Hypsithermal, Altithermal, Holocene Optimum, Holocene Thermal Maximum, Holocene Megathermal, Anthropogene;
Guest opinion: Dr. Tim Ball
There is frustration and reward when an article appears on the same topic of an article you are completing – in this case the Holocene. Such was the case this week with Andy May’s article “A Review of temperature reconstructions.” Andy points out the basic problems of reconstruction using proxy data for the most recent half of the Holocene – an issue central to historical climate and climate change studies. His paper did not alter my paper except as it reinforces some arguments.
This article examines the entire Holocene and illustrates the history that influenced the studies. There are two distinct parts to the studies, the pre and post Intergovernmental Panel on Climate Change (IPCC). The former is a genuine scientific struggle with issues of terminology and reconstruction, and the latter a scientific struggle to impose a political perspective regardless of the evidence. Because of the damage done to climatology by the proponents of anthropogenic global warming (AGW), both parts require explanation.
The title of this article lists all the names given to a single geologic period. It reflects the problem of inconsistent terminology in the early days of historic climate reconstruction. The names were a result of regional studies reflecting the lack of coordination in a pre-global village world. They were attempts to improve and advance scientific knowledge and understanding, but only created confusion because of failure to agree on the start and end points and duration of the period. The concept of relative homogeneity is critical to determine if a climatic change was regional, hemispheric or global. You cannot achieve accurate analysis if the sequence of events is unknown or incorrect – a point noted in May’s article.
Even a cursory examination of the Holocene shows why the period is problematic for promoters of anthropogenic global warming (AGW). As Steve McIntyre pointed out, the problems began when skeptics noted that the temperature for most of the Holocene contradicted their claim that the latter part of the 20th century was the warmest ever. I know they never used the term ‘ever’, rather, it was left unsaid but implied in the message to the public and not contradicted when used by the media.
McIntyre wrote;
The Team has taken a preditable (sic) position on the Holocene Optimum: that it’s a regional and restricted event.
It was predictable because it was the same argument they used for the Medieval Warm Period (MWP). Prove an event was regional, and you essentially eliminate the Sun as a mechanism of change – an issue central to the AGW CO2 argument. The restriction included the claim that only summer temperatures were warmer. Even if true, it is not possible to say based on proxy records with 40 to 70-year smoothing averages applied. Interestingly, the IPCC clung to this “Team” view as recently as AR4 (2007).
The temperature evolution over the Holocene has been established for many different regions, often with centennial-resolution proxy records more sensitive to specific seasons.
Of course, this was before Climategate and the leaked emails that destroyed the Team’s credibility.
The problem of terminology impacted global reconstruction when attempts were made to synchronize glacial/interglacial events in Europe and North America. European glacial events were labelled in 1909 by Albrecht Penck (1858-1945) and Eduard Bruckner (1862-1927) from the oldest to the most recent, the Gunz, Mindel, Riss, and Wurm. In North America, led by the work of Thomas Chamberlin (1843-1928) and Frank Leverett (1859-1943) the sequence was the Nebraskan, Kansan, Illinoian, and Wisconsin. This helped define what happened within the Pleistocene but didn’t help in defining the end and beginning of the following period or synchronicity.
The term Holocene means most recent and was first suggested by Geologist Charles Lyell whose work influenced Darwin. He anticipated the modern environmental activists because he suggested it marked the human era. The problem is human history covers a few million years, and there is no evidence the Pleistocene is ended. Although Lyell’s claim was unjustified, the idea continues today as some call the Holocene The Age of Man. Regardless, there is no doubt we are in an interglacial but is it just that, and attempts to define shorter periods only part of the political game of blaming humans for all change.
The game continues with the proposal to name the most recent portion of the Holocene the Anthropocene. The definition underscores the politicization of science. However, it requires reassessment because what occurred during the period contradicts the claims for the Anthropocene defined as.
“Relating to or denoting the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment.”
This is false if we accept the IPCC conclusion, the human influence on climate is discernible only after 1950.
Correlating Events
Another book I consider significant in the attempts to match the various records was Climate, Man, and History by Robert Claiborne published in 1970. It spoke to the contradictory dates used in different disciplines. He wanted to write a doctoral thesis on the conflicting dates and incompatibility of events used by glaciologists and anthropologists, but the idea was rejected. As a result, he quit university, the supposed bastion of innovative thought, and wrote the book. He referred to the closed mind of academia in the first sentence.
“This book will probably annoy quite a number of scientists.”
Naturally, it was immediately attacked because it questioned the prevailing wisdom and worse, crossed the boundary between science and arts. The following comment illustrates the confused reaction by obliquely acknowledging the problem but then equally obliquely questioning Claiborne.
Claiborne’s caveat in the preface to this thoroughgoing study of climate and culture is that he’s going to venture some opinions of his own, attack others’, and, in general, try to dispel the fog that has enveloped many scientific studies of man in nature. He does this somewhat modestly at the beginning, coping with the complex, often conflicting theories on the causes, conditions, and timing of the last ice ages, and then increasingly with a more idiosyncratic style and sharper tongue.
There are parallels between Claiborne’s experiences and the claims made about the weather, climate, and history today. The official story of weather and climate promulgated by governments through the IPCC and environmentalists’ state that current weather and climate are anomalous and exhibiting more extreme conditions than ever before. The message is amplified and further distorted by a complicit and duplicitous media. Recently, a UK Daily Mail headline read,
“Sizzling UK records hottest day ever.”
The story did not qualify the word “ever” by saying it was the record within the modern span of thermometer measurements. The headline is what stays with the uninformed. Put the claim in the larger perspective of the Holocene and a completely different picture emerges about the official claims. They are creating the Anthropocene to isolate it from the Holocene because it gives the lie to the entire anthropogenic global warming deception. Judith Curry provided an interesting discussion about the lack of evidence for the Anthropocene, especially its mythical threat to humanity.
Weather and climate conditions through the Anthropocene are normal; that is, they are well within the range of all previous weather and climate variations. Despite official and media claims to the contrary, there are no dramatic increases in temperature, precipitation, hurricanes, tornadoes, or any other severe weather. The climate is changing just as it always has and always will, and the rate of change is perfectly normal. Of course, that is not what the government, environmentalists, or the media promote and as a result most of the public believe. The misconception is deliberate and central to the exploitation of global warming and climate change as the vehicle for a political agenda.
What The Public Need To Know
The following is not new to skeptics but identifies issues the public need to know to understand the AGW deception. Figure 1 shows one reconstruction of the temperature of the Northern Hemisphere derived from Greenland ice cores. It provides a brief context to show the wider natural range of temperature over the last 10,000 years. It shows the meaningless identification of the Anthropocene identified by the small red bar.
Figure 1
The accuracy of the climate record is critical for determining underlying mechanisms. It is critical if you want to identify specific periods but is still difficult because of determining points of starting and ending. Figure 1 appears to show a clear start of the Holocene with a dramatic warming around 10,500 years ago, but many place the onset at 11,700 years ago. Figure 2 shows why it is not clear cut. Is the Younger Dryas part of the Holocene? Is the extent of a geologic period determined by the major causative mechanism or some arbitrary temperature threshold? Search for an explanation of the Younger Dryas generated many speculative papers. There is an entire journal The Holocene devoted to the period.
Figure 2
The Younger Dryas is the focus of intense research, but also great speculation about the causative mechanism.
Other important points from Figures 1, 2 and 3 expose the lies and distortions about the last 120 years being anomalous include,
- Current temperatures are proclaimed as the warmest on record. In fact, the world was warmer than today for 97 percent of the last 10,000 years.
- The Medieval Warm Period (MWP) just 1000 years ago was 2°C warmer than today. The public is told that a similar warming will be catastrophic.
- The Minoan warm period approximately 3500 years ago was 4°C warmer than today.
- We are told the amount and rate of temperature increase in the last 100 years is abnormal. Compare the slope with any of the previous increases in Figure 2.
Figure 3.
· Figure 3 shows the CO2 trend over the Holocene. CO2 rose as temperature declined over the last 8000 years.
The Holocene is also problematic for AGW proponents because the major causative mechanism appears to be the changing precession, one of the Milankovitch Effect (ME) trilogy along with orbital eccentricity and axial tilt. A recent article at WUWT cites from Bender’s book Paleoclimate
“The orientation of Earth’s spin axis has changed over the past 10 Kyr so that northern summers now occur when Earth is farthest from the sun, whereas at 10 Ka [10,000 BP] they occurred when Earth was closest to the sun. Northern summertime insolation reached a maximum at about 10 Ka and has declined to the present, when it is near the minimum.”
The IPCC AR4 Physical Science Basis FAQ section provides the only reference to the ME. This includes the remarkable observation that
These examples illustrate that different climate changes in the past had different causes. The fact that natural factors caused climate changes in the past does not mean that the current climate change is natural.
True, but it was the same IPCC report that said natural changes became insignificant after 1950. They ‘proved’ this by eliminating most natural changes from their reports and their computer models. The IPCC is only comfortable discussing ME on time scales greater than the Holocene. AR5 says,
There is high confidence that orbital forcing is the primary external driver of glacial cycles (Kawamura et al,. 2007; Cheng et al., 2009; Lisiecki, 2010; Huybers, 2011).
But they couldn’t leave that comment unqualified, so they added,
However, atmospheric CO2 content plays an important internal feedback role.
There is no reference to the ME in the AR5 FAQ section or the Glossary of AR4 or AR5. This supports the information that it is not included in the IPCC computer models. The justification for exclusion is the time scale, but even in the 120 years of the Anthropocene, the impact is at least marginally significant relative to CO2 changes. The bigger problem is the inability to validate the models by recreating previous conditions without including the ME.
The Holocene is an interesting warm period that many believe marks the end of the last ice advance of the Pleistocene. It fascinated early scientific attempts to understand the events and mechanisms in the early days of climate reconstructions, which were complicated by a lack of standardized terminologies and central collections of data. For example, I recall long discussions about the need for centralized data banks on tree rings. The Holocene became ignored or distorted after the advent of AGW and the IPCC because the evidence of its existence contradicted most of their claims.
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By what mechanism could CO2 ever increase before temperature to end an ice age, and by what mechanism could CO2 possibly decrease before temperature to start an ice age. This happens on a 100k yr cycle. AGW believers have no answer to those simple fundamental question. Also, look at that Holocene CO2 chart. It shows lower CO2 at much higher temperatures. I doubt that is accurate. Warmer water would have released CO2, and I’m pretty sure those low CO2 levels wouldn’t have provided the crop yields needed to feed the Roman Empire.
CO2isLife,
The CO2 levels did follow the ocean temperatures pretty close – with a lag of 800 +/- 600 years over the past 800,000 years. The ratio between CO2 and temperature in the past 800,000 years was about 16 ppmv/K, which is in the ballpark of Henry’s law (4-17 ppmv/K).
Many (C3 cycle) plants suffer below 180 ppmv, which was the case during the glacial periods, be it that the CO2 levels over land near the surface in general are ~40 ppmv higher, sufficient to have at least a few hours a day available for photosynthesis.
Thus around 280 ppmv during the Holocene is no problem for plant growth, be it that 1,000 ppmv would be better…
Leif Svalgaard,
These two statements are incorrect. The 41 kyr cycle is the dominant cycle of the Quaternary Ice Age. It is one of the periodicities that shows more strongly on temperatures.
Prof. John Baez has shown the disparity between calculations from Milankovitch theory and data from observations. A Gabor transform is a windowed time-frequency Fourier analysis. When applied to the 65°N summer insolation calculations from the orbit of the Earth during the last 800 kyr it shows the main contributors to that signal thought to be responsible of glacial terminations. The main contributor is the 23 Kyr period, followed by the 18 kyr period, both from precession cycles, followed by the less intense 41 kyr period from obliquity cycles. When the same analysis is performed over the temperature data from observations (Epica Dome C ice core record), we can see that the temperature of the Earth barely responds to precession, as the band at 23 kyr is very tenuous. Instead we see obliquity bands at 41 and 83 kyr (double harmonic) and the prominent band at 100 kyr, that cannot be the eccentricity, since it is missing what should be an even stronger band at 413 kyr, the dominant periodicity of the eccentricity cycle.
http://i1039.photobucket.com/albums/a475/Knownuthing/Figure%204_zpsqlmmmezq.png
You can also check:
Imbrie J. et al. 1993. On the structure and origin of major glaciation cycles 2. The 100,000-year cycle. Paleoceanography 8 699-735.
Where the nature of the 100 kyr problem is stated and it becomes clear that the 41 kyr cycle is the only one that it is important both on theoretical grounds (effect on 65° North summer insolation) and evidence (effect on temperatures).
A careful analysis of the data shows that even in the last million years, the 41 kyr obliquity cycle continues ruling the glacial-interglacial cycle and that the 100 kyr cycle is an artificial construct of the obliquity cycle only producing an interglacial every 2-3 times due to frequent failure in getting the planet out of glacial conditions.
http://i1039.photobucket.com/albums/a475/Knownuthing/Milankovitch_Variations2_zpsoz9tlrxg.png
In this figure colored bars correspond to rising obliquity. successful obliquity cycles in orange, failed obliquity cycles in blue. Where is the 100 kyr cycle?
The final piece of evidence is that Eemian took place 124,000 years ago, which is 41,000 times three, not 100,000 years ago.
Where is the 100 kyr cycle
The distance between the dominant red bars, is where.
You just admitted the 100 kyr cycle is a construct of the 41 kyr obliquity cycle.
Admit is the wrong word. The typical distance between the orange bars is ~100kyr. The point is that the dominant cycle the last million years [and thus still operating] has been the 100-kyr cycle. This answers your question, where the 100-kyr cycle is.
My original comment was directed at: The orientation of Earth’s spin axis has changed over the past 10 Kyr so that northern summers now occur when Earth is farthest from the sun,
The 41-kyr cycle is not about the ‘orientation’ of the spin axis [governed by the precessions] but is related to the [small] changes of the tilt angle. In any case, the temperature record [if you believe it] shows that the eccentricity rules. If you don’t believe the record, you cannot argue either way.
“The typical distance between the orange bars is ~100kyr.”
Nope. The average distance is ~100 kyr. The typical distance is bimodal, 82 and 123 kyr.
http://www.euanmearns.com/wp-content/uploads/2016/03/41000.png
I believe the temperature record, and I also believe the temperature record supports better a 41 kyr cycle that misfires than a 100 kyr cycle. The figure in the post above with the orange and blue bars is based on the temperature record and I believe it proves my point.
You are chasing a straw man [as usual]. My point was that variation of the orientation [i.e. precession] does not govern the temperature, which is dominated by the 100-kyr cycles.
http://www.leif.org/research/M-Cycles.png
This closes the discussion as far as I am concerned.
I don’t argue the irrelevancy of the precession cycle on Earth’s temperatures, I do agree with you on that. But as I said in the first post of this thread, you made two statements that are incorrect:
Current Ice Age is believed to be 2.6 million years old. For most of that time, until the Mid-Pleistocene transition, the 41,000 year cycle has been dominant. See Lisiecki and Raymo data that I posted here.
The 41,000 year cycle continues showing up in the current temperature record. I have provided John Baez figure and John Imbrie’s article that support the effect of the 41,000 year cycle on temperatures. Here you have the article. Take a look at its figure 1. It is very illustrative.
So whether you admit it or not you were wrong on both statements, and you are raising strawman’s arguments by saying that your point was that variation of the orientation [i.e. precession] does not govern the temperature. That is not the argument of yours that I have an issue with.
That is not the argument of yours that I have an issue with.
Whatever causes the 100-kyr cycle, it is still a fact that the observed temperature record has a high point every 100,000 years.
The 100-kyr peaks are wide enough to accommodate additional effects modifying the basic eccentricity effect, so it is still an observational fact that the temperature record is dominated by the large ~100-kyr variations:
http://www.leif.org/research/M-Cycles-2.png
No special pleading about ‘misfiring’ other cycles is needed.
You are a victim of the “eccentricity myth”:
“Despite eccentricity having by far the weakest influence on insolation received at the Earth’s surface of any of the orbital parameters; it is often assumed to be the primary driver of the post-EMPT 100,000 years climate cycles because of the similarity in duration. The traditional solution to this is to call for a highly nonlinear response by the global climate system to eccentricity. This ‘eccentricity myth’ is due to an artefact of spectral analysis which means that the last 8 glacial–interglacial average out at about 100,000 years in length despite ranging from 80,000 to 120,000 years. With the realisation that eccentricity is not the major driving force a debate has emerged as to whether precession or obliquity controlled the timing of the most recent glacial–interglacial cycles.”
The role of orbital forcing in the Early Middle Pleistocene Transition
Mark A. Maslin, Christopher M. Brierley
Quaternary International, Volume 389, 2 December 2015, Pages 47–55
http://www.sciencedirect.com/science/article/pii/S1040618215000701
Not at all.
My points were:
1) precession [‘orientation’] is not the driver as claimed by the article
2) there is a clear, real, and observed 100-kyr temperature cycle [regardless of its cause]
3) your ‘prediction’ of only 4000 years to the next glaciation is wrong.
4) no special pleading about ‘misfiring’ cycles.
lsvalgaard
July 31, 2016 at 5:02 pm
Where is the 100 kyr cycle
The distance between the dominant red bars, is where.
_________________________________
Nonsense.
The last four durations between ice ages were 117, 115, 90 and 90 ky. Nothing to do with a 100 kyr cycle.
And as it happens, these durations equate very closely with the precessional Seasonal Great Year cycle.
Precession years …… total ……. ice age duration
23, 21, 26, 22, 25 …… 117 …….. 117 ky
23, 22, 23, 24, 23 …… 115 …….. 115 ky.
21, 21, 27, 22 …………… 91……… 90 ky.
16, 22, 15, 17, 22 …….. 92 …….. 90 ky.
Ralph
Thank you for separating and specifying the different issues.
100% agreement on this one
I dispute this one. The 100-kyr cycle is an artifact of spectral analysis clearly dispelled by looking at the actual data. If you look at figure 2 from my post above you can see that the 100 kyr distance is coming from the 5-7b, 7a-9, 13-15b, and 15a-17 distances, i.e. from the distances between the two double interglacials at maximum eccentricity and their neighbors by skipping one of the doublet. It is therefore a false distance because there is an interglacial in between. Spectral analysis doesn’t care about that and leads to a false conclusion.
I may be wrong and it is likely that the probability that I am wrong is higher than the opposite, but you cannot be certain that I am wrong.
It is everywhere in the literature for the past decade. I suggest Peter Huybers for a start. The new generation will change our views as it should be.
I find it highly ironic that you have such a strong position that solar variability cannot be responsible for significant climate variability because is too small a factor and lacks a mechanism that could explain how it could exert a significant forcing on Earth’s climate, while you take the opposite view and believe that eccentricity is responsible for the glacial cycles despite being too small a factor and lacking a mechanism that could explain how it could exert a significant forcing on Earth’s climate. But I am forced to withhold my criticism as I am in the same position by holding the opposite view to yours on both issues.
lsvalgaard July 31, 2016 at 9:16 pm
My points were:
1) precession [‘orientation’] is not the driver as claimed by the article
2) there is a clear, real, and observed 100-kyr temperature cycle [regardless of its cause]
3) your ‘prediction’ of only 4000 years to the next glaciation is wrong.
4) no special pleading about ‘misfiring’ cycles.
___________________________________
1) Yes it is. See the image below
2) An event without a cause or explanation is half way to a faith. A bit like U F O sightings.
3) My estimation is in 2,000 years time. But a mild ice age.
4) Clearly they do ‘misfire’, as there are dozens of ‘misfired’ warming events in the paleoclimatic record that did not create full interglacials. See image below.
http://s4.postimg.org/gf6jcemnx/temp_and_eccentricity_Page_1.jpg
If eccentricity doesn’t matter, then Earth is in for another cold blast as in the past, sooner rather than later. If eccentricity is important, then the current interglacial, the Holocene, will be another super interglacial, like those 400 and 800 Ka.
Eccentricity can modify the outcome, but not this time. Current 65° N summer insolation is too low to sustain an interglacial and it is going to continue to be low for several thousand years while obliquity continues going down. In about 4,000 years the world should be entering a new glacial period. 800 kyr ago, MIS 19 was not a super interglacial. It is the closest astronomical analog to the Holocene and started the big slope like in a thousand years give or take.
http://i1039.photobucket.com/albums/a475/Knownuthing/Figure%209_zpsl52xhrtm.png
OK, maybe not super, but longer than the Eemian and than the Holocene will be, if your estimate of 4000 more years be in the ball park. And longer than the two short interglacials at c. 300 and 200 Ka.
The 400 Ka interglacial was however super-duper. It melted the Southern Dome of the GIS, as apparently so too did the 800 Ka warm spell, but maybe the Greenland Ice Sheet wasn’t as thick before it.
Eccentricity is the main driving force!
Kirk,
I’m of the tilt school (41 kyr) myself, for the reasons Javier gives. The other cycles influence this basic cycle, but, as with the seasons, axial tilt rules the glacial/interglacial fluctuations.
I agree with Javier that at 41 kyr intervals, earth makes an attempt to get out of the glacial grip, but succeeds only once in two or three attempts. The warm spells within glaciations, but still icier than interglacials (without NH ice sheets outside Greenland), occur at about that period.
It was during one of these failed integlacials in the last glaciation that modern humans entered Europe and eastern Siberia.
Kirkc,
“Eccentricity is the main driving force!”
You have been deceived into thinking that there is a 100 kyr cycle. There is not. Open your eyes and look at the data in the second figure of this post, above in this thread.
The 100 kyr cycle is the product of a mathematical fluke that does not resist a careful examination of the temperature data. The erroneous believe in a 100 kyr cycle has been perpetuated because summer insolation has been used as a defining criteria to date the start and end of glaciations in the sediments in the officially UN sponsored SPECMAP series. This causes circular reasoning arguments when supporting that insolation sets the glaciations and terminations, when it has been used to date them.
Sorry, but obliquity ruled and it still does.
Javier
The 100 kyr cycle is the product of a mathematical fluke that does not resist a careful examination of the temperature data.
Sorry, but obliquity ruled and it still does.
_________________________________________
Sorry, Javier, you are wrong.
The 100 kyr cycle is the product of the eccentricity cycle invigorating the precessional cycle, so that the latter can produce interglacials. So the ghost of eccentricity still lurks within the ice age cycle, even if eccentricity is not directly responsible. See my images above.
Sorry, but precession ruled and it still does (although obliquity does assist when eccentricity is low).
Modulation of ice ages via precession and dust-albedo feedbacks.
http://www.sciencedirect.com/science/article/pii/S1674987116300305
Ralph
“Sorry, Javier, you are wrong.”
Sorry, Ralph, you are the wrong one and Peter Huybers is right. He has published three important papers on this issue. I hope you read them.
The eccentricity cycle has a tiny forcing associated unable to reinvigorate much. Eccentricity main effect is to modify precession, but the problem is that the precession cycle does not show up in temperatures, as Leif correctly points.
Javier August 1, 2016 at 3:37 am
Sorry, Ralph, you are the wrong one and Peter Huybers is right. He has published three important papers on this issue. I hope you read them.
_________________________________
I have Javier, all of them. And Huybers uses a home-made glacial chronology that has no chronological pegs to link it with the real world. And so his chronology is pretty much worthless. You could make up any story with it. Try using Epica, it is more reliable.
Ralph
I have used
Lisiecki, L. E., & Raymo, M. E. (2005). A Pliocene‐Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanography, 20(1).
which is probably the best indicator for glacial cycles, as it is global, and fully supports Huybers findings.
Read Mark Maslin last paper from 7 months ago. He used to oppose Huybers obliquity theory but he has come around and now supports it.
http://www.sciencedirect.com/science/article/pii/S1040618215000701
And we also have Liu et al., 2008
Liu, Z., Cleaveland, L. C. and Herbert, T. D. 2008. Early onset and origin of 100-kyr cycles in Pleistocene tropical SST records. Earth Planet. Sci. Lett. 265 703-715.
You are up against some formidable opposition of experts in the field.
Your favored hypothesis fails to explain Devil hole’s data and the “stage 5 problem” where the effect precedes the cause, as I have highlighted in another comment.
Very informative Javier. Thank you.
Maybe Leif will now admit defeat on his absolutist position of the 100Kyr ME eccentricity and expand his thoughts beyond mere orbital eccentricity (and thus the near constant TSI on insolation).
Regardless of the field of the natural sciences, Absolutist positions in science are always brick walls that get knocked as younger scientists not bought in to the paradigm bring new data and perspectives to the table.
The ~100-kyr cycle is an observation. As well as the near-constancy of TSI. I don’t argue with the data.
Some observations can accommodate several possible explanations. The 100 kyr cycle creates a lot of problems. It is a bad explanation. The 41 kyr cycle that misfires has the same explanation power or more and does not create problems.
The important point here, in regards to the Holocene, is that while the 41k cycle is dominant in regards to bringing ice ages to an end, it isn’t the only forcing cycle. When the other cycles coincide with it, the likelihood of an interglacial increases. When they are out of synch, the 41k cycle can end up a dud. But the subject here is whether, once an interglacial has occurred, do the other cycles affect its temperature variations. It appears that the answer to this question is, yes, they do. The lesser cycles can still affect temperatures during a short span interglacial, either keeping them stable, or leading them back to a collapse back into another ice age. In fact, given the short term period of these lesser cycles, that seems inevitable. And hence, we have the downward trend that occurs shortly after the interglacials begin that is the subject of the OP.
People, see the forest through the trees for God’s sake. Whether or not it is bimodal, 84k years, 124k years, 100k years is 100% completely irrelevant to AGW. It makes no difference what so ever. The key point is that there is an established cycle, and there is absolutely no mechanism by which CO2 would increase prior to temperatures to end an ice age, and absolutely no mechanism by which CO2 would decrease before temperatures to drive the globe back into an ice age. Remember, the IPCC and the warmist blame everything on CO2. The important aspect is that there is no mechanism by which CO2 would cause the cyclical pattern, none what so every. That is what is important, not how long the cycle is. Keep your eyes on the prize and don’t get distracted by the irrelevant issues.
The new edition of “Evidence-based Climate Science” by Elsevier is due out sometime in August. In it are several papers with detailed comparisons of GISP2 isotope data, CET temperature changes, global temp changes, global glacial fluctuations. What these data show is an excellent correlation of GISP2 and temperature changes at the most detailed level. Before you close your mind to GISP2, take a look
at these detailed correlations–they are remarkable.
It’s obvious from the data that the 41 K cycle never went away, but still occurs within the 100 K cycles seemingly apparent for the past 1200 to 800 K years.
Sorry. Misplaced this reply. Should be to Javier or Joel, above.
https://wattsupwiththat.com/2008/12/29/don-easterbrooks-agu-paper-on-potential-global-cooling/
How’s your predictions holding up Don?
http://static.skepticalscience.com/graphics/Easterbrook_Projection_1024.jpg
So far it is on target but we need some more years to nail it. In 1999, I predicted that global cooling would set in sometime after about 2000 and that is happening, but the cooling is not yet pronounced. The next decade or so should tell for sure. There is an updated paper on this in the forthcoming Elsevier volume. Time will either prove or disprove my prediction.
Don Easterbrook July 31, 2016 at 9:57 pm
“So far it is on target but we need some more years to nail it.”
Actually it is way off target…
“I predicted that global cooling would set in sometime after about 2000 and that is happening”
No it’s not..
http://data.giss.nasa.gov/gistemp/graphs/graph_data/Global_Mean_Estimates_based_on_Land_and_Ocean_Data/graph.png
It’s been happening since February 2016. You just need a graph with more resolution, Martin.
Global temperature data is an artificial construct with no specific physical meaning.
Here is the CET’s fundamental components reconstruction extrapolation
http://www.vukcevic.talktalk.net/CET-NVa.gif
CET has already entered cooling period, with strongest downturn since 1875
Your graph uses badly corrupted data (e.g., not that the global cooling from 1945 to 1977 has been erased and the warmest decade of the century (the 1930s) doesn’t even show!). Your graph is worthless–take a look at the UAH, RSS, and balloon data to see uncorrupted temperatures showing cooling over the past decade.
Further note–the UAH, RSS, and balloon data are being published in the forthcoming Elsevier volume.
The reason why global cooling has not set in thus far is because solar activity has been to high with the exception of years 2008-2010. If the prolonged solar minimum becomes firmly established this time then the climate should respond providing duration of time is long enough.
Solar values needed in my opinion to promote cooling
solar flux 90 or lower
cosmic ray counts 6500 or higher
solar irradiance off by .15%
euv light 100 units or less
solar wind 350 km/sec or less
ap index 5 or lower.
If these values are sustained the climate should cool as a result of an increase in albedo (even as little as a 1% increase will cause cooling) due to an increase in cloud coverage, sea ice and snow coverage tied into the above.)
Don Easterbrook says
“Your graph uses badly corrupted data ….”
Professor Easterbrook
Thank you for your comment. I assume, that you replying and referring to the graph contributed by Martin Lott August 1, 2016 at 2:42 am
However, since my graph is just above your comment, if you are referring to it, I would tend to agree as I happen to think that “the global temperature data is an artificial construct with no specific physical meaning”.
If I may add, it looks to me that the CET extrapolation appear to have lot in common with the Easterbrook B projection
Katherine Hayhoe is hilarious, upon questioning her claim of “overwhelming evidence the hockeystick is accurate” she asked for peer reviewed literature after lots of arm waving and when several papers were given she deleted and blocked.
How on earth did that hack get a PhD
She is one of Mann’s merry band of deniers lol
It has taken 2 hours to absorb the amazing flow of data from this article and the comments. I feel as though I just took a graduate course in climatology. Thank you for the free education. The problem is my clustered old mind has trouble retaining it. But I am ready for the pop quiz. Wow, I feel good. Thanks to all of you for sharing your knowledge.
I second this, Mr. Coleman. There’s been good back-and-forth from all concerned, making this a particularly noteworthy WUWT entry!
The discussion is wonderful, for sure. Very educational.
Could the semi-periodic CO2 maxima of approximately 500 years in figure 3 be caused by ice-rafted debris?
Arno,
In the past 800,000 years, CO2 levels followed temperature changes with some lag, thus the CO2 variability mainly follows (ocean) temperature variability. If the resolution of the charts is high enough, that is clearly seen. Al Gore (ab)used that by suggesting that CO2 levels cause temperature changes, while it is largely the opposite…
Mr Bsll writes;
“The misconception is deliberate and central to the exploitation of global warming and climate change as the vehicle for a political agenda.”
That potential, it seems to me, is (ostensibly) considered impossible by many otherwise intelligent people, or at least unknowable. To some, it seems to me, there is a belief that all Judges are equally “honorable”, all just as earnestly striving to be objective and fair, and any differences in how they see/rule on a given matter are due solely to sincere differences of opinion/experience etc . . Their job is to do that, and we non-Judges are NEVER qualified to rightly perceive any as corrupt intentional dispensers/promoters of injustice.
To some of them, it seems to me, scientists are also all equally honest and noble, by default, and all differences in their findings/conclusions are due to sincere differences of opinion/experience etc, never because some are outright criminally minded con artists . . because that’s not their job.
To me, it seems some of those acting as though such blanket “endorsements” of all Judges, scientists, priests, Government officials, news presenters, etc, etc; Integrity, are themselves sincere and simply naive . . Most are fakers, I believe, who exploit the “presumption” of honorable and objective status of others in civil societies, themselves . . and so are opposed to the “presumption” being eroded, so to speak. Some knowingly, some sub/unconsciously . . many just plain lost in their own rationalization rituals . .
I, personally, would stick some sort of “it seems clear to me” type qualifier on that declaration Mr. Ball made which I quoted, and encourage others to do likewise . . but I believe it is an accurate assessment of the “criminally insane” aspect of the lofty CAGW pushers . . (in general ; )
Other important points from Figures 1, 2 and 3 expose the lies and distortions about the last 120 years being anomalous include,
Since none of these graphs has any data from the last 120 years it’s hard to justify this statement. More likely it could be considered as one of the ‘lies and distortions’, basically what we can expect from Ball!
“But as Phil. points out below, none of those Figs includes any data from the last 120 years. That is a central issue …”.
=================================
As all the graphs are necessarily highly smoothed it would be wrong to carry them to the present as Prof Humlum explains: “… the smoothed values cannot be calculated for the very first and last years in the data series, as the smoothed value usually is associated with the smoothing interval midpoint year. The cut-off length at each end is calculated as: (length of the reference period-1)/2 … extending smoothed graphs beyond their formal endpoints represents an unfortunate habit which should be avoided in the analysis of meteorological data series” (Climate4you, data smoothing).
Further, I think Dr Ball was referring to the fact that the Holocene climate has been highly variable and a purported ~0.8C temperature rise since 1880 is nothing unusual.
“… with the smoothing interval midpoint year [or decade or century etc.] …”.
“Further, I think Dr Ball was referring to the fact that the Holocene climate has been highly variable and a purported ~0.8C temperature rise since 1880 is nothing unusual.”
There is no proper comparison there. The plots show temperature in a single, and somewhat unusual location. The 0.8°C rise is in the global average, which is far less variable than any single location.
@ur momisugly Nick Stokes 10:24 pm.
On what basis do you make that claim?
It is no doubt true when comparing say the Central England series, which (eyeballing) can vary an average of ~1.5C from year to year while the UAH global average may vary 0.5C from year to year, but over the longer period of 35 years both series show a similar average rise of ~ 0.5C, in other words the longer the period and the greater the smoothing, the less the difference.
In fact (eyeballing) Central England records shows ~1C rise since ~1880, the same as the alleged global average.
Here is comparison of the CET and the global temperature data.
http://www.vukcevic.talktalk.net/CET-NVa.gif
Note that the scale for the GT anomaly is multiplied by factor of 2, with ‘zero’ level raised for easier visual comparison, true scale GT graph is ( here)
Red and green lines represent a reconstruction from three major components in the summer and winter data riding on a liner uptrend of 0.25C/century for the whole 500 year range. The green line is a straight forward extension of the red line into the future beyond the present time (2014)
Chris Hanley,
?w=1050&h=644
“On what basis do you make that claim?”
Well, if you want to compare a temperature at a single location with a global average of thousands, I think that is up to you to justify. The plot of CET vs global above clearly shows differences. Andy May recently showed a plot of GISP2 extended with a local Greenland average
A range of 2°. But even that was a composite of a large region. Individual variation is larger again/
@ur momisugly Nick Stokes 12:07 am.
?w=1050&h=644
Conjecture about the global average temperature as recorded over the past 140 years or so and the proxies for past 10,000 years is of interest only in so far as the recent alleged recorded temperature trend may or may not be unusual due to human GHG emissions, mainly CO2.
The temperature rise above shown ~1880 – ~1945 (whatever its provenance or accuracy) could not possibly be due to human CO2 emissions.
http://cdiac.esd.ornl.gov/images/global_fossil_carbon_emissions_google_chart2.jpg
It is not an issue of smoothing, there is no data in those figures from the last 150yrs. The smoothing effect you refer to would take them even further back!
Javier,
I have not been deceived.
I agree there is no 100k cycle. It’s “about” but trough to trough varies significantly. Here is a short blog to explain the theory. It’s a work in progress but shows the correlation. I say eccentricity rules because it is the positive rate of increase coupled with a positive increase in insolation that breaks the cold cycle. See. http://www.rounder3950.wordpress.com For my brief rundown.
You base your “theory” on incorrect data. For a correct comparison of the strength of the eccentricity cycle solar forcing that is almost never properly represented at scale with the forcing of precession and obliquity, see the Figure 1 (upper half) of the following article.
The role of orbital forcing in the Early Middle Pleistocene Transition
Mark A. Maslin, , Christopher M. Brierley
Abstract
…During the transition glacial–interglacial cycles shift from lasting 41,000 years to an average of 100,000 years.
…Despite eccentricity having by far the weakest influence on insolation received at the Earth’s surface of any of the orbital parameters; it is often assumed to be the primary driver of the post-EMPT 100,000 years climate cycles because of the similarity in duration. The traditional solution to this is to call for a highly nonlinear response by the global climate system to eccentricity. This ‘eccentricity myth’ is due to an artefact of spectral analysis which means that the last 8 glacial–interglacial average out at about 100,000 years in length despite ranging from 80,000 to 120,000 years. With the realisation that eccentricity is not the major driving force a debate has emerged as to whether precession or obliquity controlled the timing of the most recent glacial–interglacial cycles. Some argue that post-EMPT deglaciations occurred every four or five precessional cycle while others argue it is every second or third obliquity cycle…
http://www.sciencedirect.com/science/article/pii/S1040618215000701
Roe points out ( http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf ]:
” (1) the strong expectation on physical grounds that summertime insolation is the key player in the mass balance of great Northern Hemisphere continental ice sheets of the ice ages; and
(2) the rate of change of global ice volume is in antiphase with variations in summertime insolation in the northern high latitudes that, in turn, are due to the changing orbit of the Earth.”
[not the obliquity
Roe proves that the obvious hypothesis that the higher the 65° N summer insolation, the higher the ice melting, is supported by the data. This demonstrates that 65° N summer insolation is a factor in deglaciation. Nothing more and nothing else.
The Termination II problem, also known as the causality problem or “the stage 5 problem”. According to insolation, the Eemian or MIS 5 should have started at the earliest 135 Kyr ago, however data from crystals in a Nevada cave named Devils Hole in 1992 indicated that by that date glacial termination was essentially finished (Winograd et al., 1992; Ludwig et al., 1992. Glacial termination is defined as the mid point in sea level between glacial and interglacial). A great controversy erupted over that data in the literature and has not abated since. But Devils Hole data is not alone, as similar data has been uncovered from coral reefs in the Bahamas (Gallup et al. 2002), Barbados and Papua New Guinea, and from Iberian-margin sediments and Italian cave speleothems (Drysdale et al. 2009), and all of it indicates that termination was essentially completed by 135 Kya, a date when 65°N summer insolation was still below the levels of 70% of the previous 100 kyr. Additional data indicates that MIS 5 may not be the only glacial termination where the effect appears to precede the cause (i.e. the interglacial came before the 65° N summer insolation was high).
Additionally there is no rational explanation as to why there was no interglacial 100,000 years ago, after the Eemian had already finished, because 65° N summer insolation was extremely high, higher than the average insolation that does accompany interglacials. Higher even than 10,000 years ago when the Holocene started. The amount of ice 100,000 years ago was much lower than 20,000 years ago. It should have been a breeze for such higher 65° N summer insolation to melt it, yet it did not happen.
Both arguments, that glacial terminations happen even with low 65° N summer insolation, and don’t always happen with high 65° N summer insolation, support my (and others) view that 65° N summer insolation, although an important factor, it is not the main determinant for glacial terminations.
Drysdale, R.N. et al. 2009. Evidence for Obliquity Forcing of Glacial Termination II. Science 325 1527-1531.
Gallup, C.D. et al. 2002. Direct determination of the timing of sea level change during Termination II. Science 295 310-313.
Ludwig, K.R. et al. 1992. Mass-Spectrometric 230Th-234U-238U Dating of the Devils Hole Calcite Vein. Science 258 284-287.
Winograd I.J. et al. 1992. Continuous 500,000-Year Climate Record from Vein Calcite in Devils Hole, Nevada. Science 258 255-260.
Oops. there should be a bold termination tag before the first parenthesis. Perhaps a mod can fix that and delete this post.
Sorry, Again you missed the point and are not absorbing what I’m saying.
It’s not the eccentricity causing an increase in insolation but the “positive going rate of change in eccentricity” – when the orbit is rapidly elongated it contributes some additional energy to the melt but only when combined with positive climbing insolation values. This has high correlation and predictively shows the past 80 to 120 year cycles.
Epicycles all over again…
Morgan formation well exposed along the Green River in Wyoming, Colorado, and Utah. Million year period “cyclotherms” according to Markov Chain Analysis. Reasonably (but not conclusively) linked to Carbo/Permian Gondwana glacial cycles.
Maybe it wasn’t the glaciations. Maybe it was cyclical uplift, but what controlled this? Glacial or goanticlinal, not Milankovitch.
sigh
De heffalumpis semper dubitandum est
(Winnie Ille Pu)
As you point out, Tim, according to IPCC “…The temperature evolution over the Holocene has been established for many different regions, often with centennial-resolution proxy records more sensitive to specific seasons. Of course, this was before Climategate and the leaked emails that destroyed the Team’s credibility.”
Climategate is not the only documented record of falsified data they are pushing. Here is one of their “many different regions.” When I was researching for my book “What Warming?” I came across an instance of outright forgery of climate records in the eighties and nineties. According to NASA, the period beginning in 1979 and ending with the start of the 1998 super El Nino was never a warming region but would qualify as a hiatus. The fact is, it is shown IPCC records as a phony ” late twentieth century warming.” GISS, NCDC, and HadCRUT3 are all in with them. Presumably they each originally showed a different temperature which had to be adjusted after the deed was done. This was accomplished by a computer program that left identical traces of its operation in identical parts of their public files. These traces consist of sharp upward spikes near the ends of years. Two of them are visible right on top of the super El Nino peak in 1998. The eighteen year temperature segment from 1979 to 1997, which originally was flat and had a slight downturn according to NASA, is thereby given an upward slope and touted as natural warming. But the forgery dies not end there. The super El Nino that follows is also lifted up and so is the entire twenty-first century that follows. I have called attention to this numerous times but have gotten no answers. As a result, I decided to print a warning about it in the preface of my book when it went to press in 2010. Nothing has happened since then. IPCC shows a smoothly rising graph from the eighties till the twenty-first century. It would not be smooth if the eighties and the nineties were correctly shown as a hiatus. It so happens that during a hiatus carbon dioxide increases but global temperature does not. This is not allowed by their Arrhenius greenhouse theory which is thereby caught making a wrong prediction. And that, in turn, makes the greenhouse effect impossible.
Excellent article Tim. Many thanks
Lots of comments on ‘the 100k cycle’ — do you know what the chronology of dating the cycles is based on? It’s a self-proving, manipulated, expanding and contracting of ocean isotope data with astronomical data until they correlate. The ocean isotope data is stretched and expanded until it matches the astronomical data, then the argument is made that since the ocean data matches the astronomical data it must be correct! It’s an interesting story, worth digging out of the literature. Sediment deposition rates also play a role, but if it isn’t constant over hundreds of thousands of years, it introduces significant errors in chronology. There is very little independent dating beyond the range of 14C–a few magnetic reversals and rare, dated ash layers provide a few points of age, but no systematic dating. It’s actually a house of cards.
So the polar ice is not melting after all & we don’t need worry about the polar bears? I for one am relieved…
Dr Tim wrote:
Other important points from Figures 1, 2 and 3 expose the lies and distortions about the last 120 years being anomalous include,
Current temperatures are proclaimed as the warmest on record. In fact, the world was warmer than today for 97 percent of the last 10,000 years.
The Medieval Warm Period (MWP) just 1000 years ago was 2°C warmer than today. The public is told that a similar warming will be catastrophic.
The Minoan warm period approximately 3500 years ago was 4°C warmer than today.
We are told the amount and rate of temperature increase in the last 100 years is abnormal. Compare the slope with any of the previous increases in Figure 2.
These are all Distortions, if not out-right lies. If I want this kind of BS, I can get it from consensus web sites. Or read Gergis at The Conversation.
Figures 1, 2 and 3 do NOT show ANY current temperatures. Not for 2016, 2015, or 2000. Possibly not even for 1950. If I remember correctly, year 0 in an ice core is 1950. The snowfall from the last half century of more hasn’t compacted under the weight of the snow above, so the techniques used to estimate temperature during the MWP don’t work for the recent warming. Even more confusing, temperature data is noisy and therefore is smoothed. If any data from 1950 were being used, it might be smoothed from 1900 to 1950.
Any idiot knows that GMST has risen about 1 degK since the end of the LIA, not the 0.2 K uptick at the recent end of Figure 1. It is possible that temperature change in Greenland since the end of the LIA differs from global change.
Finally you mention 2 and 4 degC of warming during two warm periods. That was in Greenland. The usual estimate is that the globe warmed half as much as Greenland: 1 and 2 degC. That makes the present and the MWP roughly the same temperature.
The change in CO2 during the Holocene is about 20 ppm or about 1/10 of a doubling. If ECS were as big as 3 K, which I doubt, the warming from 1/10 of a doubling would be 0.3 K. That would be lost in the noise in Figure 1.
There are lots of interesting things about the Holocene Climate Optimum that are true. The sun was closest to the Earth during summer at that time. It was warm enough that trees grew to the shore of the present day Arctic Ocean. Despite that warmth – which lasted millennia – the polar bears and the Greenland ice cap survived. Since then, changes in our orbital have put the sun closest to Earth during summer in the southern hemisphere, so Greenland has cooled. That cooling has been less globally than in Greenland.
Even worse, as has already been mentioned, the GISP2 ice core dataset ends in 1855.
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
I prefer to find out what Richard Alley has to say about his own Greenland icesheet research, not what someone like Ball, who uses mislabeled graphs copied from some blog to present false assertions.
Interview with Richard Alley:
http://dotearth.blogs.nytimes.com/2010/02/08/richard-alley-on-old-ice-climate-and-co2/?_r=0
[Use only one user_id and login. .mod]
As I pointed out earlier, you are dead wrong that “the GISP2 ice core dataset ends in 1855.” The GISP2 ice core data extends to 1987 (see dataset by Stuiver and Grootes). You are confusing Alley’s curve (based on Cuffy and Clow, 1997 data) with the oxygen isotope data.
Excellent comment.
I mean of course: Frank on August 1, 2016 at 12:18 am !
Even worse, as has already been mentioned, the GISP2 ice core data used in those figures actually ends in 1855
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
I prefer to hear what Prof Richard Alley has to say about his own Greenland ice core research than someone like Ball who uses deceptive mislabeled graphs copied from some other blog to present false assertions.
Interview with Richard Alley:
http://dotearth.blogs.nytimes.com/2010/02/08/richard-alley-on-old-ice-climate-and-co2/?_r=0
I also find it difficult to take seriously anyone who rejects even the well established physics of the earth’s natural greenhouse effect. See Ball’s slayer book.
[Use only one user_id and login. .mod]
Figure 2 appears to have incorrect annotations. It shows the little ice age more than1,000 years ago and medieval warming even earlier.
http://wattsupwiththat.files.wordpress.com/2012/10/cp-8-1473-2012.pdf
This study shows it is not just the 100k cycle that is involved with glacial periods and there are many exceptions with no real regularity to the beginning and endings of glacial verses inter- glacial periods.
“I prefer to hear what Prof Richard Alley has to say about his own Greenland ice core research than someone like Ball who uses deceptive mislabeled graphs copied from some other blog to present false assertions.”
Exactly, so do I…..
This is some of what Alley said in that link…..
“So, using GISP2 data to argue against global warming is, well, stupid, or misguided, or misled, or something, but surely not scientifically sensible. And, using GISP2 data within the larger picture of climate science demonstrates that our scientific understanding is good, supports our expectation of global warming, but raises the small-chance-of-big-problem issue that in turn influences the discussion of optimal human response.”
That graph clearly says “Modern warming period”
When in fact it finishes before it even stated.
Deceptive – and something I keep pointing out on here.
““It is not true that GISP2 data ends in 1855”
I said “the GISP2 data”. The data used in that plot. Which Prof Easterbrook sourced: ” a graph I plotted from data in Cuffy and Clow (1997) and Alley (2000)”. That data ended in 1855, as you said. So that graph is misleading.”
and
“You’re confusing the Cuffy and Clow and Alley curve (core temp) with the isotope data.”
I’m not confusing it. I was responding to your statement that:
“Figure 2 looked awfully familiar. When I looked closer, I recognized it as a graph I plotted from data in Cuffy and Clow (1997) and Alley (2000) several years ago. Since then it has been bounced around the internet and used by others.””
Exactly Nick:
The Graph ends in 1855 irrespective of the data extending further.
It is the graph that continues to be used deceptively on here.
It’s NOT difficult it is stated here on WUWT in this page….
https://wattsupwiththat.com/2013/04/13/crowdsourcing-the-wuwt-paleoclimate-reference-page-disputed-graphs-alley-2000/
“But as Phil. points out below, none of those Figs includes any data from the last 120 years. That is a central issue.”
So how about Kobashi’s analysis of GISP2 ice core data….
http://static.skepticalscience.com/pics/kobashi2011_1000yrs.png
Your statement that “GISP2 data ends in 1855” is not true, GISP2 data extends to 1987. Perhaps the easiest way to clear this up is for you to say ‘temperature data in Fig 2 ends in 1855.’ Then we’re all on the same page.
Then don’t keep publishing a graph on here that states “modern warming period” at the point it hasn’t yet begun ….. for a place on Earth that is 10,000 ft amsl in the Arctic as EVIDENCE that the world as a whole is not warming.
As I said, that’s “deceptive” my friend (to put it kindly).
By that I mean “defend” a graph on here (as it is Ball’s “article” ).
Dr. Ball writes:
“The Holocene is also problematic for AGW proponents because the major causative mechanism appears to be the changing precession, one of the Milankovitch Effect (ME) trilogy along with orbital eccentricity and axial tilt.”
He elaborates with an excerpt from a previous WUWT post:
“The orientation of Earth’s spin axis has changed over the past 10 Kyr so that northern summers now occur when Earth is farthest from the sun, whereas at 10 Ka [10,000 BP] they occurred when Earth was closest to the sun. Northern summertime insolation reached a maximum at about 10 Ka and has declined to the present, when it is near the minimum.”
That is counterintuitive. The long-term decline in Northern summertime insolation would appear to be problematic not for AGW proponents but for those who attribute warming generally, and Arctic ice melt in particular, to changes in solar forcing.
Dr No says
Second: since there is a 100-year cycle in solar activity, the temperature will warm again in the third 100-year period, then cool again over the fourth 100-year period, then warm, then cool, etc, with no long-term trend due to the sun..
henry says
http://www.nonlin-processes-geophys.net/17/585/2010/npg-17-585-2010.html
I think there is no such thing as 100 year warming followed by 100 year cooling, I know exactly where we are in the Gleissberg= 43 years of warming followed by 43 years of cooling. We are currently in a cooling period.
I have not yet figured out where we are in DeVries. it seems to me Leif knows?
like other writers say here, it seems likely that ice ages are triggered simply by co-incidence of bad weather, mostly icy and snowy conditions leading to the subsequent approach of ice sheets toward civilization.
if and when this happens, I think mankind will be able to thwart it simply by sprinkling the approaching ice sheets with carbon dust, so that more energy will be absorbed instead of being reflected.
as I said, more carbon = more life
I know exactly where we are
Beware of cranks who know anything ‘exactly’…
@Dale Rainwater No
We know exactly what time it is when we look at the clock. Weather just works like a clock. Pity you did not look at the pointers at the front of the clock but only at the back, trying to work out how the clock works….
e.g.
potch rainfall
We know exactly what time it is when we look at the clock
As you yourself admit, you only have half a clock…
And there are many clocks, atomic clocks, pendulum clock, water clocks, hourglasses, all used at different times and many not very reliable.
Things to Note about orbital cycles and their influence on TOA insolation and glaciation.
1) Insolation changes from cycles are reported at 65N at summer solstice. TOA insolation for the whole Earth changes little through these cycles.
2) The various cycles (except eccentricity) have rather constant cycle time-periods of 41 kyr (obliquity), 26 kyr (axial precession) and 21 kyr (apsidal precession). Eccentricity has cycles of about 95 kyr & 410 kyr.
3) The amplitude (magnitude) of obliquity varies somewhat among individual cycles and the amplitude of apsidal precession is constant among cycles. However, the amplitude of eccentricity and especially the axial precession cycles vary considerably among individual cycles.
4) The combined influence of all orbital cycles determines variation in TOA insolation at 65N and the time-periods of variations in insolation. The result of combining different cycles having different time-periods and different amplitudes is that TOA at 65N varies considerably over time.
5) Because the precession cycles produce most of the variation in insolation, ~21 kyr cycles are prominent in TOA insolation.
6) Longer eccentricity cycles accentuate the shorter cycles. Therefore the ~21 kyr cycles show greater insolation changes (highs and lows) over time periods of ~100 kyr and ~400 kyr and thus produce approximate 100 kyr and 400 kyr cycles.
7) Total yearly insolation at 65N does not change during an eccentricity cycle. Rather the ratio of NH insolation received between summer and winter varies. The “cold trigger” for glaciation is when summer NH insolation remains quite low from year to year.
8) Glaciation begins in the far northern hemisphere when the summer time temperature is sufficiently low such that winter snow does not melt, but turns to land ice. Increasing NH albedo from growing ice, along with likely changes in ocean currents and other parameters, further lower temperature.
9) Glaciation begins when orbital cycles cause TOA insolation at 65N to undergo a very large decrease (e.g., ~90 w/m^2 decrease from the Eemian ~124 kyr ago). Small insolation decreases do not activate the “cold trigger” for ice. Because the largest variations in TOA insolation occur around maxima in the eccentricity cycles, these time cycles often appear in the ice.
Wow, long overdue provocative post with amazing commentary.
The hollowscene is a joke by any standard. We remain in the Pleistocene.
I take issue with figure 3 and the statement that CO2 has risen as temperature has fallen. Perhaps in comparison with figure 2, but both the ice core and benthic core direct in kind comparisons show that CO2 has been abjectly dependent on temperature per Henry’s law as far as the records go.
I submit that this relationship can be extended back per the benthic cores to a point where cold oceans were not the dominant Carbon reservoir on the planet.
Whenever that point was, the CO2 temperature relationship changes to no correlation whatsoever.
In every instance that I’ve seen, CO2 in ice cores always lags warming, both long term and short term, i.e. there is NO cause-and-effect relationship between CO2 and warming.
Not only in the ice cores, the benthic cores as well.
This is the benthic cores of Lisiecki and Ramo compared with Vostok CO2. There is no reason not to extend the relationship back much further as their extensive compilation goes back some 5 million years.
There IS a relationship between atmospheric warming and atmospheric CO2. Atmospheric warming shifts the vapor pressure gradient in favor of increased atmospheric CO2 according to Henry’s law.
Now, the ocean surface is the primary warming source for the atmosphere, so before the atmosphere warms the ocean surface warms, and this also favors transfer of CO2 from the ocean to the atmosphere.
In deep time the close relationship between temperature and CO2 breaks down and there is simply no meaningful correlation. I believe this is because a warmer ocean will not be the dominant Carbon reservoir on the planet, as our current cold ocean is. The ocean is thought to presently hold well over half the Carbon on the planet.