What is afforestation and reforestation?

In the second in our series ‘Powering to net zero’, we look at how planting more trees could help limit climate change.

At its simplest level, reforestation is the technical term that describes the process of planting new native trees in a wooded area where the number of trees is going down. It literally means ‘re-foresting’ a location.

Afforestation is what professionals call it when they create a new area of forest — by planting trees or sowing seeds where there were no trees before.

Why do reforestation and afforestation matter so much?

They’re what’s known as natural climate solutions (NCS) and are two of the most important things we can do to tackle climate change.

And for people who grow trees commercially, they can both play a vital part in making sure they’re always growing more than enough wood to satisfy the demand for sustainable wood products industries.

Reforestation is one challenge to deforestation. Deforestation not only reduces the ability of a forest to absorb carbon dioxide (CO2), but it can also destroy vital habitats for wildlife.

Afforestation is one of the ways we can avoid fertile land becoming desertified due to lack of water or intensive farming. So both are vitally important for the future of our planet.

Forests not only combat the climate crisis — but the biodiversity crisis too.

How can reforestation and afforestation affect climate change?

The more trees there are, the more CO2 they can capture and turn into oxygen as they grow. So forests can help keep a lid on the amount of greenhouse gases in the atmosphere. This in turn can help to mitigate the effects of climate change.

And the more reforestation and afforestation there is, the more help forests can give to the planet.

However it’s not quite as simple as the forest with the most trees absorbing the most CO2. Different kinds of forests absorb carbon dioxide at different rates — as do dissimilar tree species in contrasting parts of the world.

In fact, the age of trees can make a huge difference as to how much CO2 they absorb. For example, a forest made up of young trees which are growing quickly can absorb CO2 much more quickly than older, mature trees which have already absorbed a great deal of carbon.

How does reforestation work in commercial forestry?

Commercial forestry depends on creating what are called ‘working forests’. The families or businesses who own the land will invest in growing their working forest until the trees reach the stage where some or all of them can be harvested for their wood. Once this wood and its residues have been sold — for use in furniture or for timber for building materials for instance — then more trees will be planted in the cleared areas. In short, they will be reforested. This is how the wood products industry around the world makes sure its resources are sustainable.

The most common way for working forests to be worked is for landowners to harvest — and reforest — different parts of their holdings at different times, so that they can be certain that they are always benefiting from sustainable and consistent growth.

The facts about reforestation and afforestation

• We believe the world record for afforestation was set in July 2019, when more than 353 million trees were planted in just 12 hours.

· An area the size of China and the United States combined exists on earth where 1.2 trillion native tree saplings could naturally grow.

· If we increased the amount of the planet covered by forest by one quarter, the extra trees could absorb 200 gigatonnes more CO2 from the atmosphere.

· Healthy forest landscapes can generate negative emissions. Discover more about NCS techniques as well as carbon removal technologies at the Coalition for Negative Emissions.