Coral off Tahiti has linked the collapse of massive ice sheets 14,600 years ago to a dramatic and rapid rise in global sea-levels of around 14 metres. Previous research could not accurately date the sea-level rise but now an Aix-Marseille University-led team, including Oxford University scientists Alex Thomas and Gideon Henderson, has confirmed that the event occurred 14,650-14,310 years ago at the same time as a period of rapid climate change known as the Bølling warming. The finding will help scientists currently modelling future climate change scenarios to factor in the dynamic behaviour of major ice sheets. During the Bølling warming high latitudes of the Northern hemisphere warmed as much as 15 degrees Celsius in a few tens of decades. What exactly caused the Bølling warming is a matter of intense debate: a leading theory is that the ocean's circulation changed so that more heat was transported into Northern latitudes. The new sea-level evidence suggests that a considerable portion of the water causing the sea-level rise at this time must have come from melting of the ice sheets in Antarctica, which sent a 'pulse' of freshwater around the globe. However, whether the freshwater pulse helped to warm the climate or was a result of an already warming world remains unclear...
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