Putting on my memory hat and thinking about the long ago times, I got to remembering my high school science classes. In particular, the “Earth Sciences”. One thing that I’d tended to ‘glaze over’ was the funny names they gave to pre-history times. Things like “Precambrian” and “Boreal”. It was years later before I really did more than just parrot them back for exams. The “funny names” are not very systematic and don’t have self clarity ( they are not self obvious as to what they mean and need external referent for clarity. For example Boreal really means ‘cold time’, so why not just say “cold time”? Or originally “dry time”, so why not say “cold and dry time”?)
So we are being constantly told that if the planet warms by just One More Degree (or sometimes two…) it will be the end of life as we know it and all manner of catastrophe will follow. Yet the language of Earth Science is littered with all sorts of ‘funny names’ that say just the opposite. It will take a very long time for the Thought Police to purge those ‘funny words’ from all the libraries (and minds) of the world. Nothing less than a complete rewriting of history will do it. With that in mind, a couple of references and a few funny words…
The most important one is hypsithermal. This was a ‘hotter than now’ or high temperature time. No, not a million years ago with dinosaurs, but geologically “now” for all practical purposes.
Hypsi or Hypso is a combining form from Greek meaning “high”…
The period from about 7000 to 500 B.C., proposed by E. S. Deevey and R. F. Flint (1957), during which global climate was thought to be warmer than today.
Spanning the Boreal through SubBoreal periods of the Blytt–Sernander sequence of inferred climates in northern Europe, it includes both wet and dry periods. It is followed by the general expansion of glaciers known as the Neoglacial.
Deevey, E. S., and R. F. Flint 1957. Postglacial hypsithermal interval. Science. 125. 183–184.
Sernander, R. 1908. On the evidence of postglacial changes of climate furnished by the peat-mosses of northern Europe. Geol. Fören. Förh.. 30. 456–478.
I’ve bolded that bit about warmer than today. The name, hypsithermal, is literally high-heat or high-temperature. Note, too, the date range. 7000 BC to 500 BC, or all of the prehistory up to the Roman Kingdom turning into the Republic of Rome (to become the Empire in 27 BC, then the Western Empire collapses in the cold Dark Ages of 535 AD…)
Generally speaking, those were considered to be some pretty good times. Civilization arose, Sumerians and Hittites were having a decent time of it, modulo the occasional war with Egypt (that had the Old Kingdom, and New Kingdom, come and go). There was more water in the Sahara for most of that time, the Nile had 9 main exits to the sea where now it has only 2, and more crops were available over that whole area. Israel was more livable and green too. (We now find ancient remains of abandoned cities in dead dry desert areas around North Africa to the Levant – then they were thriving, so there had to be more water; which is also attested by ancient riverbeds and more…) Also the ancient Greeks developed their democratic system and eventually the Greek Empire (eventually poached by the Romans who took over…)
Sidebar: Though I have to note that there were occasional cold spikes even during that warm time. We see one of them as the 4.2 kiloyear event with the fall of Akkad and the Old Kingdom. Even in warm times, a cold spike can really mess things up.
Is it really going to be a horrible outcome to return to the world during which Civilization first flourished?
Throughout history, civilizations flourish in warm times; collapse and fall into chaos comes with cold times. Now I’m just enough of a Pirate by nature and by ancestry to be Just Fine with the tendency for Empire to fall during ‘cold times’. Frankly, given the way the world is going today, we could likely use a few less Empire-Wanna-bees… but I’m not keen on the general economic collapse and broad death and dying that come with cold times.
So what does this say? It says that in the past, the ‘golden age’ of the rise of civilization, we had a warm time. Life was good. At present, we have a relatively warm time (compared to the Little Ice Age) and again, we are flourishing (even if it is colder than during the hypsithermal.) Warming some more does not end that. Going cold does, and likely leads to collapse of empires, wars, famines, and ruin. That’s what all of human history says. But geologic history says more. It says that warm and cold oscillate and swap. That they cycle (in a pseudo cycle kind of way – i.e. not exactly predictable). Warm inevitably gives way to cold. The only question is ‘when?’…
Back at some more words
To me, Atlantic was always an ocean. It was an annoyance to have it also defined as meaning ‘warm time’. In the cycles of things, Atlantic was a warm cycle, Boreal a cold one. Then they wanted a bit more precision so a couple of more recent cycles were named sub-Atlantic and sub-Boreal (confusingly as though they were a part of the full one or perhaps ‘below’ them, but actually the ‘sub’ means ‘after’ or maybe ‘less extreme’… I do wish folks would use simple clear statements of what they mean so less guessing would be needed… especially by young kids in school.)
It’s all part of the “Blytt-Sernander” system. This is a well known and widely accepted method of dating and classifying the past.
THE HOLOCENE “current interglacial”
“The Blytt-Sernander Sequence”
The first well-developed, widely-used subdivision of the Holocene and Late-Glacial
The Sequence grew out of studies of peat bogs in Northern Europe.
Peat is an important fuel in area and many, many exposures.
Dau (1829) observed layers of pine stumps buried in bogs, dark, oxidized peat
The Danish academy offered an award for an explanation of the layers
Axel Blytt 1876 (Norway) sequence
assumed that the oxidized layers were produced by drying of the bogs
he produced chronology of alternating wet/dry periods
drier (continental = Boreal)
wetter (oceanic = Atlantic)
Rutger Sernander 1908 (Sweden) better known scientist added late-glacial chronology and included temperature.
Gerard DeGeer Sweedish Varve Chronology
Lenart Von Post (Palynologist) (1930) and Jessen & Iversen (1941) added temperature to produce current the form of the sequence
Then again, maybe using “Boreal” saved changing it from “dry” to “cold” to “cold and dry”…
All sorts of effort has gone into trying to prove that this cycle pattern was just a local thing, and not global. Almost as much has shown it is global; though perhaps a bit muted elsewhere (or just less data preserved). I don’t really care if it was ‘only Eurasia’. It is a natural cycle that changes temperatures very broadly, and that will have global impact. Even our current (very mild) warming has more range in the Northern Hemisphere than in the Southern (where temperatures are largely static at present, and where the Antarctic has record sea ice extent).
From that same link, an interesting chart:
ENVIRONMENTAL PERIOD AGE (14C) CLIMATE SUBATLANTIC 0-2500 (wet) (Cool) POST- SUBBOREAL 2500-5000 (dry) (Warm) GLACIAL ATLANTIC 5000-8000 (wet) (Warmest) BOREAL 8000-10,000 (dry) (Warm) --------- YOUNGER DRYAS 10,000-11,000 (Cold) LATE- ALLEROD 11,000-11,700 (Cool) GLACIAL OLDER DRYAS 11,700-12,000 (Cold)
Note that the “warmest” period is not now. Now is a “Cool” period.
I’ll also just mention in passing that the 12,000 year Older Dryas lands more or less on the date for Gobekli-Tepe and that civilization change, while the Younger Dryas at about 10,000 years more or less lands on the loss of the Clovis People in North America along with the extinction of most large land mammals in N. America. Cold is not good for civilizations and other living things.
Lots of other references also remember this system of classification and the cycles of cold / warm / cold.
…palynological stratigraphy was developed in Scandinavia by Axel Blytt, Johan Rutger Sernander, and E.J. Lennart von Post, in combination with a theory of Holocene climate changes. The so-called Blytt–Sernander system was soon tied to the archaeology and to the varve chronology of Gerard De Geer. It has been closely checked by radiocarbon dating, establishing a very useful standard….
Yes, a medical site… one can only wonder why… but it is an example of how wide spread this ‘knowing’ is; even if it looks like they just copied the wiki.
The classification was devised before the development of more accurate dating methods, such as C-14 dating and oxygen isotope ratio cycles. Currently geologists working in different regions are studying sea levels, peat bogs and ice core samples by a variety of methods, with a view toward further verifying and refining the Blytt-Sernander sequence. They find a general correspondence across Eurasia and North America.
The fluctuations of climatic change are more complex than Blytt-Sernander periodizations can identify. For example, recent peat core samples at Roskilde Fjord and also Lake Kornerup in Denmark identified 40 to 62 distinguishable layers of pollen, respectively. However, no universally accepted replacement model has been proposed.
Now there’s two things here I find interesting. First, I’ve bolded the bit that says it has been shown to carry across the Northern Hemisphere. There is a known “polar see-saw”, so I’d not be surprised to find out this was an extreme example of it (likely driven by lunar / tidal changes, IMHO). At a minimum, though, we can say that the whole hemisphere ‘goes when it goes’ and since most of the land mass and people are in the N.H., “that matters”.
Second, they find a series of faster changes inside the recognized broad swings. To me, this is simply the finer grain oscillations inside the longer cycles. Like month end stock prices regularly swinging inside the annual (usually flattens and drops some, then has a ‘Christmas rally’) pattern that is inside the 10 year ‘business cycle’ of rise and plunge. That there are sub-cycles does not mean a ‘replacement’ system is needed, just a recognition that ‘cycles in cycles’ look like that. For us, this is important in that it says that though we are presently in a ‘cool’ time, we can easily have a ‘warm flip’ for a while. After all, it’s happened “40 to 62” times before…
It is also interesting to note that the various animal and plant species have had not trouble changing their ‘mix’ with those temperature cycles. The idea that the ecosystem is fragile to temperature adaptation is just nuts. A few thousand years ago the Sahara had elephants and grasslands, before that it had whales in an inland sea. Now it has camels. Things change. Plants and animals move with the change. THAT is the natural system.
Heck, even the politicized Wiki recognizes that the system exists:
with a list of 7 pages that mention it. Including this one:
(In keeping with the ‘confuse the language’ method, the Boreal / Atlantic disambiguation names use Boreal(age) and Atlantic(period)… can’t make it clear that they are two sides of the same thing with “Boreal(period)” or maybe using both with (cycle)…)
Stadials / Interstadials
Just to make it more fun, and more confusing, there’s another set of words used for a different warm / cold cycle. Stadials and interstadials. They come from marine sediments and a different set of researchers. Maybe someday the various folks can all get together and agree on “warm” and “cold”…
Stadials and interstadials are phases within Marine Isotope Stages (MISs) dividing the Quaternary period, the last 2.6 million years. Odd numbered MISs are warmer stages and even numbered ones are colder. Thus the current Holocene is MIS1 and the most recent ice age is MIS2. Stages are divided into warmer and colder intervals. Interglacial 5e (the Eemian), the hottest of the last million years, was the oldest interstadial of MIS5, with MIS3 and MIS1 being interstadials and MIS2 and MIS4 being colder stadials. In glacials a and c are stadials and b and d are warmer interstadials. Thus MIS 6a, 6c and 6e are stadials and 6b and 6d are interstadials.
Generally, stadials endure for a thousand years or less, interstadials for less than ten thousand years, interglacials for more than ten thousand and glacials for about one hundred thousand. The Bølling Oscillation and the Allerød Oscillation, where they are not clearly distinguished in the stratigraphy, are taken together to form the Bølling/Allerød interstadial, and dated from about 14,700 to 12,700 years before the present.
Greenland ice cores show 24 interstadials during the one hundred thousand years of the Wisconsin glaciation. Referred to as the Dansgaard-Oeschger events, they have been extensively studied, and in their northern European contexts are sometimes named after towns, such as the Brorup, the Odderade, the Oerel, the Glinde, the Hengelo, the Denekamp, etc.
We also get Yet Another Word for cycle thrown in: Oscillation. So we have that time cycle too. Also it notes that the Dansgaard-Oeschger events map to interstadials… Oh Joy, yet more different names for the same cycles.
The key takeaway from all this?
Climate and weather are cyclical at several time scales. Things get warmer (sometimes quite fast) and colder (often very fast) by both small and large amounts (sometimes tens of degrees) and on several different time scales from 100,000 years to 10,000 years to 1,000 years to even smaller cycles of tens and then the annual seasonal cycle.
It is the notion that there is a “normal” climate that is broken. It is a fantasy based only on our short lives, shorter memories, and desire for stability in an unstable cyclical world. A human fantasy, and failing.
In order to assign ‘guilt’ to humanity for our present warm period (that happens to be a wonderful time of warmth and plant growth), one must also explain the stadial / interstadial cycles, the Atlantic / Boreal cycles, and the Oscillations; then show they are not relevant to ‘now’. That simply can not be done since we don’t know why those various cycles happened. Lots of theories, not much settled.
Given that the Atlantic was warmest, and we are in a cool time, why is it not most reasonable to simply say we seem to be leaving the sub-Boreal and entering a new Atlantic (sub-sub-Atlantic? ;-) period/age/cycle? If that’s what the pollens and peat bogs say, I’d have to agree with them.
Eventually I’d hope that the scientists of the world could agree on a single, simple, clear and self explanatory naming system for these cycles. It would make it much easier to see what is going on in the real world. It isn’t needed to have each researcher in each field renaming the same thing with yet another invented word. But I won’t hold my breath…
Until that day, it is likely enough just to realize that there are periodic warm and cold cycles; both large and small, and that nothing at all makes this present warming out of the Little Ice Age any different from the others.