Mystery of charcoal's fate uncovered

Apr 19, 2013, 11:17 ET from Florida International University

MIAMI, April 19, 2013 /PRNewswire-USNewswire/ -- An team of researchers, led by Florida International University Chemistry Professor Rudolf Jaffe and Thorsten Dittmar of the German Max Planck Society, has uncovered one of nature's long-kept secrets — the true fate of charcoal in the world's soils.

Knowing the fate of charcoal is critical in helping scientists balance the global carbon budget, which can help understand and mitigate climate change. However, until now, scientists only had scientific guesses as to what happens to charcoal once it's incorporated into soil. Most were wrong.

"Most scientists thought charcoal was resistant. They thought, once it's incorporated into the soils, it would stay there," Jaffe said. "But if that were the case, the soils would be black."

Charcoal, or black carbon, is a residue generated by combustion including wild fires and burning of fossil fuels. When charcoal forms, it is typically deposited into the soil.

"From a chemical perspective, no one really thought charcoal would dissolve, but it does," Jaffe said. "It doesn't accumulate as well as we had believed for a long time. Rather, it is exported into wetlands and rivers, eventually making its way to the oceans."

The findings are outlined in the paper "Global Charcoal Mobilization from Soils via Dissolution and Riverine Transport to the Oceans," recently published in the journal Science. For Jaffe, who has built a career studying the environmental chemistry of the Everglades, it all started with a strange finding in the river of grass.

Dissolved organic carbon is known to be abundant in wetlands, including the Everglades, and plays a critical role in the ecology of these systems. When Jaffe discovered as much as 20 percent of the total dissolved organic carbon in the Everglades is charcoal, he wanted to find the origin. 

At the same time, Dittmar was tracing the paths of charcoal, only from an oceanography perspective. To map out a more comprehensive picture, the research teams joined forces, along with others. They concluded that charcoal is making its way to the world's waters.

Jaffe and Dittmar agree that there are still many unknowns when it comes to the environmental fate of charcoal. Jaffe said the better scientists can understand the process and the environmental factors controlling it, the better chance they have of developing strategies for carbon sequestration.

Contact: JoAnn Adkins 

SOURCE Florida International University