Are the Earth’s shifting magnetic fields causing climate change?
The Earth’s magnetic fields help sustain life on our planet but they could also be a driver for climate change and the reason why some species have become extinct.
This is the bold claim made in a scientific paper published in Science magazine this week.
The journal article argues that atmospheric changes more than 40,000 years ago had such a radical impact on the planet that it caused significant environmental damage and even extinction events.
Protecting the Earth from harmful ultraviolet radiation, the planet’s magnetic fields play a vital role in preserving life, but do vary in strength with the magnetic poles sometimes even shifting position.
Atmospheric changes more than 40,000 years ago had such a radical impact on the planet.
This phenomenon, critics of the paper’s assertions say, has never previously been conclusively connected with extinction events or major ecological disasters in the Earth’s history.
How did scientists come up with this theory?
The scientists behind the research examined the rings of kauri trees, a species native to New Zealand which reach up to 1,000 years of age and whose wood survives for tens of thousands of years in marshes and wetlands, as the basis of their theory.
Using carbon dating techniques, they found that the trees they examined were over 40,000 years old which would mean they were growing during a time known as the ‘Laschamp Excursion’.
The latter was an event in which the Earth’s magnetic fields significantly weakened. Studies of the wood samples showed a spike of Carbon-14 in the trees’ rings, suggesting the Earth had been subjected to high levels of cosmic particles and radiation from space.
The team estimates that these particles contributed to a breakdown of the Earth’s Ozone layer which in turn set in motion changes to the global climate and environmental shifts.
Some critics are skeptical
While critics suggest that the research throws up some interesting avenues of inquiry, they say the researchers are overreaching in their conclusions.
In particular, their linking together climatic changes with other events that were happening at the same time, such as the extinction of Neanderthals and the advancement of sophisticated cave painting styles.
As for the researchers – they contend that early humans were sheltering in caves because of the increased radiation and using ochre, the prime material used in cave painting, as a rudimental sunscreen. But others point out that they were known to have lived in caves and used the earth pigment for artistic purposes for tens of thousands of years before the ‘Laschamp Excursion’.
Are magnetic fields contributing to drastic changes in the world’s climate? Although the research published by Science has merits, critics conclude, the jury seems to be out in the wider scientific community.