Google just landed a deal to capture planet-heating pollution at a huge bargain: $100 per ton of CO2, the price climate tech startups around the world are racing to achieve in order to make their technologies commercially viable.

The company announced the agreement today with Holocene, a startup with an even shorter history than others in the emerging carbon removal industry that has nevertheless attracted some big-name backers.

If Holocene can actually pull it off — take carbon dioxide out of the air at a price far lower than competitors charging $600 per ton or more for the same service — it could prove that carbon removal technologies are ready to help in the climate fight. But it’s still in its early days, and there’s a lot on the line as Google’s carbon pollution continues to grow.

“We think it’s a self-fulfilling prophecy. We need to all believe we can do it and work hard to do it,” says Anca Timofte, cofounder and CEO of Holocene. “Google has to and other partners have to come to the table to support projects like this.”

Timofte was in business school at Stanford when she came across research from Oak Ridge National Laboratory on new chemistry for filtering CO2 out of the air. That became the basis of the technology Holocene uses today.

Since getting off the ground in 2022, Holocene already counts the US Department of Energy (DOE), Elon Musk’s Xprize Carbon Removal, and Bill Gates’ climate investment firm Breakthrough Energy among its funders. Timofte and a fellow cofounder previously worked at Climeworks, one of the first carbon removal companies and which is still a major player in the field with clients including Microsoft and JPMorgan Chase.

Climeworks currently operates the world’s largest carbon removal facilities, called direct air capture (DAC) plants. In June, it announced that its next generation of DAC plants should be able to bring the cost of carbon removal down to $250–350 per ton captured by 2030. That’s obviously still well above the $100 target the DOE has set for making the technology financially feasible. A tax credit for carbon removal expanded under the Biden administration is supposed to help get there, but Holocene also says that its own advances in carbon removal chemistry bring down the price.

Holocene says its technique is more efficient than others because it’s able to continuously run two chemical loops: one that takes in CO2 from the air and another that produces a pure stream of that captured CO2 so that it can eventually be sequestered underground. The first loop involves passing air through water containing amino acids that attract the CO2. Then the chemical guanidine is added to the mix, which reacts with the CO2 to form a solid crystal. Once the solids are separated from the liquid, it’s heated to between 70 and 100 degrees Celsius (the temperature of boiling water) to release the CO2 into a concentrated stream of the greenhouse gas.

Climeworks’ method, on the other hand, can be thought of as a “cartridge” system, as Timofte describes it. It uses solid filters that pull CO2 out of the air. Once the filter is saturated, it needs to be heated to release the CO2, and then the filter can load up on more CO2. In other words, there’s one material that does the loading and unloading of CO2, and you have to stop loading to start unloading. Holocene, meanwhile, does everything all at once.

Climeworks has a more proven track record than Holocene at this point, with two of the world’s first commercial-scale facilities operating in Iceland and more projects underway in the US, Norway, Kenya, and Canada.

For now, Holocene has one small pilot plant in Knoxville, Tennessee, capable of taking just 10 tons of CO2 out of the air each year. The deal it landed with Google is to capture 100,000 tons of CO2 by 2032. Google paid a “significant part” of the $10 million total up front to help bring Holocene’s plans to fruition, Timofte said. The next step is to build a demonstration plant that can capture around 5,000 tons annually and then a commercial plant that can do 500,000 tons.

The whole DAC industry needs a growth spurt if it hopes to make a dent in the carbon pollution that’s built up in the atmosphere. Only some 27 DAC plants have been commissioned around the world to date, with the collective capacity to capture just 10,000 metric tons each year.

Google’s 100,00 ton commitment is roughly the equivalent of taking 20,000 gas-powered cars off the road for a year. But it’s still a small fraction of the 14.3 million metric tons of carbon dioxide pollution Google produced last year alone. Its emissions have grown as it tries to outcompete other tech giants with energy-hungry AI tools.

That makes it even more important for companies like Google to prioritize reducing their emissions rather than relying on capturing them after the fact. Carbon removal is no cure-all for climate change. US and global climate goals — aimed at keeping climate change from intensifying to a point at which life on Earth would struggle to adapt — require slashing carbon emissions roughly in half by 2030. That deadline comes before Holocene is even slated to fulfill its task of drawing down just 100,000 tons of CO2 for Google.