Reversal of Earth's magnetic poles may have triggered Neanderthal extinction -- and it could happen again

During this time, Earth's inhabitants would have been subjected to some dazzling displays -- northern and southern lights, caused by solar winds hitting the Earth's atmosphere, would have been frequent.

The reversal of Earth's magnetic poles, along with a temporary breakdown of the world's magnetic field about 42,000 years ago, could have triggered a raft of environmental changes, solar storms and the extinction of the Neanderthals, according to a new study.

The Earth's magnetic field protects us, acting as a shield against the solar wind (a stream of charged particles and radiation) that flows out from the sun. But the geomagnetic field is not stable in strength and direction, and it has the ability to flip or reverse itself.

Some 42,000 years ago, in an event known as the Laschamp Excursion, the poles did just that for around 800 years, before swapping back -- but scientists were unsure exactly how or if it impacted the world. 

Now, a team of researchers from Sydney's University of New South Wales and the South Australian Museum say the flip, along with changing solar winds, could have triggered an array of dramatic climate shifts leading to environmental change and mass extinctions.

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Europe’s Bronze Age Farmers Adapted to Drought Conditions

(© Archeodunum SA)

GENEVA, SWITZERLAND—According to a statement released by the University of Geneva, a team of scientists led by Alessandra Varalli of Spain’s Pompeu Fabra University has analyzed the biochemical composition of plant remains and the collagen in human and animal bones discovered at Bronze Age sites in western Switzerland and southeastern France. The study suggests that between 2200 and 800 B.C., the people of the region ate mostly plants and land animals, despite the presence of nearby lakes and rivers. The amount of nitrogen in the plant remains indicates that the use of manure as a crop fertilizer became widespread.

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Climate Change In Antiquity: Mass Emigration Due To Water Scarcity

Buried forever by the desert: ruins of Soknopaiou Nesos, a village in the Fayum region

of Egypt that was lost in late antiquity [Credit: Bruno Bazzani/WikiCommons]

The absence of monsoon rains at the source of the Nile was the cause of migrations and the demise of entire settlements in the late Roman province of Egypt. This demographic development has been compared with environmental data for the first time by professor of ancient history, Sabine Huebner of the University of Basel - leading to a discovery of climate change and its consequences.

The oasis-like Faiyum region, roughly 130 km south-west of Cairo, was the breadbasket of the Roman Empire. Yet at the end of the third century CE, numerous formerly thriving settlements there declined and were ultimately abandoned by their inhabitants. Previous excavations and contemporary papyri have shown that problems with field irrigation were the cause. Attempts by local farmers to adapt to the dryness and desertification of the farmland - for example, by changing their agricultural practices - are also documented.

Volcanic eruption and monsoon rains

Basel professor of ancient history Sabine R. Huebner has now shown in the journal Studies in Late Antiquity that changing environmental conditions were behind this development. Existing climate data indicates that the monsoon rains at the headwaters of the Nile in the Ethiopian Highlands suddenly and permanently weakened. The result was lower high-water levels of the river in summer. Evidence supporting this has been found in geological sediment from the Nile Delta, Faiyum and the Ethiopian Highlands, which provides long-term climate data on the monsoons and the water level of the Nile.

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A Viking Archaeologist Shares 6 of the Most Fascinating Finds From a Slew of Recent Discoveries Made in Melting Ice

Archaeologists working to discovered Viking artifacts uncovered by ice melt at the Lendbreen ice patch. Photo courtesy of Secrets of the Ice.

Global warming has unlocked hundreds of Viking artifacts from the ice of the Norwegian mountains in recent years.

In November, archaeologists from the Secret of the Ice project, part of Norway’s Glacier Archaeology Program, discovered 68 arrows spanning a period of 6,000 years—a record for any frozen archaeological site—on the Langfonne ice patch, an ancient Viking hunting ground.

A few months earlier, scientists announced discoveries that had been frozen in the rapidly melting Lendbreen ice patch, which was once part of a Viking trade route.

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Earth used to be cooler than we thought, which changes our math on global warming

Earth was cooler than we thought 6,000 years ago.Gerd Altmann/Pixabay

A long-standing mystery about the Holocene has a potential solution.

The last 12,000 years have been much cooler than previously thought, according to research published Wednesday in the journal Nature. And in contrast, human-caused warming of the atmosphere is even more anomalous than we’d realized. That’s because the study’s authors have found a new way to estimate historical temperatures which they say filters out seasonal shifts that had made past millennia seem warmer than they really were.

The findings offer a possible solution to an outstanding riddle about the recent history of climate change. The problem, called the Holocene warming conundrum, is that previous reconstructions of the historical climate showed a warm period from 6,000 to 10,000 years ago, followed by a period of cooling. Climate models of the same period, however, suggest that the planet would have been warming steadily.

By fine-tuning how we interpret the physical evidence of the changing climate, explains Samantha Bova, a paleoclimate researcher at Rutgers University and one of the study authors, “[the data] do show a warming that’s highly consistent with what is predicted by climate models.”

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Climate change in antiquity: mass emigration due to water scarcity

 The absence of monsoon rains at the source of the Nile was the cause of migrations and the demise of entire settlements in the late Roman province of Egypt. This demographic development has been compared with environmental data for the first time by professor of ancient history, Sabine Huebner of the University of Basel - leading to a discovery of climate change and its consequences.

The oasis-like Faiyum region, roughly 130 km south-west of Cairo, was the breadbasket of the Roman Empire. Yet at the end of the third century CE, numerous formerly thriving settlements there declined and were ultimately abandoned by their inhabitants. Previous excavations and contemporary papyri have shown that problems with field irrigation were the cause. Attempts by local farmers to adapt to the dryness and desertification of the farmland - for example, by changing their agricultural practices - are also documented.

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A New Archaeology For The Anthropocene Era

Archaeological studies of low-density, agrarian-based cities such as ancient Angkor Wat

in Cambodia are increasingly being used to inform the development of more

sustainable urban centres in the future [Credit: Alison Crowther]

A paper published in Nature Ecology and Evolution aims to give pause to an audience that has been largely prepared to take such out-of-touch depictions at face value. It reveals an archaeology practiced by scientists in white lab coats, using multi-million-euro instrumentation and state-of-the-art computers.

It also reveals an archaeology poised to contribute in major ways to addressing such thoroughly modern challenges as biodiversity conservation, food security and climate change.

"Archaeology today is a dramatically different discipline to what it was a century ago," observes Nicole Boivin, lead author of the study and Director of the Institute's Department of Archaeology. "While the tomb raiding we see portrayed in movies is over the top, the archaeology of the past was probably closer to this than to present-day archaeology. Much archaeology today is in contrast highly scientific in orientation, and aimed at addressing modern-day issues."

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