How to handle the sequestration (=capture and storage) of CO2 in wood?
Sequestration of CO2 in wood is a confusing subject. Examples in LCA may lead to a better understanding of the issue. 1. The life cycle of a tree. When you plant a tree, it will grow and capture CO2. However, at the End of Life, the tree will gradually decay and emit the same amount of CO2 by oxidation. This process of decay is often speeded up by aerobic bacteria. Therefore, planting trees as such does not work against long term climate change. When the decay is caused by anaerobic bacteria, CH4 is emitted, which makes the situation much worse since CH4 is about 20 times more harmful for our climate then CO2. However, when the tree is burned in a electrical power plant or used for bio fuels, the situation is different: fossil fuels are replaced by wood in a closed loop system. In LCA’s for products made out of wood, like paper, confusion may be caused by the fact that there are two approaches in LCA on the capture of CO2 in wood: – the classical approach, followed in IDEMAT and still
