Climeworks share their insights in to how carbon capture works, and the potential for it to compliment other solutions in our drive to net zero. 

Multiple climate studies (IPCC Special Report, EASAC, NAS) clearly state that in order to limit global warming to 1.5°C, not only do we need to do everything we can to reduce emissions; we also need to actively remove carbon dioxide from the atmosphere.  

Climate scientists agree that by 2050, direct air capture needs to remove between five and 30 billion tons of CO2 annually if we want to achieve net zero emissions globally. To reach this level of carbon dioxide removal, direct air capture needs to be scaled up significantly, starting today.  

Solving the climate crisis will not be easy but, as UN Secretary-General António Guterres remarked: “the climate emergency is a race we are losing, but it is a race we can win”.  

The way we win is by tackling the challenge from multiple angles at the same time. It is going to take people all around the world working together to solve parts of the problem and create a whole solution. 

So, along with finding ways to reduce the amount of carbon dioxide we add to the atmosphere, we also need to find ways to remove unavoidable emissions as well as the CO2 already in our atmosphere.  

The obvious way to remove CO2 is by planting trees. If done well, afforestation comes with a number of important benefits such as reduced soil erosion and increased biodiversity. However, afforestation is a solution that cannot be scaled indefinitely because it requires lots of water and surface area. Also, the permanence of the removed CO2 cannot always be guaranteed with trees: wildfires or deforestation can destroy the trees and release the CO2 back into the atmosphere. We love trees and believe many more should be planted. But alongside more trees, we also need direct air capture.  

Direct air capture is a complementary approach to planting trees. Carbon dioxide removal via direct air capture is highly scalable as it requires only a small physical footprint. Further, it is fully measurable and permanent. It is much faster, too: if trees are planted, it will typically take at least ten years until the CO2 is removed from the air. Climeworks’ carbon dioxide removal takes between two and five years to be completed.  

What is direct air capture and how does it work? 

Climeworks’ direct air capture machines consist of modular CO2 collectors that can be stacked to build machines of any size. They are powered solely by renewable energy or energy-from-waste.

The CO2 collectors selectively capture carbon dioxide in a two-step process. First, air is drawn into the collector with a fan. Carbon dioxide is captured on the surface of a highly selective filter material that sits inside the collectors (‘adsorption’). 

Second, after the filter material is full of carbon dioxide, the collector is closed. The temperature is then increased to between 80 and 100°C – this releases the carbon dioxide (‘desorption’) which is then collected in both high purity and concentration. The air-captured carbon dioxide can either be upcycled into climate-friendly products such as carbon-neutral fuels and materials, or completely removed from the air by safely storing it.

Since the whole process takes energy to complete, Climeworks works closely with renewable energy providers, situating our direct air capture plants near renewable energy generation facilities to make the process as efficient as possible.  

Earlier this year, they opened our newest plant, Orca, in Iceland. Iceland meets almost all its energy needs from renewables, with around 73 per cent coming from hydropower and 27 per cent from geothermal. Climeworks works closely with Reykjavik Energy, a geothermal power producer, and its subsidiary Carbfix, which specialises in CO2 storage. Carbfix mixes Climeworks’ air-captured CO2 with water and pumps it underground where the CO2 is mineralised and turns to stone through a natural reaction with the surrounding rock. The carbon dioxide is therefore permanently and safely removed from the atmosphere.

“Climeworks’ vision is to inspire one billion people to remove carbon dioxide from the air. To achieve the vision we need to unite a strong network of different stakeholders that drive forward the direct air capture industry together, and thus help to democratize carbon dioxide removal,” says Christoph Beuttler, CDR manager at Climeworks.

How will this be achieved? 

First, a market demand for carbon dioxide removal must be created to show there is a growing interest in these solutions. Pioneering customers, both individuals and organizations, enable this. 

Second, investor support is crucial to help us scale and pre-finance our facilities. This means Climeworks, and other direct air capture companies, can increase their capacity and optimize the technology faster.  

Third, we require a political framework giving security for such investments and reflecting the true costs of CO2 emissions.  

Fourth, a structured supply chain needs to be developed to ensure we can easily move into mass production. 

Climeworks aims to make direct air capture technology available to everyone, regardless of budget, helping to create a big, exciting market. Anyone can now subscribe to our carbon dioxide removal service, which allows them to have CO2 removed from the atmosphere in their name, giving individuals a practical, affordable way to take climate action. 

By working together on a set of clear goals, implementing and developing new energy generation and direct air capture technology, and giving both companies and individuals access to permanent and safe carbon dioxide removal solutions, we can all contribute to achieving net zero emissions by 2050. By doing so, we can build a climate-positive world. 

Read more of our comments here!