Fossil carbon produced by fires and the retreat of glaciers has been discovered for the first time at depths never before seen. The discovery was part of the work of Erika Marin-Spiotta, a University of Wisconsin-Madison assistant professor of geography, and Joseph Mason, Professor of geography at the University of Wisconsin-Madison. The research was published in the May 25, 2014, edition of the journal Nature Geoscience.
The newly found layer of fossil carbon is as deep as 21 feet below the surface of a large part of the Great Plains of the United States called the Brady soil. The carbon is the result of large fires that resulted from climate change between 10,000 years ago and 13,000 years ago when the glaciers began retreating in North America. The carbon was quickly covered by dust and debris called loess. The researchers found free carbon and organic matter from ancient plants. The loess covered the plants so quickly that ancient organic matter was preserved.
The discovery presented a new understanding of the history of the Earth and presents a new potential source of carbon pollution. The U. S. Great Plains is just one of a huge number of similar carbon reserves that lie deep in the Earth. The researchers expect that the continued activities of man will eventually reach the carbon stored in the deep layers of the Earth’s soil. At present the carbon stored in areas like the Brady soil provides protection for the Earth’s atmosphere.
Inevitably, and probably in the near future, the vast carbon storage in the deep soil of the Earth will be exposed to oxygen by man’s activities. The exposure of carbon to the atmosphere would produce an increase in carbon dioxide and small-particle carbon pollution commonly called soot. Hundreds of thousands of acres of carbon-rich soil will potentially become a new source of global temperature increase.