What is Carbon sequestration?
What is carbon sequestration and how does it work?
To sequester something is to secure something for the future. The word ‘sequester’ derives from the Latin ‘sequestrare’ (“to hand over to a trustee”). Therefore, carbon sequestration is the securing or storing of carbon, especially in the form of carbon dioxide (the most common greenhouse gas), by preventing it from entering the earth’s atmosphere. It is sequestered by stabilising it in either solid or dissolved forms with the goal of reducing carbon dioxide’s warming effect on planet Earth.
Types of carbon sequestration
There are said to be three main ways to sequester carbon:
- Biological, which is the storage of carbon dioxide in biological-based ‘carbon sinks’ including plants (vegetation), soils and water bodies. This is the form of carbon sequestration that Carbon Sync’s carbon farming projects are based around.
- Geological, which is the storage of carbon dioxide underground in rocks. This typically involves capturing the carbon dioxide from an industrial source and injecting it into porous rocks for long-term storage.
- Technological, which is another emerging area of sequestration. Scientists and researchers are trying to find new ways to capture carbon dioxide from the atmosphere using innovative technologies.
Along with emissions reduction, carbon sequestration is a principle of carbon farming and forms part of the schemes that have been developed and are regulated by the Australian Government’s Clean Energy Regulator.
The soil carbon sequestration process
This process occurs in three stages:
- Removal of carbon dioxide from the atmosphere via photosynthesis. This is the process used by plants, which converts light from the sun into energy. Carbon dioxide is used by plants as a primary reactant in this chemical process.
- Carbon dioxide is then transformed by plants, along with water, into oxygen and carbohydrates that feed the plants’ growth. Excess carbohydrates and organic compounds produced via this process are excreted by the plants through their roots, feeding the soil.
- Carbon is stored in the soil in a stable form known as soil organic carbon, which has been created through the interaction of plants and microorganisms (microbial biomass). In plants, carbon is stored in the plant itself, either above ground in the trunk and leaves, or below ground in the roots and the soils surrounding them. Under the right conditions, plants can store a significant amount of carbon within their own biomass, as well as transferring carbon into the soil around them.