New peer-reviewed research finds that carbon offsets aren’t what they claim

Earlier this year, the Guardian released an article claiming that Verra’s rainforest offer credits are useless. Since then, research in Science has backed up the notion that carbon offsetting can do more harm than good.
September 14, 2023

Recapping carbon offsetting

Zero Carbon Academy have previously discussed carbon offsetting, its issues, and how the UK’s Climate Change Committee suggests we address some of these problems. To recap, carbon offsets are credits, usually paid to an offsetting company, that are invested into emission-reducing projects. Tree planting initiatives are a common example of a carbon offsetting scheme. Carbon offsetting is relevant for net zero goals because net zero is about balancing the carbon released into the atmosphere with the carbon taken out. Even if we fully decarbonise our industries, we still need to remove billions of tonnes of carbon dioxide from the atmosphere each year to not go above 2°C in climate warming.[i] That amount of carbon dioxide is the equivalent to the world’s annual food and concrete production.[ii] However, another common type of offsetting is not the removal of carbon from the atmosphere but rather avoiding the release of carbon. This is the case for at least 90% of the offsets traded in the voluntary market.[iii] For example, foresters can be paid to not cut down trees. 

REDD+ projects are a popular way of offsetting carbon. REDD+ stands for ‘reducing emissions from deforestation and degradation’. The aim of REDD+ projects is to slow deforestation. It works by comparing the carbon that would have been released due to deforestation to the carbon that has been saved because of the REDD+ project. Every 1 metric ton of carbon dioxide not emitted due to the project is then sold as a credit.

The Guardian exposé

In January 2023, the Guardian released an article claiming that over 90% of rainforest carbon offsets by the leading certifier, Verra, “are worthless” because they do not represent genuine carbon reductions.[iv] Verra strongly denied the claims, but later, its CEO stood down.

New research backs up the scandal

The Guardian was partially relying on some analysis that had not yet been peer-reviewed.[v] However, peer-reviewed research published this August backs up the idea that REDD+ projects in rainforests are not actually reducing deforestation and are instead worsening climate change.[vi] West et al. studied twenty-six REDD+ projects using Verified Carbon Standard credits in six countries across three continents. The researchers found that most of the projects did not substantially reduce deforestation. When deforestation was reduced, it was by much less than the projects claimed. Most shockingly, eighteen projects used credits to offset almost three times more CO2 than was actually prevented by the projects. There are 47.4 million more misleading credits that exist and could be sold as offsets in the future. A major reason why these credits are so misleading is because the baseline figures of how much deforestation would occur without the REDD+ projects are exaggerated.[vii]

Figure 1: Voluntary REDD+ project sites included in the study. (A) Peru and Colombia. (B) Democratic Republic of Congo (DRC), Tanzania, and Zambia. (C) Cambodia. Study areas are indicated in red. Purple areas are the sites excluded from the analysis.

Source: West et al. (2023) 

UK Watchdog response 

Since the research was published, the Advertising Standards Authority (ASA) has said that they are aware of several companies who have made false green statements after buying some of these useless offsets.[viii] Companies including Eni SpA, TotalEnergies SA, British Airways Plc and Nespresso of Nestle SA are amongst those who have purchased the credits.[ix]

This comes after the ASA published updated guidance on companies using the terms ‘net zero’ and ‘carbon neutral’ in their advertisements.


[i] Nature- Carbon offsets aren’t helping the planet — four ways to fix them

[ii] Ibid

[iii] Ibid

[iv] The Guardian- Revealed: more than 90% of rainforest carbon offsets by biggest certifier are worthless, analysis shows

[v] Science Alert- 'Worthless': Scientists Warn Carbon Offsets Are a Dangerous Illusion

[vi] West et al.- Action needed to make carbon offsets from forest conservation work for climate change mitigation

[vii] Ibid

[viii] Bloomberg- UK Watchdog Cracks Down on Junk Carbon Offsets as Stranded Assets Surge

[ix] Headtopics- UK Watchdog Cracks Down on Junk Carbon Offsets as Stranded Assets Surge

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Gemma Drake
Research Analyst

Gemma recently graduated with a degree in International Development. She is currently studying for an MSc in Sustainable Urbanism, which examines urban planning and urban design through a sustainability lens. “I’m passionate about addressing sustainability challenges in a holistic and pragmatic way. Zero Carbon Academy's diverse range of services targets many of the areas that need support if we are to transition to a liveable future. I’m excited to see the impact that the Academy makes.”

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