A new international study using ancient swamp kauri from Northland shows that Earth’s magnetic field flipped 42,000 years ago, triggering climate changes and environmental shifts. The event, known as the ‘Adams Event,’ led to global disruptions and mass extinctions.
Researchers used preserved kauri tree rings to track changes in radiocarbon levels during the Adams Event. Radiocarbon dating at the University of Waikato helped establish an accurate timeline, confirming the environmental impact of the magnetic pole reversal.
Data from kauri trees was aligned with records from ice cores, caves, and peat bogs to reveal widespread climate shifts. The study links the Adams Event to megafauna extinctions in Australia and Tasmania and suggests it may have played a role in the disappearance of Neanderthals.
During the Adams Event, Earth’s magnetic field dropped to almost zero, leaving the planet exposed to increased cosmic radiation. This loss of protection led to changes in atmospheric chemistry, including a weakening of the ozone layer.
The weakening of the magnetic field allowed more solar radiation to reach Earth, intensifying auroras and electrical storms. Researchers believe these changes contributed to shifts in global wind patterns, tropical climates, and glacier movements.
The study suggests that environmental pressures during the Adams Event may have influenced human behaviour. The increased UV radiation could have driven early humans to seek shelter in caves, coinciding with the emergence of cave art around 42,000 years ago.
The findings highlight the importance of ancient kauri trees in understanding past climate events. The study provides a new radiocarbon timescale, helping researchers connect historical environmental changes to broader patterns of planetary shifts.