How much carbon do trees store?
Plant 1, 10 or 100 trees and let them grow for 1 to 20 years. Find how much carbon dioxide they take from the air, and how many kilometres a car could drive to give out the same amount.
Core concept
Trees take carbon dioxide from the air by photosynthesis and store the carbon in their wood: a grown tree takes about 21 kg of CO₂ a year, while a car gives out about 0.17 kg every kilometre
Topic: Our planet and sky
In photosynthesis: How green plants make their own food from light, water and carbon dioxide. All key words, leaves take carbon dioxide: A gas we breathe out. Plants take it in to make their food. All key words from the air and water from the soil and, using sunlight, make sugar; the carbon ends up in the tree's wood, roots and leaves. A grown tree takes in roughly 21 kg of CO₂ a year, more for big fast-growing trees and less for young ones. Burning petrol does the opposite: an average car gives out about 0.17 kg of CO₂ every kilometre. Carbon dioxide is a greenhouse gas that warms the planet, so comparing the two shows how much planting trees can help, and how much more it helps to burn less fuel.
What you will learn
- Explain how trees take carbon dioxide out of the air.
- Work out the CO₂ taken in by a number of trees over some years.
- Compare it with the CO₂ from driving a car.
Before you start
- Know the word equation for photosynthesis.
Materials
- None
Equipment
- None
Procedure
- Record 10 trees for 10 years.
- Record 1 tree for 1 year.
- Record 100 trees for 20 years.
How this simulation is simplified
- A grown tree takes in about 21 kg of CO₂ a year (an average; it varies with species, age and climate).
- An average car gives out about 0.17 kg of CO₂ per kilometre.