Last November, the Turkish government oversaw the planting of 11 million trees in a single day. One Turkish city broke a world record for the number of trees planted in an hour (303,153 trees). By late January, though, the head of the country’s agriculture and forestry trade union was reporting that most of the trees were already dead, though the government denied those claims.
It’s one illustration of the difficulty of achieving a global goal to grow and conserve a trillion trees as part of the fight against climate change—a goal that got a boost when the World Economic Forum launched a new program in January, called 1t.org, to catalyze and coordinate action. Even Donald Trump, who has rolled back 95 environmental protections so far, said that he wanted to sign onto the campaign. Last week, Republican lawmakers proposed that the U.S. should plant a trillion trees by 2050.
If it works, the impact could be significant. In the U.S., alone, the nonprofit World Resources Institute has calculated that it’s possible to grow 60 billion new trees in the next two decades (the Republican goal of doing a trillion trees domestically, it turns out, isn’t remotely feasible), and those trees could suck up more than half a billion tons of CO2 from the atmosphere each year. Globally, a 2019 study estimated that restoring forests with around 1.2 trillion trees could store more than 200 gigatons of carbon. While some have questioned that study’s math, what’s clear is that the number is massive.
Of course, it’s only one part of the solution to climate change. Some scientists have argued that mass tree-planting and conservation is a dangerous diversion if it means that countries aren’t steeply reducing emissions from fossil fuels, the biggest lever in addressing the problem. But even the most radical scenarios for stopping climate change also call for so-called “negative emissions technologies,” something that can pull some excess carbon from the air—something like trees.
“We’ve never said that this is the solution to the climate challenge,” says Justin Adams, the director of the Tropical Forest Alliance at the World Economic Forum. “But we’re saying that this is one of the critical transitions we need.” But doing it at the scale of a trillion trees will be—unsurprisingly—very challenging to pull off.
You have to stop subtracting before you can add
The first problem: The world is still losing a U.K.-size chunk of forest each year. In 2014, a huge coalition of companies and governments pledged to cut the loss of forests in half by this year, and restore 150 million hectares of land. Last year, they reported that the goal wasn’t on track. Even as many companies work to make sure that their supply chains aren’t contributing to deforestation, tropical forests are still disappearing for the sake of hamburgers or shampoo. In places like the Amazon rainforest in Brazil, there’s still an economic incentive to cut trees down. In Southeast Asia, farmers are still clearcutting jungle to grow palm oil. And even as some multinational corporations are starting to source it sustainably, other plantations may be selling to less scrupulous buyers in China.
Keeping existing trees is even more important than planting more. “We really need to focus on protecting our existing forest first, especially primary forest,” says Jared Messinger, manager of the Global Restoration Initiative at the World Resources Institute. “Trees obviously take a long time to mature. And so when you’re cutting down standing forests that are already contributing to carbon removal and replacing them with saplings and others that will take 40 years or more to mature, the level of removal just isn’t the same.”
When new trees are planted—or when degraded land is protected so forests can begin to naturally regenerate—people also need an incentive to keep those trees standing. Any restoration effort has to start with the people who live nearby. “Decisions around land use are inherently local,” Messinger says. “You can have incentives created at the federal level and policy set, but you’re actually trying to change behavior about how people use land. So you have to meet people where they are: Engage them and make sure that it’s in their interest.”
In some cases, that might mean creating new businesses and new sources of income. In Peru, for example, one business helps poor farmers make more money by replanting high-value trees on degraded land, and then slowly and sustainably harvesting wood. In another project, coffee farmers earn money by restoring and protecting forests, which in turn helps protect their farms from erosion. In Zimbabwe, new beekeeping businesses have an incentive to keep trees standing because it helps their hives produce more honey.
Let the trees grow themselves
In some cases, forests may be able to regrow essentially on their own. At the edge of the Amazon rainforest, land that was cleared for cattle ranching can be partially fenced off, so cattle don’t eat young saplings, and trees will begin to return—one of the cheapest and easiest ways to restore forests. In other cases, trees need to be planted. But it needs to happen the right way, with trees chosen that can survive in the area and planting that happens at the right time (in the case of the tree planting in Turkey, part of the problem was likely timing and a lack of rain).
Often, trees will need support to survive. In China, most of the trees in a massive “Great Green Wall” campaign designed to fight erosion failed in part because the trees weren’t suited for the area. “Monitoring the efforts is incredibly important, and also resource-intensive and time-consuming,” Messinger says. “That’s where we’ve seen a lot of planning efforts fail, because they haven’t put enough effort or resources into the stewardship of those trees.”
In the U.S., when World Resources Institute mapped where trees could be restored without interfering with land needed for farming, it found that 21 billion trees could be planted on land that was historically forest. Another 24 billion trees could be “restocked” in forests used for in the Eastern U.S. On cattle pastures, there’s room to add 13 billion trees, which have the added benefit of offering shade, improving soil fertility, and extra income for farmers if the trees grow fruit or nuts. On some other farms, 2 billion trees can be added between row crops. In cities, there’s room for 400,000 more trees, which can help improve air quality and make city dwellers happier.
Money grows trees
It will take investment: The nonprofit estimates that planting 60 billion trees will cost at least $4 billion a year to finish the campaign within 20 years. But for context, that’s comparable to what the country spends on fossil fuel subsidies now. New government incentives could create a new tree-planting industry similar to the solar industry, where companies help landowners quickly plant and maintain trees. Government tax credits or payments could go to one of these companies—or a land trust or local government—which could negotiate contracts with landowners, take advantage of the government incentive, and then help quickly scale up restoration faster than landowners could do alone.
As tree planting and conservation efforts happen, the world will need to be able to track those trees—something else that isn’t easy to do now, though technology continues to improve. One startup now uses a combination of drones and satellite images to track how trees grow and how much carbon they’re storing. As more and more companies want to buy carbon offsets from forest projects, the World Economic Forum is also figuring out how that can happen effectively. “The working group that we’re setting up will look at what is a credible commitment, so that you’re not just saying, ‘Well, we planted 10 trees and that means that we’re a good company,’ and what’s credible in terms of your overall pathway to net zero, given that climate is the core rationale for this,” Adams says.
Though the details are complicated, Adams says that the simplicity of the basic goal is clearly resonating. “It can mobilize and inspire, whether you’re a school kid or you’re the president of a country,” he says. “That’s a big part of what we’re trying to bottle, and now we’re scrambling to really sort of figure out what are the workstreams that need to be in place to actually measure those commitments, track progress against those, so that by . . . next year, we will be able to talk more explicitly about how that would all work.”