A study of sediment cores collected from the deep ocean supports a new explanation for how glacier melting at the end of the ice ages led to the release of carbon dioxide from the ocean.
The study published in Nature suggests that melting glaciers in the northern hemisphere caused a disruption of deep ocean currents, leading to the release of trapped carbon dioxide from the Southern Ocean around Antarctica.
Understanding what happened when previous glaciers melted could help climate researchers make accurate predictions about future global temperature increases and their effects on the planet.
The evidence is strong that ice ages are driven by periodic changes in the amount of sunlight reaching the poles due to cyclic changes in Earth's rotation and orbit. Yet scientists have been puzzled by evidence that although the timing of ice ages are best explained by changes in sunlight in the northern part of the globe, the warming at the end of ice ages occurred first in the southern hemisphere, with a rise in carbon dioxide levels appearing to be cued from the south.