The Carbon Cycle
Carbon is the backbone of life on earth. We are made of carbon, we eat carbon, and our civilisations – our economies, our homes, our means of transport – are built on carbon.
We need carbon, but that need is also entwined with one of the most serious problems facing us today: climate change.
The Natural cycle
Carbon is in a constant state of movement from place to place.
It is stored in ‘reservoirs’, and it moves between these reservoirs through a variety of processes, including photosynthesis, burning fossil fuels, and simply releasing breath from the lungs. This movement of carbon from reservoir to reservoir is known as ‘the carbon cycle’.
Because the earth is a closed system, the amount of carbon on the planet never changes. However, the amount of carbon in a specific reservoir can change over time as carbon moves from one reservoir to another.
The impact of humans
The carbon cycle is vital to life on earth.
Nature tends to keep carbon levels balanced, meaning the amount of carbon naturally released from reservoirs is equal to the amount that is naturally absorbed by reservoirs.
Maintaining this carbon balance allows the planet to remain hospitable for life.
Scientists believe that humans have upset this balance by burning fossil fuels, which has added more carbon to the atmosphere and increased the rate of climate change and global warming.
Trees are the most efficient carbon-capture machines on the planet.
During photosynthesis, trees and plants ‘sequester’, or absorb, carbon from the atmosphere in the form of carbon dioxide (CO2), and turn it into energy. That energy creates new leaves, longer stems and more mass – locking away carbon.
See Why Trees? for more information on the role trees play in the fight against climate change and biodiversity loss.