Climate Cycles, Climate Mechanisms and Determining Accurate Dates

Guest opinion: Dr. Tim Ball | When Did It Occur?

Lack of information is a major problem in reconstructing and understanding climate and climate mechanisms. H.H.Lamb gave it as his reason for creating the Climatic Research Unit (CRU).

“…it was clear that the first and greatest need was to establish the facts of the past record of the natural climate in times before any side effects of human activities could well be important.”

Notice he is talking about “the facts”, which includes data and other measures. Chief among the other measures are accurate chronologies, which is why he discusses dates and dating methods at some length in Volume 2 of his Climate, Present, Past and Future.

Lamb also divided climate studies into three major areas based on time and method. The secular or instrumental period covers at most 100 years. Few stations are longer and almost all are in Western Europe or eastern North America. The historical period includes the recorded works of humans and covers at most 3000 years. The biologic/geologic record covers the remainder of time. The degree of accuracy diminishes both in measures, such as temperature and precision of dates, as you go back in time. One tragedy of the “hockey stick” rarely discussed was that it misused and demeaned the value of one of the few measures that transcends two or three of these divisions.

Climate is the study of change over time, or average conditions in a region. It is almost impossible to study climate change without accurate dates. For example, a major debate in climatology is the extent to which climate is cyclical. If the dates of events are inaccurate, it is not possible to determine the length of cycles and how they interact. You can, and likely will, draw completely wrong conclusions.

For example, I participated in a fur trade history conference when a paper by an historian claimed ice conditions on Lake Michigan occurred at very different dates than today and were proof of climate change. His source was a fur trader’s journal. Questioning revealed he was unaware that the fur trader used a Julian Calendar and the British government changed to the Gregorian Calendar in 1752, adding eleven days. (Figure 1)


Figure 1

Calendar changes are just one example of disconnects, between our thinking, understanding, teachings, and reality. Calendars are essentially fixed, human constructs, while nature is constantly changing. The Egyptians, among others, struggled with this problem. Their calendar had 12 months of 30 days, which was so out of phase with reality after 400 years they simply declared a holiday for the missing five days. Later, they decided that flooding of the Nile, critical to their food production, was the beginning and end of their year. They tied it to a physical event, namely the rising of the Dog Star, Sirius.

The Egyptian change was triggered by the growing discrepancy with natural events. The change from Julian to Gregorian was mostly pushed by the gap between the agricultural seasons and natural events. Annual climate change is problematic, but it becomes even more complex when dealing with segments of the year, such as seasons. Most significant dates in the human calendar are related to the interaction between climate, nature and food supply. The Farmers Almanac and much folklore is accumulated empirical information about agriculture, the weather and climate. The problem is so much of it is related to a specific region. For example, English proverbs say, “If the leaves do not fall before St Martin’s (November 11), expect a cold winter.” Or, A green Christmas, a fat churchyard.” It is apparent these are related to the pattern of the Circumpolar Vortex, but the impact depends on the latitude and the longer climate pattern of the time. Conditions were quite different between the Medieval Warm Period (MWP) and the Little Ice Age (LIA). The problem is exacerbated when the proverb was created in Europe and was then transposed to another part of the world.

Another problem for calendars, and dating in general, is establishing a datum. The millennium change to the 21st century triggered much discussion about eliminating AD and BC. Radiocarbon dating, discussed later, established January 1st 1950 AD as the base year and called it 1950 BP for Before Present. The switch to the new millennium was interesting because it ushered in the era of exploitation of extreme alarmism. Known as Y2K, many claimed computers would fail because of the inability to switch to the new date sequence. They scared people so much that everyone celebrated in the wrong year. Technically, the new millennium begins in 2001, but the celebration occurred in 2000. Maybe we should have a calendar that begins with the Big Bang, but then, what would the error range be?

Robert Claiborne wrote a book (1978) titled Climate, Man and History. It received little academic attention because Claiborne was, to say the least, a man of eclectic interests. He was too diversified for the increasingly narrow, specialized, academic world. The book intrigued me because it addressed an issue that troubled me, namely that I was getting different dates and sequences of events in different university courses. Claiborne noted that anthropologists were on a different time-scale than glaciologists and climatologists. As I recall, he wanted to do a doctoral thesis on the subject, but it was rejected, so he wrote the book instead.

Two Dating Categories in Climate

Lamb identified Absolute and Relative as the two major divisions of dating in climate studies. They are the same divisions anthropologists use as they try to create an accurate chronology for pre-history. It is mandatory for understanding cause and effect.

Relative Dating is the simplest because it relates events to a fixed or known date. For example, in parts of North America archeologists, a branch of physical anthropology, determine if an event is pre- or post Mazama. This is reference to a layer of volcanic ash laid down across the continent by eruption of Mt Mazama, now marked by the enormous caldera filled by Crater Lake.

Relative Dating is dependent on Absolute Dating. Technically, all you can say accurately is that an event occurred before or after the Absolute Dating event. Of course, this assumes Absolute Dating has an absolute precision, but that is not the case.

Problems occur because of the early assumption that certain natural events occur with an absolute precision. This created many problems and caused many changes in understanding sequences of events. Two examples will illustrate them as they relate to climate.

Radiocarbon dating was developed from concepts proposed by Willard Libby in 1933, however, they only became established after WW II. It was quickly adopted by archaeology and gradually intruded into other disciplines, where sequence and timing of events was critical.

Milankovitch created a cycle of climate conditions that indicated a glaciation sequence in Alaska. Radiocarbon dating of trees for a region conflicted with his chronology. Since radiocarbon was ‘new’ and ‘more scientific’ it over rode Milankovitch. Prior to 1950, his theory was generally accepted, but after that it was rejected. I recall conferences in the 1960s and 70s at which any reference of a cyclical trend to Milankovitch was automatically rejected. His son, in a poignant article about his father’s lifework, claimed he died of a broken heart. It was not until the late 1980s that I heard a paper referencing Milankovitch, with no challenge.

Milakovitch_cycleFigure 2

Part of the reason for the change was that an error in assumption about radiocarbon dating was discovered. As one article explains,

Every scientific method has its limitations. This is because the fundamental assumptions or axioms, on which a method like carbon dating is based, are only approximately true or accurate. All the physical laws we know have limits of validity. The fact that scientific methods like these, fail beyond a certain domain of approximation, doesn’t make them redundant. It only means that these need to be used with caution and with a knowledge of the limits of their accuracy.

Most forms of absolute dating involve supposedly precise measurable rates of a natural process, like the rate of decay of carbon 14. It sounds precise, but all measures are presented with a range, which increases as you extend back, to the maximum range of the technique, 60,000 years. A classic example is the radiocarbon dates for the Shroud of Turin, which are given as 1260-1390 AD with a 95 percent confidence; the range of 130 years covers most of the modern instrumental record. It is a good example because the fervent and political interest means the problems and limitations of the method are discussed to an extreme level. A computer search for absolute dating methods returns many sources from a creationist perspective. Ironically, this vulnerability illustrates the problems with scientific dating techniques.

Another form of radioactive decay and the one most widely used, is Potassium/Argon (K-Ar) dating. This measures the measures the decay of Potassium- 40 to Argon-40. A list of the assumptions required for reasonable results was set out by McDougall and Harrison (1999), and puts severe limitations on the viability of the results. A general claim is an accuracy of one percent, which sounds good. However, one percent of one million years is 10,000 years and in climate that effectively covers the Holocene. In reality, none of these so-called precise methods, even radiocarbon dating, are accurate enough for climate studies.

The Holocene is an example of another problem related to dating and climate. When did it begin? Who decided what temperature threshold was met and when? Anthropogenic Global Warming (AGW) advocates exploit this problem of dating when it suits them. For example, they claim the Medieval Warm Period or the Little Ice Age did not occur because evidence shows they were not uniformly global. Climate studies try to deal with this by the procedure of relative homogeneity. In my study of climate at Churchill, Manitoba I also examined the climate at York Factory, 220 km apart, to determine and separate regional from local change.

This article cannot cover all the forms and methods of establishing absolute or relative dating. Its goal is to raise the issue of the limits of the methods and subsequent accuracy. Both are essential to understanding climate and especially climate change. However, a brief list of those that have influenced climate change studies includes: Rhythmites, such as sediment layers, tree rings, and ice layers; Lichenometry, is based on the rate of growth of lichens, which is assumed to be slow and constant; and Palynology that counts the number of pollen types in a core to provide a relative sequence of changing vegetation. Notice the dangers of autocorrelation because all of these are caused by climate change.

The right century may be enough accuracy for a shroud, but is inadequate for a climate study. Accurate dating is essential for establishing the relationship between events. The specific periodicities are crucial in achieving accurate prediction and establishing correct relationships of cause and effect. Lamb’s concerns are just as valid today as when he expressed them. If anything, they are a bigger problem because people use them without understanding the limitations. As the earlier quote said,

The fact that scientific methods like these, fail beyond a certain domain of approximation, doesn’t make them redundant. It only means that these need to be used with caution and with a knowledge of the limits of their accuracy.



Horus non numero nisi serenas. (I count only the sunny hours) – Motto on a Sundial

The only reason for time is so everything doesn’t occur at once. – Albert Einstein

I went to a restaurant that serves “breakfast at any time”. So I ordered French Toast during the Renaissance. – Steven Wright


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Relative Dating is OK, so long as your limit it to Second Cousins.

Ian W

I thought palynology was the study of dead Norwegian blue parrots

Alberta Slim

No.. It is the study of Sarah Palyn [sp.]

Wonderful essay Dr. Ball. Thanks.
I take from it that we know so very little as fact at this time that we probably should not dismantle our industrial society over the fear of CO2.

Could it be that Absolute and Relative Dating are sex determined? Ask a man for the location of a store, he will give you the address. Ask a woman, she will tell you the shop it is located next to.


Isn’t dating relatives illegal in most states?


That depends on how near the Relative is to the Absolute

After Prince Charles, Relative Dating was made Absolutely Illegal. Even his Mom won’t let him be King.


me mom told me I was born on dec 27 1951 shortly after 20 am, me dad can’t remember.


Ahh I meant shortly after 12 am, see even I am not sure. (does that mean I exist at all?).

Alberta Slim

You don’t exist becuz there is no such time as 12:00 AM ;^D

Kip Hansen

I hope this is the first installment of a series.


“Radiocarbon dating, discussed later, established January 1st 1950 AD as the base year and called it 1950 BP for Before Present. ”
Err, no. They called “present” , 1950 becomes 0 BP

Is there any evidence at all that the climate isn’t cycles all the way down? In other words solar cycles, ENSO, annual, diurnal, Milankovitch, stadium waves, etc?


Yes, we are still here, which means that for the last 3+ billion years what has gone up has always, ALWAYS come back down.


“Most forms of absolute dating involve supposedly precise measurable rates of a natural process, like the rate of decay of carbon 14. It sounds precise, but all measures are presented with a range, which increases as you extend back, to the maximum range of the technique, 60,000 years. ”
The decay rate is precise but the great uncertainty of C14 dating is that the amount of the gas present to start with in any given year is unknown, which makes the derived dates dubious. There are several ( very irregular ) calibration curves one of which needs to be applied to get near to a reasonable estimation of age by C14 dating.
Tree-rings can be very accurate as a measure of time and have traditionally been one of the main calibration techniques for C14 dating. This respected science is called dendrochronology : chronos being greek for time.
This has nothing to do with the spurious idea of using trees as thermometers. There has been widespread and deliberate confusion where dendrothemometry has tried to be presented as “dendrochronology” in order to infer an undue accuracy and respectability to the practice.

Alberta Slim

Right on… It is good that you pointed that out.

george e. smith

All true; but you omitted the most important aspect of the errors in 14C dating.
The technique was originally predicated, on a completely unsubstantiated (and false) assumption, that the rate of production of 14C from 14N, in the atmosphere by cosmic radiation, was absolutely constant; which it turns out is not true.
The (clever) dendrochronology by use of tree rings (bristlecone pines), subsequently enabled corrections to 14C dating, that actually reversed the direction of some important technology transfers.
Certain pottery technology, believed to have originated in Mesopotamia, and transferred by trade to Spain, was subsequently shown to have actually travelled from Spain to Mesopotamia.

@tim ball
clearly, your argument lacks any results
If you had any
it would show you that 1995 was the middle of a cycle
You tell me which one?
Just so you know, the sample taken of the Shroud of Turin was anomalous


The shroud has been examined carefully by competent scientists and found to date to the early to middle 1300s.

many researchers seem to disagree with Crone’s idea of a “painted cloth”, e.g. see here
To quote from the conclusion from the above (very lengthy!) report,
“Linen-production technology indicates that the Shroud of Turin is probably older than indicated by the date obtained in 1988. There seems to be ample evidence that an anomalous area was sampled for the radiocarbon analysis; therefore, the reported age is almost certainly invalid for the date the cloth was produced. The image was definitely not painted. The observed characteristics of the image rule out any mechanism for colour formation that involves high temperatures or energetic, penetrating radiation…..” etc
In any case, bones, please “paint” for me a photographic image that has three dimension properties, like the shroud of turin has.
Perhaps if you could watch the video we could talk again


More common sense analysis from Dr. Tim. Oftentimes, I have to wonder whether educational experiences scrub the ability of (a large percentage of) PhDs from employing common sense… and I sheepishly state this as a person who only recently defended my dissertation.

I can not find the quote handy, but I think H.L. Mencken wrote something close to: “you can drag a moron through a university and even confer a PhD upon him, but he will still be a moron.”
But I know this one is one of his: “The urge to save humanity is almost always only a false-face for the urge to rule it.” ― H.L. Mencken, Minority Report

Ian W

“Strange as it seems, no amount of learning can cure stupidity, and higher education positively fortifies it.”

Stephen Vizinczey, An Innocent Millionaire

David, UK

Really interesting read, thank you Dr Ball.


“A general claim is an accuracy of one percent, which sounds good. However, one percent of one million years is 10,000 years and in climate that effectively covers the Holocene. ”
But the Holocene was not a million years ago, and 1% of a 10,000 years is 100 years and would still be good.

Steve Reddish

The potassium/argon dating technique is useless for items less than 100,000 years old. The only dating technique that could possibly work for Holocene dating is the C14 method. The 130 year range for the probable age of the Shroud of Turin is typical of the limitations of C14 dating – a 20% difference in the min vs max. And that is for an item less than 1000 years old. The greater the age of an item, the greater the percent of difference of the estimate of the min vs max age, as a small difference in C14 = a greater difference in the age the older the item is (due to exponential decay rate). An additional source of error is that the approximate age of the item has to be known in order to apply the appropriate adjustment, as determined from dendrochronology, for instance. But if the assumed age is off by a thousand years (10% for Holocene items), the wrong corrections are made. The end result is it is impossible to know the age of early Holocene items within a few thousand years.

Chris Hall

This is not quite correct. Modern Ar-Ar dating (a variant that uses neutron irradiation to convert K-39 into Ar-39) can achieve remarkable precision and accuracy if it is used on the right material. With sufficient sanidine or anorthoclase, precision comparable to C-14 can be achieved in the Holocene. A recent Science paper described dating the volcanic eruption that destroyed Pompeii. The authors rather cheekily put in the title that their calibration was by Pliny the Younger.

Steve Reddish

In re to Chris Hall’s reply below:
Chris Hall says:Ar-Ar dating can achieve remarkable dating “if it is used on the right material.”
The right materials are igneous and metamorphic rocks – only, and then only the approximate date of solidification can be determined. Knowing the age of the particles in a layer of sediment doesn’t tell us when the layer was deposited.
Even so, the Ar/Ar dating method only gives a date that is related to another sample of known date – that was dated by the potassium/argon dating method. So whatever limitations the K/Ar dating method has are carried over to the Ar/Ar dating method.


These papers on prior interglacials & the Milankovitch Cycle shows why some students of Ice Age fluctuations argue that the Holocene could be a super interglacial, like MIS 11 & MIS 19, at ~400K year intervals:
Determining the natural length of the current interglacial
Climate in continental interior Asia during the longest interglacial
of the past 500 000 years: the new MIS 11 records from Lake Baikal,
SE Siberia

Well, duh
Almost nobody will disagree with this discussion of the obvious – and almost all of those who don’t disgree will carry right on thinking it makes sense to talk about climate variances measured in parts of a degree C over a decade. Go figure!

Thanks, Dr. Ball. An interesting read. Should you change “Radiocarbon dating, discussed later, established January 1st 1950 AD as the base year and called it 1950 BP for Before Present.” to “Radiocarbon dating, discussed later, established January 1st 1950 AD as the base year and called it 0 BP for Before Present”?

Interesting Tim
Note the calibration table for calibrating radiocarbon dates is now in the INTCAL13 version (succeeding INTCAL09, INCAL04 and INTCAL98)

Good post.
Definition of Post Modern Science?
When afraid to admit insufficient info or I do not know.
Insist on the absolute precision of guestimates.


A picture paints a thousand words, saved for future refeence.

Dear oh dear…what total nonsense!
Leif Svalgaard has explained patiently and many times right here on WUWT that the Sun has no impact on the Earth’s climate. And he sounds very confident that he is right.


I hope this is sarcasm without a /sarc tag. I cringe each and every time I hear how the sun has no impact on climate, given that without it we are on a ball of ice floating aimlessly through space.

Tom in Florida

Dr S has never said that. He says that the changes in TSI can account for only a tiny amount of temperature change.

The “T” stands for Total. That is the problem. It is the change in the distribution of electromagnetic output of the sun that is important. Currently in this solar cycle the Extreme Ultra-Violet photonic output from the sun is down 60% on what it was to this point two solar cycles ago. As EUV is only a very minor component of the TSI it can be argued that this change doesn’t matter much. But try this analogy. There are 100 runners in a marathon in 1990. 90 of them are capable of running 2 hrs 20 mins and 10 are capable of running 2 hrs 10 mins. The same marathon is run in 2014. Only this time there are only 4 runners capable of running 2 hrs and 10 minutes and all the rest capable of running 2 hrs and 20 minutes. In 1990 the total time capacity of the runners in the marathon is 13,900 minutes. In 2014 the total time capacity of the runners of the marathon is 13,960 minutes. The percentage change in the total time capacity is 0.43%. Not much variation in the total is there? But having 6 less runners capable of 2 hrs 10 mins would make a lot of difference to the race.

Jeff Alberts

Leif has said no such thing. You’re either dense or wilfully misreprenting Leif’s position.


Yes, OK, perhaps there is a level of uncertainty when certain climatic events occurred and ended.
But what is really required is an explanation as to WHY these climatic events occurred, for then, and ONLY then, can climate scientists claim they really UNDERSTAND the mechanisms that drive climate.
If the historic climate can not be explained – EXPLAINED, NOT DESCRIBED as to their CAUSE !!! – then climate scientists cannot presume to predict the future climate.
What CAUSED the ice ages? What CAUSED the warming that ended the ice ages? What caused the ice ages to end?? (and the answer is NOT global warming !! for that is just a description of what occurred) . What CAUSED the cooling that initiated the ice ages? If human production of CO2 is causing warming, then what CAUSED the warming that ended the ice ages?


“If the historic climate can not be explained – EXPLAINED, NOT DESCRIBED as to their CAUSE !!! – then climate scientists cannot presume to predict the future climate.”

Careful Sir, you’re verge dangerously in the direction of telling the truth, that we don’t really have any real clue about how the earth really works and what natural variability really is. Scchhhh! Don’t tell everyone! We can just keep milking ignorance with arrogance and maintain our gigs and privilege for at least another decade or two. Look, just play stupid, we all do, and look where we are now! So if you know what’s good for you you’ll buck up your ideas and start acting like you know almost everything, like Suzuki does, but hopefully do a better job of professionally ignoring and deflecting the never ending avalanche of countervailing evidence. And make also sorts of trite poncy documentaries and videos to scare children and parents everywhere. Yes, you are going to have to get accustomed to lying quite a bit more then you ever thought possible.
Cue global warming propaganda video Copenhagen Climate Conference in 2009

See, that’s how you do it! Now hop aboard the consensus tram, we’re going on a safari to deepest darkest schmrtypantzistan!

Alberta Slim

” The answer my friend is blowing in the wind” la la tee dum..


“…They scared people so much that everyone celebrated in the wrong year…”
Actually, people celebrated because the numbers started with 20, not because they cared about a technical matter relating millenniums, and especially not because a few computers might go on the fritz. Best to revise this statement in future, it is jarring in it’s error.

I’ll go by the astronomical calendar, or the ISO rule– the first year of a millenium ends in a zero. Every civilization we’ve discovered that had a calendar used the stars, they are good enough for me.


Hayes, Imbrie, and Shackleton ( validated Milankovitch in their 1976 paper.

What nonsense, Leif Svalgaard has patiently and many times explained right here on WUWT that the sun has NO impact on the earth’s climate.

Jeff Alberts

Your statement was so stupid you had to say it twice?


He should say it outside… in Barrow Alaska… about the middle of December…


The age of the earth is often stated to be 4.5 Billion years. Yet that number is based on the same kinds of things that the above examples question. Take a rock from a known historical lava flow and it dates as over 100k. 16 different radioactive decay series will yield 100k to 1billion years for the same rock.
All this is called “science” as well and sold as fact. Sometimes the best which can be said is that you can say X occurred before Y. Some of the extinction events are such.
Dealing with signals, I constantly have to worry about error terms. It is one reason we don’t use accelerometers to measure distance, though distance is the double integral of acceleration – but with that annoying constant.
Climate Change is bad enough, but as “Expelled” showed, if you are skeptical enough to even question that abiogenesis happened about 3 billion years ago, that the earth is 4.5 billion years old, that radioactivity is sufficient so we wouldn’t be living on a cold rock (or a still molten surface), it will be a worse attack than anything the alarmists bring up.
NONE of it is science. IT IS ALL MODELS and models of things you can’t recreate or calibrate in labs. The Miller experiment that creates primordial soup would kill anything that might have started to assemble. We know the complexity of organisms so can calculate how long it would take to produce the first reproducing life form (hint: 4.5 billion years would be like winning 99% of hundreds of roulette spins on 00).
We can’t call such speculation, extrapolation, or anything except “settled science”. Lest the Scientific Inquisition threaten to torture you worse than the data they feed to their models.


The most recent 1% of Earth history is as insignificant as the first 1% of Earth history.

Robert Kral

I have often wondered about the nature of the evidence for the alleged variability, on a more than millennial scale, in the Earth’s orbit. Can anyone point this out? Perfectly willing to accept lucid explanations- just genuinely curious about what physical observations lead to this conclusion.

Ed Barbar

“Known as Y2K, many claimed computers would fail because of the inability to switch to the new date sequence. They scared people so much that everyone celebrated in the wrong year. Technically, the new millennium begins in 2001, but the celebration occurred in 2000. Maybe we should have a calendar that begins with the Big Bang, but then, what would the error range be?”
Well, it’s frankly amazing there were no serious issues with Y2K. The issue was with programmers programming two digits to signify the year in code, such as “1948” as “48”, and then a number shows up that is 2000, or zero. Subtract those two, and you get the wrong number.
You can read about it here:
Rolling and other issues are non-trivial, as many folks may write them into software they think will have limited lifetime and yet lives longer. It hasn’t been widespread only because people recognized the problems, and solved them. If action had not been taken, problems would have ensued.

richard verney

And yet probably at least 90% of the computers in the world, and the programmes they were running were not corrected, and no problems ensued.


Yes, finger trouble would have highlighted any problems in legacy systems long before the year 2000. Any programme that survived 20 or 30 years operating would have inevitably have gone through the Y2K problem due to human error.
As we’re talking about old systems, then many would have been tested by the Islamic calendar (currently 1435 H),
What causes far more of an issue is American being out of step with Europe in date formats. DD-MM-YYYY or MM-DD-YYYY being hard-coded into systems by programmers unaware of the world outside can really foul things up.

James Strom

Ha Ha. I bought a commercial program to fix the Y2K problem on my desktop. When I ran the program the computer crashed. With the program uninstalled the computer ran fine through 2003.

Ed Barbar

Sure, but where it mattered most it was corrected, as in bank interest calculations.

Actually, correcting computer programs to avoid Y2K problems was probably the largest undocumented example of focused effort in history. I had the responsibilty in my company, 17 factories, near 100 sales offices, some few thousand computer programs of more or less complexity and risk of shutdown or malfunction. The primary task of our world wide IT resource for 3 years was preparing for Y2K. At the end of the day, one program on one production line caused a 5 hour shutdown. Every supplier, every customer and every competitior that I know of went through the same effort. The big gain, apart from avoiding serious problems of various kinds was that we finished with every piece of similar equipment world wide running the same software program release, making process transfers quite easy, for the only time in company history. I retired at the end of the effort, so have no idea if the program coordination was maintained.

Rob R

One of the problems with 14C dating is that it was originally pretty much assumed that the amount of 14C in the atmosphere was more-or-less constant. Later it was found that 14C, formed in the atmsphere by interaction between 13C and 12C and incoming electromagnetic radiation, is historically somewhat variable in concentration. The causes are hard to disentangle. The production rate of new 14C is variable. But there are earthbound issues as well. The oceans represent a huge store of 14C. Changes in sea water temperature and the rate of oceanic circulation, particularly the deep cold currents, alters the rates of absorption and release of 14C from oceanic storage. Factors like this have made it quite difficult to generate a calibration curve that everyone is happy with.


Thanks Dr Ball. In this age where ‘scientists say’ is the totem at which we all are expected to bow, it is nice to be reminded that someone who is trying to understand nature using the scientific method will not be able to make pronouncements from on high, but only build a house of cards with no promise of what results the next card may bring.


>> Technically, the new millennium begins in 2001, but the celebration occurred in 2000.
A child is born at t=0, and on their 10th birthday, the child has lived one decade. The child starts his 2nd decade on his 10th birthday, not his 11th. The century from Jan 1st 1900 to Dec 31st 1999 was the 20th century. On Jan 1st, 2000, the 2nd millennia ended, and the 3rd millennia began. Everyone was correct, Dr. Ball is incorrect. Rest of the article is great though.



the issue is that there was no year 0, so the first millennium ran from 1AD to 31 dec 1000, and the following millennium ended 1000 years later, i.e. 31 dec 2000


Of course there was a point t=0, which corresponds to the birth of Jesus.


No coherent base 10 numbering system can be missing t=0. Regardless of when Jesus was actually born, the numbering system was deemed to be fixed at some point. On Jan 1st, 2000, it had been 2000 years since the time t=0. Therefore, it’s the start of a 3rd millennium.

Man Tran

Gunnar and VikingExplorer:
Try this: use the term “beginning of” and “end of” in the child’s first ten years. He was born (t0 = beginning of his first year). That is his “first year”, but he is not one year old until the end of that year.
If you make that number line and count segments, you only get nine segments when you get to the “beginning of” the 10th year. Thus his second decade starts at the “beginning of” his 11th year. That sounds like the “beginning of” 2001 for the 21st Century to me.

A child has a year zero, in which his age is measure in hours, then days, then weeks, then months.
There is no year zero in the BC/AD system, so the full 2000 years arrived at midnight between Dec 31, 2000 and Jan 1, 2001. That is why some people considered 2001 the true millennial date.
However, the system is based on the birth of Jesus Christ, and the evidence is that he was born 2 to 8 BC, so 1/1/2000 is actually extra-long. Given the uncertainties, and the fact that many of us couldn’t care less when Jesus was born anyhow, it makes the most sense to me to count the millennium when the number changed to 2000.


From the time a child is born until his first birth day, it’s considered his first year. This is only semantics, and does not imply that there is no t=0, or that on his 1st birthday, the child doesn’t start his 2nd year. Jan 1st, 2000 starts the 3rd millennium since t=0.

Man Tran

The problem was there was no year zero at the beginning of the modern era. Year one AD was the “first” year.

Problem is, there is no “year zero” in our calender. The first year is “year one”, or 1 AD. And the year previous to that is called 1 BCE, not “0”. So your example does not hold true. This means that on Jan 1, 1 AD, the calender is not one year old, it is zero years old. So the calender date is always one year behind the age of the calender.
A child, on the other hand, doesn’t turn one until their first birthday. Before that, they are not called “age zero”, but they are aged by fractions of one year (or months).
So at the end of the very first decade, or Jan 1, 10 AD, only nine years has elapsed on the calender.

Alberta Slim

Gunnar… check your info. The caledar did not start at 0 .
It was started at year 1 ; hense 2001. Dr. Ball is correct.


I’ll try once more. You are all confusing the label of the year with the tic mark separating years. Picture two line segments right next to each other. Label the tic mark t=0. Label the left segment 1 BC, and the right segment 1 AD. The left year is the first year before t=0, while the right year is the first year after t=0. In a number line, there is always a t=0, by definition. So, the year from tic mark (birthday) 9 until tic mark (birthday) 10 is called the 10th year. As such, the period from 1900 to 1999 is called the 20th century. The period from 1990 to 1999 is called the 200th decade, and the period from Jan 1st 1999 to Dec 31st 1999 is called the 2000th year. Jan 1st, 2000 was the start of the 2001th year, the 201st decade, the 21st century, and the 3rd millennium.

more soylent green!

On our calendar, the years transition from 1 BC to 1 AD. No year 0 in-between.


More soylent green, agreed, there is no year called the zeroth year. However, that does change a base 10 numbering system.
Man Tran, you should have tried it yourself. Here are the line segments.
start-end tic name of year
-1 0 1st year BC
0 – 1 first year of life, i.e. 1 AD
1 – 2 2nd
2 – 3 3rd
3 – 4 4th
4 – 5 5th
5 – 6 6th
6 – 7 7th
7 – 8 8th
8 – 9 9th
9 – 10 10th year
(Conrad, please note that on Jan 1st, 0010, 10 years had passed since birth at t=0. All during his 10th year of life, his age is 9+.
99-100 100th year
999-1000 1000th year
1999-2000 2000th year (2 millennia have passed, Jan 1st 2000 starts the 3rd millennium.)


I meant: However, that does NOT change a base 10 numbering system.
Bottom line: there is nothing unique of special about the calendar year number system. The fact that we call from 0 – 1 the first year, or 1 AD, does NOT in any way change anything. We call it the first year, because it is. In the same way, we call the period from Jan 1st 1900 to Dec 31st 1999 the 20th century, BECAUSE IT IS. No magic. The third millennium and the 21st century started Jan 1st 2000. Hence, the celebration.

more soylent green!

You’re saying January 1, 2000 marked the new millenium because the calendar began it’s 2000th year, whereas on December 31, 2000 it completed its 2000th year.
Which is the correct beginning of the millenium, then? I celebrate my birthday when I complete a year, that is, on my 50th birthday I have lived 50 years. But for a decade, a century or a millenium, we haven’t completed the period until December 31. The new decade, century, millenium starts on January 1.


>> You’re saying January 1, 2000 marked the new millennium because the calendar began it’s 2000th year, whereas on December 31, 2000 it completed its 2000th year.
No. As I’ve said, the 2000th year began Jan 1st 1999, and concluded Dec 31st, 1999. On Jan 1st, 2000, it had been 2000 years since t=0.
>> Which is the correct beginning of the millennium, then?
Jan 1st, 2000 started the 2001th year, the 201st decade, the 21st century, and the 3rd millennium. Maybe Prince should have said “party like it’s the end of the 2000th year”, which means the same, but doesn’t have the same ring to it.
>> I celebrate my birthday when I complete a year, that is, on my 50th birthday I have lived 50 years. But for a decade, a century or a millennium, we haven’t completed the period until December 31. The new decade, century, millennium starts on January 1.
You’re getting confused between two things: the last tic mark you’ve passed, and the segment you’re currently in. For a baby less than one year old, the last tic mark they passed was t=0. However, they are also in their first year of life. There is no contradiction. On your 50th birthday, you have lived 50 years, and on that day, you start your 51st year.
Bottom line: a base 10 number system can be used to successfully count things like years, without any weird +1 or -1 to worry about. Conclusion: number systems can count.


A most excellent post. Thank you for such a nice primer on dating errors as well as providing a vehicle for some more colorful and amusing comments.
The “ignoring” of real measurement errors in timescale (or anything else) is one of my pet peeves as too much noise, far inside error ranges, has been reported as valid measurement data and accepted as fact today. Several of my archaeology and anthro’ prof’s, many decades ago, were always warning about using C14 dating from different areas as equivalent. We were told to always call your chronology out as carbon years and direct date range comparisons were only done at the regional level. My how that’s changed… for the worse in almost 40 years.

Tim Ball,
Food for the intellect, thanks.

[snip off topic -mod]

Jeff Alberts

[snip off topic -mod]


[snip . . OT . . mod]

Moderator, -you cut my comment, so I think you should also take Jeff’s comment down?
REPLY: Yes and as I’ve told you before, you should stop putting links to your religious website “hour of power” in your posts (which we remove). The comment of yours that started this was about religion, and it has been snipped too.
Let me make myself clear. You’ve been warned about this. That fair warning will translate to a commenting ban next time I see a comment like that – Anthony

Jeff Alberts

Sorry, I should have shown more restraint.

I am going to be off from this site as it clearly favors those making remarks that follow the a-theistic trend that you [also] seem to prefer, e.g.
[also similar opinions by willis, l.svalgaard, j.alberts etc.]
You have a problem hearing things simply because you have a lack of faith.
I cannot help you further.
Note that the weather will always be exactly as God has designed it to be, as I have clearly proven here from my results over time.
I wish you all a good life.

REPLY: You’ve routinely violated policy (and been warned about it) designed to keep the food fights down, you know nothing about me nor my faith, so see you later then, and don’t let the door hit your butt on the way out! – Anthony

Time in time series datasets is what makes them have the characteristics unique from other classes of datasets.
The repetitive interval is crucial. Also, pinning a point in a time series to a real and well corroborated phenomenon is crucial to compare one time series to another.

george e. smith

I would suggest sending a copy of your figure 2 to Dr. Kevin Trenberth. Now the Milankovitch annotation, is somewhat irrelevant; well not to your story Tim, it obviously relates to long term solar system changes, with likely climate consequences.
But the more important, and immediate consequence of your simple diagram, of the sun-earth orbital system, is that by inspection, even a 4-H club level science student, can immediately perceive, what Dr. Trenberth is evidently unaware of.
The sun CONTINUOUSLY, AND CONTINUALLY irradiates approximately one half of the earth’s atmosphere, with a cosine varying irradiance pattern, that has a peak irradiance, at its center of approximately 1362-6 W /m^2, that varies somewhat more than that, over the annual orbital track.
But at no time, does that irradiance, at the center, ever reach a value as low as 341.3 W/m^2, that figures prominently in Dr. Trenberth’s cartoon diagram, of the earth energy budget; well at least one manifestation, of that budget.
Well specifically, the one I used is labeled: “Global Energy Flows W m^-2.” from a March 2009 American Meteorological Society paper.
I use the term “cartoon”, not in any derogatory sense; merely to indicate, that it is not any accurate scientific model, of the real “Global Energy Flows.” that actually occur on earth.
Specific examples of scientific inaccuracy, start with that very diagram title, with the concatenation of the word ” Energy” and the stated units of “W m^-2”.
The proper scientific unit of ENERGY, is the joule (J). The unit watt (W) is a unit of POWER, which is an instantaneous differential quantity, that relates to the time rate of use / supply / dissipation / conversion / whatever, of energy, or of doing work.
Further of note, in the cartoon, is the total and complete absence of ANY mention of the very substantial global energy flows, from the tropic regions, towards the polar regions, by way of both ocean currents (convection), and also by convections in the earth atmosphere. Surely, the latitudinal transport of global energy by convection, has to be one of the most important components of global energy flows, exceeded only by solar insolation, and surface LWIR radiant emission.
Yet it doesn’t even rate a mention, in the Trenberth-Kiehl cartoon diagram..
Dr. Ball’s Milankovitch figure two (2), makes it quite obvious that the sun interacts on an unbroken, continuous basis, with the earth’s atmosphere covering approximately half of that atmosphere.
Considerations of the sun’s apparent angular diameter of 30 arc minutes (roughly), and the atmospheric refraction effect of a similar amount. When the sun’s lower limb touches the apparent horizon, the sun is actually fully below the true horizon. The result is visible sun for about 182 out of 360 degrees; plus of course some atmospheric conducted twilight irradiation.
Now the sun might be able to discern, some latitudinal change, in the earth atmosphere, from tropics, to poles, but it can have very little knowledge of any longitudinal variations in earth’s atmosphere, given that the atmosphere and surface rotate somewhat independently, so air over Hawaii, cold soon be over California..
Now, the atmosphere in turn, reacts with the solar radiation in such a way, that only about 1,000 out of those 1362-6 watt m^-2 of incident radiant power, ever reach the earth surface, of which about 71%, is actually water, and mostly deep oceans.
It is also eminently clear from the Ball fig 2, that the sunlit hemisphere of the earth / atmosphere, must be at a substantially higher Temperature, than the supposed mean global Temperature of about 288 K or + 15 deg. C (5p deg. F).
The hottest ground surface temperatures in tropical arid desert regions can routinely reach Temperatures above +60 deg. C, or 333 K . At that Temperature, the appropriate black body radiant emittance, is about 708 watt m^-2, and not the 396 W m^-2 rate that Trenberth-Kiehl cite, corresponding to the 288 K mean global Temperature.
As a consequence of their misrepresentation of the sun-earth model, the real earth cooling emittance, is much higher than their budget asserts.
It is time to expunge this entirely fallacious cartoon model, of how the sun-earth system works, as regards earth climate.
In the entire history of the human race, absolutely nobody ever observed an average of ANYTHING.
Only instantaneous values of physical variables, are observable, and physical systems respond immediately, to those instantaneous values. They do not operate on averages, which are entirely a concoction of, and a property of, statistical mathematics; a completely artificial discipline, for describing quite made up numerology properties of sets of accurately known numbers; ANY numbers.

William McClenney

For those who are not aware, the more common definition of an interglacial involves the ratio, typically given in parts per mil, or o/oo, of oxygen 18 to 16. Sure, oxygen isotopes also have warts, there doesn’t appear to be a perfect thermometer, but the typical values one finds quoted are 3.5 or 3.6. See below:
“Recent research has focused on MIS 11 as a possible analog for the present interglacial [e.g., Loutre and Berger, 2003; EPICA community members, 2004] because both occur during times of low eccentricity. The LR04 age model establishes that MIS 11 spans two precession cycles, with 18O values below 3.6 o/oo for 20 kyr, from 398-418 ka. In comparison, stages 9 and 5 remained below 3.6 o/oo for 13 and 12 kyr, respectively, and the Holocene interglacial has lasted 11 kyr so far. In the LR04 age model, the average LSR of 29 sites is the same from 398-418 ka as from 250-650 ka; consequently, stage 11 is unlikely to be artificially stretched. However, the June 21 insolation minimum at 65N during MIS 11 is only 489 W/m2, much less pronounced than the present minimum of 474 W/m2. In addition, current insolation values are not predicted to return to the high values of late MIS 11 for another 65 kyr. We propose that this effectively precludes a ‘double precession-cycle’ interglacial [e.g., Raymo, 1997] in the Holocene without human influence.”
Lisiecki and Raymo 2005 (paywalled at:


“The fact that scientific methods like these, fail beyond a certain domain of approximation, doesn’t make them redundant.”
But both the commas in that sentence are not only redundant, they are misleading. They make the clause between them ungrammatical, and tend to imply that it is not part of the subject of the sentence. Perhaps the clause was originally a non-defining relative clause, but the “which” before “fail” has been accidently lost.

george e. smith

Well if you read that entire sentence without ever pausing for any reason then you wouldn’t put any commas in there.
But Doctor Richard Lederer;the world’s foremost authority on the English language says to put commas anywhere you would pause to catch your breath for example. You don’t need some arcane English grammar rule to tell you to put in a comma. Commas are supposed to help a reader to read what (s)he is reading. They are not for telling how much English grammar you learned in school.
I learned virtually NO English grammar in school after about age 9. After that “English” was nothing but reading English literature.
I still won the English prize for top marks in English in my high school graduating class final exam. I still have that book “Standard Stories from the Operas.”
So if you want to know what the opera trilogy “The Cauldron of Anwyn.” is all about I can help you with that.

Climate change is very real. For example, the average climate of the northern hemisphere is so cold as to cause the ground to be buried under a thousand feet of ice. The cycle of glacier on/glacier off takes place every several hundred thousand years and can be clearly seen in many ways. Even as the science is settled that glaciation has taken place, the causes are still undergoing vigorous debate.
With respect to the idea that humans are causing harmful changes to the climate at this very moment, I am waiting for some peer-reviewed papers that propose what the optimum climate is for our biosphere. The first question that would naturally flow would be where is our current climate and trend in relation to this finding.
Strangely, nobody seems interested in this vital comparison. Not so strangely, the solutions that are frequently demanded in the most urgent voice, all converge on a socialist worldview: statism, bigger government, higher taxes, less personal liberty. That bigger picture tells me all that I need to know about “climate science”.

more soylent green!

Known as Y2K, many claimed computers would fail because of the inability to switch to the new date sequence. They scared people so much that everyone celebrated in the wrong year.

With computer systems, it was easy to test how the new century was handled by setting the date to 12/31/99 and then testing what happened when the date rolled over to the new century. While there was surely a lot of hype involved, it was not unfounded. Businesses did not all that time and money upgrading their systems based upon being scared.


I think that broadening the discussion to ‘measurement methods, their accuracies and limitations and the assumptions implicit in their application’ would also be valuable.
Here are a few I would enjoy reading about:
1. How accurate is the assumption that tree ring widths are related solely to temperature, rather than to precipitation, sunlight levels and length of growing season (which is not the same as temperature if winters were colder but growing period was longer)?
2. How accurate currently are satellite measurements of ice thickness, ice extent and ice volume? Have repeated comparisons with manual measurements been done or are we assuming that the calibrations done at the start of the satellite record still hold?
3. Are we sure that replacing the international network of measuring buoys in the world’s oceans with satellite measurements is consistent, accurate and suitably globally available?
Measurement is a very interesting science, but it’s not very sexy to journalists.
Unfortunately, most of the exaggerations, misconceptions, misdirections and wilful lying occur due to a lack of understanding-, respect for- and analysis of the measurement technologies used to generate certain data.