New Study: Ice Age Lasted Longer Because of Chemical Reactions Under Ice

This new study suggests chemical reactions under the ice could have made ice ages last millions of years longer than we thought.
By Newsroom | Science, Earth Science |

A novel mechanism suggests chemical processes beneath kilometers of ice could have held Earth in prolonged frozen states.

Chemical reactions occurring deep beneath the planet's ice sheets, during periods known as "Snowball Earth," may have absorbed enough atmospheric carbon dioxide to significantly extend these global glaciations. This new understanding challenges previous assumptions about how the planet transitioned out of these extreme ice ages, offering a potential explanation for why some "Snowball Earth" events persisted for tens of millions of years.

The findings, published in Earth and Planetary Science Letters, emerge from research conducted by scientists at the 'Earth-Life Science Institute' (ELSI) at the 'Institute of Science Tokyo', in collaboration with the 'Jet Propulsion Laboratory' at the 'California Institute of Technology'.

Subglacial weathering may have slowed planet's escape from snowball Earth - 1

These subglacial chemical processes, specifically the weathering of rocks, could have consumed carbon dioxide at rates comparable to volcanic emissions, effectively suppressing the buildup of greenhouse gases needed to warm the planet. This geological feedback loop, previously not fully accounted for, suggests that weathering beneath thick ice sheets might have played a critical role in maintaining frigid conditions for extended geological timescales.

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A Puzzling Duration

"Snowball Earth" refers to hypothetical periods in Earth's history where the entire planet was covered in ice. These events dramatically reshaped the planet's environment, influencing the evolution of climate, oceans, and life. However, a persistent puzzle has been the variable duration of these glaciations, with some lasting considerably longer than others.

Subglacial weathering may have slowed planet's escape from snowball Earth - 2

The study proposes that weathering, the process by which rocks are broken down by chemical reactions, continued even under kilometers of ice. This subglacial weathering, fueled by meltwater, interacted with rocks, removing carbon dioxide from the atmosphere.

Reassessing the Carbon Cycle

Standard theories often assume weathering significantly diminishes under extreme glaciation. However, the new research, utilizing 'geochemical modeling' and 'simulations', suggests otherwise.

  • The models indicate that a "balance" between the supply of water and rocks at the ice-rock interface could sustain significant carbon removal.

  • This process acted as a counterforce against the natural accumulation of greenhouse gases from volcanic activity.

  • The continued removal of CO₂ would then prolong the ice-bound state, creating a feedback loop that made escape from the glaciation more difficult.

The implications of this research extend to understanding 'Earth's climate dynamics', particularly during the 'Neoproterozoic glaciations'. It provides a quantified mechanism for a major climate puzzle that has long intrigued scientists studying planetary climate systems.

Read More: Why Earth Froze 700 Million Years Ago Due to Low Volcano CO2

Background

The 'Institute of Science Tokyo' was established in October 2024, merging the 'Tokyo Medical and Dental University' and 'Tokyo Institute of Technology' with a stated mission to "Advance science and human wellbeing to create value for and with society." The research published draws on 'carbon cycle modeling' and 'geochemical simulations' to explore ancient climate scenarios. The underlying paper is titled "Continued continental weathering during snowball Earth mitigated greenhouse gas buildup and prolonged global glaciation."

Frequently Asked Questions

Q: How did chemical reactions under ice affect Earth's ice ages?
New research shows chemical reactions, like rock weathering, under kilometers of ice may have absorbed carbon dioxide (CO2). This process could have prevented the planet from warming up, making the ice ages last much longer.
Q: What is 'Snowball Earth' and why is its duration a puzzle?
'Snowball Earth' refers to times when Earth was completely covered in ice. Scientists found it puzzling because some of these frozen periods lasted for tens of millions of years, and they didn't fully understand why.
Q: What new idea do scientists have about why 'Snowball Earth' lasted so long?
Scientists now think that even under thick ice, chemical reactions between meltwater and rocks continued to remove CO2 from the air. This stopped greenhouse gases from building up, which would normally help warm the planet.
Q: Which scientists worked on this new study about prolonged ice ages?
The study was done by scientists from the Earth-Life Science Institute (ELSI) at the Institute of Science Tokyo and the Jet Propulsion Laboratory at the California Institute of Technology.
Q: How does this research change our understanding of Earth's climate?
This study offers a new explanation for how Earth's climate system worked during extreme ice ages. It shows that processes happening under the ice could have played a big role in keeping the planet frozen for very long times.