What if, when we stroll into California and feel at home, we're reminded not of any paradise of today, but rather Africa in the last ice age? The science, shockingly, checks out...

Read more at my #blog: https://www.adamasnemesis.com/2025/11/18/paradise-lost/

This post's featured image is Ice Age Earth, by Ittiz of Wikipedia (rotated by me).

#iceage #climate #paleoclimate #prehistory #paleoclimatology #science #glacialperiod #lastglacialmaximum

Caution in Attributing the Fremington Clay Series to Irish Sea Glaciation: A Case for Predominantly Fluvial and Periglacial Origins in North Devon

The Fremington Clay Series of north Devon has been central to debates on the extent of Middle Pleistocene glaciation in southwest England, often interpreted as evidence of Irish Sea ice incursion during the Wolstonian Stage (MIS 6). However,

Palaeolithic Hunter-Gatherers Made Necklaces From Marine Mollusk Fossils 20,000 Years Ago

Humans have been collecting fossils since Neanderthal times.

IFLScience

#AMOC musings and global mean temperature GMT

Says here https://www.nature.com/articles/s41561-024-01568-1.epdf?sharing_token=O3cvnzvEWDHiaPGAV-CB3dRgN0jAjWel9jnR3ZoTv0M2PsD_MIel1A6mz6UbuhaTQSv4VfXkSU9okrbFGA0gy1etRpvwJw0P0tMsHg9ro8Nv1h-GiKg-3Km08jevWj3MVZ6uFzlIrUTv-X1bF8I0K8crc3qdtYsHtgUTx9fE2Zc%3D
(Original #Pontes etal 2024 https://www.nature.com/articles/s41561-024-01568-1 )

it takes 5 years for the Southern warming signal from AMOC slowdown to appear in the Atlantic near South Africa. And another 14 years for the signal to propagate from South Africa's coast to Brazil's.

So for 14 to 19 years, GMT can be expected to drop from the cooling from Greenland to St Petersburg.
(Yay, another told-you-so-moment for climate deniers!)

But then, when the warming Atlantic is seriously trapped in the South, for a while there, GMT will be stable.

Just goes to show how meaningless the concept of GMT really is. Civilisation will have disappeared in a puff of smoke, or maybe, in a blizzard. But GMT is stable. Yay.

This study looks at a few climate elements over 1000 years after fossil fuel cessation https://esd.copernicus.org/articles/15/1353/2024/esd-15-1353-2024.html
by #King et al 2024 "Exploring climate stabilisation at different global warming levels"

Among other continued regional climate changes, they find that Antarctic sea ice will continue to decline despite stabilisation of GMT🌡️ after CO2zero.

But the paper does not mention this:
continued Antarctic #seaice decline means that #Antarctic bottom water formation slows down. Which in turn changes the ocean carbon cycle and slows down AMOC.

Since they don't mention either, how trustworthy is the overall model result?
And can it also mean that a stabilised GMT is merely the result of an AMOC shutdown where cooling over North East Atlantic is balanced by warming everywhere else?

It did mean exactly that in #paleoclimate during the #LastGlacialMaximum, #LGM:
The bellwether for global mean temperature is a place called Ceara Rise off the coast of North Brazil.
It's surface temperature proxies stayed stable-ish with minuscule changes during known AMOC shutdowns in the last #IceAge
( #Westerhold et al 2020 https://www.science.org/doi/abs/10.1126/science.aba6853)

I'm not convinced that global mean temperature has meaning at all. Haven't been for a long time now. Especially because I see climate scientists on Twix, here or Bluesky mis-using GMT as proof for something to be irrelevant if it only has an impact of 0.05°C on GMT for example.

But regional impacts of something is where it hits us, our civilisation!

The chart shows temperature at Ceara Rise as white line. It's values are the originals, not in any way amended to fit the y-axis.
Greenland's d18O in light yellow is a proxy for temperature changes. When it goes up or down, it's likely that AMOC hickupped.
But Ceara Rise, the bellwether for global mean temperature, stayed a stable holiday destination for the Neanderthals throughout the Last Glacial Maximum, with changes of maybe 0.2°C .

Weakening of the Atlantic Meridional Overturning Circulation driven by subarctic freshening since the mid-twentieth century - Nature Geoscience

Fresh meltwater entering the Labrador and Irminger seas has resulted in a slowing of the Atlantic Meridional Overturning Circulation since the 1950s, according to a combination of modelling approaches.

Nature
Scientists find evidence of hot spring oasis during last ice age in central Europe

A multi-institutional team of plant specialists, microbiologists and paleontologists in the Czech Republic and the University of Minnesota, in the U.S., has found evidence of a hot spring oasis during the last ice age in a part of central Europe.

Phys.org

@Sustainable2050 @gwagner

The new CO2 reconstruction for the last 65 Million years has put me in a sharing mood:
#NASA GISS E2.1-G (IPCC6 version) simulations for this range of CO2 values.
#Miocene #Eocene #LastGlacialMaximum #MidHolocene #Climate

Prehistoric people occupied upland regions of inland Spain in even the coldest periods of the last Ice Age https://www.eurekalert.org/news-releases/1002879 #iberia #palaeolithic #LastGlacialMaximum
Prehistoric people occupied upland regions of inland Spain in even the coldest periods of the last Ice Age

Paleolithic human populations survived even in the coldest and driest upland parts of Spain, according to a study published October 4, 2023 in the open-access journal PLOS ONE by Manuel Alcaraz-Castaño of the University of Alcalá, Spain, Javier Aragoncillo-del Rió of the Molina-Alto Tajo UNESCO Global Geopark, Spain and colleagues.

EurekAlert!
Mapped: What Did the World Look Like in the Last Ice Age?

A map of the Earth 20,000 years ago, at the peak of the last ice age, when colder temperatures transformed the planet we know so well.

Visual Capitalist
Womöglich kamen Menschen bereits lange vor dem Höhepunkt der letzten Eiszeit auf den Doppelkontinent. Das lesen Fachleute aus knöchernen Fundstücken aus Brasilien.
Riesenfaultierknochen legen frühe Anwesenheit des Menschen nahe
Riesenfaultierknochen legen frühe Anwesenheit des Menschen nahe

Womöglich kamen Menschen bereits lange vor dem Höhepunkt der letzten Eiszeit auf den Doppelkontinent. Das lesen Fachleute aus knöchernen Fundstücken aus Brasilien.

Spektrum.de
Inzwischen liegt die DNA von mehreren Hundert Menschen aus der Altsteinzeit vor. Sie zeigen unter anderem, wie ein epochales Ereignis die Genlandschaft Europas prägte.
Die Überlebenden der Kälte
#Altsteinzeit #Paläolithikum #Aurignacien #Gravettien #Solutréen #Epigravettien #Magdalénien #Paläogenetik #Eiszeit #Lastglacialmaximum #Europa #JägerundSammler #Kultur
Die Überlebenden der Kälte

Inzwischen liegt die DNA von mehreren hundert Menschen aus der Altsteinzeit vor. Sie zeigen unter anderem, wie ein epochales Ereignis die Genlandschaft Europas prägte.

Spektrum.de