Imagine the Earth is a room, and for the last 200 years, humans have been burning coal, oil, and gas, filling the room with invisible, smoky gas that traps heat and makes the room uncomfortably hot. We finally realized the room is getting too hot, so we stopped lighting new fires (reducing emissions). But the room is still full of the old, hot smoke. Just stopping the fires is not enough; the room will stay hot for centuries unless we actively open the windows and suck the old smoke out. This is the concept of "carbon removal," and a Swiss climate tech startup called Climeworks is building the world's biggest vacuum cleaner to do exactly this. In June 2026, Climeworks, in partnership with Icelandic energy companies, officially opened "Mammoth," the largest commercial Direct Air Capture (DAC) plant on the planet, located in the stark, beautiful lava fields of Iceland. This massive facility is designed to suck carbon dioxide (CO2) directly out of the ambient air and bury it deep underground where it turns into stone. It is a monumental engineering feat and a critical piece of the puzzle in the fight against climate change. Let us explore how this technology works, why it is so expensive, and why it is absolutely essential for our future.

The Science: Why Reducing Emissions is Not Enough

To understand why we need giant machines to suck carbon out of the air, we have to understand the science of climate change. For the last century, human activity has released over 2 trillion tons of CO2 into the atmosphere. This gas acts like a blanket, trapping the sun's heat. Even if we stopped all emissions today and switched entirely to solar and wind power tomorrow, the CO2 we have already emitted would stay in the atmosphere for hundreds, if not thousands, of years. The planet would continue to warm, melting ice caps, raising sea levels, and causing extreme weather. The Intergovernmental Panel on Climate Change (IPCC) has stated clearly that to limit global warming to 1.5 degrees Celsius, we cannot just reduce emissions; we must actively remove between 100 billion and 1 trillion tons of CO2 from the atmosphere by the end of the century. Nature can help a little bit. Planting trees and restoring wetlands absorbs some carbon. But nature alone cannot absorb the massive scale of emissions we need to remove. We need technology. We need industrial-scale carbon removal. This is where Direct Air Capture comes in. It is the only technology that can remove CO2 from the atmosphere regardless of where the emissions came from, and it can be located anywhere on Earth, not just next to a factory.

How Climeworks' Technology Works

The process inside a Climeworks plant is surprisingly simple in concept, though incredibly complex in execution. The Mammoth plant looks like a series of large, square shipping containers with massive fans on the front. Here is the step-by-step process: First, giant fans pull in ambient air. The air passes through a special modular filter coated with a chemical substance that has a high affinity for CO2. As the air flows through, the CO2 molecules stick to the filter, while the rest of the air (nitrogen, oxygen, etc.) passes right through and goes back out the other side. Once the filter is completely saturated with CO2, the container is sealed. Then, the temperature inside the container is raised to about 100 degrees Celsius. This heat breaks the chemical bond, releasing the pure CO2 gas from the filter. The filter is then cooled down and ready to capture more CO2 again. This cycle of capturing and releasing can be repeated thousands of times. The pure, concentrated CO2 gas that is released is then compressed and piped deep underground. The beauty of this system is its modularity. Climeworks can just add more "collector" boxes to scale up the capacity of the plant. Mammoth is designed to capture 36,000 tons of CO2 per year. While that sounds like a lot, it is equivalent to the annual emissions of about 7,000 cars. It is a drop in the ocean compared to the 37 billion tons humanity emits annually, but it is a crucial, proven drop.

A historic day for climate action. We have officially commissioned Mammoth, the world's largest direct air capture and storage plant in Iceland. We are now removing 36,000 tons of CO2 annually and turning it into stone. The era of carbon removal is here.

— Climeworks (@Climeworks) June 19, 2026

The Icelandic Advantage: Geothermal Energy and Carbfix

You might be wondering: "If the fans and the heaters need energy to run, doesn't that create more carbon emissions?" This is the most critical question about DAC. If you power the plant with coal electricity, you are creating more CO2 than you are removing. The process must be powered by 100% clean, zero-carbon energy. This is why Climeworks built Mammoth in Iceland. Iceland is a geological paradise. It sits on a volcanic hotspot, which means it has an abundance of geothermal energy. The Hellisheidi Geothermal Power Plant, located right next to the Mammoth facility, provides the plant with continuous, cheap, 100% renewable heat and electricity. The heat from the geothermal steam is used to warm the filters and release the CO2, and the electricity powers the giant fans. Furthermore, Iceland has the perfect geology for permanent storage. Climeworks partners with an Icelandic company called Carbfix. After the CO2 is captured, it is mixed with water and injected over 1,000 meters deep into the basaltic rock formations underground. The CO2-rich water reacts with the calcium, magnesium, and iron in the basalt rock. Within less than two years, this chemical reaction turns the CO2 into solid carbonate minerals—essentially, it turns into stone. This is a permanent, safe storage solution. There is no risk of the gas leaking back into the atmosphere. It is locked in the rock forever. This combination of abundant geothermal energy and perfect storage geology makes Iceland the absolute best place on Earth for this technology.

The Economics: Why is it so Expensive?

Despite the incredible engineering, there is one massive hurdle: cost. Currently, it costs Climeworks between $600 and $1,000 to remove one ton of CO2 from the air. To put that in perspective, it costs less than $50 to avoid emitting a ton of CO2 by building a solar farm instead of a coal plant. So why spend $1,000 to remove a ton when you can spend $50 to avoid emitting a ton? The answer is that we have already emitted too much. We need both. We must aggressively reduce emissions (the $50 solutions), but we also must remove historical emissions (the $1,000 solutions). The high cost of DAC is because it is a brand new technology, built at a small scale. It is like the first mobile phones in the 1980s; they were huge, clunky, and cost thousands of dollars. But as the technology matured and was produced at scale, phones became cheap and ubiquitous. Climeworks and its investors are betting that DAC will follow the same curve. By building Mammoth, they are moving down the "learning curve." Every plant they build teaches them how to make the next one cheaper, more efficient, and larger. They aim to bring the cost down to $250 per ton by 2030, and eventually to $100 per ton. At $100 per ton, DAC becomes a viable, scalable tool in the global climate portfolio.

The Market: Who is Paying for This?

If it costs $1,000 to remove a ton of CO2, who is buying it? Currently, the market for carbon removal is driven by voluntary corporate buyers. Tech giants like Microsoft, Stripe, Shopify, and Airbus have made "net-zero" or "carbon-negative" pledges. They realize that they cannot eliminate 100% of their emissions (for example, aviation fuel or concrete production will always emit some CO2). So, they need to buy high-quality carbon removal credits to offset their "hard-to-abate" emissions. These companies are signing multi-year, multi-million dollar advance market commitments with Climeworks. They are essentially paying for the construction and operation of the plant in exchange for the right to claim the CO2 removal. This upfront capital is crucial for Climeworks to secure debt financing and build more plants. Furthermore, governments are starting to step in. The US government, through the Inflation Reduction Act, is offering a tax credit of $180 for every ton of CO2 permanently stored underground. The European Union is also developing a certification framework for carbon removal, which could unlock public funding. The combination of corporate demand and government policy is creating the first real market for carbon removal, an industry that could be worth tens of billions of dollars by 2050.

Criticisms and the Moral Hazard Debate

The Environmental Controversy

Not everyone is cheering for Climeworks. Many environmentalists and climate activists are deeply skeptical of Direct Air Capture. They argue that it is a "moral hazard." This means that if big oil companies and polluters think that technology like DAC will save the day and suck up their emissions later, they will not feel the urgency to stop polluting now. They view DAC as a dangerous distraction, a "get out of jail free" card that fossil fuel companies use to justify continued drilling and burning. They argue that the billions of dollars being spent on DAC should be spent on wind, solar, and energy efficiency, which are much cheaper and actually prevent emissions in the first place. There is also a concern about land and water use. While Mammoth uses geothermal energy, scaling DAC to the gigaton level would require massive amounts of land and energy. Climeworks counters these arguments by stating that DAC is not a substitute for emissions reduction; it is a complement. They argue that the IPCC is clear: we cannot reach net-zero without carbon removal. They also point out that they are strictly focusing on "carbon removal" (taking CO2 out of the air) and not "carbon capture and storage" (catching CO2 from a factory smokestack), which they view as a way for fossil fuel companies to extend their lifespan. They insist that DAC is for addressing historical emissions and unavoidable residual emissions, not for giving polluters a free pass.

The Road Ahead: Scaling to Gigatons

The challenge ahead for Climeworks is one of the greatest industrial scaling challenges in human history. To meet the goals of the Paris Agreement, the world needs to remove billions of tons of CO2 per year by 2050. Mammoth removes 36,000 tons. To reach the gigaton scale, Climeworks would need to build tens of thousands of Mammoth-sized plants around the world. This requires not just technological innovation, but a massive build-out of supply chains, trained workforces, and infrastructure. They are currently planning their next generation of plants, which will be significantly larger and more efficient. They are also exploring locations outside of Iceland, looking for other regions with abundant renewable energy and suitable geology, such as the US Midwest, the North Sea, and parts of Australia. The road ahead is long, expensive, and fraught with technical and political challenges. But the opening of Mammoth proves that the technology works. It is no longer a theoretical concept in a university lab; it is a physical, operating industrial plant turning CO2 into stone. As the climate crisis deepens and the impacts become more severe, the demand for carbon removal will only grow. Climeworks has planted a flag in the lava fields of Iceland, declaring that humanity now has the tools to clean up its mess. The vacuum cleaner is turned on, and the long, hard work of healing the atmosphere has officially begun.

In conclusion, the commissioning of the Mammoth Direct Air Capture plant by Climeworks in June 2026 is a landmark achievement in the history of climate technology. It represents the transition of carbon removal from a scientific theory to an industrial reality. By harnessing the unique geothermal resources of Iceland and combining them with innovative chemical engineering and geological storage, Climeworks has created a scalable, permanent solution for removing CO2 from the atmosphere. While the costs remain high and the debates over its role in the broader climate strategy continue, the physical existence of Mammoth is a beacon of hope. It proves that human ingenuity can create the tools necessary to reverse the damage of the industrial age. As the world races to decarbonize the economy, facilities like Mammoth will be the essential safety net, ensuring that even our hardest-to-abate emissions and historical pollution can be cleaned up. The fight against climate change is the greatest challenge our species has ever faced, and with the successful deployment of Direct Air Capture, we have just added a powerful new weapon to our arsenal. The air is being cleaned, one ton at a time, and the future of our planet depends on the scale and speed of this remarkable technology. Read the in-depth analysis on the Financial Times.