Nature’s Carbon Capture: Understanding Trees’ Role in Climate Change
By Rose Morrison, managing editor of Renovated.
The motto “save the trees” is a hallmark of the environmentalist movement. While the phrase is undeniably memorable and states a noble goal, it’s not the most accurate picture of effective climate activism. Trees do need saving, but they may also return the favor — in the end, trees will help save humanity.
While important, technological improvements like renewable energy and vehicle electrification are not the only sustainable resources at the world’s disposal. It’s just as critical to recognize the natural tools the earth already uses to ensure a livable climate. The humble tree can play a significant role in the fight against climate change.
Trees’ Influence on Climate Change: How Trees Drive Sustainability
Trees are more than a mere source of shade and shelter. They can help regulate their surrounding environment in several ways that benefit broader sustainability initiatives.
1. Carbon Sequestration
The most obvious environmental advantage of trees is one they share with all plants — photosynthesis. Plantlife “breathes” the opposite way animals do, taking in carbon dioxide and releasing oxygen into the atmosphere. Consequently, they contain carbon naturally, removing greenhouse gases from the air to offset some emissions.
A hectare of forest can remove up to 40.7 tons of CO2 per year. That rate can vary widely, though, depending on the local ecosystem and the types of trees in question. For example, pines remove more carbon in a humid but temperate environment than in a dry one, while eucalyptus is most effective in tropical settings, whether dry or humid.
Similarly, trees’ carbon absorption rates vary as they age. Across all categories, though, trees can remove a significant amount of greenhouse gases from the atmosphere. It’s not enough to offset unabated fossil fuel consumption, but it could increase the impact of renewable energy and other carbon reduction methods.
2. Soil Preservation
Apart from photosynthesis, trees benefit their surroundings by strengthening the soil. All ground plants have roots, but trees’ root systems are extensive and robust, which helps keep the soil together and absorb moisture at a higher rate. These natural processes, in turn, stave off erosion.
Without this added strength, topsoil loses key nutrients and its structure. As a result, landslides become more common, which can endanger wildlife and pollute nearby waterways. Erosion also eliminates farmable land and promotes flooding, but a larger tree population can prevent these events.
A forested streambank prevents two to eight times more nitrogen from entering the water than an area without trees. Diverse plant life offers even greater benefits. It’s worth noting that trees alone do not eliminate the risk of runoff and topsoil degradation, but their impact is substantial enough to be a core part of preventive strategies.
3. Temperature Regulation
Trees have essential aboveground functions in the environment, too. They also keep areas cool, which is becoming increasingly important in a warming climate. Addressing the core causes of these temperature rises is the most crucial work, but trees can mitigate the effects in the meantime to promote healthier ecosystems.
Broad tree coverage can reduce temperatures by as much as 19 degrees Fahrenheit compared to areas without a tree canopy. This cooling stems from two main factors. First, leaves and branches provide shade from the sun. Secondly, the movement of water through root systems leads to evaporation from the soil, which cools the area near the ground — a process called evapotranspiration.
This temperature regulation is important for a few reasons. It can reduce the urban heat island effect, which disproportionately affects people in poorer communities, subjecting them to extreme temperatures. Similarly, it can also provide a healthier environment for local wildlife. Cooler air also makes solar panels more efficient, so trees can accelerate the green power transition.
4. Habitat Expansion
Environmental efforts also benefit from trees’ role as a home and food source for local wildlife. Many threatened or endangered species became that way because of habitat destruction. As cities expand and forests fall, animals have fewer places to live, creating a ripple effect across the broader ecosystem. Planting more trees fights this trend by providing a livable habitat.
While not every species lives in trees, many rely on them. Consequently, a recent study found that reforestation has the biggest positive impact on biodiversity of land-based mitigation climate protection strategies. Forests host the largest number of species in many areas and provide critical migratory grounds for those moving to nearby ecosystems.
As biodiversity increases, the overall micro-climate improves. A higher number and diversity of species means a healthier food chain and natural ecological self-regulation.
How the World Can Use Trees to Fight Climate Change
In light of these benefits, it’s clear that trees are vital to sustainability efforts. With that in mind, here’s a look at five ways to capitalize on this potential and fight climate change with trees.
1. Increasing Reforestation
The most important step is to ramp up reforestation efforts. Replanting forests where human expansion has removed them is essential in recovering vital ecosystems. Deforested areas also represent the greatest carbon sequestration potential, as they already pose the ideal growing environment for native trees and offer enough available land.
Ongoing reforestation efforts have already achieved impressive results. The United Nations’ Great Green Wall project has been reforesting a stretch across Africa since 2007. In that time, it has restored nearly 18 million hectares of land, leading to increased food and water security in the region on top of fostering wildlife growth.
At a rate of 40.7 tons of CO2 per year, 18 million hectares is enough to counteract 732.6 million tons of carbon emissions. Realistically, the entire area won’t produce maximum carbon sequestration results. Still, even at a fraction of that number, the project represents a considerable carbon sink.
2. Planting Urban Greenery
Relatedly, environmental groups should emphasize planting trees in urban areas. In addition to being central points of deforestation, large cities suffer some of the most severe effects of heat islands, air pollution and flooding. As such, they have much to gain from added tree cover.
More greenery in a city also reduces carbon emissions by promoting walking, running and cycling. According to a 2022 study, levels of this kind of activity are highest in areas with high greenness, suggesting a correlation between plant life and walking instead of driving.
Urban trees are most critical in heavily industrialized areas or those with extensive concrete infrastructure. These spots tend to have poorer air quality, higher heat island effects and a greater risk of flooding, so forestation does the most good in these contexts.
3. Using Lumber Responsibly
While organizations should aim to plant more trees than they use, lumber still has a role in a sustainable future as a building material. Some species can regenerate quickly and often produce fewer emissions to harvest and use than alternatives like metal and concrete.
The key is using lumber responsibly. It begins with recognizing which tree species are best for use as a material. Optimal choices are fast-growing and non-threatened trees grown on farms rather than taken from full, thriving ecosystems. Equipment selection is also important. Some arborist machinery uses rubber tracks and even weight distribution, which minimizes ground disturbances and protects nearby plant life to avoid disrupting the environment.
Planting trees after harvesting others is likewise critical. Considering how long these plants take to mature, it may be best to plant a few trees for every one cut down.
4. Preserving Sensitive Ecosystems
Distinguishing between tree farms and protected forests is another essential step. Some regions should remain undisturbed to foster growth around sensitive wildlife. However, that does not mean people should leave these ecosystems alone entirely.
Careful management is critical to ensure healthier growth and prevent issues from overgrowth like wildfires. Periodic pruning and controlled burns may be necessary, and timing is key for both. Expert arborists recommend pruning between February and March in most areas to create room for new growth in the spring. Similarly, late spring is usually best for more controlled burns to minimize damage but clear away dead matter.
Steps like this may seem like interference, but they ensure forests remain as healthy as possible. The extra care taken to provide enough room and resources for fresh growth will produce greater potential for carbon sequestration and habitat restoration while minimizing climate-related hazards.
5. Using Trees as Infrastructure
Finally, cities should consider how trees can take the place of artificial infrastructure. Plants may not be able to fill every role within public works, but taking advantage of their soil preservation and temperature-regulating qualities can reduce some emissions and waste.
Flood barriers, windbreaks and shade are all roles trees can play instead of concrete or steel alternatives. Fostering forests around bodies of water, planting shade trees in hot areas and lining open areas with tall growth can prevent damage from floods, the sun and high winds. These kinds of hazards will also become increasingly common as climate change worsens, so cities need this protection.
Trees are optimal solutions here because they don’t carry embodied carbon, which accounts for 11% of all emissions worldwide. They’ll also remove CO2 from the atmosphere as they perform other functions, helping offset any emissions from their transportation and planting.
Trees Are a Critical Piece of the Environmental Puzzle
In many ways, trees are vulnerable parts of the ecosystem. At the same time, they may be an essential part of making the world more resilient in the face of climate change. Recognizing these benefits is the first step to using trees to enable a greener future.
About the Author
Rose is the managing editor of Renovated and has been writing in the construction, landscaping and sustainable building sectors for over six years. She’s most passionate about improving environments, reducing carbon footprints and incorporating resourceful methods to promote well-being in the planet. For more from Rose, you can follow her on Twitter and connect on LinkedIn.
