Global Environmental Crisis 42000 years ago

21 Nov 2021

At ... geological archives are said to record multiple episodes of reversals of earth's magnetic poles but the effect on the world at large is unclear. The last major inversion is known as the Laschamp excursion, dated at around 42,000 years ago [on Bayesian methodology]. In their study a New Zealand Kauri tree was used to develop a detailed record of atmospheric radiocarbon levels across the excursion. They were able to pinpoint the geomagnetic reversal and perform global chemical and climatic modelling of paleoenvironmental records in order to analyse what input it had on life. There was substantial changes in atmospheric ozone concentration and circulation, and evidence of widespread shifts in climate. There seem to be, in addition, clues of extinction or mass die-ff as well as transformations in the archaeological record. In other words, the Neanderthals disappeared at this time.