Purifying the atmosphere: how Swiss technology removes CO₂ from the air
Direct air capture makes the impossible possible: CO₂ is filtered directly from the atmosphere and permanently stored as rock. This technology, developed in Switzerland and perfected in the volcanic landscapes of Iceland, opens up a new path in the global quest for climate neutrality.
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Purifying the air with direct air capture
Imagine a giant vacuum cleaner for the sky. This is exactly what direct air capture (DAC) is based on: a technology for the direct removal of CO₂ from the ambient air. In contrast to conventional CO₂ capture systems at industrial sites, DAC systems can be operated almost anywhere and filter existing greenhouse gases from the atmosphere.
Although the process is based on a simple concept, it is technically highly advanced. Large fans draw air into modular collectors with special filters that chemically bind to CO₂. Once the filters are saturated, they are heated to around 100°C using renewable energy, releasing the captured CO₂ as a concentrated gas that can be permanently stored or reused. This approach has made DAC systems one of the most widely recognised technologies for CO₂ removal in the global climate debate.
Climeworks and the rise of Swiss CO₂-capture technology
Switzerland has played a key role in this field's development through Climeworks, a company founded in 2009 as an ETH Zurich spin-off. Over the past ten years, the company has made the leap from lab research to industrial implementation and has developed several generations of DAC systems. Its plants in Iceland, in particular Orca and the recently commissioned Mammoth plant, show how Swiss research is contributing to the development of a new industry for climate technologies.
Why did Iceland become a hub for carbon storage?
Iceland has become a strategic location for this technology for two reasons: first, the country has abundant geothermal energy, which is crucial to power the energy-intensive capture process with low-CO₂ electricity and heat; second, the country's underground basalt rock formations allow the captured CO₂ to be stored permanently through rapid mineralisation. After the gas is mixed with water and injected into the ground, it reacts naturally with the volcanic rock and turns into stone in less than two years. This storage method was developed in collaboration with Icelandic partner Carbfix.
The challenges of CO₂ capture from air
However, this technology still faces considerable challenges: DAC is still costly and very energy-intensive, while its large-scale use is still in its infancy. Operating conditions can also influence performance: in Iceland, difficult weather conditions have occasionally hampered the operation of some systems. These examples illustrate the difficulties of using new climate technologies on a large scale under real conditions.
Climeworks is expanding its range of CO₂-removal systems
Climeworks has also extended its business beyond its proprietary DAC infrastructure. Since 2024, the company has been developing portfolios of CO₂ removal systems that combine technical and nature-based approaches. The aim is to adapt strategies for CO₂ removal to different customers' needs, particularly in terms of durability, budget, time frame and additional ecological benefits. Each system is assessed on the basis of scientifically defined criteria before being included in the portfolios. Today, Climeworks works with around 200 companies worldwide seeking to reduce their net emissions through CO₂ removal.
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Why is CO₂ removal important for climate targets?
Despite current restrictions, scientific consensus increasingly indicates that reducing emissions alone will not be enough to achieve the global climate targets. The CO₂ that has already accumulated in the atmosphere must also be removed on a large scale. In this context, direct CO₂ capture from the air is increasingly being viewed not as the sole solution, but as part of a more comprehensive climate strategy.
A technology that is still under development
For Climeworks and the entire direct CO₂-capture industry, the current phase is as much one for learning and industrial development as it is for global expansion. New generations of filters, lower energy consumption and larger systems are already being tested. What began as a Swiss research project is now contributing to the emergence of a global carbon-capture industry, transforming what was once a rather theoretical concept into a measurable and increasingly accessible solution for climate protection.