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Home / Science / The rapid loss of sunlight may have triggered snowball-related events in the past

The rapid loss of sunlight may have triggered snowball-related events in the past



Not all ice ages are equally brutal. In the most extreme events of the glaciation of science, the ice stretches from the polar regions of the Earth and extends to lower latitudes, literally reshaping the face of the planet.

Evidence of such epic transitions can be found in the geological record, most recently in the vast icy during the cryogenic period. Scientists believe that these extreme cooling events had potential global impact and consequences: a phenomenon called the “Snowball.”

But what could unleash such a devastating and ruthless winter on Earth that most – or all – of our planet would end up shrouded in a frozen realm of ice and snow? While the exact triggers remain unknown, scientists have now discovered a new theoretical explanation of how such a thing could happen.

“There are a lot of ideas about what caused these global glaciations, but they all really boil down to the implicit modification of incoming sunlight,”

; said MIT, a planetary science researcher at Constantin Arnscheidt.

“But in general, it was examined in the context of exceeding the threshold.”

In other words, the conventional explanation for how a snowball could prove is that in the event of some cataclysmic shadow casting, less sunlight would reach the surface of the planet, leading to a colder Earth that would freeze.

Another hypothetical explanation related to the carbon cycle would be the opposite of the global warming crisis that the Earth is now facing: what if our planet had so little heat-absorbing carbon dioxide in its atmosphere that we, along with its heat, would completely lose the Earth’s mild climate. the universe?

“Although there is still a debate about specific triggers for low-latitude glaciation in the Earth’s geological past, it is generally understood that glaciation begins when changes in radiation fluxes or CO2 fluxes exceed a critical threshold,” Arnscheidt and co-author, MIT Geophysicist MIT Daniel Rothman, explain in a new document.

Although the theory previously focused on such critical thresholds, scientists have sought to find a new way to think about Snowball Earth precursors: what if it was not a critical threshold that was met (e.g., in terms of throwing solar radiation), but a critical rate of change?

In the new modeling, the scientists simulated the Earth’s dynamic systems in ice-cold scenarios – mainly the sum of the ice-albeda feedback and the carbonate-silicate cycle.

The first is an example of positive feedback. As the Earth icees and approaches Snowball, it’s a freezing rope of ice and snow that eventually reflects more sunlight from the planet, which in turn accelerates the cooling effects already underway.

However, as the Earth becomes icy, our usual carbonate-silicate cycle is broken. With Earth’s rocks sealed under ice, they are less able to absorb atmospheric carbon, so heat is trapped in the air. Therefore, even though the Earth is far from the Sun, our planet would not theoretically get stuck in a permanent state of the Earth, despite the persistence of feedback on the ice.

With these types of factors built into their models, the researchers investigated whether guessing at an increased pace could trigger a Snowball Earth event. Under the right circumstances.

In the simulations, Arnscheidt and Rothman found that if the sun’s rays dropped fast enough for long enough, in itself could be enough to unleash a snowball – and all that could be would be about a 2 percent reduction in sunlight to the surface in 10,000 years, scientists estimate.

In the grand scheme of things (read: The Earth is about 4.5 billion years old), it’s not too long. But what could hide the Earth from the Sun for 10,000 years?

No one knows for sure, but it is likely that something like the volcanic winter of the planetary range that released the volcanic eruptions could sufficiently envelop our atmosphere. Alternatively, some kind of biological phenomenon in the Earth’s ancient past, such as the surge of moisture-producing algae, could generate clouds of condensation that could eventually freeze them and forget everything else.

Of course, all these ideas are quite nice. This does not mean, however, that we should not look for what Snowball Earth might have compelled or examine how quickly this ancient ice history may have unfolded.

Scientists say that right now we are in such a hurry in the opposite direction.

“It teaches us that we should be careful about the speed at which we adjust the earth’s climate, not just the magnitude of change,” says Arnscheidt.

“There could be other such points that could be caused by anthropogenic warming.”

The findings are set out in Proceedings of the Royal Society.


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