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 .
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.