Stripe has added these four start-ups to its climate portfolio

22 Dec 2021

Image: © Ryan/

Carbon capture start-ups 44.01, Ebb Carbon, Eion and Sustaera are the latest companies to be added to the Stripe Climate portfolio.

Stripe is spending $6m on carbon removal purchases from four new start-ups, bringing its total carbon removal commitments to $15m.

The four companies have been added to the portfolio of Stripe Climate, the digital payment company’s product that allows businesses to automatically direct a fraction of their revenue on Stripe towards carbon removal technologies. More than 15,000 companies across 40 countries have joined in Stripe’s commitments so far.

Stripe has expanded its panel of climate experts to help identify new technologies to add to its portfolio, and said its latest round of carbon removal commitments will help high-potential companies scale.

The company will provide $2m to help bring these technologies to market and will make an additional $4m worth of purchase commitments to help the companies achieve further scale if they reach a set of technical milestones.

Here are the four latest start-ups to be added to Stripe’s portfolio.


This London and Oman-based start-up is on a mission to turn carbon dioxide into rock. It aims to do so through a mineralisation process, where clean energy is used to inject CO2 underground and react with an igneous rock called peridotite that is abundant in the Earth’s mantle, permanently storing the CO2 deep under the surface.

44.01 was founded in 2020 by Oman-based investment manager Talal Hasan, who was born in a family of environmentalists. According to TechCrunch, he collaborated with Columbia University climate researchers Peter Kelemen and Juerg Matter, who are on 44.01’s scientific committee, to capitalise on Oman’s vast abundance of peridotite hills. In August, the start-up raised $5m in a seed funding round backed by Apollo Projects and Breakthrough Energy Ventures.

Ebb Carbon

Ebb Carbon aims to enhance the ocean’s ability to capture and retain CO2 from the Earth’s atmosphere as bicarbonate while simultaneously reducing ocean acidity through electrochemistry. The ocean has a natural ability to absorb carbon, but this makes the water highly acidic – threatening marine life.

Ebb Carbon’s technology is designed to work with industrial plants that treat saltwater from the oceans to turn them into drinking water. Using electrochemical processes, it is looking to make an acid that can be removed from the water and sodium hydroxide that can be returned into the water and can absorb carbon from the atmosphere – storing it for more than 10,000 years.

Ebb Carbon was founded earlier this by Ben Tarbell, Matthew Eisaman and Todd Pelman and is based in San Carlos, California.


This start-up focuses on mineral weathering, using pulverised minerals to absorb CO2 from the atmosphere in a process that can be deployed in agricultural lands.

Eion technology uses enhanced rock weathering, which accelerates mineral weathering. Using existing on-farm technology, this crushed silicate rock can then be added to agricultural soil – which, in the presence of moisture and acidity occurring in the soil, dissolves and causes CO2 to be absorbed from the atmosphere. This forms bicarbonate ions that, over time, find their way to the ocean where they are stored.

The start-up was founded last year by CEO Adam Wolf and CTO Elliot Chang.


Sustaera is on a mission to remove 500m tonnes of CO2 from the Earth’s atmosphere by 2040 using renewable energy and ceramic monolith air contractors to capture CO2 and store it deep underground. It uses a cheap and abundant alkali-based material to absorb CO2 and its process can run entirely on clean energy. Its direct air capture system is built with modular components and designed for quick manufacturing and capturing at scale.

Founded earlier this year by CEO Shantanu Agarwal and CTO Raghubir Gupta, Sustaera is based in Cary, North Carolina. The start-up recently raised $10m in a Series A funding round led by climate funds backed by Bill Gates and British billionaire investor Jeremy Grantham.

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Vish Gain is a journalist with Silicon Republic