A major climate change emissions debate is centered around a recent big tech plan for carbon removal.

• Tech-led corporations are adopting various strategies to address carbon emissions, but the effectiveness of CO2 capture and storage methods is still a topic of discussion.
• The companies Google, Meta, Microsoft, and Salesforce are collaborating on a new strategy to remove carbon from the atmosphere through natural CO2 storage systems, including reforestation, afforestation, and revegetation.
• Some experts argue that nature-based carbon storage is less secure than advanced technologies such as direct air capture and industrial carbon sequestration facilities.

The certainty of corporations' commitment to combating climate change has decreased since a few years ago when many major companies set ambitious carbon reduction targets with minimal opposition. However, some companies have seen their emissions increase, particularly those whose energy needs for AI have grown. As a result, some companies are reevaluating or abandoning their ambitious carbon goals due to concerns about cost, timeline, and potential legal action.

The four largest technology companies, namely , , , and , are collaborating to develop a new strategy in the contentious area of CO2 removal and storage. They have recently established the Symbiosis Coalition to create an "advance market commitment" for nature-based removal credits in the carbon market, as stated in a press release from the group.

The importance of market efforts to remove carbon is growing, as climate experts have stated that reducing emissions from industrial usage alone will not stop the climate crisis. According to the International Panel on Climate Change, 20 billion metric tons of carbon need to be removed annually, which has raised the profile of negative emissions, or the actual removal of CO2 from the atmosphere, through methods such as direct air capture, carbon capture and storage, and nature-based removal and storage.

Symbiosis adopts a nature-based scale approach inspired by a vaccine model, where a buyer or group of buyers agrees to purchase or subsidize an effective vaccine for a neglected disease if it is developed, with the aim of incentivizing development by frontloading demand.

Julia Strong, Symbiosis' executive director, emphasizes the importance of promoting "high-quality nature-based carbon removal" technologies and committing to purchasing up to 20 million tons of removal credits by 2030. Experts note that while "nature-based" is relatively straightforward to define, "high-quality" and "measurable" remain challenging to define amid growing pressure on companies to demonstrate the credibility of their carbon accounting mechanisms.

According to Strong, meeting our climate goals requires immediate support for nature conservation and restoration.

Symbiosis is committed to promoting the development of climate-positive technologies through specific initiatives such as afforestation, reforestation, and revegetation projects. Each project has its own set of criteria, and Symbiosis aims to encourage the use of nature-based approaches to achieve real, measurable positive climate impact.

Nature as a climate solution is under attack

The method of using nature for climate mitigation is also being criticized, and the approach being taken by tech giants highlights a disagreement among climate experts about the most effective way for companies to address emissions, with some arguing that nature-based carbon storage has limitations.

Dr. Allanah Paul, a CO2 removal and carbon accounting expert based in Europe, stated that nature-based carbon removals, such as soil carbon sequestration, temporarily store carbon in living biomass. However, these methods offer "less reliable carbon storage" than non-nature-based methods, with natural storage systems vulnerable to natural impacts like forest fires, torrential rains, and earthquakes. Additionally, human activities, such as changes in land usage, can disrupt the functioning of these carbon storage systems in ways that non-nature-based strategies are not subject to.

While nature-based systems may be effective in storing carbon temporarily, tech-based solutions like direct air carbon capture can permanently store carbon in minerals or reservoirs deep in the Earth's crust. Chemically engineered processes may be more effective in locking captured carbon away in geological formations permanently, according to Paul.

Nature-based methods may be disrupted by climate change, including weather extremes and shifting population locations, and the focus should be on reducing carbon emissions rather than capturing it, according to Paul. "Offsetting an avoidable emission with a temporary removal does not align with the physics of our climate system," she said, emphasizing that it enables mitigation deterrence.

The Coalition for Negative Emissions states that nature-based carbon removal has several advantages, including being immediate, inexpensive, and highly effective in the short-term. However, afforestation, which can be pursued at a local level without significant infrastructure and investment, faces a challenge in terms of its permanence.

Despite the potential for verifying the success of such methods, critics argue that carbon capture simply allows emitters to pay their way rather than make meaningful changes to reduce their emissions, which is the more effective climate action. "By offsetting emissions in this way, we are at best maintaining the status quo and at worst perpetuating business as usual and hiding the cracks with accounting tricks," they said.

The energy demands of the current AI boom have brought those emissions into greater focus, as tech firms invest heavily in AI data centers.

The complexity of carbon accounting remains a challenge for Symbiosis, and Paul is skeptical about the project's ability to overcome this hurdle. She warned that the project may result in greenwashing if verifiability is not ensured. If verifiability is a priority, Paul suggested reducing emissions as a more direct route.

The tech sector needs to prioritize certain interventions, such as climate infrastructure and renewable energy deployment, to fully decarbonize their activities, she argued.

The Integrity Council for the Voluntary Carbon Market Core Carbon Principles was pointed out by Strong, indicating that companies joining its coalition not only demonstrate demand for nature-based carbon solutions but will also drive investment.

The rise of negative emissions

The central point of criticisms of nature-based carbon removal is overlooked by other climate experts. According to Paul Davies, a member of the Coalition for Negative Emissions and the report's primary author, there is no hope of staying below 1.5 degrees of warming if an industry that can remove CO2 from the atmosphere at scale is not developed. As a purchaser looking to offset residual emissions, companies should prioritize purchases of robust negative emissions, Davies stated.

The Symbiosis Coalition, with the players involved, will accelerate and intensify the growth of nature-based carbon-capture techniques. However, the program emphasizes that this is not the only solution, but rather that the most effective nature-based methods must be verified for their effectiveness.

Nature-based and tech solutions are necessary to achieve significant carbon removal, according to Haley Leslie-Bole, manager, US Lands and Climate, at the World Resources Institute. She explained that purely nature-based approaches aim to increase the amount of carbon sequestered by natural processes like photosynthesis that remove carbon from the air as plants grow.

While nature-based carbon removals have their advantages, such as the potential for long-term carbon storage, they also present challenges. These challenges include the shorter duration for carbon removal relative to tech-based approaches, the higher risk of subsequent re-release of sequestered carbon, and the difficulty and cost of accurately measuring and monitoring nature-based carbon removals. For instance, the potential for long-term reversals of sequestered carbon introduces accounting complexities.

"Leslie-Bole stated that Symbiosis aims to increase the demand for high-quality nature-based carbon removal by setting stringent removal quality standards. The companies in Symbiosis have committed to purchasing CDR from projects that meet their high-quality criteria, with the goal of enhancing the overall quality of nature-based CDR projects."

Symbiosis, which is backed by some of the same companies, is also involved in a sister initiative, Frontier, that demonstrates their approach of pursuing both nature and technology. Frontier is a market commitment for tech-based CDR with the same goal of scaling carbon-capture. Leslie-Bole, who supports efforts to scale all types of CDR, stated that all pathways must meet robust quality criteria and deliver real removals.

The Coalition for Negative Emissions has stated that no one is arguing that carbon removal is a superior strategy to emitters reducing their actual emissions, or should be viewed as a "get out of jail free" card.

"While reducing emissions is crucial for meeting climate targets, the reality is that negative emissions, such as certified carbon removals, are a preferred method over simply investing in credits for emissions reductions of others."

By 2030, companies will have the option to purchase negative emissions at scale.

The State of Carbon Dioxide Removal organization's most recent report highlights the challenge of reducing emissions quickly enough, which makes CDR a necessary backup plan for climate restoration. However, its true scale of application remains uncertain.