How Wildfires Trap Carbon for Centuries to Millennia

Charcoal produced by wildfires could trap carbon for hundreds of years and help mitigate climate change. (Image: via   pixabay  /  CC0 1.0)
Charcoal produced by wildfires could trap carbon for hundreds of years and help mitigate climate change. (Image: via pixabay / CC0 1.0)

Charcoal produced by wildfires could trap carbon for hundreds of years and help mitigate climate change, according to new research just published. The extensive and unprecedented outbreak of wildfires in the arctic and the vast amounts of CO2 they are emitting have been hitting the headlines across the world.

But a new Nature Geoscience study quantifies the important role that charcoal plays in helping to compensate for carbon emissions from fires. And the research team say that this charcoal could effectively “lock away” a considerable amount of carbon for years to come.

In an average year, wildfires around the world burn an area equivalent to the size of India and emit more carbon dioxide to the atmosphere than global road, rail, shipping, and air transport combined. As vegetation in burned areas regrows, it draws CO2 back out of the atmosphere through photosynthesis.

This is part of the normal fire-recovery cycle, which can take less than a year in grasslands or decades in fire-adapted forests. In extreme cases, such as arctic or tropical peatlands, full recovery may not occur for centuries. This recovery of vegetation is important because carbon that is not recaptured stays in the atmosphere and contributes to climate change.

Deforestation fires are a particularly important contributor to climate change, as these result in a long-term loss of carbon to the atmosphere. Now, a new study by researchers at Swansea University and Vrije Universiteit Amsterdam has quantified the important role that charcoal created by fires — known as pyrogenic carbon — plays in helping to compensate for carbon emissions.

Lead author Dr. Matthew Jones, who recently joined the UEA’s School of Environmental Sciences from Swansea University, said:

The paper, which was co-authored by Dr. Cristina Santin and Prof. Stefan Doerr, from Swansea University, and Prof. Guido van der Werf, of Vrije Universiteit Amsterdam, explained that, as well as emitting CO2 to the atmosphere, landscape fires also transfer a significant fraction of affected vegetation carbon to charcoal and other charred materials.

The researchers say this pyrogenic carbon needs to be considered in global fire emission models. Dr. Jones said:

There are still important questions to be answered about how a warmer, more drought-prone climate will affect the global extent of wildfires in the future. For example, will there be more fire in arctic peatlands as we are experiencing this summer, and what proportion of CO2 emissions will be recaptured by future vegetation regrowth?

But this new research shows that pyrogenic carbon production should be considered as a significant product of fires and an important element of the global carbon cycle. Global fire emissions buffered by the production of pyrogenic carbon is published in the journal Nature Geoscience.

Provided by: University of East Anglia [Note: Materials may be edited for content and length.]

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