and the importance of trees for the climate is an environmentally friendly search engine that aims to make the most sustainable impact possible through its daily searches. With a portion of the revenue generated by searches, the company has trees planted around the world. To this end, it commissions non-profit organizations that counter environmental problems such as deforestation by planting new trees and thus halting climate change. Among others, supports the Berlin-based company GrowMyTree, which has already planted more than 500,000 trees of various species. Each of the trees, consisting mostly of native varieties, is certified to ensure transparency of donations.

How significant are trees in the fight against climate change?

Global warming is progressing faster than we suspected. Our polar ice caps are melting and our forests are burning. We are in a climate emergency that threatens our planet. By 2100, experts say we are on track for an increase of between three and four degrees Celsius, though these are just global average temperatures. At the poles and on land, the rise may be higher, possibly even double. That's why we need to act quickly, because if temperatures rise, it can have devastating consequences.

The Intergovernmental Panel on Climate Change (IPCC) has warned that a rise in global temperatures of more than 1.5 degrees Celsius must be prevented. We have already exceeded one degree Celsius. Therefore, we must reduce our emissions and find a solution to limit the damage already done. The simplest solution and also the strongest weapon in the fight against climate change is trees.

Planting trees has enormous potential to restore damaged ecosystems and help achieve important conservation and climate goals.  Research from ETH Zurich in 2019 found that reforestation is one of the most effective strategies to combat climate change. Planting new trees could absorb about two-thirds of the CO₂ emissions harmful to the climate that we have caused so far.

What role does carbon dioxide play?

Carbon (also known as carbon dioxide, CO₂, or greenhouse gas) is one of the most abundant elements in our atmosphere and a major component of all living things. However, humans are drastically changing the carbon balance within Earth systems by altering the land and burning wood, oil, coal, and natural gas. Along with phasing out fossil fuels and expanding environmentally friendly renewable energy, trees can actually reduce the amount of carbon in the atmosphere. This makes tree planting, along with other measures such as maintaining existing forests or preserving wetlands, a significant biological measure in the fight against climate change.

Trees naturally store carbon

Not only are trees incredible plants that provide food, shelter, and medicine to animals and humans alike, they are also storing or sequestering carbon dioxide (CO₂) from the atmosphere, which occurs through the process of photosynthesis. Carbon sequestration occurs throughout the forest ecosystem, including living wood, roots, leaves, dead wood, surrounding soils, and associated vegetation. With the help of water and sunlight, trees convert CO₂ into sugar, which in turn promotes tree growth. The remaining oxygen is then released back into the atmosphere.

More than 400 tons of carbon can accumulate on a one-acre patch of forest planted with mixed native tree species, as well as on the roots and soil. Even when trees go through their natural life cycle until they die, the carbon is not fully returned to the atmosphere. As trees decompose, the soil around them absorbs some of the carbon, which is especially important for keeping soil healthy. Soils must remain in good condition to store carbon.

We can think of the greenhouse gases in our atmosphere as a landfill. The more humans emit or cause carbon, the larger the amount of landfill becomes. However, if humans emit less greenhouse gases, the garbage pile remains. For this reason, trees are extremely important in managing the effects of climate change. Each year, forests absorb about 2.6 billion tons of carbon dioxide. This is equivalent to about one-third of the CO₂ emissions released when fossil fuels are burned. It is estimated that nearly two billion hectares of degraded land around the world provide opportunities for restoring the devastated and deforested area, which is about the size of South America. Therefore, increasing and maintaining forests is an essential solution to climate change.

Reducing carbon takes a long time

Halting the loss and degradation of forest ecosystems and promoting their restoration has the potential to account for more than one-third of the total climate action needed by 2030 to meet the goals of the Paris Agreement, according to scientists. What happens around 2030 and beyond depends on the choices we make today. Trees take a long time to grow; as a result, they also take a long time to absorb much carbon. For example, a tree with a diameter of more than 75 cm can absorb over 400% more carbon each year than a tree with a diameter of less than 45 cm. Therefore, the size of the trees plays a big role in sequestering carbon. Different tree species also grow differently. Faster growing trees, such as some coniferous species, take up more carbon in the early years than other woody plants. However, these species die earlier than others. In comparison, slow-growing trees such as oaks take longer to store carbon. Over the years, they absorb more carbon for this purpose than fast-growing trees.

Trees offer more than just carbon storage.

Habitat destruction around the world through unchecked clearing of forests and changes in land uses is the main cause of biodiversity loss. Climate change only exacerbates this problem, so planting trees and forests, even on a small scale, can restore vital habitats for plants and animals and help address climate change and species extinction simultaneously.

As a result of climate change, the frequency of severe weather events such as flooding is increasing, the number of hot days with temperatures above 30 °C is increasing, and pollution and smog pollution are increasing. To avoid this, trees can make a significant contribution. They prevent flooding by intercepting rain.  In urban areas, the green space required for a tree provides a permeable surface that reduces runoff, and tree roots prevent water from soaking into the ground even faster. In addition, tree canopies provide shade, so air quality is improved and temperatures are more comfortable. Pollution from car exhaust and smog can be greatly reduced.

How important are trees for biodiversity?

Forests are not just full of carbon. They are also complex ecosystems rich in biodiversity and host a wealth of wildlife, from shade-loving plants and delicate fungi to nesting birds, a wide variety of mammals, and rare insects. Old growth forests, in particular, harbor more species than any other land-based habitat. The larger the range and number of these plants, fungi, microbes, and animal species, or the more species-rich an area is, the healthier an area's ecosystem is considered to be. This is because a more robust and complex habitat can provide the different conditions to meet the specific needs of a variety of species. Our forests are home to approximately 80 percent of all land-based plant and animal species in the world.

When a forest is destroyed by logging or natural disasters, this can also wipe out the incredible diversity of animals that live there. Even if a forest is restored, it will never be the same again. In some circumstances, it may take hundreds or even thousands of years for plants and animals to fully recover, if that ever happens. While old trees are strong and resilient, young trees are weaker and more vulnerable to stressors such as wildfires and drought disasters. In healthy forests, younger trees benefit from older trees by sharing water and nutrients through underground fungal networks. Young trees often do not survive if there are no older trees in their vicinity. Some forests harbor endangered species that are found nowhere else in the world. If a particular species goes extinct, there's no going back, no matter how many new forests we grow.

What happens to trees that have been newly planted?

Reforestation is not as simple as planting a thousand seedlings. On the contrary, it is an ongoing process that requires deliberate management. Young trees must be cared for after planting to ensure their survival. Without proper aftercare, the seedling survival rate may be very low. Therefore, instead of focusing on the number of trees planted, it is better to focus on the number of trees grown. In other words, how many seedlings actually survived and grew into trees?

Once the trees are fully grown, you can expect good progress. But the goal is still a long way off. What will happen to the trees in 10 or 20 years? Will they be cut down? Or will they still be standing? One study found that half of Costa Rica's regenerated forests were gone within 20 years. Another study found that in parts of Brazil, regenerated forests were generally cleared within five years. Therefore, it should be ensured that a permanent forest is grown, not just a temporary plantation that will be cut down in a few years. Once the forest has grown, it should be managed responsibly to ensure that it provides benefits to people, wildlife, and the environment. Ultimately, planting new trees or restoring forests is only one part of the fight against climate change. Protecting existing forests should be a top priority.