The world’s largest decarbonization plant is now available.

Mammoth, the largest industrial plant built to filter carbon dioxide from the air, has started operations in Herisheidi, Iceland. Operated by Swiss climate technology company ClimateWorks, the plant has customers including JP Morgan Chase, Microsoft, Stripe and Shoppify.

The facility is a state-of-the-art industrial facility built to absorb carbon dioxide from the air through a process known as direct air capture (DAC) DAC is seen as a way to combat climate change by removing greenhouse gases that build up in the atmosphere. It needs to prove that it can be scaled up to a sufficient scale to have a meaningful impact.

It remains to be seen whether its initial success can be replicated in the US, a growing market.

Mammoth is currently the largest DAC facility in operation. However, from an overall perspective, it is relatively small compared to other projects in the pipeline. Climeworks’ operations in Iceland were intended to show the world that the technology works. Now it has to see if it can repeat its initial success in the US, a growing market.

In 2017, Climeworks became the first company to absorb CO2 from the air and market it as a product for use in carbonated beverages and greenhouses; in 2021, it took a big step forward in Iceland, opening Orca, its DAC plant for CO2 capture and sequestration permanently underground for customers including Microsoft.

Orca is the largest DAC plant ever operated. When fully operational, Mammoth will be able to capture about 10 times as much CO2 as Orca, or about 36,000 tons per year. That’s still not a lot, considering that Microsoft emitted about 13 million tons of carbon dioxide in 2022.

Carbon dioxide removal is a collective term for a range of technologies being developed to remove carbon dioxide from the atmosphere. These technologies can help slow climate change by capturing some of the pollution that fossil fuels have released over the years. But there are still concerns about their cost, safety and potential to slow the transition from fossil fuels to carbon pollution-free energy. Experts say carbon removal is no substitute for preventing greenhouse gas emissions in the first place.

But ClimateWorks and similar climate technology companies have much bigger ambitions in the US. The Biden administration has secured $3.5 billion in federal funding from the Bipartisan Infrastructure Act for the development of at least four DAC centers.

So far, two major projects have been selected and funded to the tune of US$1.2 billion. These include Crimeworks in Calcasieu Parish, Louisiana, and an initiative that will use DAC technology from California-based start-up Heirloom Carbon Technologies. Microsoft is already one of the first customers of the Louisiana centers. Each of the federally funded hubs will have the capacity to capture at least 1 million tons of CO2 per year. ClimbWorks established its new headquarters in Austin, Texas earlier this year to accelerate its growth in the US.

In Iceland, Climeworks’ DAC facility consists of modular ‘collector containers’ equipped with fans that suck in air. The air passes over special filters that absorb carbon dioxide. When the filter is fully saturated, the CO2 is released by heating it to about 100 degrees Celsius (212 degrees Fahrenheit). Climeworks has partnered with Carbfix to trap the collected CO2 in Icelandic basalt so it is not released back into the atmosphere. They mix the CO2 with water and pump the slurry deep underground, eventually turning it into solid rock.

Climbworks takes advantage of the abundance of geothermal energy and natural underground storage in Helicheidi. It can therefore run on renewable energy and does not need to install an extensive pipeline network to transport the captured CO2. Plans to build a GDR facility are already facing concerns about high costs and polluting energy use; GDR companies are also likely to face opposition from residents close to the pipeline’s construction.

Mammoth, on the other hand, is still incomplete. Only 12 modular containers have been installed at Mammoth so far, but 60 more will be installed by the end of this year to complete construction, according to ClimateWorks.