Guest post by Alec Rawls
Beneficial climate change allowed modern humans to emigrate out of Africa and spread around the globe says the new PBS documentary “First Peoples,” but it fails to mention that the era it designates as “good times” was several degrees warmer than today.
A critical moment in human history is intoned with intense drama (21:08-21:52 here):
The movement of prehistoric people was affected by the climate, which fluctuated over thousands of years.
I turned up the volume, knowing that if there was anything a warming alarm-dog could find to bark about, it was about to be featured front and center.
In bad times the Sahara was an un-crossable barrier, but in good times, when the climate was wet, the desert disappeared. Any adaption that emerged in one part of Africa could spread to other parts of the continent….
On screen an outer-space view of North Africa and the land bridge to Asia and Europe changed from arid to green (top image), then the segment ended.
“That would have been a warm period,” I said to the television
Not just because the PBS warming-alarm-dog would have barked if it was the bad/dry period that was warmer, but because a warmer planet, with more evaporation and more rain, should on average be wetter. Then there is the known effect that the most recent period of global warming had on North Africa, seen in the greening of the Sahel between 1982 and 2003:
It was the Eemian
A quick search for “wet Sahara” and modern human migration turns up this from Popular Archeology magazine:
Study Confirms Ancient River Systems in Sahara 100,000 Years Ago
Evidence from past research has suggested that, sometime during the period between 130,000 and 100,000 years ago, the Sahara desert region we know today was wetter, featuring rivers and lakes, providing an environment that many scientists theorize permitted the earliest modern humans to migrate northward from points southward in Africa toward the Mediterranean coastline and areas eastward into the Levant.
And something on Eemian temperature history:
Greenland ice cores reveal warm climate of the past
The new results show that during the Eemian period 130,000 to 115,000 thousand years ago the climate in Greenland was around 8 degrees C warmer than today.
Thou shalt provide no ammunition to climate deniers
Like the dog that didn’t bark in Conan Doyle’s Silver Blaze, a warming-alarm-dog will never bark at its master, or its paymaster. There is a lot of funding available for academic experts on climate-driven human migrations. So says the primary climate change funding guide. From AR5, WGII, Summary for Policymakers, page 11:
Uncertainties about future vulnerability, exposure, and responses of interlinked human and natural systems are large (high confidence). This motivates exploration of a wide range of socioeconomic futures in assessments of risks.
But that funding is only available to those who toe the “consensus” line that human activity is causing dangerous amounts of global warming. Telling the world that mankind’s big climate break came when global temperatures were several degrees higher than today would needlessly put a paleoanthropologist’s academic and television career at risk.
Much wiser to just leave that inconvenient truth out, and who wants to give ammunition to those nasty science deniers anyway? They’ll just spread the truth to even more people.
Bonus dog that didn’t bark
The research paper reported in Popular Archeology magazine (confirming ancient river systems in Sahara 100,000 Years Ago), is a hydrological modeling study, driven first and foremost by the temperatures that prevailed in the era under study, so the five authors know in great detail that they are modeling a substantially warmer period than today, yet the full published study never mentions this key fact. The closest they come to mentioning that the Eemian was warmer than today is this hint from the first paragraph of their “Discussion” section:
This reconstruction is highly compatible with evidence of widespread palaeosols deposited on the margins of this system during the less pronounced Holocene humid period [22].
Okay, so they are admitting that the Holocene is humid. Everyone knows that the Holocene is an interglacial so they are kinda-sorta admitting that warm is humid, at least in North Africa, and they tell us that the Eemian was more humid, so they are hinting that the Eemian was warmer than today, only they just can’t bring themselves to actually say that it was warmer, even though this is the key explanatory variable in their wet-Sahara theory.
The authors say they did not get any funding for this research. Either they are trying really hard to change that or they are ideologically self-driven not to speak any inconvenient scientific truths that “science deniers” could propagate. Only anti-deniers can be counted on to keep the truth suppressed.
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Didn’t know that the Eemian was named after the Eems river, which in the North of The Netherlands forms the border with Germany. There is a lot of literature which shows the findings in the sediments of the river bed which can be traced back to the previous interglacial.
This time Wiki indeed is a good source:
https://en.m.wikipedia.org/wiki/Eemian_interglacial
“This time Wiki indeed is a good source”
Not really, there are several errors in it.
It’s not the Mikulin interglacial in Russia, it is called Mikulino.
“The Eemian climate is believed to have been about as stable as that of the Holocene”
Wrong. There was a very marked cold interval with significant sea-level drop (=glaciation) in the mid-Eemian.
“global annual mean temperatures were probably similar to those of the Holocene”
Since we know that most of the Earth was significantly warmer this would mean that there must have been some large areas that were markedly colder than now. Very odd that we haven’t found any of them yet.
“North Cape, Norway (which is now tundra)”
Wrong. Alpine heath.
“The hippopotamus was distributed as far north as the rivers Rhine and Thames.”
True as far as it goes, but hippopotamus actually occurred as far north as Yorkshire (Victoria Cave)
“Hardwood trees such as hazel and oak grew as far north as Oulu, Finland.”
Also true as far as it goes, but hazel occurred as far north as Svappavaara, 300 km north of Oulu and well north of the Arctic Circle.
“south of the Alps, conditions were 1–2 °C cooler than today”
No evidence for this except in computer models. Tropical mollusks actually occurred in the Mediterranean, the well-known “Strombus” or “Senegalese” fauna.
“Scandinavia was an island due to the inundation of vast areas of northern Europe and the West Siberian Plain”
You always see this mentioned about the Eemian. However it was only true for a brief interval at the beginning of the interglacial.
tty
Thanks – your point about the plu-perfect paragon – ahhhhh you’ve read the rest. Wiki-perfection can start you off – but I tend to add a little disclaimer . . . .
Mods – careful – there may be a hint of sarcasm about the paragon in there.
Thanks!
Auto
Thanks tty,
Always nice to see that someone has better information than Wiki… Even so it is quite a miracle that the Wiki article was already admitting that it was (at least partly) warmer than now and wasn’t “corrected” by William Connolley…
Ferdinand
This article fails on many levels. As any good researcher will tell you, you have to look in the past to understand the future! The issue today is: Accelerated global warming/climate change as a result of the increased use of unsustainable fossil fuels and the destruction of the very thing that mitigates poor air quality at alarming rates.
I’m not sure who funds this article but in my honest opinion it is a poor reflection on the main issues facing biodiversity on the blue planet.
adam better to hide and just listen for a while, I’m sure there some skepticism in there somewhere…Perhaps you’ll eventually have an epiphany.
My take on how non-Neanderthals finally managed to handle European glaciation post-Eemian: they developed sewing, and could laugh at cold. As Eskimos etc. still do.
IMO the oldest needles known date only to Solutrean time, at the last glacial maximum. I might be outdated, however.
My guess is that prior modern human cultures used awls to make holes, then ran sinew through them rather than sewing garments. My impression is that Neanderthal clothing was more rudimentary, consisting of hides tied on or together in ad hoc ways.
Oops, meant after the last but one glacial retreat
getting back to my earlier comment, its a wonder given the large variety of skin pigmentation that there is no historical record of either blue peoples or green peoples even orange peoples seem to have missed the basket. Perhaps those self identifying as greenish people may eventually reached an enlightened skin pigmentation or use some chemical injections to augment nature.
Green men (whether little or large) may come to pass.
Why not add chloroplasts to human egg cells, so that we can produce our own sugar when exposed to light, provided our CO2 exhalation be somehow recycled into our cells rather than released at 100 time ambient concentration (contrary to the laughable lie of the Skeptical Science site maintained by a cartoonist who likes to dress up like a N@zi).
Last sentence should end with a question mark.
The “out of Africa” human migration story is based on the fact that Africans have far more mutations [than] other people, but few people are willing to consider the other possibility that also fits the evidence, that they simply mutated faster than other people. And the accepted supposition is “supported” by a lack of evidence.
On the contrary, the ‘out of Africa’ theory is well supported by the genetic data and is the prevailing view based on the preponderance of the evidence. The multiregional hypothesis does have some supporters but fewer than previously and in a weaker form, due to improvements in the genetic data available (mostly these days it persists in Chinese groups partly motivated, apparently, by Chinese nationalism). The prevailing current position is of several out of africa migrations with limited interbreeding with extinct archaic humans, neanderthal and denisovans, for example, in particular this appears through persisting immune system genes.
The “preponderance of the evidence” claim for that is largely based on the fact that Africans have far more genetic diversity (mutations) than all of the other populations combined and thus on guesses about mutation rates.
It assumes that every population had the same molecular clock, which means that every population had exactly the same repair enzymes, their environments were the same, population sizes were the same, average age of marriage was the same, and family sizes were the same. But we know these things aren’t true.
Larry,
The strongest evidence for the recent out of Africa hypothesis (where recent means 60-125 Ka) is the fact that all non-African mtDNA descends from the L3 haplogroup.
But there is also good supporting evidence in favor of this hypothesis.
Whether the bearers of this haplogroup left Africa just once, via the Red Sea crossing, or multiple times, to include via the Sinai, remains an issue. If a great many bands entered Eurasia, however, more haplogroups should be represented outside Africa.
Sturgis,
According to the most popular hypothesis, mitochondrial L0 gave rise to L1 and L2, then L2 gave rise to L3, which gave rise to M, N and R. But this hinges on the assumption that the molecular clock in every population runs at the same rate, then the population with the most mutations is inferred to be older. Since Africans (L) have the most mutations, they are inferred to be the oldest, so everyone else derived from them.[1]
However, the underlying assumptions about the shared common molecular clock rates are false.[2][3][4]
1. http://mbe.oxfordjournals.org/content/24/3/757.full.pdf
2.https://www.africandna.com/adna_static/ScienPapers/Do_the_Four_Clades_of_the_mtDNA_Haplogroup_L2_Evolve_at_Different_Rates.pdf
3. http://www.nature.com/hdy/journal/v101/n2/full/hdy200852a.html
4. http://www.nature.com/scitable/knowledge/library/neutrality-and-molecular-clocks-100492542
If anyone can be bothered, the “out of africa” therory is practically proved with mDNA. My mDNA can be traced to africa. Inhereted from our mothers. And so too does yours. So far there is no other theory to dispute that!
As noted just above, the Out of Africa hypothesis was based on assumptions about generic clocks that have been falsified by the mtDNA data.
WUWT readers shouldn’t be strangers to the many reason why certain ideas remain popular with some scientists, even after having been refuted by that data. Among those reason are politics, funding, inertia and egos.
By the way, everyone who takes a DNA test is now told that their ancestors ultimately trace back to sub-Saharan Africa, but that isn’t based on any analysis of inherited STR markers. It’s based on the assumption that the Out of Africa hypothesis is true.
In fact, unless you’re directly descended from a black African, you don’t share mutation markers with any sub-Saharan African haplogroups, which is why you don’t see any percentage of your actual ancestry showing up down there.
Yes you do. It ls in mDNA, inherited from mothers.
I say this because I have been tested over the recent 5 years for various genetic disorders by some of the best genetisists in Aus. My sister too has been tested by one very prominent genetisist in England. We know our DNA roots.
Patrick,
By saying that our mitochondrial DNA proves that we’re all descended from sub-Saharan Africans, they’re assuming that (among other things) the mtDNA mutates at the same rate in everyone, but that’s been proven to be false.
If the assumptions upon which the inference was based is false, then the inference fails. We may all be descended from southern Africans, but the data doesn’t currently support that hypothesis. Many people still support it, but the data doesn’t.
Yet another warm period, apparently, is the Hypsithermal Interval (http://glossary.ametsoc.org/wiki/Hypsithermal_period) , from 7000 to 500BC.
It is commonly said that tribal people have occupied southern Vancouver Island for 4000 years, which goes back into that era, but on the mainland perhaps three times that long.
Just a note, unsure what it might mean.