“If no one had ever said, ‘Plant a trillion trees,’ I think we’d have been in a lot better space”

Says Thomas Crowther, AKA Mr. Trillion Trees himself

PHOTO Credit: Crowther criticises “the tunnel vision around this focus on carbon” while focussing on, er, carbon.

Thomas Crowther is a professor of ecology, and head of the Crowther Lab at the Swiss federal institute of technology, ETH Zürich. He’s famous, or infamous, for a 2019 paper in Science titled “The global tree restoration potential”. The research for the paper was led by the Crowther Lab.

The first line of the abstract states, “The restoration of trees remains among the most effective strategies for climate change mitigation.” The researchers found that there was enough room to plant 1.2 trillion additional trees across the planet.

The Crowther Lab hired a PR company, Greenhouse, to promote the paper’s findings. Greenhouse boasts that “Around 700 pieces of media coverage were published” as a result of its work for the Crowther Lab.

On 4 July 2019, ETH Zürich put out a press release under the headline “How trees could save the climate”.

The results were predictable. There are now three campaigns to plant one trillion trees and Big Polluters are increasingly using tree plantations to generate carbon offsets to greenwash their continued pollution.

Here’s how the World Rainforest Movement describes the problem in its most recent Bulletin:

Destructive extractive industries are tapping into the public concern about climate chaos to promote misleading tree plantation projects as a solution for their increasing fossil fuel emissions. Plantation companies hope for new sources of revenue while fossil fuel-dependent industries seek an alibi to continue with their pollution. The result is the intense growth of tree plantation projects for carbon offsetting and a steady increase in the demand for carbon credits.

Crowther at COP28: “Kill greenwashing”?

9 December 2023 was “Nature Day” at COP28 in Dubai. Crowther was a speaker at one of the events.

A recent article in Wired covered Crowther’s presentation:

Mass plantations are not the environmental solution they’re purported to be, Crowther argued. . . . The potential of newly created forests to draw down carbon is often overstated. They can be harmful to biodiversity. Above all, they are really damaging when used, as they often are, as avoidance offsets — “as an excuse to avoid cutting emissions,” Crowther said.

In November 2023, Crowther was one of more than 200 authors, led by the Crowther Lab, of a new paper which found that preserving existing forests can store more carbon than planting trees. The focus is on “community-driven ecosystem restoration and management”.

ETH Zürich’s press release makes clear that if we want forests to store carbon, they will only do so “if we also reduce greenhouse gas emissions”.

Wired journalist Alex Luhn writes that, Crowther “then brought the results to COP28 to ‘kill greenwashing’ of the kind that his previous study seemed to encourage — that is, using unreliable evidence on the benefits of planting trees as an excuse to keep on emitting carbon”.

Crowther spoke on 10 December 2023 at Nature4Climate’s Nature Positive Pavilion in Dubai. Nature4Climate was created by Big so-called Environmental NGOs including The Nature Conservancy.

The membership of Nature4Climate is heavily dominated by carbon trading proponents:

Several of these organisations run REDD offsetting projects. Several of them see nothing wrong with working together with the oil industry. Nature4Climate is a greenwashing operation.

The Director of Nature4Climate, Lucy Almond, previously worked for The Nature Conservancy and before that for BP. She is also strategic communications lead, nature-based solutions at the World Economic Forum.

Crowther’s greenwash at COP28

Unfortunately, Crowther didn’t go into the belly of the greenwashing beast to kill greenwashing.

Instead Crowther’s presentation in the Nature Positive Pavilion was an extraordinary attempt to re-write history.

“I feel like this year has been such an interesting year,” he begins.

“There’s been all sorts of conversations around this topic but the conversation around nature has matured. Five years ago it felt like every pledge was around the number of trees. Whereas every pledge now is about how much indigenous land rights can we protect? How much conservation can we ensure? It’s this enriching of the conversation and maturity of the conversation that’s been a real development this COP, that’s been quite exciting.”

Crowther doesn’t mention the series of studies and reports that came out this year that have found serious problems in one after another REDD project.

He doesn’t mention that in November 2023, Renat Heuberger resigned as CEO of South Pole, the world’s biggest carbon consulting firm, following a series of investigative reports into South Pole’s flagship Kariba REDD project in Zimbabwe.

Neither does he mention that in May 2023, David Antonioli resigned as head of Verra, the world’s largest carbon credit certifying organisation. His resignation followed a nine-month investigation by journalists at The Guardian, Die Zeit, and SourceMaterial.

Crowther makes a bizarre statement about how long carbon is stored in forests:

“Obviously, we all know, forests capture, like all vegetation, captures billions of tonnes of carbon which can be stored for millions of years in the vegetation and soil below. Which is a vital contribution to our climate fight.”

Kate Dooley is a researcher at the School of Geography, Earth and Atmospheric Science at the University of Melbourne. Last year she was lead author of a paper titled, “Carbon removals from nature restoration are no substitute for steep emission reductions”.

She told Wired that, “Carbon storage in nature is temporary and therefore is not equivalent to permanent fossil fuel emissions.”

Crowther is attempting to argue that storing carbon in forests, trees, and soils is permanent and therefore equivalent to the carbon stored underground in the form of fossil fuels. This is the greenwash that the fossil fuel industry has been hiding behind for decades.

In 2020, more than 40 scientists signed on to a statement titled “10 myths about net zero targets and carbon offsetting, busted”. Here’s how they bust the myth that we can offset fossil fuel emissions using “nature-based solutions”:

Fossil fuels are part of the slow carbon cycle. Nature-based solutions are part of the fast, biological carbon cycle, meaning that carbon storage is not permanent. For example, carbon stored in trees can be released again by forest fires. Fossil emissions happen today, while their uptake in trees and soils takes much longer. The overall capacity of nature-based solutions is also limited, and is anyway needed to help remove the carbon dioxide that we have already released into the atmosphere.

One trillion trees

In Dubai, Crowther refers to a 2015 study for which he was lead author: “Mapping tree density at a global scale”. The study found that there are about three trillion trees on the planet. “Which was a nice bit of context, when there was a lot of conversation around billion tree campaigns and trillion tree campaigns coming along,” Crowther says.

Except that, there were no trillion tree campaigns in 2015. The first came in 2018, when Felix Finkbeiner’s outfit Plant for the Planet launched its “Trillion Tree Declaration”.

Crowther signed on to the declaration. He was also chief scientific adviser to Plant for the Planet.

Finkbeiner was actually the inspiration for Crowther’s research. In 2012, the 14-year-old Finkbeiner sent an email to a researcher at Yale School of Forestry and Environmental Studies asking “How many trees are on Earth?” The researcher was Crowther’s roommate.

In Dubai, Crowther moves on to his next research project:

“Within these degraded lands, we identified that if we could protect them in the long term and allow these ecosystems to recover, that there’d be room for about a trillion new trees. Which seemed pretty harmless at the time of doing the research. That could contribute around a third of our carbon drawdown goals, about 205 gigatonnes of carbon, which was all very exciting.

“But when the media hit the headlines, we were overwhelmed and it was immediately one of the most controversial topics of our times. Many of you will know about the conversation around the trillion trees campaign, because suddenly trees and carbon were front page news everywhere, which was in some ways good, it really increased the awareness of this topic, but it also gave rise to massive misconceptions as I mentioned earlier.”

Crowther is attempting to re-write history here. Either that, or he has a really bad memory.

The paper he’s talking about was published in July 2019 in Science. Crowther was a co-author of the paper, which was titled, “The global tree restoration potential”. The authors argued that, “there is room for an extra 0.9 billion hectares of canopy cover, which could store 205 gigatonnes of carbon”.

The funding for the research came from DOB Ecology, a Dutch Foundation, an NGO called Plant for the Planet, and the German Federal Ministry for Economic Cooperation and Development. A condition of DOB Ecology’s funding was that Crowther had to set up a digital marketing team to publicise the results. Crowther hired a PR firm called Greenhouse.

The media coverage was spectacular:

ETH Zürich’s press release about the research quoted Crowther as saying that afforestation was “the best climate change solution available today”.

In October 2019, Science published six critiques of the Crowther Lab’s paper, signed by more than 50 scientists. These were not critiques of the media coverage of Crowther’s paper - they were critiques of the paper itself.

As a result, the authors corrected their paper to say that tree restoration was only “one of the most effective carbon drawdown solutions to date”.

Two more trillion tree campaigns

Crowther makes no mention of the corrections to the 2019 paper in his Dubai presentation. He moves on to the 2020 launch of the World Economic Forum’s trillion trees campaign:

“When the World Economic Forum and trillion trees campaign emerged out of the world, many people were pledging commitments to the conservation and restoration of nature, but many others as we know were seeing a great opportunity to bang a few trees in the ground and not worry about the challenges of cutting emissions and protecting the ecosystems that we have.

“So this gave rise to some really serious controversy.”

There are now three “trillion tree” initiatives. In addition to Plant for the Planet’s, Wildlife Conservation Society, WWF, and BirdLife International run another, and The World Economic Forum runs a third.

Crowther is keen to play down the huge role that he played in Plant for the Planet’s and the World Economic Forum’s trillion trees campaigns. “If no one had ever said, ‘Plant a trillion trees,’ I think we’d have been in a lot better space,” Crowther told Wired.

In his presentation in Dubai, Crowther doesn’t mention that he was at the World Economic Forum meeting in 2020 for launch of the the Trillion Tree campaign.

Crowther doesn’t mention that in his speech at the launch Marc Benioff, the billionaire founder of Salesforce, mentioned the “incredible” research Crowther and his team had carried out:

“Tom would you just stand up and be recognised. 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.”

Neither did Crowther mention that he was on the advisory council of the World Economic Forum’s trillion trees campaign.

“We didn’t realise for a second”

In Dubai, Crowther claims to be completely surprised that anyone would use the Crowther Lab’s research to create a campaign to plant one trillion trees:

“The controversy is around this tunnel vision on carbon. For many people, the message, and I have to take massive responsibility in this, that as a naive 29-year-old scientist, talking about the value of trees, we were unbelievably excited to say that nature can contribute and we didn’t for a second realise that that would be translated into planting a trillion trees will save the world.”

It’s good that Crowther accepts “massive responsibility,” but there are lies in this statement. The first is fairly trivial. The second is a whopper.

First, he’s lying about his age. Crowther was born in 1986. In 2015, when his first paper was published, he was 29. In 2019, when the “trillion trees” paper came out he was 33.

Second, Crowther’s claim that “we didn’t realise for a second” that their paper would lead to campaigns to plant vast numbers of trees is not believable.

ETH Zürich’s press release about the research was titled, “How trees could save the climate”. How can Crowther now claim to be surprised that newspapers reported that trees could save the climate?

The press release stated that,

Around 0.9 billion hectares of land worldwide would be suitable for reforestation, which could ultimately capture two thirds of human-made carbon emissions. The Crowther Lab of ETH Zurich has published a study in the journal Science that shows this would be the most effective method to combat climate change.

The press release also stated that, “there is currently an area of the size of the US available for tree restoration”.

The press release included the following quotation from Crowther himself:

“We all knew that restoring forests could play a part in tackling climate change, but we didn’t really know how big the impact would be. Our study shows clearly that forest restoration is the best climate change solution available today. But we must act quickly, as new forests will take decades to mature and achieve their full potential as a source of natural carbon storage.”

Crowther’s claim about being surprised that anyone in the media took any of this seriously is ridiculous. As is his comment to Wired that his message was “misinterpreted”.

At the time, the Crowther Lab was delighted with the media coverage. Tom Elliot, the Managing Director, Crowther Lab, is quoted on Greenhouse’s website as saying that, “Communicating science in a way that is relatable and inspires action is not easy, but Greenhouse were instrumental in getting this vital message to a truly global audience.”

ETH Zürich subsequently slightly amended their press release, but the damage had already been done.

“I got absolutely brutalised”

In his presentation in Dubai, Crowther attempts to deflect the issue by talking about monoculture tree plantations:

“So it gave rise to this massive upsurge of controversy. Because these plantations are often used as an excuse to continue emissions which would cause so much more harm than good. It’s also hugely threatening to biodiversity across the planet because these monocultures are not nature. And this also in my world gave rise to a lot of scientific controversy. When I say controversy, I mean I got absolutely brutalised.

And this was a really challenging time for the environmental movement because people linked this controversy around mass plantations with questioning whether nature has any role in the fight against climate change and it led to this really undermining moment in the environmental movement that I think we’ve been struggling with for the last few years.

“Every month there’s a new article coming out saying trees can do more harm than good as if not everyone in the environmental movement knows this. But it’s important that journalists are still pushing this topic forward to try and avoid those challenging times.

Obviously, industrial tree plantations are not a solution to the climate crisis.

But the controversy about offsetting emissions from fossil fuels against carbon stored in trees is not just about plantations. We simply cannot offset the carbon stored in forests, soils, and trees against continued emissions from fossil fuels if we want to stand any chance of addressing the climate crisis.

Crowther doesn’t mention offsets once in his presentation. Neither does he mention fossil fuels.

Crowther turns to his most recent paper, “Integrated global assessment of the natural forest carbon potential” published in Nature:

“But to address this for the first time ever scientists published, hundreds of scientists across the globe published the integrated global forest assessment with data from 1.1 million locations across the globe. For the first time we could build a really comprehensive and robust understanding of this carbon storage potential now.

“And it was recently published in the journal Nature, providing greater and newer insights into the potential for carbon storage that we could additionally store in these ecosystems.”

Once again, Crowther comes up with a very large figure for the amount of carbon that could “stored” in forests and trees:

“This gave rise to this new understanding that we could capture 226 billion tonnes, again a staggering number, but the exciting thing about this time is that we knew all the challenges of the past so we could do some better framing.”

The problem with the 2019 paper was not “framing”. The paper was based on an extraordinary level of top-down thinking, and assumptions about “degraded” land. A very large amount of this so called “degraded” land is already in use - often by subsistence farmers - or is grassland that actually stores more carbon and is more biodiverse than it would be if it were covered in trees.

The same top-down thinking plagues the Crowther Lab’s latest paper. It fails totally to take into account grass-root struggles against deforestation. Addressing the drivers of deforestation is absent from the analysis. It’s as if Crowther can wave a magic carbon wand and deforestation will simply go away.

Crowther says,

“The average forest on our planet is only 30% of its maturity. Which means that, if we could allow just conserving those ecosystems and allowing them to recover to maturity can represent 61% of our carbon drawdown potential. It is the greatest contribution of our carbon drawdown needs, and the remainder can be achieved by equitable development, empowering millions of local communities and populations on the ground who are the stewards of nature to promote the revitalisation of biodiversity in degraded landscapes.”

The paper concludes that diverse forests capture more than 53% more carbon than monoculture plantations.

Crowther says that “Biodiversity can contribute more than a third of our carbon drawdown goals.”

He adds that, “This cannot be achieved without emissions cuts. We were able to calculate what it would mean if emissions continued to rise in the way that they do, what that would mean for the potential of forests.”

He tells us that fires, floods, droughts, devastation are going to continue to deplete these ecosystems. The potential carbon drawdown would be one-third less by 2030 if we continue on the trajectory we are currently on, according to Crowther.

“This time though,” Crowther says, “the message came crystal clear in the media.” It’s as if Crowther actually believes his own lie that he had nothing to do with the media coverage about the 2019 paper.

“It gave rise to no controversy and I was delighted,” he says. “I was much more delighted about the scientific consensus that emerged.”

He quotes a couple of complementary comments about the paper. Then he quotes Simon Lewis, professor of Global Change Science at University College London. Crowther doesn’t mention his name. He claims that Lewis was was “our harshest critic in 2019”, which may be true, but Lewis was certainly not alone.

Crowther says his harshest critic “summarised the work of 400 scientists over the last four years as ‘reasonable’, which I am, that’s a win for me as a scientist. That’s job done. I can pack up and leave now.”

But Lewis didn’t just say “reasonable”. And he wasn’t summarising the research. Crowther doesn’t mention what else Lewis had to say. The Guardian quotes him as saying,

“There is a lot of spin and bluster about what trees can do for the environment. To cut through this always ask: what is the amount of carbon taken up by a hectare of land, and over what time period. The spin on what trees can do for the climate will no doubt continue. But there is still only a finite amount of land to dedicate to forests, and ability of trees to sequester carbon is limited. The reality is that we need to slash fossil fuel emissions, end deforestation, and restore ecosystems to stabilise the climate in line with the Paris agreement.”

Back to Crowther in Dubai:

“So these forests are important in helping a third of our climate goals. But that is only a tiny part of the value of these ecosystems. They contribute so much more. These are our biodiversity goals, our equitable development, climate adaptation, resilience, all the things that people need to survive come from nature. And that means we cannot be doing these mass plantations, we need to as a first focus, companies and governments need to be looking into their own deforestation rates, taking steps to end deforestation within their supply chains, and then we must be taking every step to restore what we possibly can with diverse ecosystems.”

The statement that “forests are important in helping a third of our climate goals” is repeated ad nauseam by proponents of offsetting and other false solutions to the climate crisis. The figure comes from a 2017 paper titled “Natural Climate Solutions” which is based on a series of flawed assumptions. For example, the researchers rely heavily on reforestation for about half of the carbon storage which would require covering an area the size of Australia in trees.

Restor, Crowther’s offsetting company

Crowther talks about the need for transparency. But he’s not talking about the need for transparency in the carbon offsetting industry. Carbon traders have a fondness for tax havens, such as the British Virgin Islands, Guernsey, and Delaware. Instead, Crowther is talking about companies and their supply chains.

He ends his presentation with a plug for his new organisation Restor.

It presumably just slips his mind to mention that some of the projects listed on the Restor website are offsetting projects. And that in November 2023, Restor started a US$1.1 million partnership with Terraformation.

Yishan Wong, CEO and founder of Terraformation recently explained that,

“We founded Terraformation to accelerate global reforestation as what we considered to be the most promising, and that’s a sort of non-legible word I’m going to use, solution to climate change. We sort of looked at all the possible organisational structures and we decided that a Delaware C-Corp is sort of the fastest way to driving collective action.”

So Crowther’s new venture is a carbon offsetting company that partners with Terraformation, a company aiming at “global reforestation” as a “solution to climate change” and which is incorporated in the tax haven of Delaware.

So much for killing greenwashing.

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