How Much Carbon Is Stored in a Tree?
A growing tree locks carbon into its wood. Model the trunk as a solid of revolution to estimate its volume, then work out how much carbon it's storing, and how that compares to a well-known offset claim.
Where this idea comes from
Start here — this is the source that inspired this exploration.
Introduction
A tree's trunk tapers from a wide base to a narrow tip. If you model the radius as a function of height and integrate, you get the trunk's volume, and volume, wood density and a fixed fraction for carbon content are enough to estimate how many kilograms of carbon a single tree has stored while it grew. This idea uses the same integration technique as measuring timber, but for a different question: what is the tree actually worth to the atmosphere?
Guiding Questions
- A tree trunk tapers. Model the radius as a function of height from measurements or photographs of a real tree.
- Integrate to find the trunk's volume, and compare it with a simple cylinder or cone estimate.
- Look up the density of the wood and the typical fraction of dry wood mass that is carbon. Convert your volume into an estimate of stored carbon.
- A company might claim planting one tree 'offsets' a certain amount of CO2. Using your estimate, is that claim realistic for a tree this size? What assumptions does it rely on?