Geologists determine probable cause of extreme ice-age climate 700 million years ago

The ancient glaciation from this period can be observed in the Flinders Ranges in South Australia

Author information:

Author: Adriana Dutkiewicz

Institution: University of Sydney

The glaciation period, also called the Sturtian glaciation, kicked off roughly 700 million years ago, long before the existence of dinosaurs and complex plant life on land. It lasted for 57 million years, which is exceptionally long.

This extreme ice age was triggered by historically low volcanic carbon dioxide emissions, according to a new study published in Geology. The researchers concluded that reduced plate tectonics resulted in less carbon dioxide release from volcanoes, while weathering processes on a large pile of volcanic rocks in Canada absorbed carbon dioxide from the atmosphere.

The cause of the Sturtian glaciation has been a mystery, with various theories suggesting triggers and ending factors. The new study helps to understand how the Earth's thermostat works and how sensitive the global climate is to atmospheric carbon concentration.

According to the study, atmospheric carbon dioxide fell to a level of less than 200 parts per million, less than half the current amount.

Human-induced climate change is occurring ten times faster than this type of geological climate change, according to the study.

The Earth is also on a decreasing trajectory of carbon dioxide emissions from volcanoes. Currently, continental collisions are increasing, and the plates are slowing down.

Study lead author Adriana Dutkiewicz concluded that the Sturtian ice age was likely caused by a double whammy of plate tectonic reorganization and the erosion of a large volcanic province in Canada, which consumed atmospheric carbon dioxide.

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