COP21 and “4 per thousand” – Storing Carbon in the Soil.
“Let us start with the analogy of a football field (Soccer, not rugby!). Imagine it is a fifth larger than normal – making it one hectare in size. The top layer of soil on the field, 30 cm deep, is known as the topsoil.
“Carbon is the main ingredient of organic matter, so organic matter is often referred to as ‘soil organic carbon’. In Australian soils, this organic matter makes up on average, between 1 and 3 percent of the topsoil. For the purpose of the exercise, we will assume that the topsoil on the football field contains 1.5 percent carbon. This equates to 58 tonnes of carbon in the topsoil across the whole football field.What the French Government is calling for is to increase that 58 tonnes by 0.4 percent per annum – in our imaginary football field that would equate to an increase of 0.2 tonnes (or 200 kg) of carbon in the topsoil each year.”
