Massive Amounts of Charcoal Deposited in the Oceans: New Implications for Carbon Sequestration

Wildfires may not just burn down trees; they also may be affecting our oceans to a large extent. Researchers have found that the fires that turn millions of acres into charcoal each year are having a lasting impact on our world's oceans.

The carbon cycle is important for researchers to fully understand. This biogeochemical cycle, by which carbon is exchanged throughout Earth, can allow scientists to understand exactly how it may be affecting climate change as more carbon dioxide is released into our atmosphere. Since the carbon cycle is completely interconnected, something that happens in the oceans could affect landmasses--and vice versa.

"To understand the oceans we have to understand also the processes on the land, from where the organic load enters the sea," said Throsten Dittmar from the Max Planck Institute for Marine Microbiology in a press release.

In order to better understand this cycle, the researchers analyzed 174 water samples from all over the world, including from rivers like the Amazon, the Congo, the Yangtze and even from the Arctic. After examining the samples, they found that rivers from all across the world contained about 10 percent of organic carbon dissolved in the water came from charcoal. They then estimated the global flux of this dissolved charcoal based on previous scientific studies; they found that, surprisingly, about 25 million tons of dissolved charcoal is transported from land to the sea each year--that's a huge impact on the carbon cycle.

The surprising thing is that scientists didn't always realize how much charcoal could enter waterways. "Most scientists thought charcoal was resistant. They thought, once it is incorporated into the soils, it would stay there," said Rudolf Jaffé from Florida International University's Southeast Environmental Research Center in Miami, in an interview with Science Codex. "But if that were the case, the soils would be black."

In fact, these findings could have a huge impact on carbon sequestration, the process of taking carbon out of the atmosphere and storing it. One technique involves the addition of biochar to soils. Biochar technology is actually based on vegetation-derived charcoal that is added to agricultural soils as a means to store carbon. Although biochar may seem promising, it also has the potential to dissolve and make its way to the sea--as this study showed.

There are still many factors to take into consideration when it comes to the environmental fate of charcoal, but the researchers are moving forward. The scientists plan to examine how charcoal moves through the carbon cycle and what the environmental consequences are. The findings could lead to a better understanding of carbon and could allow researchers to develop better and more environmentally-friendly techniques for carbon sequestration.

The findings are published in the journal Science.