June 29, 2022

Photosynthesis tool for carbon sequestration

ST. LOUIS — Over the last decade, many pieces of U.S. climate and environmental policy have sought to make use of the climate change mitigation potential of carbon sequestration and carbon markets have been developed.

Some have criticized carbon capture and storage or sequestration as a false solution to the climate crisis, arguing that it would allow the industry to “green wash” itself by funding and engaging in, for example, tree planting campaigns without significantly cutting their carbon emissions.

Whatever the side of the fence one may be on, here are the nuts and bolts of carbon sequestration.

Carbon sequestration is the process of naturally capturing carbon dioxide from the atmosphere through biological, chemical, or physical processes. These changes can be accelerated through changes in land use and agricultural practices.

Carbon dioxide is absorbed by trees, plants and crops through photosynthesis and stored as carbon in biomass in tree trunks, branches, foliage and roots and soils.

Forests and stable grasslands are referred to as carbon sinks because they can store large amounts of carbon in their vegetation and root systems for long periods of time. Soils are the largest terrestrial sink for carbon on the planet.

The ability of agriculture lands to store or sequester carbon depends on several factors, including climate, soil type, type of crop or vegetation cover and management practices, according to the U.S. Environmental Protection Agency.

The amount of carbon stored in soil organic matter is influenced by the addition of carbon from dead plant material and carbon losses from respiration, the decomposition process and both natural and human disturbance of the soil.

By employing farming practices that involve minimal disturbance of the soil and encourage carbon sequestration, farmers may be able to slow or even reverse the loss of carbon from their fields.

“This issue from an environmental perspective is we’re taking oil and other kinds of fossil fuels out of the ground, we’re combusting them, and putting the carbon into the atmosphere. The concern is that that’s causing climate change,” said Brent Sohngen, a professor of environmental and resource economics in the Department of Agricultural, Environmental and Development Economics at Ohio State University.

Sohngen was a panelist in a recent American Soybean Association-sponsored webinar, Carbon and American Farms: Fad or long-term asset?

“The question is can we do anything to reduce the amount of carbon that goes into the atmosphere, and we know photosynthesis provides a great opportunity for that and what we’re doing on our farms and our forestland every day is basically photosynthesizing, at least in the summertime during the growing season,” Sohngen said.

“So, we can take some of that carbon out of the atmosphere and put it in agricultural soils or in trees, and other places like wetlands, grasslands, etcetera, on the farm. That then becomes a commodity.

“That becomes a commodity that you potentially can market to people on the demand side of this equation. That is people who are flying airplanes, people who are using the electricity to produce goods and services that society needs.

“This issue here is we have a potential for a new commodity in agriculture that can take carbon out of the atmosphere and that’s valued because there are people in society who want to reduce that carbon in the atmosphere.”

Tom Doran

Tom Doran

Field Editor