Stripe’s first carbon removal purchases

Why Stripe is buying carbon removal now

Climate models consistently show that staying within the 2 degree warming target adopted by many governments will require removing roughly 6 gigatons of CO2 from the atmosphere per year by 2050 — approximately the annual emissions of the United States. Last year, Stripe announced its Negative Emissions Commitment: at least $1M per year to pay, at any price, for direct carbon removal and secure long-term sequestration.

The projects that applied in response to Stripe's request fall into two broad categories. Storage in the biosphere — trees and soil-based agricultural practices — is cheaper and available today, but carbon held there can be released by fire or short-lived soil dynamics, and models suggest these solutions alone are unlikely to sustain the needed 6-15 gigatons of annual removal. Storage outside the biosphere, a more nascent field, includes direct air capture with underground injection into rock formations and mineralization of CO2 in concrete. These approaches are scarce and dramatically underfunded, but they offer thousand-year permanence and large storage capacity that doesn't compete with arable land.

Stripe has decided to focus its purchasing on the latter category, where early demand can help drive these technologies down their cost curves.

The first four purchases

From 24 applications reviewed by a panel of independent scientific experts, Stripe selected four projects. Stripe is the first purchaser from three of the four, and has pre-purchased volume for future years in cases where 2020 capacity is limited.

Climeworks

• Capture + storage
• Zurich, Switzerland
• 322.5 tons at $775 per ton

Climeworks uses renewable geothermal energy and waste heat to capture CO2 directly from the air, concentrate it, and, in partnership with Carbfix, permanently sequester it underground in basaltic rock formations. The approach is early in scaling but theoretically nearly limitless in capacity, permanent, and straightforward to measure. Climeworks targets a long-term price of $100-200 per ton.

Project Vesta

• Capture + storage
• San Francisco, USA
• 3,333.3 tons at $75 per ton

Project Vesta relies on coastal enhanced weathering: ocean waves grind down the mineral olivine, increasing its surface area, and as the olivine breaks down it captures atmospheric CO2 from the ocean and stabilizes it as limestone on the seafloor. The approach promises permanent sequestration at potentially very high volume and low cost, but safety and viability still need validation through lab experiments and pilot beach projects. Stripe's purchase — its first as a customer — will accelerate that safety study and deployment timeline.

CarbonCure

• Storage only
• Halifax, Canada
• 2,500 tons at $100 per ton

CarbonCure mineralizes CO2 into calcium carbonate within concrete, which has the side effect of strengthening the material. The technology is permanent, relatively low cost, and could scale with the global concrete market to sequester over 0.5 gigatons of CO2 annually. Today most of its CO2 is sourced from industrial emitters such as ethanol, fertilizer, and cement plants; as direct air capture becomes economical, it could supply the CO2 and turn the process into a full negative emissions technology. This is Stripe's first purchase of carbon sequestration from CarbonCure, and the transaction will subsidize the company's costs.

Charm Industrial

• Storage only
• San Francisco, USA
• 416 tons at $600 per ton

Charm Industrial produces bio-oil from biomass, retaining much of the carbon naturally captured by the plants, and injects it into secure geologic storage. That makes the carbon storage permanent. Stripe is the first customer for this approach, and the purchase allows testing to begin this year.

Open-sourcing the evaluation process

To guide the selection process, Stripe brought together experts across a range of disciplines and institutions. The full set of materials — project applications, project database, original purchase criteria, and expert review forms — has been published on GitHub, so other potential purchasers have better information and the process is auditable. CarbonPlan, a non-profit that evaluates carbon removal technologies, will keep a public database of project reports with independent analysis and visualization of the public data, including each application Stripe considered.

Expanding the effort beyond direct purchases

Stripe plans to broaden its commitment to carbon removal in two ways: funding early-stage research to grow the pipeline of projects with credible paths to ambitious impact, and raising money from other businesses — including many Stripe users who have offered to purchase alongside it — to create a larger market for carbon removal.

Stripe has also published a target criteria set characterizing the kinds of solutions needed to fill the gaps in the carbon removal portfolio. Projects don't need to meet these criteria today; the goal is to support approaches that could plausibly achieve them by 2040.

Stripe continues to look for projects, purchasers, and experts to work with, and can be reached at [email protected]. Engineers and designers interested in climate impact are also being recruited directly to join the team.