by Dr. Martin Hertzberg
As the saying goes:
“If all you have in your hand is a hammer, then everything looks like a nail”.
It is hopeless to expect that Hansen could possibly analyze data objectively – all he has in his head is “CO2 climate forcing” and everything else has to be “forced” into that ridiculous paradigm. It makes no difference to him that the predictions of his past half-baked computer models based on “CO2 climate forcing” were completely wrong.
It is not worth my time (or anyone else’s in my opinion) to try to critique the entire paper, but the final paragraph on his p. 11 stands our like a sore thumb. In it he states:
” Earth orbital (Milankovic) parameters have favored a cooling trend for the past several thousand years, which should be expected to start in the Northern Hemisphere (NH). For example, Earth is now closest to the sun in January, which favors warm winters and cool summers in the Northern Hemisphere.”
Those statements are typical of the misunderstanding in the popular literature of the Milankovic cycles. Since we are now further from the sun in the NH summer, he argues that the NH should get less solar insolation in the NH summer thus “favoring the growth of glaciers and ice-caps in the NH”. So why then we may ask are we now in an Interglacial Warming? What Hansen fails to realize is that when we are further from the Sun in NH summer we move more slowly in orbit, and are therefore exposed to the summer sun for a longer period of time.
From the graphs in the web-site http://individual.utoronto.ca/kalendis/seasons.htm , one can calculate that in 2010 the NH summer half of the earth’s orbit from the Spring Equinox to the fall Equinox lasts 186.1 days. The NH winter half of the orbit lasts 179.0 days. So the summer half gets 7.1 more days of solar insolation than the winter half. (Go to your calendar and count!)
Exposure time in this case is more significant that daily insolation caused by our further distance during the NH summer. And that is why we are in an Interglacial Warming and why Hansen is completely wrong in arguing that we should be “favoring the growth of glaciers and ice-caps in the Northern Hemisphere”.
Now some 10,000 years ago, because of the precession of the Equinoxes, summer and winter would have nearly flipped but with not much change in the earth’s orbital eccentricity. From the same web-site, in the year 8,000 BC, the NH summer half of the earth’s orbit lasted 178.5 days while the winter half lasted 186.6 days, so that the winter half exceeded the summer half by 8.1 days.
So 10,000 years ago the earth was further from the sun during NH winter and it spent a longer time on the winter half of the orbit, thus both effects re-enforced each other to give us a marked Glacial Cooling. (Actually the peak in that Glacial Cooling occurred several thousand years earlier than 8,000 BC.) Today, while we spend a longer time during the NH summer half of our orbit, we are further away in the summer, so the effects tend to cancel, but the longer time exposure is more important than the further distance.
The following discussion from my Chapter 12 of our recently published book “Slaying the Sky Dragon – Death of the Greenhouse Gas Theory” is a more general critique of the Hansen paper. Simply substitute “Hansen” for “Gore”.
The Legend of the Sky Dragon and Its Mythmakers
There is a simple way to tell the difference between propagandists and scientists. If scientists have a theory they search diligently for data that might actually contradict the theory so that they can fully test its validity or refine it. Propagandists, on the other hand, carefully select only the data that might agree with their theory and dutifully ignore any data that disagrees with it.
One of the best examples of the contrast between propagandists and scientists comes from the way the human caused global warming advocates handle the Vostok ice core data from Antarctica (6). The data span the last 420,000 years, and they show some four Glacial Coolings with average temperatures some 6 to 8 C below current values and five Interglacial Warming periods with temperatures some 2 to 4 C above current values. The last warming period in the data is the current one that started some 15,000 to 20,000 years ago. The data show a remarkably good correlation between long term variations in temperature and atmospheric CO2 concentrations. Atmospheric CO2 concentrations are at a minimum during the end of Glacial Coolings when temperatures are at a minimum. Atmospheric CO2 concentrations are at a maximum when temperatures are at a maximum at the end of Interglacial Warmings. Gore, in his movie and his book, “An Inconvenient Truth”, shows the Vostok data, and uses it to argue that the data prove that high atmospheric CO2 concentrations cause global warming.
Is that an objective evaluation of the Vostok data? Let’s look at what Gore failed to mention. First, the correlation between temperature and CO2 has been going on for about half a million years, long before any significant human production of CO2, which began only about 150 years ago. Thus, it is reasonable to argue that the current increase in CO2 during our current Interglacial Warming, which has been going on for the last 15,000 – 20,000 years, is merely the continuation of a natural process that has nothing whatever to do with human activity. Gore also fails to ask the most logical question: where did all that CO2 come from during those past warming periods when the human production of CO2 was virtually nonexistent? The answer is apparent to knowledgeable scientists: from the same place that the current increase is coming from, from the oceans. The amount of CO2 dissolved in the oceans is some 50 times greater than the amount in the atmosphere. As oceans warm for whatever reason, some of their dissolved CO2 is emitted into the atmosphere, just as your soda pop goes flat and loses its dissolved CO2 as it warms to room temperature even as you pour it into the warmer glass. As oceans cool, CO2 from the atmosphere dissolves back into the oceans, just as soda pop is made by injecting CO2 into cold water.
But the real “clincher” that separates the scientists from the propagandists comes from the most significant fact that Gore fails to mention. The same Vostok data show that changes in temperature always precede the changes in atmospheric CO2 by about 500-1500 years.
The temperature increases or decreases come first, and it is only after 500-1500 years that the CO2 follows. Fig 3 shows the data from the termination of the last Glacial Cooling (Major Glaciation) that ended some 15,000 – 20,000 years ago through the current Interglacial Warming of today. The four instances where the temperature changes precede the CO2 curve are clearly shown. All the Vostok data going back some 420,000 years show exactly the same behavior. Any objective scientist looking at that data would conclude that it is the warming that is causing the CO2 increases, not the other way around as Gore claimed. I am indebted to Guy Leblanc Smith (guy.lbs@rockknowledge.com.au) for granting permission to use Fig. 3 as it was published in Viv Forbes’ web-site www.carbon-sense.com .
It is even more revealing to see how the advocates of the human-caused global warming theory handle this “clincher” of the argument. It is generally agreed that the Vostok cycles of Glacial Coolings and Interglacial Warmings are driven by changes in the parameters of the Earth’s orbital motion about the Sun and its orientation with respect to that orbit; namely, changes in the ellipticity of its orbit, changes in its obliquity (tilt relative to its orbital plane), and the precession of its axis of rotation. These changes are referred to as the Milankovitch cycles, and even the human caused global warming advocates agree that those cycles “trigger” the temperature variations. But the human caused global warming advocates present the following ad hoc contrivance to justify their greenhouse effect theory.
The Milankovitch cycles, they say, are “weak” forcings that start the process of Interglacial Warming, but once the oceans begin to release some of their CO2 after 500-1500 years, then the “strong” forcing of “greenhouse warming” takes over to accelerate the warming. That argument is the best example of how propagandists carefully select data that agrees with their theory as they dutifully ignore data that disagrees with it. One need not go any further than to the next Glacial Cooling to expose that fraudulent argument for the artificial contrivance that it really is. Pray tell us then, we slayers of the Sky Dragon ask, what causes the next Glacial Cooling? How can it possibly begin when the CO2 concentration, their “strong” forcing, is at its maximum? How can the “weak” Milankovitch cooling effect possibly overcome that “strong” forcing of the greenhouse effect heating when the CO2 concentration is still at its maximum value at the peak of the Interglacial Warming? The global warmers thus find themselves stuck way out on a limb with that contrived argument. They are stuck there in an everlasting Glacial Warming, with no way to begin the next Glacial Cooling that the data show.
But one has to be sorry for Gore and his friends, for after all, they are in the global warming business. Global cooling is clearly someone else’s job!”
I can think of nothing more inappropriate and insulting to Milankovic than having Hansen speak at a Symposium in his honor.
===============================================================
Published originally at SPPI
Reference: Jan. 18, 2011: Paleoclimate Implications for Human-Made Climate Change: Draft paper for Milankovic volume. James Hansen
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Thanks Dr. Hertzberg good post. Hansen, and Holdren, are certifiable and it is a worry to me that the US government does not gag Hansen since they employ him. Perhaps they are working together to further tax increases on the long suffering Americans.
All I can say is thank you for this remarkably clear explanation of a part of the puzzle I have pondered before and not found included in any of the current Warmist arguments. Sadly I doubt any of the government’s – even if they believe this – will publicly change direction, there is far too much pressure from eco-terrorists like Greenpeace, Fiends of the Earth and WWF for it to happen until we begin to see what I am sure must come soon – a big dip in temperatures and a sudden increase in ice.
BTW, what would be the likely effect of the sudden flooding of a large part of the Great Rift Valley in Africa? It has been spreading over the last God alone knows how many years, but vulcanologists expect it to rift and flood ‘soon.’ Though I suspect that ‘soon’ on a geological timescale may be several hundred or several thousand years away!
Wow.
Some times I am baffled by my own oversights. Of course the orbital eccentricity leads to more summertime irradiance. This is the opposite of what I learned at the university, where the view presented by Hansen was the common perception.
A suggestion:
I think a thorough presentation of the Milankovic cycles would be much appreciated, as the Wikipedia entry is (methinks) a bit too short and somewhat difficult to comprehend.
@Herzberg
> So the summer half gets 7.1 more days of solar insolation than the winter half.
> (Go to your calendar and count!)
But do those cooler excess 7.1 days (summer= lower insolation rate) somehow make the other summer days warmer? Seems to me that would add up to a net loss (compared to 7.1 days at higher insolation). It doesn’t add 7.1 days to the calendar, so that’s a week compounded at a lower temperature rate.
The seasonal difference in solar irradiation is about 100 watts per square meter, much larger than the CO2 and other GHG “forcings” that we read about. So the more time spent at the lower insolation means more climate cooling effects. Right?
If the AGW proponents were correct about CO2, the earth would have tipped long ago and had temperatures nearly as high as Venus. The fact that there has never been a tipping point confirms that earth’s atmoshere is remarkably stable and self regulating and the fact that we are here today to debate this issue confirms that the AGW argument is not correct.
It appears that Hansen only ever half thinks things through, and this explains why he comes up with half baked conjectures. I share the sentiment that Hansen speaking at this symposium is an insult to Milankovic.
Is the graph of Northern Hemisphere seasons is a difficulty when those who estimate global warming find a mismatch between NH and SH temperatures? Or is it already accounted for in the estimates?
In my opinion, beginning a supposedly serious piece of writing by saying
“It is hopeless to expect that Hansen could possibly analyze data objectively – all he has in his head is “CO2 climate forcing” and everything else has to be “forced” into that ridiculous paradigm. It makes no difference to him that the predictions of his past half-baked computer models based on “CO2 climate forcing” were completely wrong.
It is not worth my time (or anyone else’s in my opinion) to try to critique the entire paper…”
makes it not worth my time reading any further.
It is clear that the author is not objectively discussing the science pesented but is using this as a platform for his own biased opinions.
I would much rather read an unbiased, balanced, thoughtful critique which this is obviously not.
How long until one of the regular warmists on here get half-way through your post, see the “CO2 lags temperature” bit and jumps immediately to comments to explain to you that “a small warming starts the CO2 increase, which then takes over and makes it worse”? I give it until comment 19.
I’ve often wondered how they justify it ever getting cold again once that “feedback” starts 🙂
“It is hopeless to expect that Hansen could possibly analyze data objectively – all he has in his head is “CO2 climate forcing” and everything else has to be “forced” into that ridiculous paradigm. It makes no difference to him that the predictions of his past half-baked computer models based on “CO2 climate forcing” were completely wrong.”
This is what happens when you put a Venus specialist in charge of researching the Earth’s atmosphere. He knows what happened to Venus, therefore he knows what’s going to happen to Earth: runaway global warming.
He is the first victim of Venus Syndrome. The sooner he retires the better.
@Herzberg
So the summer half gets 7.1 more days of solar insolation than the winter half.
The ‘winter’ [bad word here] insolation is higher because we are closer to the Sun. This is a non-trivial difference. About 100 times larger than the solar cycle variation.
Louise says:
“It is not worth my time (or anyone else’s in my opinion) to try to critique the entire paper…”
makes it not worth my time reading any further.”
Louise, I remember when I finally decided I had to find proof to back up my assumption that global warming must be true, because there was no way so many people would believe it unless it was well backed.
After several months wading through paper after paper after paper, trying to track down that illusive “foundation” of manmade global warming theory, I began to realise that there’s nothing behind all these statements except statements that there are statements that back up their statements.
There comes a point when doing them the courtesy of reading what they wrote … giving them the benefit of the doubt … become gullibility not to see through the blanket that hides the lack of any scientific basis for what they say.
Perhaps if you did read it, Louise, you might actually learn something.
@Louise: agree that the opening is impatient bordering on petulant, which is unfortunate because the substantive discussion that follows is, I think, intriguing and worth closer study and reflection. I would like to see a little math answering John Day’s point (longer summer but at less-intense level of insolation =?= shorter summer at more-intense level of insolation). That kind of accounting for energy/irradiance over time presumably has been done to support the argument about Milankovitch cycles, and it would be good to see it at least summarized or referenced here.
It would then be appropriate to call Hansen a fool and a charlatan –at the END of the paper!
Louise, your response suggests you are unable to take any science from the discussion, and instead focus on the personalities. Which begs the question, what is more important to you, the personalities, or the science? Your response shouts the answer.
Louise wrote:
“I would much rather read an unbiased, balanced, thoughtful critique which this is obviously not.”
So did you read the article to see what it was about and to come to that conclusion?
That’s right Louise, play the man and not the ball !
Great post, thanks Martin. A very clear explaination for the lay people.
“half-baked computer models”? My local baker would take offence at any comparison of his excellent product and Hansen’s rubbish models.
http://thepointman.wordpress.com/2011/01/21/the-seductiveness-of-models/
Pointman
@Louise says:
January 24, 2011 at 4:00 am
If you have the time, why don’t you look at Hansen’s paper and apply the scientific method to it (I would suggect not using anything that has been produced by a model), I would start by relicating any work you can.
Although Hansen has proved in just one paragraph that he is wrong and until this is corrected then this paper is bunk. Would you use a drug that had incorrect theories showing it was safe?
Wasn’t at least one of Hansen’s degrees in astronomy/astrophysics or something along those lines? Shouldn’t he understand innately the subtleties of orbital eccentricity? Is there anything left in his head except CO2 forcing? Wow….just wow.
Louise says:
January 24, 2011 at 4:00 am
You need to get past this reluctance to read papers written in this style. Nearly all comments over at RC, DC etc begin like this. You will never be in a position to make a valid judgement unless you do. I still brace myself to go read RC just in case something important appears among the rubbish. There may be a diamond in the bin but you will never find it unless you wade through the rubbish. Give it a try.
Dear Dr Hertzberg,
Thank you for this interesting post. In particular your point about the implausibility (or absurdity) of the climate establishment’s explanation of glacial/interglacial transitions as a small initial Milankovic-cycle-generated temperature change kick-starting a delayed and much larger CO2-mediated positive feedback chain reaction deserves wider prominence.
However I don’t think your argument is strengthened by your statement that “Thus, it is reasonable to argue that the current increase in CO2 during our current Interglacial Warming, which has been going on for the last 15,000 – 20,000 years, is merely the continuation of a natural process that has nothing whatever to do with human activity.” In fact I groaned inwardly when I read that passage.
Yes, a small part of the recent increase on atmospheric CO2 can be attributed to continued warming and degassing of the oceans. But most of it? Hm. The levels didn’t get much above 300ppm during previous interglacials, so either there is something wrong with the ice core CO2 data, or there is something out-of-the-ordinary causing the recent rise to over 380ppm. I suspect most well-informed people, including sceptical climate scientists, would prefer the latter explanation.
The misinterpretation by the IPCC and the rest of the climate change establishment of the glacial/interglacial temperature-CO2 relationship is IMO one of the weakest points in the whole AGW paradigm. I fear your attribution of recent CO2 rises to a continuation of the natural post-glacial de-gassing will simply make it easier for your (and my) opponents to ignore or sideline the more telling points you have made. I’d drop that bit.
But keep up the good work!
The argument put forward in the Hansen quote is puzzling: cool summers and warm winter in the northern hemispere should be a signal of natural cooling?
My elliptical maths are insufficient to argue in a numerical way against the argument that “the longer time exposure is more important than the further distance”, but I hold that there is no support offered for this pretty crucial statement. The only convincing argument is that it should tend to get colder when shorter time exposure and longer distance coïncide in the northern hemispere. I do not believe that paleoclimatology can contribute a great deal to the current AGW debate, which has a much shorter time span than any of the subject cycles, nor that there will be convincing scientifical evidence for either side, which in fact poses a more than convincing argument for the sceptical position.
I agree that the introduction to this post is a little OTT and may detract from the substance of the post. The introduction is unnecessary and pales beside the significance of the observation made half way through the post, namely that:-
“There is a simple way to tell the difference between propagandists and scientists. If scientists have a theory they search diligently for data that might actually contradict the theory so that they can fully test its validity or refine it. Propagandists, on the other hand, carefully select only the data that might agree with their theory and dutifully ignore any data that disagrees with it.”
I think set against that observation, one can see to which camp Hansen belongs.
sHx says:
January 24, 2011 at 4:13 am
“This is what happens when you put a Venus specialist in charge of researching the Earth’s atmosphere. He knows what happened to Venus, therefore he knows what’s going to happen to Earth: runaway global warming.”
I question whether he actually properly understands Venus since he fails to take into account the effect caused by the pressure of that atmosphere.
where did all that CO2 come from during those past warming periods when the human production of CO2 was virtually nonexistent? The answer is apparent to knowledgeable scientists: from the same place that the current increase is coming from, from the oceans.
These falsehoods damage the skeptic position much more than whatever any warmist may say. Knowledgeable scientists have become convinced long ago that the source of the current increase of atmospheric CO2 is human, and that oceans are currently a sink for CO2 because of the imbalance of the concentrations created by our emissions. It wasn’t like this in the distant past, when there weren’t human emissions. But it is that way now.
Patience is a virtue, Louise, for which you would have been rewarded if you had not been impatient. I, too, found the intro something of a ‘turnoff’, but kept going and now appreciate the authors’ viewpoint in this excellent post. In the recent past I have struggled to understand the import of the Malinkovitch Cycles as much of the referrence material I searched seemed impossibly obscure but this article pulled the curtain of my own ignorance aside for me!
I guess Hansen’s wildly anti-American and hyperbolic speeches tend to make more rational and patriotic American scientists more than a little scornful of him.