Volcanoes may have trapped Earth in a 56-million-year ice age

Climate models can explain both how a global ice age begins and how it ends – carbon dioxide from volcanoes builds up in the atmosphere, the planet warms, and glaciers retreat.

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Around 717 million years ago, volcanoes erupted across what is now the high Arctic, flooding the region with lava and blanketing a massive area in fresh basalt.

The volcanoes may have helped trigger the Sturtian ice age by removing huge amounts of carbon dioxide from the atmosphere.

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Sturtian sedimentary deposits found on every continent – from Australia to Svalbard – are not uniform.

The layers show evidence of glacial advance and retreat, which is not the kind of pattern expected from one unbroken ice age.

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Until this study, no model could sustain a 56-million-year Sturtian glaciation without invoking conditions unsupported by the geological record.

The new work removes that barrier. The findings suggest that ancient volcanoes may have helped drive Earth’s longest ice age by repeatedly exposing fresh lava rock that stripped carbon dioxide from the atmosphere.

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