Direct carbon capture is key to reducing the dangerous amount of greenhouse gases that humanity has put into the atmosphere. One startup is taking a new approach to the problem by capturing CO2 from the atmosphere at a height of 52,800 feet.

Called High Hopes, the Israel-based company has figured out a way to make direct-carbon-capture more energy-efficient and less expensive to run compared to existing technologies.

“If you look at the numbers, a huge part of it is energy,” said Eran Oren, co-founder and chief scientist at High Hopes. “So it makes sense to think of this problem as, how can I constrain the amount of energy needed per metric ton of carbon dioxide that I capture?”

That question prompted Oren to come up with the idea of changing the location of carbon-capture technologies, which typically pull in the greenhouse gas near the ground. Instead, Oren decided to find a way to make the technology work its charm at high altitudes, where temperatures can dip to -70C (-94F).

At -80C, carbon dioxide freezes into dry ice meaning that, with relatively little energy, the air can be cooled enough to freeze the carbon out of the air and capture it in an adsorbent material. The captured gas is then brought back to earth, to be buried underground or used to make vodka and even jet fuel.

As reported by Fast Company, since the equipment will work at an altitude where the wind constantly is pushing more CO2 into the balloons, it also won’t require the large fans that are used by companies working on the ground. This could drive the costs of capturing the carbon down to $50 a ton, compared to current costs which range from $250 to $600 per ton.

Using balloons, early trial missions demonstrated that the process is feasible. As explained by Oren, the basic machine is rather simple: “If you just cut it open, what you see is something relatively similar to a fridge, meaning a compressor and cooling fluid.” At full scale, Oren says that balloons would carry the equipment upwards for eight to ten hours, capture the cold CO2, bring it back on the ground and then repeat the process.

Once the technology is tweaked to be able to capture a metric ton of CO2 each day, the plan is to deploy a network of balloons on a massive scale. According to High Hopes, the first facility is expected to start with 100 balloons, capturing around 30,000 metric tons of CO2 each year. Paired with renewable energy and reforestation projects, solutions like High Hopes could really make an impact against climate change.