Glasgow Science Festival - Measure a Tree Activity
How much carbon is in a tree?
Scientists measure trees using lasers, to estimate how much carbon they have absorbed from the atmosphere. Here is how you can measure a tree without any fancy equipment.
You will need:
- a tape measure,
- pen and paper,
- and a calculator
Step 1 - Find a Tree
Step 2 - Get to know your tree
- Where is your tree? Note a description that you will remember, or try a GPS app such as What3Words on your phone.
- What environment does your tree live in? E.g. street, woodland, field, river-bank, hillside… flat or steep terrain.
- What species does your tree belong to? If you aren’t sure, try out the Woodland Trust’s identification app https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/tree-id-app/
- How would you describe the shape of the tree? Are there any unusual features? Are there any signs of missing branches or other damage?
- How tall would you guess the tree is?
Step 3 - Give your tree a hug
Step 4 - Measure the height
- Fold your piece of paper at the corner to make a 45 degree angle.
- Face the tree and hold the paper up so that the bottom edge is horizontal, and one of your eyes is looking directly along the 45 degree edge.
- Adjust your position until your view aligns with the top of the tree. Now, use your measuring tape to measure the distance from where you are standing to the base of the tree.
- Finally, add on the height of your eye from the ground, and you will have the height of the tree. Was your estimate in step 2 close?
Step 5 - Calculate the Carbon
- Carbon – kilograms of carbon in your tree.
- 0.0537 – this factor takes into account the geometry of a tree and how much carbon is contained in wood. See the “how does it work?” section below to learn more.
- Density – the wood density in kg per cubic metre. The denser the wood, the more carbon it will contain. This depends on the tree species – use the table to find your tree’s wood density, or use a rough value of 600.
- Height – as you measured it in metres.
- Circumference – as you measured it in metres. Remember to square this value.
So, how much carbon is that?
How does it work?
The bottom line