Carbon dioxide (CO2) can be sucked out of the atmosphere for less than $100 per ton, a price tag less than one-sixth the cost of previous estimates for the geoengineering technique known as direct air capture, scientists report this week in Joule. David Keith, a physicist at Harvard University and co-founder of the startup Carbon Engineering, and his colleagues analyzed the output of a pilot plant in British Columbia in Canada that uses a four-step chemical process to capture CO2. A liquid takes in the gas initially, then releases it as a concentrated stream of gas that the plant combines with hydrogen to make gasoline and other fuels. Keith’s team projected that a large commercial plant using similar technology could capture CO2 for between $94 and $232 per ton. At that price, Carbon Engineering claims fuels could be made for about $1 per liter. Fuels based on carbon removal could be cost-effective in regions such as California where regulations allow them to command a premium price, says Stephen Pacala, an ecologist at Princeton University who is leading a study about CO2 removal technologies for the National Academies of Sciences, Engineering, and Medicine.