Although massive eruptions can also release plenty of climate warming carbon dioxide – which eventually overwhelms the sulfur cooling effect – this was not the case 717 million years ago, and the climate had no chance of experiencing any warming. It was, as they say, a perfect storm.
The ice initially began to emerge from the poles, before spreading quickly towards the equatorial regions. When enough of the planet was covered in ice, too much sunlight was reflected back into space, and the planet’s cooling accelerated beyond the point of (almost) no return. Global temperatures reached a staggeringly chilly -50°C (-58°F).
Volcanoes, however, ended up saving the day. Other studies reveal that the end of the “Cryogenian” Period was brought about by the breakup of the supercontinent Rodinia. When such large-scale tectonic trauma takes place, a particular type of volcanism rich in carbon dioxide proliferates, which always leads to a warming of the world.
In this case, the carbon dioxide was dumped into the oceans through many underwater volcanoes, which heated them up enough to shatter the ice and end the perpetual winter. If this never took place, complex life on Earth would likely not have emerged, and you wouldn’t be around to comprehend this possibility.
Good thing volcanoes saw the error of their ways. Adellyne/Shutterstock