From theory to practice: how marine CDR deals come to life

Behind the deal: Boeing and Equatic

In April 2023, Boeing, the leading global aerospace company, purchased up to 62,000 tonnes of CDR from Equatic. As part of the deal, Equatic, a company that has developed an electrolytic process for atmospheric CDR that leverages the ocean, was also contracted to deliver up to 2,100 metric tonnes of carbon neutral hydrogen to Boeing.

As one of the earliest transactions in the space, Boeing's strategic offtake from Equatic marked a significant vote of confidence for mCDR – especially given the targeted focus on the project's co-benefit of producing green hydrogen – and aligned with both Boeing's and industry-wide decarbonisation goals.

Project profile: Equatic

Equatic is a marine CDR company that uses an electrolytic process to remove atmospheric carbon, first developed at UCLA. This innovative approach involves pumping seawater through an electrolyser which increases alkalinity. In turn, this increased alkalinity reacts with atmospheric CO₂, locking it away as either solid carbonates or in a dissolved bicarbonate form within the ocean.

One of the key benefits of this approach is the project's ability to accelerate a natural process: an Equatic plant has the capacity to remove a ton of CO₂ in just five minutes, while an equivalent surface area of the ocean would take 12 months. Crucially, Equatic's process also eliminates the need for geological sequestration, bypassing the complexities and costs associated with CO₂ pipelines and subsurface storage.

Another key benefit is the closed system nature of the project. This means that Equatic is able to directly measure what is coming in and out of the system, increasing verifiability and, in turn, buyer confidence.

The process is also highly energy efficient, partly due to the co-production of green hydrogen – a valuable commodity that can be sold. In addition, the production of calcium carbonate, which can be used for shoreline replenishment, serves as another co-benefit.

Electrolyser technologies have been a proven scientific method for over a century, making them an excellent choice of technology to scale.

Buyer profile: Boeing

A household name, Boeing is a multinational corporation and leading global aerospace company. Boeing develops, manufactures and services commercial airplanes, defense products and space systems for customers in more than 150 countries.

Boeing integrates CDR into both its internal corporate strategy as well as broader aviation industry goals. Internally, the company has been offsetting its Scope 3 corporate travel emissions since 2020, with a primary objective to increase the permanence of its portfolio over time. Durable CDR will be essential for the aviation industry – and Boeing is exemplifying this transition within its portfolio, demonstrating how a shift to permanent CDR can be achieved.

The company's selection criteria for CDR are stringent and continuously evolving, emphasising diversification across pathways. Beyond fundamental principles – such as additionality, leakage avoidance, and prevention of double counting, all of which align with CORSIA criteria – Boeing also endeavours to incorporate the best available science on the market.

Therefore, it is perhaps unsurprising that Boeing was interested in both aspects of Equatic's dual process. Not only does the Equatic facilitate best-in-class CDR, but it also produces green hydrogen – a key feedstock that can be used for sustainable aviation fuel (SAF), directly aligning with Boeing's sectoral interest.

Why does it matter?

This landmark transaction was one of the earliest and most substantial publicly announced mCDR deals.

Boeing's willingness to engage with mCDR early – even before established protocols from registries such as Isometric or Puro were fully in place – was crucial, and demonstrated its confidence in the technology.

As an early mover in the space, Boeing sent a clear market signal that encourages mCDR development and adoption, recognising that initiating with a project early is essential for securing future volumes.

Behind the deal: SkiesFifty and Gigablue

In January 2025, SkiesFifty, a unique investment company dedicated to sustainable aviation, announced that it had purchased 200,000 tonnes of CDR from Gigablue. This represents the largest mCDR transaction to date.

The record-setting deal with Gigablue, pioneers of the Marine Carbon Fixation and Sequestration (MCFS) sub-pathway, highlights the growing demand for scalable, affordable mCDR solutions that leverage and enhance natural oceanic processes.

Project profile: Gigablue

Founded in 2022, Gigablue is an mCDR company that applies the MCFS methodology – a process that uses the power of photosynthesis leveraging phytoplankton to convert carbon into organic matter and remove it from the atmosphere and export it to the bottom of the ocean, safely sequestering carbon for thousands of years to come.

This innovative approach aims to durably return carbon to ocean sediments, offering a natural and financially viable climate solution that requires little infrastructure: no large facilities, land, engines, or pumps.

The MCFS solution developed by Gigablue involves a proprietary substrate, described as a ‘tiny pellet’, that acts as an optimal environment for local phytoplankton to grow and convert carbon into organic matter, capturing CO2 in the surface ocean. After 10-18 days, a gravity core within the pellet triggers its sinking. The trigger is based on geo-optimisation using a data platform that adjusts to various environmental factors.

One of the key benefits is Gigablue's measurement, monitoring, reporting, and verification (MMRV) framework that offers full traceability of CO₂ capture all the way to sequestration, and also allows for physical samples from the deep ocean. In collaboration with Gigablue, Puro.earth has launched the first MCFS methodology for public consultation (as of July 2025). This public consultation allowed scientific experts around the world to provide feedback on the suggested protocol, overall contributing to a more robust framework. Due to the complex nature of open-system methodologies, a robust scientific framework is key to ensuring safe ocean mCDR practices and accurate MMRV.

Looking ahead, Gigablue aims to scale up to 750 kilotones by 2027, megaton (MT) scale by 2028, and 18 MT in 2030.

Buyer profile: SkiesFifty

SkiesFifty is a unique London-based investment company dedicated to “funding the journey to carbon-neutral skies by 2050” and investing in the technologies that will make a difference to a carbon-neutral future for aviation.

The company recognises that the aviation sector, like many others, cannot continue emitting without effective carbon removal and has incorporated durable carbon removal (CDR) as a critical part of its strategy.

Their founding partner Simon Talling-Smith explained, “We are constantly evaluating projects and we were deeply impressed by Gigablue’s ocean-based CDR solution. It stood out due to its combination of environmental safety, durability, scalability and robust scientific measurement. We believe CDR will be an important part of the portfolio of solutions that will lead us to net zero for aviation by 2050.”

SkiesFifty approaches projects as a commercial investor, seeking financial returns with purpose with the belief that value and impact go hand in hand.

Why does it matter?

The transaction between SkiesFifty and Gigablue represents the largest mCDR deal to date, and signals strong confidence in the pathway, particularly given SkiesFifty’s role as a major player in the aviation industry.

The transaction further underscores that buyers are increasingly looking for large-volume, affordable, and scalable solutions to meet their net zero commitments and prepare for potential future regulatory obligations as the need for removals becomes hard to ignore.