An international team of researchers has uncovered that during the so-called Laschamps Event—a brief disappearance of Earth’s magnetic field 41,000 to 42,000 years ago—the planet underwent severe climate upheaval. The findings were published in the journal Science.
The key to the discovery was found in fossilized kauri trees (Agathis australis) preserved in New Zealand. Analysis of their tree rings showed a sharp surge in atmospheric radiocarbon, caused by the collapse of the magnetic field. During this period, ionizing radiation nearly destroyed the ozone layer, which led to global climate change.
The scientists link these consequences to the extinction of megafauna in Australia and Tasmania, as well as to changes in the lifestyle of ancient humans. According to them, the disappearance of the magnetic “shield” forced people to seek shelter in caves and may have influenced the emergence of the first waves of cave art. Specifically, the researchers suggest that handprints covered in ochre were an attempt to use the mineral as a primitive “sunscreen.”
