We have 29 years to get to zero carbon, and we need the trees.
Here’s a bit of CO2 focused ‘Dendrology’* for anyone who (like me) loves trees and the idea of tree planting, but is keen to understand a bit more about how it all works.
-Trees absorb carbon at different rates as they grow, starting when they are about 1 yr old and levelling off when they are fully grown, at 30 – 40 yrs old.
-Trees are approximately 50 % carbon.
-Carbon moves continually between the atmosphere and trees, litter (fallen leaves, dead twigs etc.), soil and harvested wood products.
-There is usually more carbon held in the soil and litter than in trees.
-Broadleaved trees (trees with flat leaves) make themselves with more carbon than conifers (trees with needles).
-Silvicultural practices - the ways in which we care for forests, for instance what type of thinning regime is used - effect the amount of carbon trees store.
-The amount of carbon a tree stores is its ‘C’ stock. This is a different thing from the amount of carbon it is actively taking in at any point in its life.
-Carbon stored in a tree can be entirely released at the end of its life – if it is used for fuel for instance, or stored indefinitely – for instance if it is used for construction.
-Maintaining high CO2 uptake rates in the long term depends on rapid establishment of trees, the right type of tree management and harvesting trees at appropriate ages.
It it good to understand this stuff, but my own language here, speaking of trees as resource, tool, and means to an end, bothers me.
Graph to show sequestration of carbon at different ages