Britaldo Silveira Soares Filho was on a boat on Brazil’s Rio Negro river the first time he was asked to help rubber-stamp a carbon offsetting project.

The professor and expert in deforestation modelling spent three days on the boat in 2007 — along with an array of other academics focused on the Amazon rainforest — tasked by a Brazilian NGO with examining the science behind a forest conservation programme.

Later, in an office in São Paulo, he decided he didn’t want his world-leading software used for the project or others like it. To this day airlines hope backing schemes like this will help them hit climate targets.

“It’s a scam,” he said. “Neither planting trees nor avoiding deforestation will make a flight carbon neutral.”

Fossil fuels have long been the cheapest and most efficient way to fuel planes, and sustainable fuels that can be used at scale are still a long way off. But the aviation sector, which has pledged to cut emissions in half by 2050, while still allowing more and more people to fly, desperately needs to find ways to reduce its carbon footprint quickly. Increasingly airlines are turning to offset programmes to help achieve this — including reduced deforestation projects where companies buy carbon credits from projects that promise to preserve forests. 

Last year, British Airways announced that its passengers could “fly carbon neutral” by buying credits for protection schemes in threatened forests. EasyJet relies on offsetting projects in Peru and Ethiopia as part of its drive to “become a more carbon neutral airline” and Delta, one of the world’s biggest airlines, uses avoided deforestation projects to support its claim that it is set to become the “first carbon neutral airline globally”. Air France, Iberia, Qantas and United Airlines have all unveiled similar programmes designed to offset passenger emissions through protecting forests.

But a detailed examination of how these schemes calculate their carbon savings by  Unearthed and the Guardian, with SourceMaterial, has found evidence that raises serious doubts about the ability of these projects to offset emissions in line with the claims of major airlines. The investigation also suggests that the current flagship system for offsetting emissions through avoided deforestation may not be fit for purpose.

We analysed 10 reduced deforestation offsetting projects relied on by major airlines as part of their emissions reduction pledges and certified by Verra, the biggest issuer of carbon credits in the world. We conducted satellite analysis of deforestation in and around projects backed by BA, easyJet, and United Airlines, examined project documentation, interviewed multiple leading experts, and commissioned on-the-ground reporting.

The investigation revealed that, although projects often provide benefits to the environment and local communities, attempts to quantify, commodify and market the resulting carbon savings as a “carbon offset” are based on shaky foundations.  

We found that despite multiple audits the reduced deforestation offsetting schemes used to justify eye-catching promises of carbon neutrality and guilt-free flying cannot prove they have produced enough carbon savings to justify these bold claims.

Avoided deforestation schemes generate and sell carbon credits based on the amount of deforestation they claim to prevent. In order to work out these carbon savings, they try to predict how much deforestation would take place if the project didn’t exist. Although the scenario is hypothetical, offsetting schemes use deforestation rates in comparable areas of nearby forest, so-called reference regions, to come up with an estimate. 

The key findings that emerged from the investigation:

  • Satellite analysis of tree cover loss in the projects’ reference regions, carried out by leading consultancy McKenzie Intelligence Services, found no evidence of deforestation in line with what had been predicted by the schemes.
  • The analysis of schemes backed by BA, easyJet and United suggest the scale of the carbon benefits they offer is impossible to verify and may be exaggerated.
  • The offsetting market may not be fit for purpose because projects calculate their climate benefit using what some experts viewed as simplistic methodologies that fail to account for the impact of markets and governments on deforestation.
  • One environmental expert whose deforestation modelling software was used by many projects said flawed methodologies could generate “phantom credits” that represent “no impact on the climate whatsoever”.  
  • Discussing a project backed by BA, a government official responsible for reduced deforestation projects in Peru called the calculations behind offsetting schemes a “Pandora’s box” and “arbitrary”.
  • Projects are only set to last a short period of time, sometimes only a couple of decades, meaning that the carbon savings claimed by airlines for forest preservation are not guaranteed over the longer term.
  • One of the projects is run by two logging companies that cut down ancient and rare trees. 

“It’s a scandalous situation,” Philip Fearnside, an ecologist at the National Institute for Research in Amazonia, said of the current state of the REDD+ system. “Most of this is pure public relations.” 

The findings come as the carbon offset market is reaching a crucial turning point. The UK chancellor Rishi Sunak is aiming to make London the global hub for the trade of voluntary carbon offsets and former Bank of England governor Mark Carney is leading an effort to grow the sector with a task force of organisations involved in the market.

They also come as Verra, the largest issuer of avoided deforestation credits is overhauling its methodologies to help the market scale-up and following repeated media stories about the validity of the credits it produces. 

In a statement, Verra said that Unearthed and the Guardian did not understand how its methodologies work, that the investigation was “fatally flawed” and had not produced fact-based journalism, ignoring their success at preserving forests. 

The Verra methodologies are not robust enough. That means there is room for projects to generate credits that have no impact on the climate whatsoever


Thales West, former REDD+ auditor

A guessing game

Protecting forests is crucial if the world is to avoid catastrophic climate change and carbon offsets are intended to offer a mechanism to achieve this. 

Since at least 2005, the UN has been discussing the idea of paying to protect forests. The idea was formalised in a collection of policies known as Reducing Emissions from Deforestation and Degradation (REDD), later REDD+, to fund conservation projects in developing countries, with the goal of mitigating climate change. The first REDD+ project began issuing carbon credits in 2011. 

There is no central body to regulate these projects and carbon offset markets, meaning various companies have carved out a niche issuing carbon credits and certifying standards. These include Verra, the certifier of all the projects analysed in this investigation. It has certified nearly 1,700 projects around the globe, including projects that prevent deforestation. Today if a company needs to cut its emissions quickly, it can buy offsets from a Verra-certified project that stops trees from being cut down in an area of threatened forest. 

A project has to go through a series of checks before it gets certified, to show that it will help conserve an area that faces a real threat of deforestation. Crucially, it needs to prove “additionality” — that the trees would not have been saved if the project had not existed. 

To do this, a project calculates a baseline scenario of deforestation it predicts would happen if it didn’t exist. This is the yardstick a project measures itself against and the basis on which it generates carbon credits for preventing deforestation. The higher the baseline, the more credits a project can issue. 

Illustration: Georgie Johnson/Unearthed

But the way baselines are calculated makes it possible for projects to overestimate their climate benefit by miscalculating the level of deforestation that would occur if they didn’t exist. 

To come up with a baseline a project identifies a “reference region”, which is usually an area of forest near the project with similar characteristics. Projects use estimates of deforestation in this region — sometimes along with specific threats to the project area itself such as a new road or population growth —  to assess the threat of deforestation in the project area itself.

Aviation companies buying REDD+ credits are just postponing action. It would be better to spend money investing in research on more efficient jets or alternative fuels


Britaldo Silveira Soares Filho, deforestation modelling expert

The decision of which region to choose introduces further complications. An offsetting project supported by easyJet in a remote area of forest in the Madre de Dios region in Peru, for example, used a much more heavily populated area as a reference region, meaning its deforestation potential was much higher. 

Importantly, reference regions are not intended as a control a way of validating how much deforestation would have taken place in the real world without the project. That means there is no way to check if deforestation would have fallen without the project, due to factors beyond the its control. The carbon savings sold to consumers by airlines are defined by models that are not tested against reality. It’s a situation that concerns some scientists and experts.

Verra does not accept these concerns but is adapting its methods. The US-based not-for-profit is planning significant changes to baselines. Instead of choosing reference regions, historic and future deforestation will be calculated at the national level before being broken down locally. Projections of future deforestation will be based on past deforestation in that region, removing the possibility to pick and choose their reference regions. Verra also says baselines will be based only on recent deforestation and will be reviewed every four to six years. 

But gaps remain. Credits will still be issued to projects for avoiding deforestation regardless of major changes in national policy; projects can issue credits even if deforestation in the country they are based in continues to rise; there is no guarantee forests will not be cut down in future after projects some of which are only scheduled to last 20 years end and, crucially, there remains no way of verifying if projects’ claims for their impact, based on historical models, are accurate in the real world. 

The changes will also only apply going forwards. The credits sold by airlines today, and in the past, won’t be affected.

Alexandra Morel, an ecosystem scientist at the University of Dundee, told us that it’s difficult to judge if the emissions reductions claimed by REDD+ projects are real. 

“It’s impossible to prove a counterfactual,” she said. “Rather than just valuing what forests are actually there, which are actively providing a carbon sink or store right now, we have to surmise which forests would still be here versus which ones are the bonus forests that were spared from the theoretical axe. It is so abstract.” 

“The Verra methodologies are not robust enough,” said Thales West, who previously worked for five years as an auditor of REDD+ schemes. “That means there is room for projects to generate credits that have no impact on the climate whatsoever.” 

West, a scientist at the New Zealand Forest Research Institute, said that Verra generates many carbon credits from projects where the benefit is much easier to quantify, such as those related to renewable energy use and reforestation, or tree-planting. “The problems come with these REDD+ methodologies,” he said, “where you simulate these deforestation baselines because there’s no perfect way to create those.”

Verra’s proposed changes, West said, “will likely make the problem smaller, but the problem will still be there”. He pointed out that using historical rates to predict the future means changes in the wider world, like fluctuations in agricultural prices or shifting government policies, will be ignored.

West was the lead author of a study published in September 2020, which looked at 12 projects offering carbon credits for avoiding deforestation in the Brazilian Amazon. The research found that the schemes had been too simplistic in drawing up their baselines. 

By focusing on average historic deforestation rates, the projects had failed to account for the impact of government policies introduced in the mid-2000s long before President Jair Bolsonaro took office which reduced deforestation. “We find no significant evidence that voluntary REDD+ projects in the Brazilian Amazon have mitigated forest loss,” the study concluded.

One of the projects the study examined was the Floresta de Portel REDD+ project in Pará, northern Brazil, which is part of Air France’s commitment to offset all the emissions from its domestic flights. West’s study found that despite claims the project was protecting the area from devastating deforestation levels, it had very similar deforestation levels to an unprotected control area West identified nearby.

Since this study, under the presidency of Jair Bolsonaro, deforestation levels have shot up in Brazil. But even if this now means some of the predictions of forest loss by REDD+ projects in Brazil have come true, it does not vindicate Verra’s methodologies, said West.

“It’s not ideal to rely on luck to generate carbon credits. You want to rely on a methodology that is robust enough, so it doesn’t have to rely on perfect conditions.”

When asked to comment on its support for the Portel project, an Air France spokesperson said carbon offsetting is “part of a larger scheme to address our GHG emissions”. Michael Greene, a spokesperson for the Floresta de Portel project, said the project had acted as a bulwark against the impacts of illegal loggers and cattle ranchers, noting how deforestation was now increasing.

Modelling carbon savings 

To try to predict deforestation more accurately, Verra currently permits projects to use a piece of software called Dinamica EGO. This allows users to forecast land-use changes over time and was developed by Soares Filho.

Unearthed and the Guardian found 13 projects that cited Dinamica EGO when discussing how they designed their projects.

But this software was never intended for use by REDD+ projects. Dinamica’s website features the disclaimer: “We do not support the application of deforestation modelling to fix REDD baselines for crediting purposes.”

Instead, Dinamica was designed to be used to monitor the potential impact of specific policy decisions, said Soares Filho. In 2006, for example, he and his colleagues used it to model the devastating impact the expansion of the cattle and soy industries could have in the Amazon basin. What the software can’t do, Soares Filho said, is make a definitive estimate about future forest loss in a given area, due to all the different factors that come into play. 

Soares Filho said: “Models are used to avert an undesirable future, not predict the future. Models are not crystal balls. Models are a sign to help devise policy and evaluate policy choices.” 

Farm Africa, the charity that manages one of the projects backed by easyJet that used Dinamica EGO, said in response to our story: “We remain confident that the deforestation scenarios the model produced are the best that science could provide at that time.” They also stated that they were not aware of Dinamica’s online disclaimer and were not sure if it was present on the website when the analysis was conducted in 2013. 

For Soares Filho, the issue goes beyond the use of one model. “Aviation companies buying REDD+ credits are just postponing action,” he told the Guardian and Unearthed. “It would be more efficient investing in research on more efficient jets or alternative fuels, for example. But of course, it is always more expensive than a REDD+ project.” 

“Deforestation modelling to fix REDD+ baselines results in phantom carbon credits,” he added.

‘Fly carbon neutral’

The projects used by airlines are subject to multiple audits and checks by Verra and independent third parties. But we have learned that projects do not have to check whether their predictions about the threat of deforestation, which form the basis of all carbon credits issued, turn out to be true, because there is no control region. 

To get an indication of whether or not the projects’ future deforestation forecasts had come to pass, Unearthed and the Guardian commissioned a new satellite analysis. Of the 10 schemes that we examined, four, backed by BA, easyJet and United, had made deforestation projections about a surrounding reference region that could be easily examined.