By Chris Lang
“I hate that people keep asking me: where are you going to plant these trillion trees?” Thomas Crowther told The Guardian recently. “I’ve never in my life said we should plant a trillion trees. It gives the impression of plantations everywhere.”
The idea of planting a trillion trees has a strange backstory. And Thomas Crowther played a key role in promoting the idea.
As journalist Tin Fischer pointed out recently in a Twitter thread, the story begins in 2011, with a 13-year-old boy giving a speech at the United Nations in New York:
The boy’s name is Felix Finkbeiner. “We children often make consultations, we often discuss what we have to do,” Finkbeiner said in his UN speech in New York. “And in our most recent consultation, we asked ourselves what would we do if we were the heads of government.”
A three point plan
The children came up with a three point plan: Zero emissions by 2050; end poverty through climate justice (including a carbon budget of 1.5 tons per person per year); and planting a trillion trees. Here’s how Finkbeiner described the last point:
And the third point we children found is trees. Trees and forest. We have to protect the forest, the already existing forest. We have to keep the rainforest from disappearing.
And in addition, we have to plant trees. It is now more than four years ago that we children started the Plant-for-the-Planet children initiative, planting one million trees in each country of the world. It is also more than four years ago that Wangari Maathai started the billion tree campaign.
It is now time that we work together, we combine our forces old and young, rich and poor. Together we can plant a trillion trees. We can start a trillion tree campaign. We children think that we can manage to plant a trillion trees in 10 years. The Americans made it to the moon in ten years. The Chinese planted 2.7 billion trees in 2009. And to be honest a trillion trees is only 150 trees per person. So we can manage.
Felix Finkbeiner is, of course, the founder of Plant-for-the-Planet. Finkbeiner’s father, Frithjof Finkbeiner, told Stern journalist Joachim Rienhardt earlier this year that they came up with the one trillion figure in the aeroplane on the way to New York.
Enter Thomas Crowther
In 2012, Finkbeiner sent an email to a researcher at Yale School of Forestry and Environmental Studies with the question: How many trees are on Earth? A 2019 article on the Science website explains that Finkbeiner wrote that he “was curious because he ran a nonprofit that was working with the United Nations to encourage people to plant 1 billion trees”.
As it happened, Finkbeiner email was to Thomas Crowther’s roommate. Crowther, an ecologist who had recently completed his Ph.D. at Cardiff, was intrigued by the question about how many trees are on earth. He set to work to find out. In September 2015, Crowther and colleagues published a paper in Nature. There are about three trillion trees on the planet, according to the research.
The paper’s acknowledgements include the following: “We also thank Plant for the Planet for initial discussions and for collaboration during the study.”
Trillion tree declaration
In 2018, Plant-for-the-Planet launched a Trillion Tree Declaration. “We, the signatories, pledge to plant and protect one trillion trees,” the Declaration states. Thomas Crowther was one of the signatories.
The global tree restoration potential
Plant-for-the-Planet was also acknowledged in a 2019 paper co-authored by Crowther: “The global tree restoration potential”. By then, Thomas Crowther had raised enough money (from DOB Ecology, a Dutch Foundation) to set up his own Crowther Lab at ETH-Zürich.
The 2019 paper claimed that global tree restoration is “our most effective climate solution to date”.
The Crowther Lab hired a PR firm called Greenhouse to promote the tree restoration research findings. They were remarkably successful, with about 700 media pieces covering the research.
There was also a an extremely critical reaction from other forest and climate scientists. One response paper stated that “The claim that global tree restoration is our most effective climate change solution is simply incorrect scientifically and dangerously misleading.”
“We messed up the communications so badly,” Crowther told The Guardian. But the scientists were responding to what Crowther and his colleagues had written in their paper – not to the communications strategy.
Crowther and his colleagues wrote an erratum that admits that their statement about tree restoration being the most effective climate solution “was incorrect” and that, the authors of the paper,
did not mean that tree restoration is more important than reducing greenhouse gas emissions or should replace it, nor did they mean that restoring woodlands and forests is more important than conserving the natural ecosystems that currently exist.
A trillion trees
But the damage had already been done. In February 2020, the World Economic Forum launched an initiative to plant one trillion trees. Even Donald Trump joined in.
Thomas Crowther was in the audience in Davos and stood up and waved when Marc Benioff, founder of Salesforce, acknowledged his research. In his speech Benioff said,
Tom did the incredible work for the trillion tree vision, his team is doing extraordinary things and took artificial intelligence and low-hanging satellites and other fourth industrial revolution technologies and is showing us where these trillion trees are going, and also the amount of carbon that they can sequester, and the mathematical models and the environmental models.
PHOTO Credit: Marianne Lucien, “Planting a trillion trees? Ambitious, but doable”, ETH-Zürich, 23 January 2020.
In the article Crowther highlights some of the risks involved with planting a trillion trees. The article starts as follows: “An ETH Zurich professor’s research found there is space on earth to plant a trillion more trees. The World Economic Forum has launched an initiative to do just that.”