About 700-800 million years ago, the earth entered into an extremely severe ice age. The earth was covered from the North Pole to the South Pole with a thick layer of ice. This period of time is referred to as snowball earth. However after a relatively short period of time in earth's history, the ice and glaciers receded and temperatures rose. One of the pressing questions to this event is how did the earth get out of a snowball earth? With greenhouse gas levels so low what could be a possible trigger for the receding of the glaciers?

My hypothesis is that the trigger for the ending of the snowball earth period was the carbon dioxide that comes from volcanoes. The carbon dioxide emitted from volcanoes would trigger a gradual shifting of the earth's climate. From this springs the question how could volcanoes possibly emit enough carbon dioxide to change the climate of earth? Well, 700 years ago the earth certainly had more volcanic activity than it does today. Larger and more numerous eruptions means that carbon dioxide is put into the atmosphere at a faster rate.

The carbon cycle is very important in the present day earth. It affects all of the spheres of the earth, from the atmosphere to the biosphere. In fact the carbon cycle plays a major part in keeping earth's climate stable. However when the earth froze over, the carbon cycle grinded to a halt. There was no more rain to take the carbon dioxide out of the atmosphere and into the geosphere. This allowed for the buildup of carbon dioxide in the atmosphere.

As more and more carbon dioxide was released into the atmosphere from volcanoes, earth gradually grew warmer. Once some areas of earth went above 0 degrees Celsius the ice began to melt. When the ice melted the carbon dioxide trapped inside of it was released also and this caused an even faster rate of warming. Why didn't this warming spin out of control? The answer also lies in the carbon cycle. When the carbon cycle was restored carbon from the atmosphere could be taken into the geosphere and this stabilized the temperature of earth.

It is evident that volcanoes and the carbon cycle played a huge part in helping earth get out of one of the most extensive ice ages it has ever experienced.