Original upload date: Jan 14, 2020

Re-upload from deviantART.

A depiction of a cataclysmic climate disruption that happened on this planet roughly 720 million years ago, when a freak mix of conditions, like excessive weathering and the rise of photosynthetic organisms scrubbed too much CO2 from the atmosphere caused a runaway "ice-house" affect, and the polar ice caps grew and extended right to the tropics, meeting and sealing up at the equator. Earth was literally Hoth from Empire Strikes Back for another 85 million year after that until the pressure from from the volcanoes around the world that had been pushed down by trillions of tons of glacial ice finally broke through, releasing billions of tons of CO2 and Methane all at once, allowing the planet to warm and the ice to melt again. All the new chemicals and oxygen [produced during this melting kick-started the Cambrian Explosion, the biggest burst in diversity multi-cellular oceanic life in geological history.

(Also for any would-be commenters claiming this to be a "solution" to climate change...no. One, this happened when the Sun was roughly 10% dimer than it is today, and as the sun ages it will gradually get warmer. Of course the warming sun is NOT the reason for current global warming since it takes hundreds of millions of years for that warming to make a difference whereas we're trashing the planet in just a few hundred years, and 2, even if this WERE to happen again {the Earth would actually have to migrate out past the orbit of Mars, which would require a massive, gas giant-sized rogue planet to enter the inner solar system and screw around with the orbits of ALL the inner planets, which would be disastrous in-and-of itself}, there is no way we'd survive such a complete freeze-over, with the glaciers around the globe covering even the highest mountain tops and temperatures lower than that even on Mars, Mars would actually be MORE habitable. Of course global warming may make the Earth more Venus-like, which of course makes Mars our last life-boat too. We'd be screwed either way.)

Here's the Wikipedia page on it: https://en.wikipedia.org/wiki/Cryogenian

And here's a video documentary: https://www.youtube.com/watch?v=YOLbE8frMrM