WATCH: We know what carbon is, but what is carbon sequestration?

Carbon capture and storage (CCS) discussions and plans in South Africa have been around since as early as 2004, says the writer. Picture: Gerd Altmann/Pixabay

Carbon capture and storage (CCS) discussions and plans in South Africa have been around since as early as 2004, says the writer. Picture: Gerd Altmann/Pixabay

Published Jan 15, 2022

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What is Carbon Sequestration?

Several countries have begun employing numerous methods and solutions to help mitigate the impacts of climate change with some even hoping to reverse it entirely.

The World Bank shared 5 ways to reduce the drivers of climate change, including putting a price on carbon emissions, ending fossil fuel subsidies, building low-carbon, sustainable, resilient cities, increasing energy efficiency and use of renewable energy and implementing climate-smart agriculture and nurturing forest landscapes.

There is just too much carbon dioxide in the atmosphere. Most of this carbon dioxide came from burning fossil fuels. How do we get it back into the ground? Carbon sequestration.

We know what carbon is, but what is carbon sequestration? The United States Geological Society defines carbon sequestration as “the process of capturing and storing atmospheric carbon dioxide.

It is one method of reducing the amount of carbon dioxide in the atmosphere to reduce global climate change.”

There are two types, biological sequestration and geologic sequestration.

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Geologic carbon sequestration is the process of storing carbon dioxide (CO2) in underground geologic formations. The CO2 is usually pressurised until it becomes a liquid, and then it is injected into porous rock formations in geologic basins.

Biologic carbon sequestration refers to the storage of atmospheric carbon in vegetation, soils, trees, and aquatic environments.

By encouraging the conservation and planting of vegetation, particularly larger plants and trees, advocates of biologic sequestration hope to help remove CO2 from the atmosphere.

This method is much slower than geologic sequestration as it takes time for a plant or tree to grow to a size where it can absorb significant amounts of carbon dioxide.

Carbon capture and storage (CCS) discussions and plans in South Africa have been around since as early as 2004 with the Department of Minerals and Energy requesting that the Centre for Scientific and Industrial Research (CSIR) to explore the potential carbon storage capabilities of South Africa.

The CSIR found that around 60% of the country’s annual carbon emissions were sequestrable.

Carbon Collect Limited, an Irish company based in Dublin, specialises in the development of carbon sequestration and storage technologies.

The company has developed a mechanical “tree” that can capture carbon dioxide directly from the air, just like a real tree, and store this carbon underground.

According to the company’s website, “the mechanical tree can be deployed for the capture of current and

historical emissions for permanent removal via sequestration. Installed onsite, it can provide a source of green CO2 for a range of uses in food and beverages, industrial applications, construction and agriculture, replacing CO2 manufactured from fossil fuels, and eliminating transport and logistics.”

Direct air capture is the practice of separating CO2 from ambient air. This occurs typically through chemical or physical separation, allowing the greenhouse gas to be captured and purified for use as an industrial gas or safely sequestered in underground geological formations, thereby removing the CO2 permanently from the atmosphere.