Flipping of Earth's magetic poles may have led to demise of the Neanderthals, new study suggests

The flipping of the Earth’s magnetic poles together with a drop in solar activity 42,000 years ago could have generated an apocalyptic environment that may have played a role in a major events ranging from the extinction of megafauna to the end of the Neanderthals, researchers say.

The Earth’s magnetic field acts as a protective shield against damaging cosmic radiation, but when the poles switch, as has occurred many times in the past, the protective shield weakens dramatically and leaves the planet exposed to high energy particles.

One temporary flip of the poles, known as the Laschamps excursion, happened 42,000 years ago and lasted for about 1,000 years. Previous work found little evidence that the event had a profound impact on the planet, possibly because the focus had not been on the period during which the poles were actually shifting, researchers say.

Now scientists say the flip, together with a period of low solar activity, could have been behind a vast array of climatic and environmental phenomena with dramatic ramifications. “It probably would have seemed like the end of days,” said Prof Chris Turney of the University of New South Wales and co-author of the study.