Why Engineered Carbon Removal May Never Cost $100/mt
At New York Climate Week in September 2025, a Wall Street Journal Journal House panel tackled one of the toughest questions in climate tech: Can engineered carbon removal ever become affordable?
For Chris Greig, a senior research scientist at Princeton University, the answer was blunt.
“The push to reduce the cost of engineered carbon removals to $100 per metric ton is a simple case of delusion transcending to deception,” Greig said.
The Real Cost of Pulling Carbon from the Sky
Today, direct air capture (DAC) technology costs developers anywhere from $700 to $1,000 per metric ton of carbon removed. And according to Greig, those numbers aren’t going to fall dramatically anytime soon.
“Under perfect conditions, it could get to $600/mt,” he said, adding that the same holds true for carbon capture, utilization, and storage (CCUS) projects.
He used an ethylene cracker—a plant that breaks down hydrocarbons to make plastics and detergents—as an example. Implementing CCUS there would cost about $200/mt, and with technological advances, perhaps $150–$180/mt at best.
“If you can get your removals down to $400–$500/mt, congratulations, that’s a good job well done,” Greig said. “That last bit of decarbonization—that last 100 million tons in the U.S.—we are going to pay $500/mt for that.”
Early Innovators Face Growing Pains
DAC developer Deep Sky is one of the companies trying to make that vision more realistic. CEO Alex Petre, who also joined the panel, acknowledged that the costs and energy demands of DAC remain daunting—but defended the industry’s early pioneers.
“Sometimes we forget how important it is to have those innovators, the people who are very bold,” she said. “On their path to being very bold, sometimes they might make a mistake or a wrong step.”
Petre added that first movers were unfairly scrutinized for high energy use and low operating times, emphasizing that such challenges are part of developing any new technology.
Beyond the Price Tag: The Carbon Footprint of Carbon Removal
Cost isn’t the only concern. The embodied emissions of engineered carbon removals—which are created during construction and maintenance—are also under scrutiny.
In an August white paper, Calyx Global and Meta noted that there’s still “no consensus on how embodied carbon dioxide emissions should be integrated into engineered CDR accounting.” While most emissions occur upfront during infrastructure buildout, others continue throughout a project’s lifespan.
That same month, Calyx gave Climeworks’ Orca DAC facility a Tier 3 rating, citing “a high risk that the project … is significantly over-crediting.” Deep Sky’s own Alpha project has yet to receive a rating.
“A Really Good Quality Ton”
Despite the industry’s growing pains, Petre believes DAC still offers unmatched quality in carbon removal.
“This requires the developer to measure the ton underground to ensure there is no leakage, and it actually stays there for 1,000 years,” she said.
She posed a question to the audience—and the broader carbon markets—that gets to the heart of the debate:
“For those last few tons, do we really need it to be $100 per metric ton—given the amount of effort that goes into it?”