A Warm Period by Any Other Name – The Climatic Optimum

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.

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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.

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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.

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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.

 

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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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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 orientation of the spin axis has nothing to do with the shape of the orbit, so this ‘explanation’ is nonsense.

tomwys1

I think you are misinterpreting the comment. Precession of the equinoxes doesn’t alter the shape of Earth’s orbit. It merely changes the Hemisphere that receives the most Solar insolation in that part of the orbit closest to the sun.

SteveC

Ditto. Well said @tomwys1.

The 100,000 year glaciation cycle is due the changes of when in the year the earth is closest to the sun, not to the precision of the spin axis which has a 26,000 year period.

lsvalgaard,
The article refers to the past 10K years not the past 100K years so your comment is misplaced.

No, because the temperature follows the 100k year cycle.

Arsivo

Dr Svalgaard: Wouldn’t the northern hemisphere, with a majority of land vs ocean, receiving the most insolation during the summer months cause an effect on weather patterns? Land doesn’t absorb near the amount of energy that the oceans do. Wouldn’t that allow for less energy transport from the tropics to the poles?
While I don’t think it would cause a glaciation by itself, I could see this, over a long period of time, helping to either usher in a glaciation with other factors and/or keeping a glaciation in progress.

The temperature follows the 100,000 year cycle, not the 21,000 year cycle.

The temperature follows the combined effect of multiple cycles which sometimes complement and sometimes offset one another.

For the past several million years the 100,000 year cycle has been dominant.

Not disputed but irrelevant.
On other timescales other cycles dominate for short periods.

No, because these other cycles have not shown up in the current temperature record.

Of course they have, in terms of short term modulations of the 100.000 year cycle.
I’m aware of your life’s project to remove solar effects from the climate record by ironing flat the records of solar variabilityso I don’t expect you to agree.
I do note that however flat you try to make the solar record the basic variations remain even though diminished in scale.

Sure, the Sun has an effect of the order of 0.1C.

rbabcock

I have a little issue with the Sun having only .1C influence on the Earth. Other than heat coming from inside (geothermal), which is minuscule, almost all the heat and radiation coming to Earth is from the Sun.
Changes in the Sun cause direct and indirect changes on Earth. If 7% more direct radiation comes into the North Hemisphere, it melts more ice, heats more water and does a lot of things we may or may not know. That can change ocean currents, jet streams, increase decrease cloudiness and alter long term patterns. It may have a big or small effect, but it will have an effect.

The solar input varies due to the orbit by 50-100 times more than the variation due to solar activity, so you can see that the activity-related variation drowns compared to the annual variation due to the varying distance to the sun.

Bill Illis

Northern Hemisphere summer solar insolation does NOT follow the 100,000 year ice age cycle we have experienced in the last 4 ice ages. (Note it really wasn’t 100,000 years before the last 4 ice ages).
If one combined the Milankovitch Cycles with the fact that the ice age glaciers change the Earth’s Albedo by up to 4% and the glaciers are slow to melt as the Milankovitch Cycles change (ie. it takes a sustained period or several periods of high Milankovitch solar insolation to break the back of the glaciers and return the Albedo to normal levels), then it starts to make sense. But the 100,000 year cycle is just a fluke of combining solar insolation and the Albedo changes. Its just a fluke really.
——-
The Sun is only capable of a max 0.1C changes between solar cycles. But if you have 5 cycles in a row of +0.1C changes, the energy will accumulate in the oceans / on land so that after decades, one will have a warmer Earth. Even right now, the 0-2000 metre ocean is warming by 0.2C per century / accumulating 0.6 W/m2/year so that sustained periods of “slightly” higher solar input will result in a warmer Earth.
The issue is that it takes decades, not just one 11 year cycle to provide for the higher temperatures. Energy accumulation at very very small rates, 0.6 W/m2/year even, eventually changes the Earth’s climate.

But if you have 5 cycles in a row of +0.1C changes, the energy will accumulate in the oceans / on land so that after decades, one will have a warmer Earth.
Since cycles vary by about a factor of two, the average solar cycle variation is more like 0.05C and that has accumulated in the oceans for billions of year, so if your argument has value, we would have had run-away warming long ago. I take it that this means that your argument does not hold water.

Bill Illis

Solar TSI at 1,362.5 W/m2 in scenario1 versus 1,360.0 W/m2/year in scenario2 .
In scenario 1, the Earth accumulates 0.8 X 10^22 joules per year and warms by 1.0C over 100 years at which point it reaches equilibrium and it stops warming. Versus scenario 2 where the Earth loses 0.8 X 10^22 joules per year and cools off by 1.0C over 100 years before it reaches equilibrium.
Right now, the Sun (after Albedo) is providing 384.2 X 10^22 joules of energy to the Earth each year but the amounting escaping back to space is 383.4 X 10^22 joules / year. Energy accumulating at 0.8 X 10^22 joules per year. This what is happening at 1362.5 W/m2/year average solar TSI.
If Solar TSI falls to scenario2, 1360 W/m2/year, the total energy received falls to 382.7 X 10^22 joules and NOW, the Earth is emitting the same 383.4 X 10^22 joules per year and there is a deficit of 0.7 X 10^22 joules per year. Over 100 years, it cools off by 1.0C before it reaches equilibrium again.
A decline of just 2.5 W/m2/year in Solar TSI is just enough to tip the balance over decades.

First, the imbalance is much smaller than you think, so the warming/cooling is much less than you think. Perhaps 0.5 W/m2 between the Maunder Minimum and now. 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..

rob conway

All three cycles have dominated over the last 2.6 my during the Pleistocene. The first 1.7 my of Pleistocene was dominated by 22 and 41 k yr cycles. One only need to become familiar with the 104 marine isotope stage record and notice not only the dominant trend changes between stages, but also all the minor change of trends within cycles. We are currently in warming trend #52 (Holocene) which followed #52 cooling trend (Wisconsinan). Only the last 900 ky has the 100 ky cycle been dominant…..

lsvalgaard
The temperature follows the 100,000 year cycle, not the 21,000 year cycle.
It looks indeed like the 100kyr eccentricity cycle, since the MPR, but it turns out that it may in fact be a complex derivative of the precession 22kyr cycle, according to Maslin and Ridgewell:
http://sp.lyellcollection.org/content/247/1/19.short

Regardless of what causes the 100-kyr cycle, it is there and that is the point. Temperatures the last million years have followed a 100-kyr cycle. There are certainly other cycles, but they are not dominant. In particular, the oft claimed 41-kyr obliquity cycle is not a change of the orientation of the spin axis so has nothing to do with the claim of the article that “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” and that that is the controlling factor in glaciations. It is not.

What we are looking at is a weakly forced nonlinear oscillator. Its not monotonic but complex, eccentricity is playing a pacing role but the cycle is not slavishly following eccentricity. (If it was then that would be a strongly forced nonlinear oscillator.) Some interglacials are even two-headed, interestingly at the peaks of eccentricity asymmetry where you would expect forcing to be strongest, not weakest. By contrast interglacials are sharper and better defined at the nodes of subdued eccentricity forcing.

co2islife

Dr Svalgaard: Wouldn’t the northern hemisphere, with a majority of land vs ocean, receiving the most insolation during the summer months cause an effect on weather patterns?

I would image the S Hemi is an infinitely better heat sink than the N Hemi. Is there evidence that the inter-glacial period is due to the earth being closest to the sun when the S Hemisphere is in Summer, and the earth tilted so most sunlight falls on the S Hemi? That would explain the cycle, no need to even consider CO2.

Duster

lsvalgaard July 31, 2016 at 1:50 pm
For the past several million years the 100,000 year cycle has been dominant.

That assertion is questionable at best and outright wrong at worst. The 100 K cycle arguably only becomes prominent in the last million years at best. Five million years ago long-term variability seems to have been far lower in amplitude – perhaps no more than , marked by much shorter “cycles,” and the mean temperature significantly warmer than at present. So “several million years” seems quite an exaggeration. For instance, see:
Lisiecki, L. E., and M. E. Raymo (2005), A Pliocene-
Pleistocene stack of 57 globally distributed benthic d18O records,
Paleoceanography,20, PA1003, doi:10.1029/2004PA001071
The reciprocal of the dO18 value is proxy of the movement of temperature.
The later Pleistocene pattern is quite distinct from that of the early Pleistocene and Pliocene. The Pliocene appears to be dominated by a year cycle, possibly as short as 20 ka, while the early Pleistocene is marked by steady, gradual cooling and an amplification of the “cycles” between warm and cool periods – if that is what they really are. The prominence of the 100 ka pattern really doesn’t emerge until a million years ago at most. All that assumes that there really is some sort of genuine cycle or multiple superimposed cycles. I have read arguments to the effect that the “cycle” may have more in common with a Lorenz – type strange attractor, which appears quasi-cyclic and changes states abruptly.

The 100 K cycle arguably only becomes prominent in the last million years at best
I’ll give you that, but it does not change anything, namely that the 100-kyr cycle is dominant NOW and is an observational fact, regardless of how it produced..

While the direction of the earth’s tilt may not affect global temperatures, the tilt does affect the records/proxies. This is because most of the records collected thus far are from the northern hemisphere.
North toward the sun at the earth’s closest approach to the sun –> warmer summers in the NH. (And colder winters.) Where you collect your data affects the results.

Frederik Michiels

felt to react with a series of questions to Isvalgaard:
if only the 100 kyr cycle is relevant what causes the following found cyclic events that were discovered in the ice core records:
– the approximate 1400 – 1500 Oescher dansgaard cycles in the glacial periods?
– The opposite Bond events of the same cycle length in the interglacials?
– The suess Devriess cycles?
– The off synched oceanic oscillations (that sometimes amplifies or cancel out each other)?
– the correlation between solar input and temperature? (ok we know correlation doesn’t mean causation but that could apply to the 100kyr cycle as well see a bit further)
in the article they talk about the last 10,000 years, not 100,000 years so the 100 kyr cycle doesn’t apply but above mentioned ones do. Evading this question is evading the scope of the article.
now the “100 kyr problem”:
when we look at the 100 kyr cycle we see actually also other cycles of the same class:
– the 21 kyr cycle
– the 40 kyr cycle
– the 100 kyr cycle
– the 400 kyr cycle
in that way correlation with only the 100 kyr cycle doesn’t mean causation as otherwise we would see or smaller but similar 21, 40 and 400 kyr signals in the records, but they aren’t there.
imho even that there is a clear 100 kyear signal in the current ice age, i suspect there is more then only the flat 100 kyr cycle that triggers interglacials. otherwise we would have seen it from the beginning, but it didn’t. Till 800 kyear ago there was the more important 41 kyr cycle signal. All you can say is that the glacial cycles’ resonance frequency with the milankovich cycles suddenly changed 800 kyr ago. who says this resonance frequency won’t change again?
and finally: science doesn’t even know how AMO and PDO is impacting our current climate which are on a geological scale such small oscillators, so how could the science then be settled about a 100 kyr cycle resonance change?

in the article they talk about the last 10,000 years, not 100,000 years so the 100 kyr cycle doesn’t apply but above mentioned ones do. Evading this question is evading the scope of the article.
The dominant cycle is the 100-kyr cycle. That is the elephant in the room.

ben

seems to make sense that closer to the sun the hotter it is.
http://spaceweather.com/glossary/perihelion.htm: “Averaged over the globe, sunlight falling on Earth at perihelion is about 7% more intense than it is at aphelion,” says Roy Spencer of NASA’s Global Hydrology and Climate Center (GHCC).

BFL

So then, how come it doesn’t get hotter by altitude (I actually had a millenial tell me this as a fact)?

ben

space is cold 😉

Samuel C Cogar

@ BFL
Duh, it does get hotter by altitude.
Why every start of Spring around here, iffen there is any snow or ice upon the hilltops it will get “hotter” enough up there to melt it all.

co2islife

Incoming radiation is 7% higher between the Perihelion and aphelion. From that we should be able to calculate out the ΔW/M^2 and the ΔTemp. CO2 only traps around 3W/M^2, so from these numbers we should be able to calculate out if it is even plausible for the minuscule amount of energy CO2 traps to actually change the temperature of the atmosphere.

co2islife

“Averaged over the globe, sunlight falling on Earth in July (aphelion) is indeed about 7% less intense than it is in January (perihelion).” That’s the good news. The bad news is it’s still hot. “In fact,” says Spencer, “the average temperature of Earth at aphelion is about 4o F (2.3o C) higher than it is at perihelion.” Earth is actually warmer when we’re farther from the Sun!
How can that be? It’s because our planet is –in a sense– lopsided. Continents and oceans aren’t distributed evenly around the globe. There’s more land in the northern hemisphere and more water in the south. During the month of July –near the start of northern summer– the land-crowded northern half of our planet is tilted toward the Sun. “Earth’s temperature (averaged over the entire globe) is slightly higher in July because the Sun is shining down on all that land, which heats up rather easily,” says Spencer.
Above: Earth’s land-masses are found more north of the equator than south. But it wasn’t always that way.

Note, 7% more high energy incoming radiation only warms the earth 2.3°C. If 7% high intensity visible light can only warm the globe 2.3°C, how could trapping a fraction of the outgoing radiation be expected to increase temperatures by a similar amount? The numbers just don’t add up.
http://science.nasa.gov/science-news/science-at-nasa/2001/ast03jul_1/comment image

Hi Doc
Nice to see there are few more ‘cranks’ prepared to question the absolutistic dictatorship of understanding you are so readily prepared to enforce.

cranks are cranks, no quotes needed. Good to see that you admit being one. Although we all knew that.

Eric Barnes

we being those who claim to know all based on a few measurements that span an inconsequential amount of time of the period in question.

Sigurdur

Dr. Svalgaard: You have an open question on Solarcycle 24. Thank you in advance for your response.

Be a bit more specific.

AndyJ

Correct. The only reason northern summers are farther from the sun is eccentricity.
But it’s not the northern summers that are important, it’s the southern summers. That’s where the oceans pick up all the heat and transfer it north into the Greenland Sea. As we move back into minimum eccentricity, the southern summers are farther from the Sun and less heat is moving into the Artic, hence we always have glaciation at minimum eccentricity.

Either way, the result is the same.

Tom in Florida

No AndyJ. Precession of the Equinoxes is responsible for the times when summers in either hemisphere are closest or farthest form the Sun. Currently NH summer solstice is at aphelion but about 13,000 years ago NH summer was at perihelion.

Santa Baby

To better understand the Anthropocene and what is going on, it should be relabeled Marxpocene?

Santa Baby

Marxcene that started with the Frankfurt school Marxists idea about domination of nature. That is Marxism domination of Nature.

PA

http://hyperphysics.phy-astr.gsu.edu/hbase/Solar/earthprecess.html
Currently the polar axis points toward Polaris. In thirteen thousand year the axis will point 47° away from Polaris.
Assume the orbit shape never changed, and 13,000 years ago the north pole summer occurred at perigee, and the southern winter occured at apogee.
Today, 13,000 year later the north pole summer would occur at apogee and the south pole summer would occur at perigee.
The orientation of the spin axis has nothing to do with the shape of the orbit. It has everything to do with the timing of perigee and polar summer.

Just for clarification: perigee and apogee relate to distance from the earth. The corresponding terms for distance from the sun are perihelion and aphelion.

leafwalker

PA, wouldn’t the northern summer and southern winter occur at the same time? Also, I believe the terms would be perihelion and aphelion…

PA

1. Fine, aphelion and perihelion are the correct terms
PA, wouldn’t the northern summer and southern winter occur at the same time?
2. Astute observation. It should have read: “…north pole summer occurred at perihelion, and the southern summer occurred at aphelion.”
The essential point is the precession of the axis controls the relationship of the poles to aphelion or the point of maximum energy.

PA

“The essential point is the precession of the axis controls the relationship of the poles to perihelion or the point of maximum energy.”
Fixed it first.

JPeden

PA August 1, 2016 at 12:34 am
Assume the orbit shape never changed, and 13,000 years ago the north pole summer occurred at perigee, and the southern winter occured at apogee.
I’ve never studied Astronomy, but it seems obvious to me that “If one thing is moving, everything is moving.” In other words, there is no Fixed Plane of Reference anywhere in the Infinite Universe. In which, for example, there is no Center, but at the same time everything is at the Center because “space” continues on to be infinitely distant from everything, that is, if it’s ok to at least imagine a straight line proceeding directly/radially away from these “centers”; although if you tried to actually do it, you’d almost have to get lost at some point.
So does the Earth “really” change its axis relative to the Sun 47 deg. every 13,000 years? Or is this only what “it looks like” if you use Polaris as “fixed”, but that Einstein’s equations correct well enough for our Frame to explain and get things done? And likewise that, ignoring the unknowns, Milankovitch Cycles and everything else so far known that immediately-enough affects the Earth’s climate, including precession, can be used to bring at least some order out of Chaos?
Also, I’m always thinking that it’s nice to have a Constant around if everything’s moving, but it sounds to me a bit impossible to have one. So maybe this problem and its solution is that we have to measure “everything moving” using Light?
At least this topic is less unsettling than having to face “Politics”, except when we have to deal with CO2-Climate Change Believers:
Thank you again, Dr. Ball!

Michael J. Dunn

JDPeden: In the case of orbital motion, the orientation of the angular momentum vector of the Earth’s rotation (i.e., its axis) can be measured relative to the orientation of the angular momentum vector of the Earth’s orbit (or, equivalently, the plane of the ecliptic). Clocking of that angular separation can be measured relative to the “fixed stars” (fixed over most times of interest, at least). And it would be well to study astronomy.

PA

JPeden August 2, 2016 at 9:14 am
I’ve never studied Astronomy,

That’s obvious.
The point was about 4 times during the 100,000 year cycle of orbital eccentricity the worst case alignment of northern summer and aphelion will occur and 1 time will be when aphelion is the maximum or almost maximum distance.

Santa Baby

In Norway most glaciers did not exist between 8.000 – 5.300 years ago. They reappeared 5.300 years ago and have since grown cyclical. Last glacier maximum was around 1740-44. We had cold Summer’s no bees and no fruit. I worry more about glaciers than global warming.

Samuel C Cogar

Right on, Santa Baby, ….. to wit:

Holocene Treeline History and Climate Change Across Northern Eurasia
Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P
During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentality with eustatically lower sea level, and extreme Arctic penetration of warm North Atlantic waters. The late Holocene retreat of Eurasian treeline coincides with declining summer insolation, cooling arctic waters, and neoglaciation.
Read more @ http://www.sciencedirect.com/science/article/pii/S0033589499921233

ralfellis

lsvalgaard July 31, 2016 at 12:43 pm
The orientation of the spin axis has nothing to do with the shape of the orbit, so this ‘explanation’ is nonsense.
The 100,000 year glacial cycle is due to the changes of when the Earth is closes to the Sun, not precession which has a 26,000 year cycle.
_____________________________________________
Nonsense Leif.
For a start the precessional cycle is roughly 23 ky, not 26 ky. How could you forget about apsidal precession Leif? Eh? And even 23 ky is an over simplification, because precession varies from 15 ky to 27 ky.
Secondly, the glacial cycle is not 100,000 ky. That is a gross simplifaction. The cycle over the last 400 ky has been more like 85 ky and 105 ky.
Thirdly, on its own the roughly 100,000 ky eccentricity cycle adds no extra insolation forcing to the Earth energy budget, and nor does it redistribute it (without the help of precession).
Your central problem, Leif, is that you cannot explain why a cyclical system should skip several cycles, and only have an effect after four or five cycles. But I have already explained that, in my peer-review paper.
High NH ice albedo can reject any increased insolation from precession or obliquity, and this rejection only stops when the ice sheets get covered in dust. And to generate the dust we need low C02, which kills off plantlife, created C02 deserts, creates dust, and coats the ice sheets with dust. And all of this is confirmed in the ice core records from both Greenland, Antarctica and the dust record of the Loess Plateau.
But you will not entertain nor discuss the possibility.
Ralph
Modulation of ice ages via precession and dust-albedo feedbacks.
http://www.sciencedirect.com/science/article/pii/S1674987116300305
.

ralfellis

>>The cycle over the last 400 ky has been 85 ky and 105 ky.
Sorry, I meant to type 90 ky and 116 ky.
So nothing to do with 100 ky.
Ralph

Hi Ralph
Have downloaded copy of your paper some time ago, impressive research.

Samuel C Cogar

ralfellis, I like the way you explain the FACTUAL science, also.
Cheers, Sam C

David Smith

Try to be a bit more polite please Leif.
Whenever someone states something that doesn’t conform with your pet theory you start shouting, “nonsense!”, like some sort of mad professor stuck in his dusty attic.
Such an attitude won’t endear you to many people, but maybe you don’t care about that.

John Leggett

lsvalgaard
July 31, 2016 at 1:50 pm
Where you say “For the past several million years the 100,000 year cycle has been dominant.” I believe you are incorrect. There is the following.
“The mid-Pleistocene revolution (MPR) is characterized by an increase in mean global ice volume, and a change in the dominant period from 41 to 100 thousand years Milankovitch cycle (Imbrie et al., 1993; Raymo et al., 1997).
Its timing is often considered to be at about 900 thousand years ago. “
also
“Orbital Forcing of Subtropical Climate
The Earth’s axial rotation is perturbed by gravitational interactions with the moon and the more massive planets that together induce periodic changes in the Earth’s orbit, including a 100,000 year cycle in the shape of the orbit (eccentricity), a 41,000 year cycle in the tilt of the Earth’s axis (obliquity) and a 20,000-year cycle in the “wobble” — much like a top wobbles — of the Earth’s axis (precession). All three of orbital cycles — called Milankovitch cycles — impact African climate on long geologic timescales.
The cycle with the most influence on the rains in Africa is the “wobble” cycle, precession. The main climatic effect of precession is to shift the season when the Earth has its closest pass to the Sun. Today, perihelion occurs in northern hemisphere winter but 10,000 years ago (half of a precession cycle) it occurred in northern hemisphere summer, and summer radiation over North Africa was about 7% higher than it is today
This strengthening summer-season solar radiation causes the North African landmass to heat up relative to the Atlantic Ocean because land heats quicker that water. The warmer land mass creates a broad low pressure zone, causing a flow of moist air from the tropical Atlantic onto North African landmass. Leading to stronger summer monsoonal rains.
This strengthening summer-season solar radiation causes the North African landmass to heat up relative to the Atlantic Ocean because land heats quicker that water. The warmer land mass creates a broad low pressure zone, causing a flow of moist air from the tropical Atlantic onto North African landmass. Leading to stronger summer monsoonal rains.
This weaker winter-season solar radiation causes the North African landmass to cool off relative to the Atlantic Ocean because land cools quicker that water. During winter, the land cools relative to the ocean and the winds reverse, returning dry conditions across North Africa. Since precession controls summer insolation, it effectively controls the amount and northward penetration of the monsoonal rains into North Africa. Atmosphere-only climate models shown that a 7% increase in summer radiation, what occurs during the AHP, results in more than a 17% increase in African monsoonal rainfall, and up to 50% if ocean feedbacks are included.”

Samuel C Cogar

results in more than a 17% increase in African monsoonal rainfall,
And 10K years ago the Sahara was not a desert and it “bloomed” each Springtime and life therein/on was good.

MarkW

Good thing he never claimed that the spin has anything to do with the shape of the orbit.

RBom

Perhaps some “warmists” will claim that the Younger Dryas IS evidence that an extraterrestrial civilization visited Earth, terra-formed it to produce food-stock (us) but became extinct by microbial-borne disease.
Ha ha 😀

dp

Did you mean “Anthropogene” in the title? If so the term is new to me.

I meant Anthropogene.
http://www.oxfordreference.com/view/10.1093/oi/authority.20110803095416338
It is remarkable how many names for the same period. I think it exceeds any other geologic period.

It’s Anthropocene, it is a proposed term for the current period when some say man dominates geology. It is a stupid idea IMHO, since one major glacial period would wipe out most of what man has built. It has not been accepted as a geological period by any geological society that I know of.
Sorry if I inadvertently stole some of your thunder Dr. Ball. I like your post a lot. What is “ME” some abbreviation for variations in the Earth’s orbital cycles?
Isvalgaard: What Dr. Ball wrote is correct. “Precession” has oriented the Northern Hemisphere in such a way that now the perihelion occurs about January 3 in the middle of winter, this lessens the impact of perihelion on Northern Hemisphere winters. This is why it is cooler now in the Northern Hemisphere than 5000 years ago. I discuss this (with references) here: https://andymaypetrophysicist.com/climate-and-human-civilization-over-the-last-18000-years/

Yet, the temperature record does not show any marked 21,000 or 26,000 year variation, so the dominant cause is the variation of the eccentricity.

Pop Piasa

Dr. S, can you post a link for further study of that? (please)

Not sure what you are asking for, but here is a defense of Milankovitch
http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf

Interglacials have been occurring roughly every 100,000 years for the last million years, but the correspondence to the eccentricity cycle is not very close. Also, there is no compelling or agreed-upon physical mechanism to link the two cycles. Interglacials always begin suddenly, and often end the same way, with the entire thing over and done with inside ~20,000 years.
The so-called 100 kY cycle is the consummate example of “cyclomania”.

Pop Piasa

Re: Dr.S, Thanks, I’ll digest this as much as I’m able.

donb

After the peak of the Eemian interglacial ~126 kyr ago, insolation at 65N on the summer solstice had dropped by ~90 watts/m^2 some 11 kyr later. That drop was the effect of the ~22 kyr-long precession cycle, not the longer eccentricity cycle. Temperature did not response immediately because some time is required for albedo to significantly change, and because insolation subsequently rose (via precession) into another insolation peak. Temperature changes into the last glaciation clearly show the effect of the various ~22 kyr precession cycles, as the eccentricity cycle proceeds. Glaciation is a CUMULATIVE effect that requires time to proceed, requires a NH cold trigger to initiate significant ice albedo changes, and probably requires factors other than ice albedo (e.g., changes in ocean and air currents, clouds, land and vegetation albedo) to fully develop.
Although Earth is currently near a low in 65N insolation due to orbital cycles, there is no glacial buildup. Reasons include the fact that we are near the minimum o f a ~100 kyr cycle and because no NH cold trigger temperature has occurred.

ralfellis

lsvalgaard
July 31, 2016 at 2:11 pm
Yet, the temperature record does not show any marked 21,000 or 26,000 year variation, so the dominant cause is the variation of the eccentricity.
____________________________________
Nonsense.
Take a look at the image below, which shows a clear correspondence between the precessional Seasonal Great Year cycle (top) and the ice age temperature cycle (bottom). (Note: this is axial precession including apsidal eccentricity precession, and therefore a ~23 ky cycle, not a ~26 ky cycle…..)
And on the way through you will see that these same orange shaded ‘high insolation precession bands’ all line up with the ~100 ky eccentricity cycle. So the ~100 ky eccentricity cycle is not the cause of warming, as such, it is merely the agent of assistance to the precessionary cycle.
So the ghost of eccentricity still shows up in the ice age record, even though eccentricity alone has absolutely no effect whatsoever.
http://s4.postimg.org/gf6jcemnx/temp_and_eccentricity_Page_1.jpg
Image courtesy Mike Palmer.
.
lsvalgaard
July 31, 2016 at 3:38 pm
Not sure what you are asking for, but here is a defense of Milankovitch
http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf
______________________________________
Nonsense. As you know, Leif, that paper is highly disingenuous.
What it says is that a rate of change is the same as change itself.
Or in other words, a weekly rise in temperature from 18 ºc to 20ºc is EXACTLY the same as a weekly rise in temperature from 18ºc to 35ºc, because they went up at the same rate.
Obfuscatory nonsesnse that proves nothing.
Ralph

Mickey Reno

Andy, ME = Milankovitch Effect(s) This acronym was rightly defined (thank you) the first time Dr. Ball used it.

I agree with Leif Svalgaard that since the MRP glacial/inrterglacials have approximately followed the
100,000 year eccentricity cycle. But it’s not as simple as none cycle or another, several can be involved because its a complex, not simple, nonlinear forcing. Its analogous to tidal forcing in an bay with a narrow outlet to the sea. Lots of frequencies start appearing.
It looks indeed like the 100kyr eccentricity cycle, since the MPR, but it turns out that it may in fact be a complex derivative of the precession 22kyr cycle, according to Maslin and Ridgewell:
http://sp.lyellcollection.org/content/247/1/19.short
What we are looking at is a weakly forced nonlinear oscillator. Its not monotonic but complex, eccentricity is playing a pacing role but the cycle is not slavishly following eccentricity. (If it was then that would be a strongly forced nonlinear oscillator.) Some interglacials are even two-headed, interestingly at the peaks of eccentricity asymmetry where you would expect forcing to be strongest, not weakest. By contrast interglacials are sharper and better defined at the nodes of subdued eccentricity forcing.

If the eccentricity were zero, all the other cycles would have no effect as the distance to the Sun would not vary with time.

ralfellis

lsvalgaard August 1, 2016 at 12:44 pm
If the eccentricity were zero, all the other cycles would have no effect as the distance to the Sun would not vary with time.
________________________________
Oh, Leif, Leif, Leif….
As you know (or should know), the effects of obliquity remain even if there was no orbital eccentricity at all.
Ralph

Not being clear enough. I meant ‘related to precessions’ which were the topic being discussed in the original posting and my first comment.

More evidence that we should pay attention to the Minoans and their SUV’s, as that was such a dreadful period 🙂

Their Minotaur was a ruminent. Flattulant CO2.

Pop Piasa

Well said, but what of flatus and CH3?

Pop Piasa

Brain fart, or bad typing, not sure which. I was referring to Methane, CH4.

It is pretty well established what caused the onset of the YD. Meltwater formed Lake Aggaziz behind a ginormous ice dam in what is now the St. Lawrence seaway. When that ice gave way, Aggasiz provided an enormous pulse of meltwater into the north Atlantic that shut down thermohaline circulation. Among the geological evidence is seaway rock scour in upstate New York and the alluvial detritus plain on the seabed. The comet theory has been fairly thoroughly debunked.
What is not well understood is why it ended so rapidly. Leading theory is sudden detachment/ subsequent disintegration of the resulting massive Greenland ice shelf extending toward Iceland.
MWP was global. Evidence was found in ikaite mineralization on the Antarctic peninsula.

Gabro

The YD impact hypothesis has been thoroughly discredited in every detail.
There is nothing unusual about the YD. It was preceded by similar events during the deglaciation leading to the Holocene, during the glacial phase itself (Heinrich Events) and during prior glacial and interglacial intervals.

whiten

ristvan
July 31, 2016 at 1:21 pm
What is not well understood is why it ended so rapidly. (YD)
Leading theory is sudden detachment/ subsequent disintegration of the resulting massive Greenland ice shelf extending toward Iceland.
—————————————–
Maybe there is a simpler explanation for it, maybe, an explanation that needs no theories or hypothesis to explain it.
It simple seems or looks as it ended rapidly because the whole YD event is actually exaggerated and it was not such as “large” as represented and considered.
Is the effect of the “ice core data” interpretation, a kind of interpretation that makes you believe that the ice ages (the long ones not the glacial periods) really do exist, when as far as I can tell there is no any real evidence for such as.
Is the very same effect that makes us consider the end and the start of a glacial period as rapid when considering the length and time duration of a glacial period.
Is the very effect which makes the interglacial periods to be considered in climatic term as very rapid swings and very rapid thermal variations.
cheers

donb

Or a meltwater pulse may have exited via the McKenzie River.

Pop Piasa

Dr, Ball, Thanks for the great cartoon to add to my wall decoration. I’m concerned that someone might question the CO2 graph though, as it does not appear to reflect the current 400 ppm.

François

The usual problem : date of year 0 in all those reconstructions?.

whiten

Pop Piasa
July 31, 2016 at 1:31 pm
Dr, Ball, Thanks for the great cartoon to add to my wall decoration. I’m concerned that someone might question the CO2 graph though, as it does not appear to reflect the current 400 ppm.
————————–
And you will be the first to have raised the question…:)
If the CO2 graph did represent the current 400ppm and the rapid swing up of it, you would have there a brand new hockey stick……..:)
And that will be contrary to the Dr. Ball claim of it causing trouble for AGW “science”.
It would be much more effective in converting people to AGW and CAGW.
I for once when looking at that graph, even without it reflecting the current 400ppm, am tempted to be converted to the AGW believe, if I have to consider that graph as proper and fairly accurate representation of reality….
cheers

Pop Piasa

No Whiten, eager as you are to jump on a friendly critique, the graph only represents the Holocene and not the Anthropocene era. Half-educated folks like myself (and you, obviously) sometimes miss these details.

Marcus

…Which part of “Ice Core” data can you not read ?

Pop Piasa

My bad…

I assume he’s referring to the 21,000 years cycle caused by the combined effect of axial precession and the precession of the earth’s elliptical orbit.

Sorry, this was meant as a reply to Isvalgaard July 31, 2016 at 12:43 pm .

The temperature and amount of glaciation does not follow the 21,000 year cycle.

Martin Hertzberg

The total solar insolation on the earth during the Summer side of its orbit depends not just on the distance from the Sun but also on the time spent during that half year. Further from the Sun means less insolation but also a longer exposure time since the Earth moves more slowly in orbit when it is further away. The effect cancel now. But at the next half cycle of the precession of the equinoxes, the two effects do not cancel for the Northern Hemisphere. If you are still around then, go south young man!


The Holocene is an interesting warm period that many believe marks the end of the last ice advance of the Pleistocene.

This is an opinion devoid of evidence and the opposite of reality. The pleistocene temperature history makes it clear that glaciation is deepening, not lessening – the last Wisconsin glaciation was the deepest of the pleistocene. It is not the last glacial but this interglacial, that may be the last.

AndyJ

I think he’s referrring to the Alarmists who are convinced the ice will never return.
As long as there is a warm current flowing into the Greenland Sea, the glacial/interglacial cycle will occur with the change in eccentricity. How the continental drift will affect the thermohaline circulation in the next ten million years will determine if the cycle continues.

The “last” ice advance could simply mean “most recent”, without any prejudice as to whether or not there will be another one in the future.

Yes I realise Tim was citing prevailing opinion and not his own – sorry if that was not clear

rob conway

No, MIS 12 (420 ky) was coldest glacial on record, and the following MIS 11 interglacial was warmer than the Holocene maximum 7 k yrs ago….

gnomish

great scholarship and another excellent article.
in an age sorely lacking for real heroes, he is a man who never broke down and never gave up.
i still think there should be a gold coin minted with dr ball on it.
then you could get whatever you wanted if you had the balls.

John Harmsworth

Dr. Ball is Canadian. We have a gold coloured coin we call the Loonie (unofficial nickname). I’m not sure Dr. Ball would want his name tied to that coin. At least until he’s proved right.

Dr. Tim Ball,
We finished the detailed Holocene analysis, explaining each temperature spike upwards and
downwards, in http://www.knowledgeminer.eu/climate/papers.html. Part 1 to 5 cover 8500 BC
to 1 AD, published already. The following parts, Part 6 and 7, covering 1 AD to 2110 AD, will be
out in a few weeks, thus, 10,000 years were/are consistently covered, which AGW is
unable to do so….. Also google: “Climate Pattern Recognition”.
As said before, each and every climate change within the Holocene was/is analyzed, soon
reaching the present CE period ……
Only 0.32°C of warming is still open to reach the maximum temperature plateau of 2050-2110
AD, with its central periodicity peak in 2080 AD. Global warming, therefore, proceeds on its exact
path upward into the Commen Era Warm Period (CEWP), without any nonsensical CO2/AGW
contribution.
JSei..

The constant in climate change is that the remedial solutions that progressives demand all converge on bigger government, less personal liberty and less prosperity. Every action, demand, study and slogan is an excuse to that achieve end goal.

commieBob

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 modern environmental activists have it backwards.
We have had ten thousand years of unusually stable climate over a wide swath of geography. It is unlikely that civilization would have developed if this were not so.
We are what we are because of the Holocene not vice versa.

Why didn’t human beings make civilization fifty thousand years ago? … “Well, it was the ice age. And also this ice age was so climatically unstable that each time you had the beginning of a culture they had to move. Then comes the present interglacial– ten thousand years of very stable climate. The perfect conditions for agriculture. link

Tom Dayton

Tim Ball knows perfectly well that the “Present” he’s marked on the temperature graphs is 1855, not 2016: http://www.skepticalscience.com/10000-years-warmer.htm. He also knows perfectly well that those measurements are from a single spot in Greenland, and therefore not reasonably representative even of the Northern Hemisphere let alone the entire globe: http://www.skepticalscience.com/the-two-epochs-of-marcott.html

AndyG55

Sorry Tom, but Michael Mann clearly shows that the top of that little tick-up is around 1970.
And you wouldn’t want to say he was wrong, would you 😉comment image

Steve McIntyre

Use of the Cuffey-Clow GISP2 series ought to be discouraged. However, SKS’s account is much worse. While the Cuffey-Clow series ends in 1855, GISP2 d18O data comes to 1987 and does not show elevated late 20th century values. Nor does the limited other d18O data available from Greenland – which is execrably archived.
I agree that one cannot rely on Greenland for a Holocene perspective, but there is convincing evidence of early Holocene warmth in the Southern Hemisphere as well – a topic very poorly discussed by IPCC.
The actual situation is not what SKS portrayed. In particular, the hockey stick portion of Marcott is invalid. Marcott’s work should have been retracted and the failure to do so is highly unethical in my opinion,

Don Easterbrook

Steve, the GISP2 ice core data correlate remarkably well with glacial fluctuations globally and there is excellent correlation with the CET record. Comparison of these is about to be published in the new Elsevier volume with relevant data. These data suggest that your criticism of GISP2 is not well founded.

David Smith

” are from a single spot in Greenland”
Isn’t that a bit like using a single tree in the Yamal Peninsula to get a hockey stick that spans the globe 😉

Kirkc

After some study…I have found that although the net NH summer insolation follows an approximate 20-25k year cycle- it is not an indicator of global temperature. It also needs to be coupled with the positive going rate of eccentricity in order to create the correct glaciation cyclic of ~100K years. This simple algorithm is predictive of the long term interglacial phases as well as the lower level intermediate temperature swings. Work so far suggests that we have begun the long decline into the next big freeze and can expect ~48,000 years before the following interglacial “melt” and the next about 70,000 years after that. This suggests the 100K rhythm is finished.

Steve McIntyre

While I strongly encourage people to look closely at the Holocene, I really urge people to stop using the GISP2 series as a prism – a point that I’ve made over and over. Vinther has convincingly shown that elevation lowering of the Greenland ice cap have distorted the GISP2 d18O record. A better perspective is given by the Renland d18O series (shown below) and it is really one that “skeptics” ought to like better:
The Renland series convincingly shows long-term d18O over the Holocene in accordance with Milankowitch theory and that modern warming has not resulted in proxy values outside the Milankowitch envelope.
Use of the GISP2 series over-focuses on speculations about the Roman Warm Period, Minoan Warm Period and Medieval Warm Period – rather than the very large scale changes over the Holocene.
Over-emphasis on the Greenland data also results in too little attention to Southern Hemisphere and tropical data, both of which have important stories.

AndyG55

“(shown below)” ?????

Bill Illis

I fully agree with Steve M. here. Throw out the temperature estimates from GISP2 because the dO18 isotopes have been recalibrated from the correct temperature/dO18 conversion formula to an INCORRECT borehole/assumption model.
Sorry, but this is the fate from ALL Greenland ice core temperature reconstructions because the Greenland ice core scientists (unlike the Antarctic ice core scientists) have “chosen” to use an incorrect borehole temperature model rather than the scientifically measured dO18/temperature model, probably because it makes the temperature changes seem so much more drastic.
The ups and downs need to be dampened down by 50% to be accurate just for the Greenland Ice Sheet and then by 75% if one is trying to approximate the northern hemisphere average temperature.
Ie. the Younger Dryas northern hemisphere temperature change was only about 2.5C versus Richard Alley’s GISP2 10.0C (and then there was an Older and Oldest Dryas a few thousand years earlier that the Greenland ice core scientists like to ascribe to the Younger Dryas because it adds to the “alarm factor”).
Richard Alley can come on here and correct me if he chooses to.

Don Easterbrook

The Cuffy and Clow data has a different basis than the isotope data. What is remarkable is that both show the same temperature changes and both correlate very well with global glacial fluctuations.

Cuffey and Clow 1997 use the borehole temperature to dO18 isotope method and have temperature change from the last glacial maximum to today of -23C on the Greenland ice sheet. The Antarctic ice cores using the correct dO18 isotope to temperature conversion formula is only -10C.
So, polar amplication is supposed to be 2X, yet Cuffey and Clow are at 4.5X. Sorry, but is just a mistake and/or climate science scam. The other Greenland ice core scientists continued on with the incorrect methodology/scam and people do not see what has happened here.
http://onlinelibrary.wiley.com/doi/10.1029/96JC03981/abstract

Steve McIntyre

Don says: “The Cuffy and Clow data has a different basis than the isotope data. What is remarkable is that both show the same temperature changes and both correlate very well with global glacial fluctuations.”
No, this isn’t correct either. The Cuffey-Clow reconstruction uses isotope data, which they combine somehow with borehole data with the borehole data modifying low-frequency properties. The similarity to isotope data is not “remarkable” since it contributes to the reconstruction.

ralfellis

>>Bill Illis
>>So, polar amplication is supposed to be 2X, yet Cuffey and Clow are at 4.5X.
Sorry, Bill, but where do you get 4.5X from. The Cuffey and Clow paper says “20ºC warming from LGM to Holocene”, which is more like 2X.
Ralph

Bill Illis

Global temperature change from LGM to Holocene (/today) –> +5.0C
Cuffey and Clow 1997 Greenland ice-sheet temperature change from LGM to Holocene (/today) –> +23.0C
23.0C / 5.0C = 4.6 times
Cuffey and Clow 1997 Greenland Temp reconstruction using borehole calibration..
http://kaltesonne.de/wp-content/uploads/2014/10/don5.gif

Javier

Best comment so far. Greenland temperatures are not world temperatures, and GISP2 is unreliable for a climatic history of the Holocene.

The Minoan warm period approximately 3500 years ago was 4°C warmer than today.

Must be a typo, because it is absurd. If not I would like to see a scientific citation supporting it.
Temperatures during the Holocene are following obliquity, as they usually do.
http://www.euanmearns.com/wp-content/uploads/2016/05/Figure-9.png
The wiggles are due to different factors, freshwater outflows, solar variability, oceanic variability, and lately anthropogenic warming.

I disagree with with the anthro warming. The only thing I’m sure of is that temperature controls co2, at least in the last 50 years for sure. What caused the recent warming? Variability of orbit, solar variability ?… Maybe… I think we are missing something. From the record perhaps cosmic rays, or magnetic strengthening or weakening. Its a matter of seeing the pattern in it. The information is there.
* temperature controls co2, but its not the only thing. Solar activity influences cosmic rays and cosmic rays influence co2.

FerdiEgb

Rishrac:
temperature controls co2, but its not the only thing. Solar activity influences cosmic rays and cosmic rays influence co2.
Wow, didn’t know that. As far as I can see, the temperature of the ocean surface did control CO2 levels for millions of years until some 160 years ago… By Henry’s law for the solubility of CO2 in seawater, that should be currently around 290 ppmv in dynamic equilibrium between ocean surface and atmosphere.
I don’t see with what mechanism solar influences or cosmic rays could add 110 ppmv, while humans added some 200 ppmv extra without any resulting increase?
All what temperature does is mainly causing the variability in uptake, only a fraction of the upgoing trend and all what cosmic rays do is producing some 14C from 14N, but that is many orders of magnitude smaller than the 110 ppmv extra…

HenryP

sorry, @Javier
my investigations show there is no man made global warming
there is no room for it in my equation…

Steve, I agree we need much more data than Greenland alone to try to decipher the paleo climate. Here is a comparison of two Greenland and two Antarctic ice core proxy estimates of temperature anomalies, referenced to each data set average for 200 to 1,200 years ago as zero (to normalize the different sources). The HadCRUT4 global temperature anomaly estimates referenced to 1961-1990 are plotted in red for perspective.comment image
And here is a closer view of these same estimates for the last 4,000 years.comment image
A very noisy climate signal indeed, much of which may be uncertainty. Just for grins, I averaged all four of the ice core proxies together for the last 2,000 years.comment image
It would be nice to have some tropical and subtropical proxies to add to the mix.

oz4caster, since you’re posting ice core graphs, here’s another time/temperature comparison of the Arctic and the Antarctic:comment image
Ice core temperature changes move in the same direction simultaneously in both hemispheres, making the polar temperature record a good proxy for global temperature changes. The ∆temperature becomes more pronounced at higher latitudes, but it’s clear that the synchronicity in both polar temperatures reflects global warming and cooling.
Since polar ice core evidence shows synchronous global warming and cooling, it supports the hypothesis that the MWP and LIA were global events.

Steve McIntyre

Again, I urge interested readers to thoroughly assimilate Vinther’s observations about the effect of elevation changes. Vinther observed that Renland and Agassiz were less impacted by elevation change and in my opinion they are better choices. Vinther estimated GISP2 elevation changes and re-estimated its d18O for consistency with Renland/Agassiz. You’d be better off looking at this data.
In Antarctica, I suggest that you look at James Ross Island, as its elevation has not changed a great deal over the Holocene. You have to examine elevation changes at each site as the Holocene history depends on it – see Masson et al 2000 for interesting comparisons.

Steve, thanks for the info. I was able to find a PDF copy of the Mason paper here, in case anyone else may be interested:
http://climate.colorado.edu/reprints/Masson-DelmotteEtAl_JClimate_2008.pdf
The Vinther paper seems to be pay-walled, if I found the right one.
http://www.sciencedirect.com/science/article/pii/S027737911400434X
Are the reconstruction data from these sources available on the web to be downloaded?

co2islife

Steve, these issues are a distraction. Stay focused on the big issues, not the minutia. There is absolutely no mechanism defined by anyone I know that explains how CO2 would ever lead temperatures to pull the globe out of an ice age, nor is there a mechanism by which CO2 would ever decrease in advance of temperatures to start an ice age. Facts are CO2 can’t possibly cause a cyclical trend in temperatures. There has to be something other than CO2 driving the temperature on a grand scale. CO2 has a natural “off switch” and absorbs less and less energy on a marginal basis once you get above 50 or so ppm. CO2 has been 7000 ppm and never caused CAGW, why would this time be different. If Warmists can’t explain why CO2 would cause cyclical temperatures, they can’t explain the climate.

In the beginning the MWP and the LIA didn’t happen. They couldn’t happen. CAGW would have to explain their flat graphs of co2. How could temperatures vary if co2 didn’t vary? Now they’ve acknowledged that both happened, but the explanations are vague.
Two years ago I pulled the anomalies of temperature and co2 for the years. While co2 production continued to increase, the ppm of co2 varied with temperature. They’ve slightly adjusted the record increasing many in the last few years and decreasing many in past years. What they’ve done is skew the data by rearranging so that co2 leads temperature rather than lags. No reason as to how co2 ppm vary year to year. In some cases as much co2 as was produced. I wonder why they have to keep adjusting the Data? Did the equipment fail ? Where they wrong then and right now ? Or is it ” it’s worse than we thought” ? If the current year was wrong, why were are the previous years wrong ? How many times are they going to do that ? I sound like a crank if I submit a paper with the wrong data on it. Any organization that I submit the paper to will discard it. ” you’re not really a scientist are you? “… but it’s ok when they use out of date, wrong, or assumptions that later become fact via by magic, information.
The only thing CAGW has is the manipulation of data.

HenryP

true
I can testify that the data in Gibraltar (UK) has been changed as it did not tie up with three surrounding stations, one in Morocco and two in Spain.

This isn’t science anymore. It’s all make believe. They will have enough useful idiots to support them. There is a way to stop them, but it isn’t going point by point. It’s to degrade the entire field of climate science. I’ve jokingly said I should have went into astrology. My apologies to the astrology field. Climate science is several floors beneath astrology.
As proof that CAGW is not only wrong but using the wrong formulas, there is no way that an organization with so many trained people, access to the most sophisticated equipment, and so well funded… could make so many failed predictions/projections and yet persist in no uncertain terms that they are right. Not only right but have most or all scientific organizations and allegedly scientists too. What’s the use of arguing with Mosher, or any warmist, when it’s fixed to start. In report after report, which will probably disappear now, they used the wrong TSI number. They knew as far back as 2002 that it was wrong. 10 w/m^2 results in a 1/3 of global warming not happening. That is a significant amount from co2 math they use.

Latitude

I hate graphs with these stupid big scales…pare them down to a scale that people can relate to
..and they are all flat lines
But then where’s the scary part in that?

Tom Dayton
joelobryan

Trillions of dollars of wealth redistribution lie in those little wiggles. That’s the man-made part that is mostly a “take-it on faith that things will get worse” dogma.
Now hand over your wallet please, and your credit cards. The Left is also gonna need your IRA and/or 401K eventually, as the they will keep running out of one pot of OPM and always looking for new ones.

Bindidon

Latitude on July 31, 2016 at 3:05 pm
To Tom Dayton’s comment I’ll add: don’t forget to read some of the comments, e.g.
Robert7 November 2010 at 16:21

ulriclyons

“Figure 1 shows one reconstruction of the temperature of the Northern Hemisphere derived from Greenland ice cores.”
No it does not, it shows a temperature proxy for Greenland, which is largely in the inverse of the mid latitude temperatures.
“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 warmest part of the Medieval Warm Period for Europe, was in the 8th century, where the GISP2 proxy is at its second coldest for the Holocene. And of course Greenland temperature changes are larger than for the mid latitudes.
“The Minoan warm period approximately 3500 years ago was 4°C warmer than today.”
Calling that very warm spike on GISP2 at ~1350-1150 BC the Minoan Warm Period, is one of the greatest errors ever made in climate science. The Minoans, as did many other cultures worldwide, expanded and prospered from around 2700 BC, where GISP2 is at its third coldest in the Holocene, their demise along with several other cultures was around centered around 1200 BC. Because that was a very cold-dry period for the mid latitudes, one of the worst through the Holocene.
And I bet there is evidence for a brief warm period in the mid latitudes at the 8.2Kyr event.

William Astley

In reply to Leif.

July 31, 2016 at 1:23 pm
The 100,000 year glaciation cycle is due the changes of when in the year the earth is closest to the sun (William: What changes?) , not to the precision of the spin axis which has a 26,000 year period.

A paradox is an observation that cannot be explained by a theory.
When there are piles and piles of paradoxes a field of science should be in crisis. Climate science is in crisis. There is a massive cyclic forcing function that has not been taken into account which explains why climate science has piles and piles of urban legends
P.S. The mysterious unknown forcing function is the sun. Where or where have large sunspots gone?
Why are there massive coronal holes that stretch across the solar equator? The solar cycle has been interrupted. The sun is entering a different state.
Are at least 12 different observations and analysis results that support the assertion that insolation changes at 65N are physically not capable of causing the temperature changes observed in the paleo record and did not cause what is observed. For example the causality problem or the Younger Dryas problem or the Southern Hemisphere cools at the same time as the Northern hemisphere problem.
The following is a sample of the paradoxes which disproof the theory.

Milankovitch believed that decreased summer insolation in northern high latitudes was the dominant factor leading to glaciation, which led him to (incorrectly) deduce an approximate 41 ka period for ice ages.[18] Subsequent research[19][20][21] has shown that ice age cycles of the Quaternary glaciation over the last million years have been at a 100,000-year period, leading to identification of the 100 ka eccentricity cycle as more important, although the exact mechanism remains obscure.

1) 100,000 year problem

The 100,000-year problem is that the eccentricity variations have a significantly smaller impact on solar forcing than precession or obliquity – according to theory- and hence might be expected to produce the weakest effects. However, the greatest observed response in regard to the ice ages is at the 100,000-year timescale, even though the theoretical forcing is smaller at this scale.[10] During the last 1 million years, the strongest climate signal is the 100,000-year cycle. In addition, despite the relatively great 100,000-year cycle, some have argued that the length of the climate record is insufficient to establish a statistically significant relationship between climate and eccentricity variations.

2) Southern Hemisphere cools cyclically at the same time as the Northern Hemisphere
http://www.news.wisc.edu/9557

Glacial records depict ice age climate in synch worldwide
“During the last two times in Earth’s history when glaciation occurred in North America, the Andes also had major glacial periods,” says Kaplan.
The results address a major debate in the scientific community, according to Singer and Kaplan, because they seem to undermine a widely held idea that global redistribution of heat through the oceans is the primary mechanism that drove major climate shifts of the past.
“Because the Earth is oriented in space in such a way that the hemispheres are out of phase in terms of the amount of solar radiation they receive, it is surprising to find that the climate in the Southern Hemisphere cooled off repeatedly during a period when it received its largest dose of solar radiation,” says Singer. “Moreover, this rapid synchronization of atmospheric temperature between the polar hemispheres appears to have occurred during both of the last major ice ages that gripped the Earth.”

3) Stage 5 problem (Causality Problem)

The stage 5 problem refers to the timing of the penultimate interglacial (in marine isotopic stage 5) that appears to have begun ten thousand years in advance of the solar forcing hypothesized to have caused it (also known as the causality problem)(putative effect precedes cause).

4) Effect exceeds cause

The effects of these variations are primarily believed to be due to variations in the intensity of solar radiation upon various parts of the globe. Observations show climate behavior is much more intense than the calculated variations.

5) The unsplit peak problem

The unsplit peak problem refers to the fact that eccentricity has cleanly resolved variations at both the 95 and 125 ka periods. A sufficiently long, well-dated record of climate change should be able to resolve both frequencies.[15] However, some researchers[who?] interpret climate records of the last million years as showing only a single spectral peak at 100 ka periodicity.

6) The transition problem

The transition problem refers to the switch in the frequency of climate variations 1 million years ago. From 1–3 million years, climate had a dominant mode matching the 41 ka cycle in obliquity. After 1 million years ago, this switched to a 100 ka variation matching eccentricity, for which no reason has been established

http://en.wikipedia.org/wiki/Milankovitch_cycles#/media/File:Five_Myr_Climate_Change.svg
7) Identifying dominant factor

Milankovitch believed that decreased summer insolation in northern high latitudes was the dominant factor leading to glaciation, which led him to (incorrectly) deduce an approximate 41 ka period for ice ages.[16] Subsequent research[17][18][19] has shown that ice age cycles of the Quaternary glaciation over the last million years have been at a 100,000-year period, leading to identification of the 100 ka eccentricity cycle as more important, although the exact mechanism remains obscure

The solar cycle has been interrupted. The sun is entering a different state
Since you never define was ‘interrupted’ means, your comment is void, but apart from that the, Sun is just behaving normally, been that, done that.

O sole
O sole mio
è che il tuo viso
http://www.vukcevic.talktalk.net/Image7.jpg

Kirkc

As I suggested in a post above, it’s not obscure. The cycles are not a series of additive values but are rate specific.

AndyJ

The mechanism is simple if one looks at the formations of the ice caps as a starting point. Moving continents changing the thermohaline circulation currents and therefore the heat circulation process in the oceans. The Artic glaciated because the Panama Current ended when North and South America connected and the Pacific was not dumping it’s heat directly into the Gulf Stream,
If one looks at the TC currents, all the warm currents from the southern oceans are channeled between Africa and South America and sent north to end in the Greenland Sea. When we are at minimum eccentricity, those currents are weaker and cooler due to increased distance from the Sun in the southern summers. Less heat enters the Greenland Sea, which during glaciation and subsequent sea level drops, is the only entrance to the Artic Ocean.
The previous 41ky cycles were probably due to Greenland being much closer to Scandinavia with much less heat penetrating so deep into the Artic during max eccentricity, therefore obliquity dominated.
That’s my theory. It’s the oceans.

Gabro

The switch from 41 K to 100 K cycles occurred only about a million years ago. Greenland and Scandinavia were only around 20 km. closer together then, assuming a spreading rate of two cm per year.

Javier

Milutin Milankovitch was right. The 41 kyr cycle rules the glacial-interglacial cycle. It just fails to get the world out of a glacial state about half of the times or more because the world has been getting colder as the Ice Age advances.
http://i1039.photobucket.com/albums/a475/Knownuthing/Glacial%20cycles_zpst84kkzo4.png
Since the Pleistocene started 1.8 million years ago some obliquity cycles have failed to reach interglacial temperatures (red line) and can only raise to a declining temperature (blue line). This produces the false impression that other factor is now responsible for interglacials.
1) 100,000 year problem: Solved
2) Hemispheric symmetry of glaciations: Solved
3) Stage 5 problem (Causality Problem): Solved
4) Effect exceeds cause: Feedbacks can explain that.
5) The unsplit peak problem: Solved
6) The transition problem: Solved
7) Identifying dominant factor: Solved

Gabro

A quibble:
The Pleistocene Epoch now includes the Gelasian Age, 2.58–1.80 Ma, so that all the NH glaciations occur within it. The Gelasian used to be the last age of the Pliocene, but that made little sense.
There is now not much left of the truncated Pliocene Epoch, wedged in between the long Miocene and Holocene, which of course is really just another interglacial in the Quaternary glaciations.

Jeff Alberts

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.

Actually the “problems” began much earlier, when a “global temperature” was presented. There is no such thing, there never will be such a thing. It’s a fantasy masquerading as science on both sides of the debate.

Robert from oz

One thing is for certain , the longer we go back the less scary it gets .
Most of our hottest ever ,wettest ever ,most destructive ever only goes back 20 – 30 years but weather and climate have been going on for billions of years and will still be changing for billions more with or without us humans .

Greenland ice proxies are faithful recorder of the Iceland’ volcanic eruptions affecting its weather and not much else.
https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-13.98,65.70,1137/loc=-21.861,65.347
Dr. S. may advise to be otherwise

Jeff Alberts

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.

None of those assertions are supportable, because there is no global temperature. You can certainly make those assertions about parts of Greenland, but not globally.

This claim that there is no 21,000 year Milankovitch effect on climate is a false one. There is one, it’s well studied and described as one of the orbital/axial forcings, but it’s constantly modulated by the other cyclical forcings, in a manner that commonly hides its effect in the overall temperature record. It’s certainly true that there is no clear 21,000 year cycle in that record, but the 21,000 year forcing does indeed effect shorter term temperature rises and falls. Including especially during our current holocene period. The fading of that forcing is a major factor in the gradual cooling of the holocene. It also contributes to the 100,000 year cycle, even though there is no actual cycle of any single forcing that is 100,000 years in length. It’s a complex multiple of a number of smaller forcings that creates peaks and valleys, some of which are regular, others not.
https://en.wikipedia.org/wiki/Milankovitch_cycles

Don Easterbrook

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. I also plotted the oxygen isotope curve from the same core using data from Stuiver and Grootes. Both show essentially the same temperature changes, which are well correlated with global glacier fluctuations, so they relected global temperature changes.
We can learn a lot from these graphs, not only about past temperature changes, but also about possible causes of those changes. Perhaps the most important of aspect of the temperature changes is their abruptness and magnitude, along with the number of sudden climatic changes (see Easterbrook, 2010, 2014 and numerous posts on WUWT). They are important because they place limits on possible causes. For example, take a look at the Younger Dryas on Fig. 2–the climate changed abruptly from nonglacial values
back to full glacial conditions in about a century, stayed there for more than 1000 years, then back to full interglacial in about a century. Obviously, whatever caused the Younger Dryas was capable of causing a full glaciation in a very short period of time. The abuptness of these climatge changes from full nonglacial to glacial and back to interglacial proved that they could not possibly be caused by Milankovitch orbital variations and cast serious doubts on the Milankovitch theory. Another problem with the Milankovitch
theory is that when the N. Hemisphere was in a glacial phase, the S. Hemisphere should have in an interglacial, and we now know from many hundreds of isotope dates that climate changes in both hemisphere are almost exactly synchronous. Anyone who still adheres to the Milankovitch orbital theory as the cause of ice ages must explain how variations that take many thousands of years can cause
climate changes from interglacial to full glacial to interglaciation in about a century. It can’t be done! It doesn’t work even if some short-term climate fluctuation is superimposed on orbital changes (this has been attempted, but doesn’t work).

” Since then it has been bounced around the internet and used by others.”
Yes, misleadingly, as in this post. There is a big arrow saying “Present global warming”. And a green line saying “Present temperature”. But, as Steve McIntyre notes above, and have also many others, the GISP2 data ends in 1855.

Steve McIntyre

As too often, Nick Stokes misrepresents what I said and provides incorrect information. It is not true that GISP2 data ends in 1855 or that I “noted this above”. GISP2 data is available until 1987, as I observed. It is ludicrous that Stokes should claim that GISP2 data ends in 1855.
As I actually observed, it is the Cuffey-Clow temperature reconstruction from GISP2 that ends in 1855. The Cuffey-Clow version has been widely used in “skeptic” articles, but there is really no need to use it since isotope data is available to 1987 and use of the Cuffey-Clow version permits cheap responses such as Stokes.

“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.

” cheap responses such as Stokes.”
It’s a very central response. A key proclamation in this rant is

Other important points from Figures 1, 2 and 3 expose the lies and distortions about the last 120 years being anomalous include,
…list

But as Phil. points out below, none of those Figs includes any data from the last 120 years. That is a central issue.

Don Easterbrook

No, that’s not true. The GISP2 core data ends in 1987 (see the Stuiver/Grootes data set. You’re confusing the Cuffy and Clow and Alley curve (core temp) with the isotope data.

“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.”

AndyJ

Could the Younger Dryas be due to massive initial melting creating vastly increased cloud cover and re-insulating the planet for a brief period?

ulriclyons

The Bølling-Allerød interstadial, as well as Dansgaard-Oeschger events, would be the reduction of ice shelves and opening of the Arctic to warm Atlantic ocean transport. The Younger Dryas, and termination of DO events would be the closing off of warm ocean transport to the Arctic ocean, and the polar see-saw effect should cease during a glacial Arctic, and it’s temperature change in unison with the Antarctic.

CO2isLife

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.

FerdiEgb

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…

Javier

Leif Svalgaard,

For the past several million years the 100,000 year cycle has been dominant.
No, because these other cycles have not shown up in the current temperature record.

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.

Javier

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.

Javier

“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.

Javier

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:

For the past several million years the 100,000 year cycle has been dominant.

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.

No, because these other cycles have not shown up in the current temperature record.

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.

Javier

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.

ralfellis

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

Javier

Thank you for separating and specifying the different issues.

1) precession [‘orientation’] is not the driver as claimed by the article

100% agreement on this one

2) there is a clear, real, and observed 100-kyr temperature cycle [regardless of its cause]

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.

3) your ‘prediction’ of only 4000 years to the next glaciation is wrong.

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.

4) no special pleading about ‘misfiring’ cycles.

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.

ralfellis

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

Gabro

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.

Javier

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

Gabro

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.

Kirkc

Eccentricity is the main driving force!

Gabro

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.

Javier

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.

ralfellis

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

Javier

“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.

ralfellis

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

Javier

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.

joelobryan

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.

Javier

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.

co2islife

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.

Don Easterbrook

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.

Gabro

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.

Gabro

Sorry. Misplaced this reply. Should be to Javier or Joel, above.

Don Easterbrook

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

Javier

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 1875comment image

Don Easterbrook

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.

Don Easterbrook

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

Mark - Helsinki

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?

FerdiEgb

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…

JohnKnight

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!

Chris Hanley

“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.

Chris Hanley

“… 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.

Chris Hanley

@ 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,
“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
comment image?w=1050&h=644
A range of 2°. But even that was a composite of a large region. Individual variation is larger again/

Chris Hanley

@ Nick Stokes 12:07 am.
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.comment image?w=1050&h=644
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!

Kirkc

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.

Javier

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.

Javier

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

Javier

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.

Javier

Oops. there should be a bold termination tag before the first parenthesis. Perhaps a mod can fix that and delete this post.

Kirkc

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.

Leo Smith

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.

George McFly......I'm your density

Excellent article Tim. Many thanks

Don Easterbrook

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.

Frank Ciccarelli

So the polar ice is not melting after all & we don’t need worry about the polar bears? I for one am relieved…

Frank

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.

Ceist

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]

Don Easterbrook

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.

Bindidon

Excellent comment.

Bindidon

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.

Toneb

“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

Don Easterbrook

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.

Toneb

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).

Toneb

By that I mean “defend” a graph on here (as it is Ball’s “article” ).

Marlo Lewis

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.

HenryP

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.comment image
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’…

HenryP

@dr 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 rainfallcomment image

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.

donb

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.comment image
Whenever that point was, the CO2 temperature relationship changes to no correlation whatsoever.

Don Easterbrook

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.comment image
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.