Reply: Could use a rephrasing please. ~ ctm

JET
August 7, 2009 7:36 pm

If Milankovich cycles are solely responsible for glaciation, would not the Earth experience a continuous cycle of glacial advance and retreat?
How do we explain the geological record that suggests glaciation is confined to periods of several million years separated by about 200 million years?
The Solar System completes its orbit around the centre of the Milky Way Galaxy once each 226 million years – can periods of continental glaciation have an extra-Solar System cause? One that may be modified in some way by Milankovich’s Cycles – but not caused primarily by those relatively short (geologically speaking) variations in planetary orientation and orbit?

August 7, 2009 7:39 pm

Sometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age – unless some other forces stop or slow it. But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.
“One of the biggest concerns right now is how the Greenland and Antarctic ice sheets will respond to global warming and contribute to sea level rise,” Clark said. “This study will help us better understand that process, and improve the validity of our models.”

One of the most irritating things I see in papers like this is the need of the authors to grovel to the prevailing panic so as not to lose face (or funding) or be a marked man (or woman) by the alarmists.

Ken S
August 7, 2009 7:41 pm

“Ken S (07:44:03) :
Has anyone seen the papers by Australian engineer Dr. Peter Harris
He authored a paper entitled “Probability of Sudden Global Cooling.”
and “An Urgent Signal For The Coming Iceage”
Link at Iceagenow
http://www.iceagenow.com/Probability_94%25_for_imminent_global_cooling%20.htm
His papers have a nice graph that he uses to show what he thinks is the relationship of Preccssion, Obliquity, Eccentricity, and Solar Forcing to each of the
Stages of recent Glaciation.”
Would at least one knowledgable person please look at the paper at the second link Titled – “An Urgent Signal For The Coming Iceage”.
Here is a different, but direct link to the pdf file.
http://westinstenv.org/wp-content/ANURGENTSIGNALFORTHECOMINGICEAGE.pdf
I was wondering what others thought of Dr. Peter Harris’s ideas?
Thanks,
Ken S

Evan Jones
Editor
August 7, 2009 7:44 pm

The recent data shows El Nino are correlated with the oscillations in global temperature, but are not related to the overall long term 30 year trend.
But, surely, that was never the correlation at all, was it?
The correlation is with the Pacific Decadal Oscillation (et al). And the PDO affects Ninos and Ninas, minimizing the one and enhancing the other, depending on its phase.
From 1976 to 2001 half a dozen or more major oceanic-atmospheric multidecadal cycles turned from cold to warm. Then, the taps all being on hot, temperatures stabilized–at a high level. Recently, the PDO went cold, and temperatures have dropped. Is that so very hard to assimilate?
There is your correlation. Your 30-year trend. Not conclusively proven, but standing to reason. Over the last century the cycles correlate better with known climate than does CO2.
Ninos and Ninas continue, but they are merely short-term drivers which are affected by the bigger picture. Both will occur no matter what the overall phase of the Southern Oscillation and PDO.

August 7, 2009 7:49 pm

Nasif Nahle (19:34:06) :
eric (17:44:20) :
It is pretty clear that you don’t understand the influence of GHG’s on the climate of the globe. Without the GHG’s 100% of the upward radiation from the earth’s surface would escape to outer space. The GHG’s send about half of the radiation they absorb back toward the surface of the earth. That mechanism has been understood by physicists for 150 years since Tyndall pointed this out. This is not an assumpton. It is proven physics and is the basis for the atmospheric greenhouse effect. It has been refined by computer calculations which include the lapse rate of the atmosphere to make more accurate calculations of the greenhouse effect than Arrhenius was able to make in 1896.
It is pretty clear that I don’t believe [snip]. Answer each one of the questions from my post at Nasif Nahle (14:34:53), and then we’ll talk.
Reply: Could use a rephrasing please. ~ ctm

Oops! Sorry… Rephrasing my comment:
It is pretty clear that I don’t believe in arguments made a priori, but in experimentation and good, clear physics. Answer each one of the questions from my post at Nasif Nahle (14:34:53) and then, we’ll talk.

DaveE
August 7, 2009 8:18 pm

Patrick K (20:44:40) :

However, I have to complain about the graphic and the caption attached to it. Both of the ellipses shown are extremely exaggerated and neither is anywhere close to the actual ellipticallity (sic) of the Earth’s actual orbit which ranges from an almost perfect circle to only slightly elliptical. Even at it’s most extreme elliptical orbit, the earth’s orbit is very close to a perfect circle (A perfect circle is e=1, the Earth’s most extreme orbit is e=0.97). In fact it is so close that a human cannot usually distinguish it from a circle.

How do you illustrate an undetectable change without exaggeration?
Show two identical (to the naked eye) illustrations & the influence is apparently non existent.
Which part of “not to scale” did you not understand?
DaveE.

crosspatch
August 7, 2009 8:20 pm

” Bill Illis (19:13:19) : ”
Another subtle point people miss. If Chicago is under a mile of ice, then the surface of that ice is at 5000 feet altitude. Temperatures at 5000 feet above Chicago might be somewhat different than at the surface today.
In fact, the Northern Rockies might practically disappear under the ice. You might be able to walk Westward from Chicago, gaining altitude as you do, and see some hilltops sticking out of the ice, if that.

Gary Pearse
August 7, 2009 8:25 pm

Archonix (13:49:05) :
Julius gave us July but you neglected to inform us that Augustus gave us August – maybe it was just too obvious. Maybe the ice ages occurred because there were two months of summer missing.

rbateman
August 7, 2009 8:34 pm

I am assimilated by PDO. If the Earth plunges into another Ice Age, we will return to the Stone Age, and all that coal & oil in the North will be buried under a mile of ice. Our age will be a strange blip in the geologic record that future geologists will puzzle over. Where’d that radiated soot layer come from? No one will e – ver know.

anna v
August 7, 2009 9:16 pm

wattsupwiththat (06:11:17) :
Of course this is nothing new, nobody doubts the role of CO2 in providing a portion of the warming effect, so also does water vapor. But it is a lag effect of CO2 released in response to the change in earth’s wobble and thus not the main driver of the event.
I would say a small and lagged portion of the warming effect.
Consider:
Water vapor rises immediately according to the heat of the air over the oceans, not according to the temperature of the oceans. The sun heats the air immediately, the oceans slowly. CO2 has a 800 to 2000 year lag in response, while the oceans warm and the permafrost melts.
In addition CO2 is less than 10% in contribution to the green house effect of the contribution of H2O.
I am always amazed how people postulating runaway effects from GH gasses can ignore these simple physical characteristics of H2O and can still look at ice age records and talk of CO2 feed backs at the time. It invalidates for me any worth in their paper.

Paul K
August 7, 2009 9:18 pm

[snip – rant]

August 7, 2009 9:45 pm

anna v (21:16:14),
Excellent post, as always.

eric
August 7, 2009 9:50 pm

Nassif Nahle wrote:
“To qualify carbon dioxide as a secondary amplifier of the Earth’s atmosphere warming, answer the following questions:
What’s the absorptivity-emissivity of carbon dioxide at its current partial pressure in the atmosphere?”
This question is answered by Modtran based on the HiTran data base:
http://en.wikipedia.org/wiki/MODTRAN
“MODTRAN (MODerate resolution atmospheric TRANsmission) is a computer program designed to model atmospheric propagation of electromagnetic radiation from 100-50000 cm-1 with a spectral resolution of 1 cm-1.
The spectral region covered is the far-infrared (100 cm-1 is 100µm wavelength), through visible light, to the deep ultraviolet (50000 cm-1 is 200 nm).
Some aspects of MODTRAN are patented by the US Air Force. Software licenses are issued by the USAF but distribution is handled by Ontar Corporation. MODTRAN core modules are written in FORTRAN.”
The answer to your question depends on the partial pressure, altitude and temperature.
“What’s the total emittancy of carbon dioxide at its current partial pressure in the atmosphere?”
I am not familiar with the word emittancy. If you mean emissivity this can be found for whatever conditions you like using MODTRAN.
“What’s the real value for climate sensitivity to carbon dioxide?”
This is uncertain the nominal value seems to be about 3C with a range of +/- 1.5.
“What’s the heat capacity of carbon dioxide at its current density in the atmosphere?”
A question that is irrelevant to the understanding of how CO2 influences the radiation balance of the earth’s atmosphere. Collisions between CO2 and other molecules in the atmosphere will distribute the energy absorbed by CO2
to the air as a whole. The heat capacity of air depends on its pressure.
What’s the specific heat capacity of carbon dioxide at its current density in the atmosphere?
“What’s the thermal diffusivity of carbon dioxide at its current density in the atmosphere?”
Also an irrelevant question. CO2 is spread from its sources through the atmosphere by the motion of the air due to winds.
“What’s the specific volume of carbon dioxide in the atmosphere at the present time?”This depends on the temperature and pressure. Assuming CO2 is close to an ideal gas
V=RT/PM, where M is the mass of a mole of CO2 or approximately 44gms.
R is the ideal gas constant and T is the absolute temperature.
What’s the real effect of carbon dioxide in the atmosphere?
It absorbs specific bands of radiation and emits raditiation in all directions equally. As a result of this less radiation emitted from the surface leaves the earth atmosphere system than would be the case without it. The effect of CO2 is amplified by the ability of water to vaporize at higher densities in the atmosphere with increasing temperature. The presence of absorbing gases in the atmosphere makes the temperature of the earth’s surface 33C warmer than it would be without them, and reduces the difference in temperature between day and night, allowing for the survival of complex life forms.

crosspatch