How much CO2 does one tree absorb?

Well, that depends! Not the answer you were hoping for when clicking on this blog, right? But don’t worry—we’re here to break it down so that the next time someone asks, “How much CO2 does one tree absorb?” you’ll have all the facts and might just look like the smartest person in the room.

In simple terms, think of trees like humans. Just as we all have different personalities and abilities, different tree species have unique attributes that affect how much CO2 they can absorb.

For example, over their lifetimes:

- 1 mangrove tree stores 12.3kg of CO2e per year over its lifetime ( that’s 600kg for 50 years )

- 1 oak tree stores 25kg of CO2e per year over its lifetime ( that’s 4,964.35kg over 200 years

- 1 red maple stores 15.01kg of CO2e per year ( that’s 901kg over 60 years )

Source: Life cycle assessment of a field-grown Red Maple tree to estimate its carbon footprint components, Page 8

As you can see, the numbers vary quite a bit. In this blog, we’ll explore how trees emit CO2, why absorption rates differ, and what factors impact how much CO2 each tree can absorb. And don’t worry, we’ll stop comparing trees to humans now!

So, how do trees actually absorb CO2?

Trees absorb carbon dioxide through photosynthesis, a process that gives them energy and helps them grow. During photosynthesis, trees take in carbon dioxide, water, and sunlight, then produce oxygen and glucose. The glucose provides the energy they need to grow, while the carbon becomes part of the tree’s structure—its trunk, branches, and roots—where it’s stored as the tree develops. This process of capturing carbon dioxide from the atmosphere and storing it in solid materials like wood is called carbon sequestration.

Source: Bill Munger, Harvard University, ‘Are Forests Helping in the Fight Against Climate Change’

However, the amount of carbon absorbed by each tree species varies greatly depending on several factors.

What factors influence the absorption of CO2?

The capacity of an individual tree to absorb CO2 over its lifetime depends on:

- Age of the tree: young trees absorb CO2 more quickly as they grow, since they photosynthesise at higher rates to generate the energy they need. As they mature, the rate of absorption slows down (we’ll resist making a human ageing joke here!).

Once the absorption rate slows down, the trees absorb less carbon, and become known as carbon stocks, where they hold carbon dioxide, which is typical in more mature, older forests.

Source: NCASI, Forest Carbon from Young vs Old Forests

- Tree species: different species have varying capacities for CO2 absorption. For example, fast-growing species like eucalyptus and mangroves can absorb more CO2 in their early years compared to slower-growing species like oaks and pines.

- Size and health: larger and healthier trees with extensive leaf cover can absorb more CO2, as they have a greater amount of chlorophyll, a substance found in leaves that facilitates the photosynthesis process. Trees in optimal health, free from disease and stress, are also more efficient at photosynthesis and carbon sequestration.

- Growing conditions: trees growing in favourable conditions with adequate sunlight, water, and nutrients will absorb more CO2 compared to those in suboptimal environments. This is because they can grow at their maximum rate, allowing them to reach peak maturity.

- Wider ecosystem: planting the right trees in the right environment can significantly enhance carbon absorption. For example, mangrove trees, when planted in their native coastal areas, have been shown to have enhanced carbon sequestration capacities, as the trees and surrounding soil work together to store more carbon. Additionally, more diverse forests—those with a variety of different tree species—tend to absorb even more carbon. In fact, diverse mangrove forests were found to have nearly 20 % higher carbon stocks than those with less species diversity!

How do we measure a tree’s absorption of CO2 over time?

Measuring CO2 absorption is more straightforward than you might think! The most common method involves assessing the tree’s mass—approximately half the weight of the tree is made up of carbon . For living trees, this can be estimated by measuring the circumference of the tree! From there, you can calculate the approximate amount of carbon a tree has absorbed over its lifetime.

Interestingly, carbon dioxide is stored in different parts of the tree. The ‘above-ground’ carbon, which includes the trunk, branches, and leaves, makes up the majority. However, don’t overlook the roots—they also hold a significant amount of carbon! As trees grow, their rates of carbon absorption and storage change, underscoring the importance of allowing them to reach full maturity.

When measuring a tree’s carbon absorption rate, it’s crucial to consider its location and surrounding environment. Trees tend to be more effective at sequestering carbon when they’re planted in larger wooded areas, where they work in harmony with the wider ecosystem. That’s why we often calculate CO2 absorption at larger scales; it gives us a more accurate picture of carbon absorption in action.

If you’d like to learn more about CO2 absorption in trees, we recommend reading more about the UK’s Woodland Carbon Code , which gives more detail on how we record and monitor CO2 absorption by trees in the UK.

Treeapp’s Commitment to Reforestation

At Treeapp, we recognise the vital role trees play in combating climate change. We understand the significance of planting the right trees in the right places and nurturing them to grow into healthy forests and woodlands. Our mission is to make reforestation accessible to everyone, empowering individuals and businesses to plant trees and contribute to a healthier planet.

For individuals, our user-friendly app allows you to support tree planting simply by watching an ad. Users can then track their impact, and witness the positive environmental difference they’re making by viewing project updates, images and videos from sites.

For businesses, Treeapp collaborates directly with organisations to integrate tree planting into their offerings. Whether it’s trees planted for each product sold, new contracts, corporate gifts, or establishing a private forest, we help businesses create a meaningful impact.

Utilising allometric equations, field data, and established academic sources, we estimate the total carbon sequestration potential of our forests over their lifespan. These calculations allow us to derive average impact metrics for individual tree planting, which we share with our app users and business partners. This conservative approach ensures that we accurately communicate the environmental impact of our initiatives to our stakeholders.

How You Can Help

- Support tree planting with Treeapp: Use our app to support our global reforestation projects. Each tree you support contributes to carbon sequestration and builds biodiversity.

- Spread awareness: Educate your community about the importance of trees in absorbing CO2 and fighting climate change. Encourage others to join the Treeapp movement.

- Support sustainable practices: Adopt eco-friendly practices in your daily life. Reducing your carbon footprint complements the positive impact of tree planting.

- Engage your business: Companies can partner with Treeapp to incorporate tree planting into their corporate social responsibility (CSR) initiatives and showcase the brand’s commitment to sustainability.

Conclusion

Trees are indispensable in our fight against climate change, capable of absorbing significant amounts of CO2 over their lifetimes. They provide a low-cost and effective way to sequester carbon emissions, as well as providing a whole host of other environmental benefits. By understanding their role and taking action through platforms like Treeapp, we can collectively make a substantial difference. Start planting today and be a part of the solution for a greener, healthier planet.

Download Treeapp and start your reforestation journey today!

Appendix

- 1 oak tree can absorb approximately 25kg of CO2 per year over its lifetime.

- 1 mangrove tree can absorb 12.3kg of CO2 per year over its lifetime.

- 1 spruce tree can absorb approximately 20.1kg of CO2 per year over its lifetime

- 1 red maple can absorb around 3kg of CO2 per year during its first four years of growth.

- 1 hectare of eucalyptus trees can absorb 37 tons of CO2 per year during its first 20 years.