The story begins more than half a billion years ago when our planet was an enormous “snowball” moving through space. The entire world was covered by glaciers, all the way to the equator. This ancient “snowball” Earth event, according to geologists, happened at least twice in the Earth’s early history. Also, scientists have found that the second “snowball event” ended suddenly about 635 million years ago. This fast ending could be linked with the actual global warming.
But What Exactly Happened With the Ancient “Snowball” Earth?
A paleobiologist at Virginia Polytechnic Institute and State University, in Blacksburg, Shuhai Xiao, stated that the ice had melted several thousand years ago in no more than 1 million years. That could mean that the globe has reached a tipping point.
However, the researchers don’t exactly know what triggered the melting, but a guess is made on the ancient volcanoes that emitted carbon dioxide. The carbon dioxide has caused a greenhouse effect, and the ice sheets began to melt rapidly.
What Evidence Do We Have About the Ancient Volcanoes?
Xiao and his colleagues have discovered in China’s Yunnan province some volcanic rocks that were attached to another kind of stones. The enclosed rocks are some unique deposits of limestone and dolostone formed during the ancient “snowball” Earth event. Regarding the age of the volcanic rocks, with the help of radiometric dating techniques, they dated them to be around 634.6 million years old, plus-minus 880,000 years.
Moreover, in 2005, a different team of scientists has done some researching of their own in China as well, but in the Guizhou province. The rocks found there are dated to be 635.2 million years, plus-minus 570,000 years. The two volcanic rocks sample are more precise, with an error of fewer than 1 million years, rather than other samples from the past that had errors of a million years or more.
Unfortunately, the two new samples are not enough to determine the exact time when the ancient “snowball” Earth melted down because it would be required to have samples from all over the world, says Carol Dehler, a geologist at Utah State University, in Logan. But those results could help scientists know how to deal with nowadays global warming.
Erin VanDyke lives on her family farm and has more than 35 years of hands-on experience with the use of livestock guard dogs for predator control. On their farm, Jan and her family use corgis as herding dogs and have raised Shetland sheep, Fainting goats, Morgan and Trakehner horses, and historic breeds of chickens and turkeys. Erin is also an active beekeeper.