Directly capturing CO2 from the air has become one of the most talked about tools in the fight against climate change. But much of the conversation revolves around a single, seemingly magical number: $100 per ton of CO₂. This benchmark has been hailed as the tipping point where direct air capture (DAC) becomes economically viable, unlocking its potential as a scalable climate solution. But how realistic is this figure, and should it even be the goal? Let’s dive into the history of the $100 per ton CO₂ mark, the current state of DAC costs, and why other metrics like the social cost of carbon are a more relevant benchmark for assessing DAC’s true value.
The Origin of the $100 Benchmark
The $100 per ton of CO₂ target emerged over a decade ago, born from early skepticism about the feasibility of capturing CO₂ directly from the air. In 2011, the American Physical Society estimated that DAC costs would range from $600 to $1,000 per ton of CO₂, calling into question its economic viability. Critics claimed DAC was fighting against entropy, with no clear pathway to affordability.
Then in 2018, Carbon Engineering published a paper estimating that its technology could eventually capture CO₂ for $94–$232 per ton. Around the same time, economist William Nordhaus, awarded the Nobel Prize for his work on the economics of climate change, estimated the social cost of carbon—the future damages caused by emitting one ton of CO₂—at $102 per ton by 2050. These two numbers, combined with a United States Department of Energy funding program targeting DAC technologies at $100 per ton of CO₂, elevated the benchmark to near-mythical status.
But inflation-adjusted calculations paint a different picture. The $100 per tCO₂ figure from 2016 corresponds to roughly $130 per ton in today’s dollars and could climb to $215 per ton by 2050 assuming modest inflation. These adjustments raise an important question: Should the $100 benchmark still be treated as the ultimate target, or is it a relic of outdated economic assumptions?
The Reality of Direct Air Capture Costs Today
Despite the optimism surrounding the $100 per ton of CO₂ goal, the current reality is sobering. Most DAC systems today operate at costs closer to $500–$1,000 per ton, depending on the technology and scale. Companies like Climeworks, one of the largest companies in the space, have acknowledged that their long-term costs might stabilize around $300 per ton CO₂ by 2030—not even close to the original $100 target.
Earlier this year, startup Holocene made waves by announcing the sales of 100,000 carbon credits to Google at a cost of $100 per ton, becoming the first DAC company to sell credits at that price. Notably, Google is paying up front to financially support Holocene, with deliveries expected by the early 2030s. This is an ambitious move, as this price likely undercuts the true costs of DAC and Holocene has only just commissioned a 10 ton per year pilot.
Why are costs so high? Capturing CO₂ directly from ambient air is inherently more challenging than capturing it from concentrated industrial sources. Air contains only about 0.04% CO₂, meaning DAC systems must process massive volumes of air to extract relatively small amounts of carbon. This requires significant energy input and costly materials, such as solid sorbents or liquid solvents.
The $100 Benchmark in Context
One way to contextualize the $100 per CO₂ target is by comparing it to the cost of other commodities traded on a per-ton basis. The results are striking – very few commodities sell for less than $100 per ton. Even basic materials like cement, coal, and iron ore typically trade between $100 and $200 per ton. Gravel and sand used in construction are among the rare exceptions, trading at $35–$70 per ton, but these are bulk materials produced at gigaton scales with minimal processing. $100 per ton is literally as cheap as dirt.
When viewed through this lens, the $100 per ton CO₂ target appears exceptionally ambitious. Achieving it would mean commoditizing CO₂ to a cost level comparable to some of the cheapest materials on the planet. For DAC to reach such a price point, it would require extraordinary breakthroughs in technology, scale, and efficiency—on par with or exceeding those seen in industries like solar power or wind energy. While not impossible, deployment needs to exponentially increase starting now to reach this goal.
Why the Social Cost of Carbon Should Be the Real Benchmark
While $100 per tCO₂ has become a convenient shorthand for DAC affordability, it may not be the most meaningful metric. Instead, the social cost of carbon offers a more comprehensive framework for evaluating DAC’s value.
The social cost of carbon quantifies the economic damages caused by one ton of CO₂ emissions, factoring in impacts like climate-related disasters, health effects, and agricultural losses. Recent estimates suggest this cost is significantly higher than $100 per ton. Recently published scientific research placed the social cost of carbon in the United States at $185 per ton of CO2, while the Government of Canada defines the official social cost of carbon to be $266 per ton of CO2 today.
These figures highlight that society already values carbon removal, in cost to avoid the damage it causes, well above $100 per ton. Using the social cost of carbon as a benchmark, even DAC systems operating at $300–$500 per ton could deliver substantial net benefits by avoiding future climate-related costs. Moreover, as carbon markets and emissions trading schemes evolve, the price of carbon could rise further, making higher DAC costs more acceptable.
Reframing the Goal
Rather than fixating on $100 per ton of CO₂, it’s time to adopt a more nuanced view of DAC’s role in the climate puzzle. Achieving $600 per ton today or $300 per ton in the near future still represents progress, particularly when paired with policies that reflect the true costs of carbon emissions.
Scaling DAC will take years, and costs will decrease as deployment grows and technologies mature. But whether DAC ever achieves the $100 per ton milestone is almost beside the point. What matters is whether DAC systems can reach the social cost of carbon, the economic cost that we all collectively bare for climate change.
DAC is not a silver bullet, but it remains a critical tool for addressing the climate crisis. As the industry evolves, it will need to balance innovation, investment, and realistic cost targets. By focusing on the broader benefits of carbon removal—and tying them to the true cost of carbon emissions—DAC can play a vital role in building a sustainable, net-zero future.
The question isn’t just whether DAC will ever cost less than $100 per ton. It’s whether society is willing to pay the price for averting the worst effects of climate change. The answer should be a resounding yes.
Disclaimer: I lead engineering at the Canadian carbon removal project developer Deep Sky.
