Carbon Sequestration – The Basics

Carbon sequestration describes the process in which carbon dioxide (CO₂) is removed from the atmosphere and subsequently stored through biological, chemical, or physical processes.

In the case of woodland creation, trees use solar energy to convert CO₂ and water into carbohydrates and oxygen through photosynthesis. These carbohydrates form the building blocks for the biomass of the tree and, therefore, the storage of carbon.

One often forgotten caveat is that trees not only photosynthesise but respire also. Through this process, trees convert some of these carbohydrates and oxygen back into CO₂, water, and energy.

As trees grow, the process of photosynthesis dominates that of respiration, sequestering carbon. Once they reach maturity, however, these processes are pretty much in equilibrium. Subsequently, the trees are emitting as much CO₂ as they are sequestering.

This balance between photosynthesis and respiration is embedded in the Woodland Carbon Code’s carbon calculator. It’s forecast for a standard woodland’s sequestration schedule over 100 years (see chart 1 ) shows that CO₂ removals peak between years’ 16 and 25 of a tree’s life. Thereafter, they gradually decline so that, by year 100, they are approaching equilibrium.