Chapter 1: The Debate Around Carbon Capture

The concept of extracting carbon dioxide from the atmosphere has often been dismissed as impractical and overly complex. Many argue that efforts should instead focus on preventing greenhouse gases from entering the atmosphere, such as by expanding solar and wind energy. Mark Jacobson, a Stanford engineering professor, recently likened carbon capture technologies to the failed startup Theranos, which falsely promised breakthroughs in blood testing.

Critics also suggest that "direct air capture" (DAC) is merely an illusion of environmentalism, pointing to the involvement of major oil firms like Chevron, Exxon Mobil, and Occidental Petroleum, which plan to utilize the captured CO₂ to enhance oil extraction from their existing fields.

However, companies at the forefront of commercializing direct air capture technologies—such as Carbon Engineering from Canada, Climeworks from Switzerland, and Global Thermostat from the U.S.—assert that their innovations are intended to complement, rather than replace, renewable energy solutions. They counter accusations of greenwashing by advocating that the utilization of CO₂ in oil fields represents a transitional phase in the broader effort to decarbonize the global economy. A key long-term objective involves sequestering captured CO₂ in basalt formations to permanently remove it from the atmosphere.

Most critically, these companies aim to demonstrate that direct air capture can be economically viable on a large scale. A pivotal study by the American Physical Society in 2011 estimated the cost of capturing a metric ton of CO₂ at approximately $550. However, a 2018 paper by Harvard physicist David Keith and colleagues in the journal Joule suggested that costs could be reduced to between $94 and $232 per ton using readily available technologies.

Carbon Engineering, co-founded by Keith, is currently working on establishing a facility designed to extract one million tons of CO₂ from the atmosphere each year, making it the largest of its kind globally and equivalent to offsetting emissions from 250,000 vehicles. The announcement of this ambitious plan came just months after the company initially set a target of half a million tons annually.

This facility will be constructed in collaboration with Occidental in an undisclosed location within Texas's Permian Basin, and it is expected to begin operations in 2023. If successful, Carbon Engineering plans to replicate this model with hundreds, if not thousands, of similar facilities worldwide.

In a promotional video on the company's website, CEO Steve Oldham indicates that they aim to achieve a cost of $100 to $150 per ton for CO₂ removal. More recently, he has tempered expectations, stating only that the costs would remain below $200.

The other primary players in the carbon capture market are also striving to increase their capacities. Climeworks, based in Zurich, operates 14 smaller facilities across Europe, with its largest capturing 900 tons of CO₂ annually at a cost of $600 per ton. The company hopes to drive down costs to $200 per ton within three to four years and ultimately to $100 by 2030. Meanwhile, Global Thermostat plans to capture 2,000 tons of CO₂ annually at a new facility in Tulsa, Oklahoma, led by former Exxon Mobil research chief Peter Eisenberger.

Though direct air capture presents formidable challenges, it is essential to recognize that even with potential cost reductions, it will remain more expensive than direct emissions reduction strategies. Additionally, it cannot compete with other negative emissions solutions: for instance, planting trees costs approximately $15 to $50 per ton of CO₂ sequestered, as noted in a recent National Academies of Sciences report. Extracting CO₂ from concentrated sources, such as power plant emissions, is also generally more economical than capturing it from the ambient air, where it constitutes just four molecules in every 10,000.

So why pursue this technology at all? Because merely reducing emissions will not suffice to halt climate change. Emissions will persist for decades—consider the long timeline for the development of battery-powered aircraft. Furthermore, there is insufficient land available to plant the vast forests needed to counteract global warming, nor is there enough cropland to grow biomass for fuel. Capturing carbon from smokestacks is also insufficient, given that half of global emissions arise from less concentrated sources.

Direct air capture technologies are based on the chemical properties of CO₂, which can react with various bases to form salts. Carbon Engineering's approach involves using fans to push air through plastic sheets coated with potassium hydroxide, yielding potassium carbonate. In a subsequent step, this compound reacts with calcium hydroxide to create calcium carbonate pellets, which can then be processed in a high-temperature furnace to produce calcium oxide (lime) and CO₂. The captured CO₂ can subsequently be utilized in beverages, converted into fuel, or sequestered underground.

The clock is ticking. A report from the National Research Council in 2015 projected that it could take 30 years for direct air capture to achieve an annual removal of one billion tons of CO₂, with a maximum potential of 10 billion tons. For perspective, the combustion of oil, gas, and coal globally produced around 34 billion tons of CO₂ last year, according to the BP Statistical Review 2019.

But progress must begin somewhere. “Time is against us,” emphasizes Graciela Chichilnisky, CEO of Global Thermostat. “We need to be constructing these plants.”

This video explores the complex realities and advancements in carbon capture and storage technologies, shedding light on their potential and challenges.

Chapter 2: The Need for Reality Checks in Carbon Capture

As the discourse surrounding carbon capture evolves, it becomes crucial to scrutinize its feasibility and actual impact.

This video discusses the necessity for a realistic approach to carbon capture technologies, evaluating their role in combatting climate change.