Scientists believe that more than half a billion years ago, Earth was covered in glaciers up to the equator. The "snowball phenomena" is believed to have occurred at least twice in the Earth's historic past. Today, scientists have found evidence that the last thawing out of the snowball earth happened roughly 635 million years ago. This geologically rich even happened too fast that it is believed to have implications to the global warming the world is suffering from.
It took several thousands of year for ice to build up and blanket the entire Earth, but scientists believe that it only took less than a million years to thaw it all out. Shushai Xiao is a paleobiologist at the Virginia Polytechnic Institute was part of the team that led to this breakthrough discovery. Given that the earth only has 4.56 billion years of history behind it, the thawing out of the Earth's atmosphere happened in a blink of an eye.
The research findings suggest that the Earth reached its tipping point all too suddenly. Although the team has yet to determine what caused the thawing out of the Snowball Earth, they believe that the carbon emissions from the ancient volcanoes have created the greenhouse effect, which then led to the melting of the ice rapidly.
To shine some light to this theory, Xiao and colleagues collected ancient rocks from volcanic eruptions. They got their primary samples from Yunnan province. This is found in the southern part of China. The volcanic rocks were embedded below cap carbonates. These are another type of rock that is formed from unique deposits of dolostone and limestone. Such types of rock formation may have come about due to the Snowball Earth's shutdown as the level of carbon dioxide in the atmosphere increased creating that greenhouse effect.
Using what scientists refer to as the radiometric dating technique, they have found volcanic rocks that date back to 634.6 million years. This single discovery could help scientists determine the speed of how the melting happened. The sample has helped determine the quick thaw of less than a million years.
To be able to paint the picture of the Earth Snowball thawing out in the ancient past, scientists must also collect datable volcanic rocks from the other regions of the world. Carol Dehler from Utah State University said that "these volcanic rocks may just be waiting to be discovered."
Meanwhile, the understanding of how the theory of the Earth being a huge snowball in the past will help us further determine why global warming is happening. Apart from the increasing emission of greenhouse gases into the atmosphere, the fact that the thawing out of the Earth happened at extreme speed, it also means that it can possibly happen again.
"The extreme ways the earth is changing can happen in both long term and short term scale," Dehler said. "It is important that we understand this as it could be the eye-opener to a lot of people that burning of fossil fuels will only speed up the process and make it even faster."
