The emergency of climate change and global warming is forcing a drastic reduction of carbon dioxide (CO2) and other greenhouse gases produce by human activities. One way of reducing the concentration of CO2 is to store it in any medium other than the atmosphere. Due to this climate crisis, new innovative solutions to capture carbon have recently emerged, but unfortunately, these technologies are not economically feasible and are not easily deployed globally at large scale. Afforestation, the activity of creating new forests where there were none before has been studied as one of the most effective ways of carbon capture. In fact, it is estimated that as much as 18% of the carbon dioxide emitted through fossil fuel is absorbed by trees. Studies show that afforestation could store 18.06 billion tons of CO2, whereas if we consider reforestation in suitable areas, this activity could store 205 billion tons of carbon. Contrarily, the activity of deforestation and changes in land-use currently accounts for around 13% of world CO2 emissions, and if this activity was a forest, it would rank 3rd in carbon emissions, just below China and The United States.
Recently, there has been some controversy around the actual potential of trees to offset human carbon emissions, especially regarding costs, land, benefits, and actual capacity of carbon reduction.
How many trees do I need to plant?
There are a lot of organisations and companies offering to plant trees to reduce emissions. But in reality, trees take a long time to grow and capture emissions. Even if you plant a tree now, a small seedling would be able to absorb only 3 to 5kg the first year. In 50 years, an average to small tree can absorb as much as 500kg of CO2.
To get an order of magnitude, we would need to plant 12 trillion trees NOW to offset current worldwide emissions. This equals to covering Europe completely with trees, or half of Russia. This is just below the available area the world has right now for reforestation.
If you take a round-trip to New York by plane, you would need to plant 4 trees so you can offset your emissions in 50 years, If you want to offset your emissions in one year, you would need to plant around 194 small trees.
Doing the maths
Let’s say you want to become carbon neutral by planting trees and you have a carbon footprint of 7 tonnes a year. Over a 10-year period, you would have emitted 70 tonnes of CO2. One tree in 10 years, can accumulate around 110kg of CO2.
This mean, that in order to become “carbon neutral” 10 years from now, you would need to plant 636 trees NOW.
If you want to plant trees monthly through an organisation, and considering the time it takes trees to grow each month, you would need to plant around 6 to 7 trees each month to become “carbon neutral” in ten years. Afterwards, you will become heavily carbon negative as your forest continues to grow and remove more and more CO2. This is considering the tree is not cut down or burned, and continues to lives for a long time.
Planting trees is good for the environment, as the biggest plants on the planet, they give us oxygen, store carbon, stabilise the soil and give life to the world's wildlife. However, planting trees is not the ultimate solution to reducing our emissions. They take long time to grow, and if the tree is cut down or burned the CO2 would eventually go back to the atmosphere. Consider planting trees as another alternative to reduce emissions, coupled with behaviour change and using environmentally friendly services and products