Tree planting has a reputation for being an all encompassing environmental solution–it’s a low-risk method of absorbing CO2 and restoring ecosystems. It’s a common method of carbon offsetting–paying for ‘carbon capture’ to compensate for emissions–and many governments are ramping up tree-planting efforts.
With this much capital being funneled into tree planting, it’s important to look one level deeper. How does tree planting help the environment and is it worth the money? Should Jeff Bezos have donated $5 million to this cause? This article is sure to plant some seeds of curiosity about the topic.
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Table of contents
Let’s explore the pros and potential cons of tree planting.
How does planting trees help the environment?
Plants are indispensable for the survival of animals on this planet. While plants are commonly appreciated for their ability to produce oxygen for us, they also do a lot more.
Firstly, trees help mitigate climate change through their natural carbon absorption methods. Trees use photosynthesis to produce energy. By taking in sunlight, carbon dioxide, and water, they produce sugar and oxygen. This process is important to fight against climate change because when plants absorb carbon dioxide (the most common greenhouse gas), they store the carbon in their cells. So long as a tree lives, that carbon stays within it – and trees can live for decades or centuries. Essentially, trees pull greenhouse gasses out of the atmosphere and use them to grow into beautiful, green living structures. It sounds too good to be true.
Through photosynthesis, forests absorb roughly ⅕ of global emissions annually. A study from 2019 found that a global planting program could sequester two-thirds of the greenhouse gasses in the atmosphere emitted by humans. Forests also promote biodiversity of flora and fauna, prevent erosion, and reduce flooding. They are an extremely important ecosystem service that interacts with every aspect of the environment in ways we don’t even realize.
It’s important to note that the benefits of forests are magnitudes higher in primary forests. According to the IUCN, primary forests are “essentially forests that have not been disturbed or harmed by humans and retain their native biodiversity”. These forests provide unparalleled advantages for local communities, carbon sequestration, and other environmental services.
The advantages of protecting forests are almost un-ending. It follows that we should stop cutting and burning forests, and start protecting the ones that are still standing.
Does planting trees actually help climate change?
Now that we’ve identified the undeniable importance of forests, let’s get into the nitty-gritty details. How much does tree planting help the environment as a whole? Is it worth the money? Are there better options?
While this topic is complex and controversial, according to several experts, planting trees may not be worth the price. Every year, billions of dollars are invested in tree planting. Meanwhile, forest cover is not increasing. This leaves us to wonder, where is this money going?
Typically, when a tree planting project is started, the focus is on planting saplings, and not on keeping them alive or working with local communities to do so. This creates a large issue–many tree planting projects fail to survive. In China’s Three-North Shelter Forest Program up to 85 percent of the plantings had failed. In 2019, Turkey planted over 300,000 trees, but within three months, up to 90 percent of the new saplings inspected by Turkey’s agriculture and forestry trade union were dead. For tree planting projects to implement a tracking and monitoring program, costs can be expected to increase 11 to 17 percent.
On occasion, tree planting operations can have dramatic negative consequences. Since 1974, Chile has been encouraging private landowners to plant trees through subsidies. But landowners are allowed to use these subsidies to replace native forestlands with profitable plantations. As a result, Chile’s new plantings not only didn’t increase carbon storage, they also accelerated biodiversity losses, researchers reported in Nature Sustainability.
So, what’s the deal? If forests are vitally important, why doesn’t planting them always help? It turns out that the difference between aforementioned primary forests and secondary forests is massive. Secondary forests are those that have been regrown after being cut down, making them less mature forests, highly subject to human design. On the flip side, primary forests are unparalleled in the benefits they provide to regulating climates and hosting biodiversity, disease and wildfire resilience, supporting livelihoods, and providing ecological and environmental services which support human health. In one investigation of the Brazilian Amazon, researchers found that secondary forests have only 41.1% of the average carbon and 56% of the tree diversity of primary forests in the region.
In most tree-planting operations, forests are planted as monocultures, meaning only one species of tree is planted in a given area. Primary forests host a diversity of tree species, contributing to their indispensable benefits. When a monoculture is planted, a fast-growing, commercially valuable species is typically chosen with the goal of harvesting the trees down the line. Eucalyptus and palm oil are common choices for their use in toilet paper and palm oil production. The value of tree planting projects is almost entirely negated once these trees are cut down.
A level deeper: Other downsides of tree planting
The most common critique of tree planting is that it steers attention away from important climate mitigation tactics. In 2019, Canada’s Liberal government pledged to plant 2 billion trees over the next decade, costing around $3 billion. While this plan was fairly well-received by the Canadian public, some have questioned if it acts as a distraction from the country’s promise to achieve net-zero emissions by 2050. Tree planting is great, but perhaps blinds the public from the fact that emissions in 2030 are projected to be “a mere 7% below 2005 levels, based on the policies in place as of September 2020”, which Climate Action Tracker rated as “highly insufficient”.
These concerns surrounding tree planting extend past the great white north. It is argued that calling tree planting the “most obvious climate solution to date” overlooks a more simple and effective solution: reducing emissions. Planting trees might be more popular than cutting fossil fuel emissions, but global climate mitigation goals cannot be achieved without the latter. In 2014, a researcher warned that relying on planting trees to slow climate change was too risky in a New York Times op-ed.
There are also ecosystems which forests simply should not overtake. There are plans in place to cover the entire width of Africa with forests by planting trees over the savanna ecosystem. Recent studies have sparked doubt in how much carbon can be stored by afforestation in this region, but the issues with this plan go deeper. By drastically transforming an ecosystem, an ecological disaster could be triggered, hurting water supplies and threatening plant and animal species.
For these reasons and more, many experts suggest encouraging natural forest regrowth and halting deforestation as opposed to actively planting trees.
What can we do instead to help the environment?
While tree planting has many benefits, it might not be our planet’s saving grace. But fear not, there are other effective ways to tackle the climate crisis.
Aside from planting trees, there are many natural solutions to climate change that are vitally important. Preserving and restoring ecosystems to absorb carbon dioxide is a type of climate mitigation called ‘nature-based solutions’, and it’s regarded as one of the most important aspects of limiting global warming. According to one study, “cost-effective nature-based solutions could contribute about 20% of the mitigation needed between now and 2050 to keep global warming below 2°C”.
One vital nature-based solution is the preservation of primary forests. Unlike planting trees, protecting old forests ensures the biodiversity of those forests stays intact. Old forests also have great climate adaptation advantages, such as reducing flood, wildfire risk, and erosion, and protecting soil health.
There are other ecosystems worth protecting, too. For example, peatlands–swamp-like terrestrial wetlands–are a massively overlooked natural carbon sink. Although they only occupy 3% of the global land area, peatlands contain about 25% of global soil carbon, twice as much as the world's forests. Peatland degradation releases 5-10% of GHG emissions. However, if politicians announced a $3 billion plan to restore peatlands, it would likely be met with push back and confusion.
One drastically overlooked natural carbon sink is the soil right beneath our feet. While trees get a lot of hype, over 70% of all carbon on land is stored in soil, while only 30% is stored in plants. Sadly, every year, our soils are becoming more and more degraded and carbon is continually being released into the atmosphere. By improving soil health, we could sequester millions of tons of CO2 into soil and biomass. As soil gets healthier, we also reduce nitrous oxide emissions from fertilizer reductions, increase cooling through more land covered with living plants, and reduce food waste and methane emissions.
Top 5 FAQs on effects of planting trees on climate change
The trees are burning, and so are these questions. Let’s get the answers.
1. Does planting trees add CO2 to the atmosphere?
No! Planting trees is an effective way to pull carbon dioxide out of the atmosphere, since plants absorb carbon dioxide and store the carbon as plant matter. However, the amount of carbon sequestration achieved by tree planting projects varies greatly, as some planted forests are later harvested, releasing the stored carbon once again.
2. What will planting 20 million trees do?
According to an analysis by the U.S. Forest Service, planting 20 million trees would absorb 1.6 million tons of carbon. This is the equivalent of removing 312,753 gasoline-powered cars from the road for one year. While this is a great achievement, this is around half of the number of trees cut down daily. 20 million trees is around 0.00066% of the total trees in the world.
3. Can planting trees reverse climate change?
Afforestation has potential to absorb a lot of the world’s greenhouse gas emissions. A study from 2019 found that a global planting program could sequester two-thirds of the greenhouse gasses in the atmosphere emitted by humans. However, this study has been questioned, making it difficult to say the potential of tree planting to reverse climate change.
4. How much does planting a tree offset your carbon footprint?
On average, a fully grown tree will absorb as much as 48 pounds of CO2 every year. This is the equivalent of driving 54 miles in an average gasoline-powered vehicle. By the time the tree is 40 years old, it will have absorbed 1 tonne of carbon dioxide, the equivalent of driving 2,482 miles, or burning 1,106 pounds of coal. According to TenTree, “the average North American will need to plant 920 trees in order to offset the average carbon footprint”.
5. How can you help with nature-based solutions to climate change?
One obvious solution is to plant a tree! However, as discussed, the impact is minimal. A more impactful way to help sequester carbon naturally is to restore soil health. This can be achieved by composting your food and using the finished compost in your garden, houseplants, or on your lawn. The easiest way to compost is with Lomi, a revolutionary electric composter that turns your food waste into fertilizer at the click of a button.
Tree planting is among the most agreeable environmental solutions, with the far-left and climate-skeptics alike agreeing upon its positive impact. However, like all climate absorption strategies, it has its fall-backs. Trees are often planted as monocultures and later harvested, or simply planted over ecosystems where forests don’t belong. Tree planting also potentially distracts from more important efforts like reducing fossil fuel emissions or restoring soil health.
If you want to do your part for the planet, try planting your favorite fruit tree in your backyard. If you don’t have the time or space for tree-planting, you can contribute greatly to carbon sequestration by composting with Lomi! Whatever you choose to do, the planet will surely be a cooler place thanks to your efforts.
Written by: Cassia Attard