Uncovering the Mystery: Did Our Planet Become a ‘Snowball Earth’ 720 Million Years Ago?

About 720 million years ago, Earth experienced one of its harshest climate events: a global freeze known as Snowball Earth. The planet was covered in ice from pole to pole for millions of years. Scientists have debated what caused this dramatic chill, and a new study points to an ancient volcano in the Canadian Arctic as a possible culprit.

Typically, such massive climate shifts are linked to volcanoes, meteor impacts, or changes in Earth’s orbit. Some researchers previously suggested that an asteroid might have brought about this freeze by sending dust into the atmosphere, blocking sunlight. However, strong evidence for an impact during this time is still lacking.

A team from Harvard University revisits the idea that volcanic activity played a key role in this icy period, specifically the eruptions from the Franklin Large Igneous Province, which erupted around the time Snowball Earth began. This region is a vast geological formation located in the Canadian Arctic and northwestern Greenland.

The researchers used climate models to explore how volcanic eruptions might have affected carbon dioxide levels. They found that if the Franklin eruptions exposed large amounts of silicate rock, the weathering of these rocks could react chemically with carbon dioxide. This process might have effectively reduced the gas in the atmosphere, leading to cooling temperatures.

However, only 10% of their simulations indicated that the volcanic activity could lead to the drastic cooling needed for a Snowball Earth scenario. This suggests that while volcanic eruptions could contribute to significant climate changes, certain conditions must align perfectly for this to happen.

Interestingly, the Earth’s climate was already cooler before the Snowball Earth event. In contrast, during warmer periods, volcanic eruptions like those from Franklin did not create a similar ice age. Increased vegetation during warmer times might have also reduced the rate of erosion, impacting the weathering process.

While this research narrows down factors contributing to Snowball Earth, many questions remain. For instance, scientists are still unsure about the exact timing and duration of the Snowball Earth period. What’s clear is that this extreme climatic event remains one of the great mysteries of Earth’s history.

The study can be found in the Journal of Geophysical Research: Planets.

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