Overview of Climeworks

Climeworks is a Switzerland-based company that does Direct Air Capture (DAC) and either sequesters collected CO2 underground or sells it for commercial purposes including to a Swiss greenhouse and to Coca-Cola Switzerland. Climeworks has a policy against working with fossil fuel production companies, which are a common partner for DAC companies as certain types of fossil fuel extraction can be made more efficient and productive by injecting CO2 underground in a process called Enhanced Oil Recovery (EOR). The climate impact of these projects is debated, which is why Climeworks’ focus on other types of projects is compelling.

The company uses technology it created to collect CO2 from the surrounding air. This happens through a two-step process of drawing air into a “collector” using large fans and then using filters to capture CO2. After the CO2 is in the filters, the company heats the filter which releases the CO2 and enables capture. The company has two operational facilities, one in Switzerland that uses the CO2 for commercial purposes and one in Iceland that uses the CO2 for Carbon Direct Removal (CDR) credits:

  • Commercial purposes: Climeworks’ facility in Switzerland captures CO2 and provides it to commercial partners for use in their businesses. They have partnered with a Swiss greenhouse that purchases their captured CO2 for use in agricultural practices. They also sell CO2 to a Swiss Coca-Cola bottler, where it is used to create the bubbles in soft drinks. They hope to expand their commercial work to more companies that want eco-friendly ways of obtaining CO2.

  • CDR credits: Climeworks also sells CDR credits on the voluntary market through their facility in Iceland. After capturing CO2, Climeworks injects the CO2 deep underground into geological formations where the CO2 reacts with the minerals around it and forms solid materials. This is considered the safest way to store CO2 as it is extremely unlikely to leak back into the atmosphere. When someone purchases a carbon offset from Climeworks, the company puts that money into the operational costs associated with running their CCS project. The Climeworks team claims that the CDR credits that they sell go directly to removing additional tons of CO2 removed from the atmosphere, as all of the money they receive goes into operational and modular expansion costs (more on this below).


There are a few elements to establishing causality of DACS projects:

  • Successful carbon capture

  • Successful sequestration

  • Leakage of CO2

  • Energy cost of running machines

Successful carbon capture

We believe that Climeworks is successfully capturing CO2. They are still undergoing the process of carbon offset verification with two independent agencies, after which we will have better data on how their claims of carbon capture match with reality. But all indications that we have received (including having spoken with experts about their work) lead us to believe that they successfully capture carbon.

Successful sequestration

Climeworks does a good job of tracking and making available information on their carbon sequestration process. They inject CO2 underground in areas where the CO2 will react with the underlying geology and form solid material. They have filmed this process to confirm its validity. We trust that they are successfully sequestering the CO2 that they capture.

Leakage of CO2

Unlike most DACS projects that inject CO2 underground and hope that it does not leak back to the surface, Climeworks injects their CO2 in specific areas to ensure that it changes into a solid material. They also track this process to double-check that it is actually happening. We view the likelihood of leakage of CO2 with Climeworks as very low.

Energy cost of running machines

DACS projects can be energy-intensive. To combat this, Climeworks has built their system on top of a geothermal power plant which provides them renewable energy meaning that the carbon footprint of their operations is relatively low. We are sufficiently convinced by their operating model to believe that their carbon footprint is far outstripped by the CO2 they capture and sequester.

While we believe that the tenants of Climeworks’ carbon removal are solid, they are not certified by any of the offset certifiers. Climeworks says they are working on this, and hope to have certification in 2021. This would give an added layer of certainty, since it would require verification of Climeworks’ activities by a third party.

Overall, we think the causality of Climeworks’ projects is very clear, and rate it as ‘High’.

Project-level additionality

Climeworks’ projects require a significant upfront capital investment and ongoing operational costs. The funds from CDR credits purchased from Climeworks are used to cover the ongoing operating costs of offsetting CO2 at the Iceland facility, which is where Climeworks captures CO2 and sequesters it underground. There are additional ancillary benefits from each offset purchased, including that they act as a signal of consumer demand for Climeworks’ CDR credits and thus encourage investors to invest in Climeworks. Private sector investment is crucial to Climeworks’ future as it enables R&D and setting up new facilities. We created the following graphic to explain how the Climeworks team described the importance of carbon offset to Giving Green:

  • Purchasing CDR credits from Climeworks leads to more revenue for Climeworks as shown by the GREEN boxes (which can be used in many ways).

  • As shown in the BLUE boxes, the Climeworks team claims to use CDR credits primarily for covering operational expenses related to CCS and to go towards paying back the loans they took to build the CCS facilities (not the main business, but just the loans for the CCS facilities). Selling CDR credits on the market also provides a signal to investors of the market potential of this technology.

  • This signal of market potential will hopefully attract additional investors into the market. Additional investment is used for R&D and setting up new projects, which are represented by the ORANGE boxes.

Because of the compelling need for CDR credits, we place their project-level additionality at ‘Medium’.

Marginal additionality

Climeworks’ operational costs are extremely high, including expensive maintenance on their machines and the cost of injecting the CO2 underground. CDR credits go towards these operational costs and, according to the company, directly enable more CO2 to be captured and injected underground by “keeping the lights on.” As such, we are confident that Climeworks’ CDR credits are highly additional.

Beyond the immediate CO2 removed at the Iceland facility, there three other reasons that buying these CDR credits could help in combating climate change:

  • These CDR credits signal to investors that there is a market for DACS technology (point #2 from the previous section), which means that more investors are likely to push money into developing better DACS technology and expanding the company’s projects. We believe that this will have downstream effects on the amount of CO2 that can be captured and stored in the long-run.

  • Climeworks has built their technology to be modular, meaning that they can add small additional units that increase their capacity for CCS. While we do not believe that CDR credits are currently being used to expand the number of units they use (the company is not profitable and they are still using CDR credits to cover operational costs), it is possible that CDR credits will be used for this purpose if enough are purchased.

While Climeworks states that offset income is used to support their carbon sequestration activity, there’s always the possibility that it also supports their commercial side, since money is fungible. We are comfortable with this possibility because we also suspect that the commercial side of Climeworks' business is carbon negative relative to the next best alternative, meaning that any benefits from buying CDR credits to the overall business (e.g. expanded investment) will also have climate impact by reducing the climate footprint of the companies that partner with Climeworks. For instance, Climeworks partnered with a bottler for Coca-Cola to provide CO2. If they had not provided the CO2, then that bottler would have gotten it from another source, either produced for that purpose or captured from industrial processes. While we have not focused on this part of their business in this investigation, we expect Climeworks CO2 to be more carbon negative than the average alternative CO2 that their partners would purchase.

Another concern with marginal additionality is that Climeworks is a for-profit company, which means that their offset income may eventually go to profits as opposed to removing CO2. While this can be concerning with some companies, we are not yet worried about this with Climeworks for two reasons: (1) they are not currently profitable meaning that the concerns mentioned above are not currently problems. (2) They require a significant upfront capital investment to create their technology and plants. This is unlikely to happen without a profit motive for investors, meaning that a for-profit structure is likely one of the only ways that this technology and these projects could exist. While we are currently satisfied with the information we have received from Climeworks, we hope that in the future they will share their financial publicly so that CDR purchasers can be sure the offset funds are being used for CO2 removal.

We rate Climeworks’ marginal additionality as ‘High’. We believe that each CDR credits purchased from Climeworks will meaningfully contribute to removing CO2 from the atmosphere.


We view Climeworks’ DACS process as highly permanent. They inject the CO2 into areas where it will react with the local geology and form solid material. They have tracked this carefully and we are confident that the process works as they outlined. By converting the CO2 into a solid material, it avoids the normal problems about leakage that many carbon offset projects face and, thus, we judge this to be one of the most certain carbon offsets available.


There are no co-benefits from Climeworks’ CDR credits.


We recommend purchasing CDR credits from Climeworks for the following reasons:

  1. We are very sure that their project is permanently removing CO2 from the atmosphere.

  2. We believe that each dollar invested in their work will additionally remove carbon.

  3. We are convinced that investments in their work right now are entirely being used to offset carbon as opposed to simply maximizing profit.

  4. We see long-term potential in their DACS technology.

The main drawback of Climeworks is that it is currently very expensive (around $1000/ton) to remove carbon relative to other options. This may be justified by the fact that supporting Climeworks will hopefully go toward reducing the cost of their frontier carbon-removal technology. You can purchase CDR credits from Climeworks at this link.

We thank Dr. Jan Wurzbacher, Co-Founder of Climeworks, and several other experts for a series of conversations that informed this document.

Select sources

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“The Concept of Geologic Carbon Sequestration.” USGS , Mar. 2011,

Brennan, S.T., Burruss, R.C., Merrill, M.D., Freeman, P.A., and Ruppert, L.F., 2010, A probabilistic assessment methodology for the evaluation of geologic carbon dioxide storage: U.S. Geological Survey Open-File Report 2010–1127.

Sundquist, Eric, Burruss, Robert, Faulkner, Stephen, Gleason, Robert, Harden, Jennifer, Kharaka, Yousif, Tieszen, Larry, and Waldrop, Mark, 2008, Carbon sequestration to mitigate climate change: U.S. Geological Survey Fact Sheet 2008– 309.

“What’s the Difference between Geologic and Biologic Carbon Sequestration?” What's the Difference between Geologic and Biologic Carbon Sequestration?, 2020,

Douglas W. Duncan and Eric A. Morrissey. “The Concept of Geologic Carbon Sequestration, Fact Sheet 2010-3122.” USGS Publications Warehouse, 2010,

“CCS Explained.” UKCCSRC, 13 Dec. 2019,

Roberts, David. “Pulling CO2 out of the Air and Using It Could Be a Trillion-Dollar Business.” Vox, Vox, 4 Sept. 2019,

“Geologic Sequestration in Deep Saline Aquifers.” Geologic Sequestration in Deep Saline Aquifers | EARTH 104: Earth and the Environment (Development), 2020,

“Sequestration Map MIT.” Google Maps JavaScript,

Elliott, Rebecca. “Carbon Capture Wins Fans Among Oil Giants.” The Wall Street Journal, Dow Jones & Company, 12 Feb. 2020,,natural%20gas%20or%20making%20cement

Kintisch, Eli. “Can Sucking CO2 Out of the Atmosphere Really Work?” MIT Technology Review, MIT Technology Review, 2 Apr. 2020,

Peters, Adele. “We Have the Tech to Suck CO2 from the Air–but Can It Suck Enough to Make a Difference?” Fast Company, Fast Company, 17 June 2019,

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